[Retroperitoneal mixed malignant mullerian tumor : exceptional localisation and prognosis]

Primary retroperitoneal carcinosarcoma or mixed malignant mullerian tumor (MMMT) is an extremely rare clinical entity. These aggressive tumors arise most commonly from genital tract. The retroperitoneal location is exceptional. Here we report the case of a 63-years old female diagnosed with heterologous, extra-genital, retroperitoneal carcinosarcoma, with malignant cells in the ascitic fluid and extra-ovarian metastatic implants. She was treated with complete radical surgical treatment consisting of resection of the retroperitoneal tumor, with omentectomy, hysterectomy, bilateral salpingooophorectomy and lumbo-aortic and pelvic lymphadenectomy. She received adjuvant chemotherapy with 6 cycles of Carboplatin and Paclitaxel. She is in complete clinical and radiological remission since the end of chemotherapy, for a total of 113 months. To our knowledge, this is the longest reported disease free survival of the extra-genital retroperitoneal MMMT. This case and the review of the literature illustrate the importance of surgical treatment. However, there are no evidence-based guidelines for the systemic management of these tumors.

Abstract CT101: D-BEYOND: A window of opportunity trial evaluating denosumab, a RANK-ligand (RANKL) inhibitor and its biological effects in young pre-menopausal women diagnosed with early breast cancer

Background

Breast cancer (BC) in young women has unique biology and poor prognosis. Previous reports suggest that they often express RANKL, which was also shown to play a role in mammary tumorigenesis and the etiology of BRCA1/2 related BC. Here, we present the primary results of D-BEYOND, a window of opportunity study investigating the biological activity of the RANKL inhibitor; denosumab in pre-menopausal BC patients.

Methods

D-BEYOND is a prospective, phase IIa, single-arm, multicenter study assessing the effect of denosumab on BC biology in premenopausal women with early BC (NCT01864798). Patients received two subcutaneous injections of denosumab (120mg), one week apart, followed by breast surgery. Blood, tumor and normal adjacent breast tissue were collected at baseline and at surgery. The primary endpoint was geometric mean change in tumor Ki67 assessed by immunohistochemistry (IHC) from baseline to surgery. Absolute Ki67 responders were defined as having <2.7% IHC staining in the post-treatment tumor. Serum levels of soluble RANKL (sRANKL), OPG and C-terminal telopeptide (CTX) were assessed by ELISA. Ki67, RANK and RANKL expression were assessed by IHC. The percentage of tumor infiltrating lymphocytes (TILs) were also evaluated. Pre- and post-treatment values were compared using a paired t-test.

Results

A total of 27 patients were enrolled in the study between October 2013 and July 2016. The median age was 45 years (range 35-51 years). Tumors of 21 patients were hormone receptor positive (77.8%), 4 were HER2 positive (14.8%) and 2 were triple negative (7.4%). No serious adverse events were reported, the most frequent non-serious adverse event being arthralgia (14.8%). After treatment, serum levels of CTX and sRANKL decreased in all patients (P < 0.001) whereas serum levels of OPG increased in 76.9% of patients (P = 0.009, 95% CI 0.56-0.91). There was no significant reduction of Ki67 values from baseline (geometric mean change after treatment; 0.98, 95% CI 0.76-1.26; P = 0.90) and there were no absolute Ki67 responders. Twenty-four pre- and post-treatment tumor pairs were available for RANK/L staining and TILs assessment. There was no significant difference in RANKL and RANK H-score in tumors after treatment (P = 0.842, P = 0.142, respectively) but we observed a decrease of RANKL H-score in 3 tumors (12.5%) and an increase of RANK H-score in 5 tumors (20%). Interestingly, there was a significant increase in the percentage of stromal TILs after treatment (geometric mean change of 2.51, 95% CI 1.58-3.97; P = 0.004). There were 10/24 patients (41.7%) with a change in TILs of at least 10%, all of them having an increase in TILs presence (P = 0.002).

Conclusion

Short course of denosumab did not reduce tumor proliferation rate. However, it induced a significant increase in TILs. These findings suggest that denosumab may potentiate immunotherapy efficacy, at least in young BC patients. Additional results including immune cell profiling by multiplex IHC and RNA-sequencing of tumor and normal tissues will be presented at the meeting.

Citation Format: Bastien Nguyen, Marion Maetens, Roberto Salgado, David Venet, Peter Vuylsteke, Laura Polastro, Hans Wieldiers, Philippe Simon, Geoff Lindeman, Denis Larsimont, Gert Van den Eynden, Chloe Velghe, Francoise Rothe, Soizic Garaud, Stefan Michiels, Karen Willard-gallo, Hatem A. Azim, Sherene Loi, Martine Piccart, Christos Sotiriou. D-BEYOND: A window of opportunity trial evaluating denosumab, a RANK-ligand (RANKL) inhibitor and its biological effects in young pre-menopausal women diagnosed with early breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT101.

Abstract 4689: Immune functions and regulation of follicular helper CD4+CXCR5+T cells in human breast cancer

Introduction: High levels of tumor infiltrating lymphocytes (TIL) have been associated with good clinical outcomes in patients with HER2-positive (HER2+) and triple-negative (TN) breast cancer (BC) . Recently, we demonstrated that 60% of BC TIL are organized in tertiary lymphoid structures (TLS) located in the stroma. We further identified a CXCL13-producing CD4+ T follicular helper cell (Tfh) subpopulation and demonstrated that this chemokine, important for TLS formation, is associated with positive clinical outcomes in BC. The aim of the present study was to investigate how conventional CD4+ Tfh cells, expressing the CXCL13 receptor CXCR5, contribute to immune function and regulation in BC-associated TLS.

Methods: We prospectively collected fresh primary BC tissues and prepared enzyme-free homogenates to prepare tumor supernatant and TIL for flow cytometric analysis and sorting. Matching formalin-fixed paraffin-embedded (FFPE) were used for subsequent spatial analysis by dual IHC and confocal microscopy.

Results: Flow cytometric analyses show that ~15% CD4+, ~13% CD8+ and >95% B cell TIL express CXCR5 while confocal microscopy reveals that these CXCR5+ TIL subpopulations co-localize in BC TLS and their presence is tightly correlated. BC Tfh TIL (compared to activated tonsillar Tfh) have a memory phenotype and express ICOS and PD-1 suggesting they are activated, but BCL6 is undetectable and CXCL13 positive cells are rare in only some tumors. RNA analysis detected high expression of IL-21, IL-10 and CXCL13 in Tfh TIL. Investigation into the role of Tfh cells in TLS functionality was accomplished via an in vitro assay where Tfh TIL were activated with allogeneic splenic B cells. These experiments reveal that only ICOS+PD-1+Tfh TIL from TN/HER2+ BC are capable of inducing IgM and IgG secretion by B cells. A comparison of ICOS+PD-1+ with ICOS-PD-1- Tfh TIL confirms an activated, functional nature for the former characterized by high levels of IL-21, IL-10 and CXCL13 mRNA expression. We also found specialized follicular regulatory T cells (Tfr), expressing CXCR5, CD25, demethylated Foxp3 and GARP, localized in TLS. To understand the regulation of Tfh function(s) by Tfr we quantified immunoglobulins in the primary tumor supernatant, finding a correlation between the Tfh/Tfr ratio (fresh tissues) and IgG and IgM production (supernatant) in TN/HER2+ BC. These data suggest that the balance between effector and regulatory Tfh influences B cell differentiation in TLS.

Conclusions: We show that it is possible to isolate functional Tfh TIL from fresh BC tissues, demonstrate their activation and functional state and link a Tfr presence with negative regulation of TLS function. These data begin to shed light on anti-tumor immune responses occurring in TLS at the tumor site, whose functional activities may have important treatment implications, particularly for immunotherapy in BC.

Citation Format: Mireille Langouo, Gregory Noël, Gert Van den Eynden, Alexandre De Wind, Soizic Garaud, Pushpamali De Silva, Cinzia Solinas, Anais Boisson, Celine Naveaux, Hugues Duvillier, Ligia Craciun, Denis Larsimont, Martine Piccart-Gebhart, Karen Willard-Gallo. Immune functions and regulation of follicular helper CD4+CXCR5+T cells in human breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4689.

CDK4 phosphorylation status and a linked gene expression profile predict sensitivity to palbociclib

Cyclin D-CDK4/6 are the first CDK complexes to be activated in the G1 phase in response to oncogenic pathways. The specific CDK4/6 inhibitor PD0332991 (palbociclib) was recently approved by the FDA and EMA for treatment of advanced ER-positive breast tumors. Unfortunately, no reliable predictive tools are available for identifying potentially responsive or insensitive tumors. We had shown that the activating T172 phosphorylation of CDK4 is the central rate-limiting event that initiates the cell cycle decision and signals the presence of active CDK4. Here, we report that the profile of post-translational modification including T172 phosphorylation of CDK4 differs among breast tumors and associates with their subtypes and risk. A gene expression signature faithfully predicted CDK4 modification profiles in tumors and cell lines. Moreover, in breast cancer cell lines, the CDK4 T172 phosphorylation best correlated with sensitivity to PD0332991. This gene expression signature identifies tumors that are unlikely to respond to CDK4/6 inhibitors and could help to select a subset of patients with HER2-positive and basal-like tumors for clinical studies on this class of drugs.

Genomic hotspots but few recurrent fusion genes in breast cancer

The advent of next generation sequencing technologies has boosted the interest in exploring the role of fusion genes in the development and progression of solid tumors. In breast cancer, most of the detected gene fusions seem to be "passenger" events while the presence of recurrent and driver fusions is still under study. We performed RNA sequencing in 55 well-characterized breast cancer samples and 10 adjacent normal breast tissues, complemented by an analysis of SNP array data. We explored the presence of fusion genes and defined their association with breast cancer subtypes, clinical-pathologic characteristics and copy number aberrations. Overall, 370 fusions were detected across the majority of the samples. HER2+ samples had significantly more fusions than triple negative and luminal subtypes. The number of fusions was correlated with histological grade, Ki67 and tumor size. Clusters of fusion genes were observed across the genome and a significant correlation of fusions with copy number aberrations and more specifically amplifications was also revealed. Despite the large number of fusion events, only a few were recurrent, while recurrent individual genes forming fusions with different partners were also detected including the estrogen receptor 1 gene in the previously detected ESR1-CCDC170 fusion. Overall we detected novel gene fusion events while we confirmed previously reported fusions. Genomic hotspots of fusion genes, differences between subtypes and small number of recurrent fusions are the most relevant characteristics of these events in breast cancer. Further investigation is necessary to comprehend the biological significance of these fusions.

Association of p27 and Cyclin D1 Expression and Benefit from Adjuvant Trastuzumab Treatment in HER2-Positive Early Breast Cancer: A TransHERA Study

Purpose: To assess the prognostic and predictive value of selected biomarkers involved in cell-cycle regulation or proliferation in patients with HER2-positive early breast cancer.Experimental Design: Protein expression of TOP2A, Ki67, cyclin D1, and p27 was immunohistochemically determined in tissue microarrays of surgical specimens from 862 patients randomized to trastuzumab (1 or 2 years; N = 561) and observation (N = 301) arms of the HERA trial. The primary analysis endpoint was disease-free survival (DFS). Biomarkers were examined as continuous or categorical variables (predefined cutoffs). Interaction terms between biomarkers and treatment were assessed in multivariate Cox models adjusted for variables of clinical interest.Results: A significant interaction was detected between p27 and treatment (adjusted P = 0.0049). Trastuzumab effect was significant in the p27-low subgroup (≤70% p27-positive tumor cells; N = 318). HR _{Comb Trast vs. Obs} 0.44, 95% CI, 0.29-0.65 (P < 0.001). No trastuzumab effect was observed in the p27-high subgroup N = 435; HR _{Comb Trast vs. Obs} 0.97, 95% CI, 0.66-1.44, P = 0.89), indicating that these patients derived little or no benefit from trastuzumab treatment. A prognostic effect of p27 on DFS was observed, with p27-high patients experiencing half the hazard of a DFS event compared with low ones (HR _{p27 High vs. Low} 0.49, 95% CI, 0.32-0.75). TOP2A, Ki67, and cyclin D1, as categorical variables were not predictive, whereas cyclin D1 as continuous variable was predictive of trastuzumab benefit.Conclusions: In TransHERA, patients with HER2-positive early breast cancer with low p27 expression in their tumors benefited from trastuzumab treatment, whereas patients with high p27 expression did not. Clin Cancer Res; 24(13); 3079-86. ©2018 AACR.

Distinctive Desmoplastic 3D Morphology Associated With BRAFV600E in Papillary Thyroid Cancers

CONTEXT

Although 60% of papillary thyroid carcinomas are BRAFV600E mutant (PTCV600E), the increased aggressiveness of these cancers is still debated.

OBJECTIVE

For PTCV600E we aimed to further characterize the extent of the stroma and its activation, the three-dimensional (3D) tumor-stroma interface, and the proliferation rates of tumor and stromal fibroblasts.

DESIGN

We analyzed exomes, transcriptomes, and images of 364 papillary thyroid carcinoma (PTCs) from The Cancer Genome Atlas (TCGA), including 211 PTCV600E; stained 22 independent PTCs for BRAFV600E and Ki67; sequenced the exomes and stained BRAFV600E in 5 primary tumor blocks and 4 nodal metastases from one patient with PTCV600E; and reconstructed the 3D volumes of one tumor and one metastatic block at histological resolution.

RESULTS

In TCGA, BRAFV600E was associated with higher expression of proliferation markers and lower expression of thyroid differentiation markers, independently of tumor purity. Moreover, PTCV600E, in line with their overall lower purity, also had higher expression of fibroblast- and T cell-associated genes and presented more fibrosis. Tumor cells that appeared disconnected on two-dimensional histological slices were revealed to be part of a unique tumor component in the 3D reconstructed microvolumes, and they formed a surprisingly complex connected space, infiltrating a proliferative stroma. Finally, in our PTC set, both stromal fibroblasts and tumor cells presented higher proliferation rates in PTCV600E.

CONCLUSIONS

Our results support the increased aggressiveness associated with BRAFV600E in PTC and shed light on the important role of the stroma in tumor expansion. The greater and more active fibrotic component predicts better efficiency of combined targeted treatments, as previously proposed for melanomaV600E.

Somatic mutation, copy number and transcriptomic profiles of primary and matched metastatic estrogen receptor-positive breast cancers

BACKGROUND

Estrogen receptor-positive (ER+) breast cancers (BCs) constitute the most frequent BC subtype. The molecular landscape of ER+ relapsed disease is not well characterized. In this study, we aimed to describe the genomic evolution between primary (P) and matched metastatic (M) ER+ BCs after failure of adjuvant therapy.

MATERIALS AND METHODS

A total of 182 ER+ metastatic BC patients with long-term follow-up were identified from a single institution. P tumor tissue was available for all patients, with 88 having matched M material. According to the availability of tumor material, samples were characterized using a 120 mutational hotspot qPCR, a 29 gene copy number aberrations (CNA) and a 400 gene expression panels. ESR1 mutations were assayed by droplet digital PCR. Molecular alterations were correlated with overall survival (OS) using the Cox proportional hazards regression models.

RESULTS

The median follow-up was 6.4 years (range 0.5-26.6 years). Genomic analysis of P tumors revealed somatic mutations in PIK3CA, KRAS, AKT1, FGFR3, HRAS and BRAF at frequencies of 41%, 6%, 5%, 2%, 1% and 2%, respectively, and CN amplification of CCND1, ZNF703, FGFR1, RSF1 and PAK1 at 23%, 19%, 17%, 12% and 11%, respectively. Mutations and CN amplifications were largely concordant between P and matched M (>84%). ESR1 mutations were found in 10.8% of the M but none of the P. Thirteen genes, among which ESR1, FOXA1, and HIF1A, showed significant differential expression between P and M. In P, the differential expression of 18 genes, among which IDO1, was significantly associated with OS (FDR < 0.1).

CONCLUSIONS

Despite the large concordance between P and matched M for the evaluated molecular alterations, potential actionable targets such as ESR1 mutations were found only in M. This supports the importance of characterizing the M disease. Other targets we identified, such as HIF1A and IDO1, warrant further investigation in this patient population.

Assessing Tumor-Infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method from the International Immuno-Oncology Biomarkers Working Group: Part 2: TILs in Melanoma, Gastrointestinal Tract Carcinomas, Non-Small Cell Lung Carcinoma and Mesothelioma, Endometrial and Ovarian Carcinomas, Squamous Cell Carcinoma of the Head and Neck, Genitourinary Carcinomas, and Primary Brain Tumors

Assessment of the immune response to tumors is growing in importance as the prognostic implications of this response are increasingly recognized, and as immunotherapies are evaluated and implemented in different tumor types. However, many different approaches can be used to assess and describe the immune response, which limits efforts at implementation as a routine clinical biomarker. In part 1 of this review, we have proposed a standardized methodology to assess tumor-infiltrating lymphocytes (TILs) in solid tumors, based on the International Immuno-Oncology Biomarkers Working Group guidelines for invasive breast carcinoma. In part 2 of this review, we discuss the available evidence for the prognostic and predictive value of TILs in common solid tumors, including carcinomas of the lung, gastrointestinal tract, genitourinary system, gynecologic system, and head and neck, as well as primary brain tumors, mesothelioma and melanoma. The particularities and different emphases in TIL assessment in different tumor types are discussed. The standardized methodology we propose can be adapted to different tumor types and may be used as a standard against which other approaches can be compared. Standardization of TIL assessment will help clinicians, researchers and pathologists to conclusively evaluate the utility of this simple biomarker in the current era of immunotherapy.

Immune Checkpoint Molecules on Tumor-Infiltrating Lymphocytes and Their Association with Tertiary Lymphoid Structures in Human Breast Cancer

There is an exponentially growing interest in targeting immune checkpoint molecules in breast cancer (BC), particularly in the triple-negative subtype where unmet treatment needs remain. This study was designed to analyze the expression, localization, and prognostic role of PD-1, PD-L1, PD-L2, CTLA-4, LAG3, and TIM3 in primary BC. Gene expression analysis using the METABRIC microarray dataset found that all six immune checkpoint molecules are highly expressed in basal-like and HER2-enriched compared to the other BC molecular subtypes. Flow cytometric analysis of fresh tissue homogenates from untreated primary tumors show that PD-1 is principally expressed on CD4⁺ or CD8⁺ T cells and CTLA-4 is expressed on CD4⁺ T cells. The global proportion of PD-L1⁺, PD-L2⁺, LAG3⁺, and TIM3⁺ tumor-infiltrating lymphocytes (TIL) was low and detectable in only a small number of tumors. Immunohistochemically staining fixed tissues from the same tumors was employed to score TIL and tertiary lymphoid structures (TLS). PD-L1⁺, PD-L2⁺, LAG3⁺, and TIM3⁺ cells were detected in some TLS in a pattern that resembles secondary lymphoid organs. This observation suggests that TLS are important sites of immune activation and regulation, particularly in tumors with extensive baseline immune infiltration. Significantly improved overall survival was correlated with PD-1 expression in the HER2-enriched and PD-L1 or CTLA-4 expression in basal-like BC. PD-1 and CTLA-4 proteins were most frequently detected on TIL, which supports the correlations observed between their gene expression and improved long-term outcome in basal-like and HER2-enriched BC. PD-L1 expression by tumor or immune cells is uncommon in BC. Overall, the data presented here distinguish PD-1 as a marker of T cell activity in both the T and B cell areas of BC associated TLS. We found that immune checkpoint molecule expression parallels the extent of TIL and TLS, although there is a noteworthy amount of heterogeneity between tumors even within the same molecular subtype. These data indicate that assessing the levels of immune checkpoint molecule expression in an individual patient has important implications for the success of therapeutically targeting them in BC.

Assessing Tumor-infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method From the International Immunooncology Biomarkers Working Group: Part 1: Assessing the Host Immune Response, TILs in Invasive Breast Carcinoma and Ductal Carcinoma In Situ, Metastatic Tumor Deposits and Areas for Further Research

Assessment of tumor-infiltrating lymphocytes (TILs) in histopathologic specimens can provide important prognostic information in diverse solid tumor types, and may also be of value in predicting response to treatments. However, implementation as a routine clinical biomarker has not yet been achieved. As successful use of immune checkpoint inhibitors and other forms of immunotherapy become a clinical reality, the need for widely applicable, accessible, and reliable immunooncology biomarkers is clear. In part 1 of this review we briefly discuss the host immune response to tumors and different approaches to TIL assessment. We propose a standardized methodology to assess TILs in solid tumors on hematoxylin and eosin sections, in both primary and metastatic settings, based on the International Immuno-Oncology Biomarker Working Group guidelines for TIL assessment in invasive breast carcinoma. A review of the literature regarding the value of TIL assessment in different solid tumor types follows in part 2. The method we propose is reproducible, affordable, easily applied, and has demonstrated prognostic and predictive significance in invasive breast carcinoma. This standardized methodology may be used as a reference against which other methods are compared, and should be evaluated for clinical validity and utility. Standardization of TIL assessment will help to improve consistency and reproducibility in this field, enrich both the quality and quantity of comparable evidence, and help to thoroughly evaluate the utility of TILs assessment in this era of immunotherapy.

Reliability of tumor-infiltrating lymphocyte and tertiary lymphoid structure assessment in human breast cancer

The presence of tumor-infiltrating lymphocytes (TIL), reflecting host immune activity, is frequently correlated with better clinical outcomes, particularly in HER2-positive and triple-negative breast cancer. Recent findings suggest that organization of immune infiltrates in tertiary lymphoid structures also has a beneficial effect on survival. This study investigated inter- and intra-observer variation in TIL assessment using conventional hematoxylin-eosin versus immunohistochemical staining to identify immune cells. Global, intratumoral, and stromal TIL, as well as tertiary lymphoid structures were scored independently by experienced pathologists on full-face tumor sections (n=124). The fidelity of scoring infiltrates in core biopsies compared to surgical specimens, and pathological assessment compared to quantitative digital analysis was also evaluated. The inter-observer concordance correlation coefficient was 0.80 for global, 0.72 for intratumoral, and 0.71 for stromal TIL, while the intra-observer concordance correlation coefficient was 0.90 for global, 0.77 for intratumoral, and 0.89 for stromal TIL using immunohistochemical stains. Correlations were lower with hematoxylin-eosin stains, particularly for intratumoral TIL, while global scores had the highest concordance correlation coefficients. Our study concluded that tertiary lymphoid structures are accurately and consistently scored using immunohistochemical but not hematoxylin-eosin stains. A strong association was observed between TIL in core biopsies and surgical samples (R²=0.74) but this did not extend to tertiary lymphoid structures (R²=0.26). TIL scored by pathologists and digital analysis were correlated but our analysis reveals a constant bias between these methods. These data challenge current criteria for TIL and tertiary lymphoid structure assessment in breast cancer and recommend that how pathologists evaluate immune infiltrates be reexamined for future studies.

ICG-fluorescence imaging for detection of peritoneal metastases and residual tumoral scars in locally advanced ovarian cancer: A pilot study

BACKGROUND AND OBJECTIVES

No intraoperative imaging techniques exist for detecting tumor nodules or tumor scar tissues in patients treated with upfront or interval cytoreductive surgery (CS) after neoadjuvant chemotherapy (NAC). The aims of this study were to evaluate the role of indocyanine green (ICG) fluorescence imaging (FI) for the detection of peritoneal metastases (PM) and evaluate whether it can be used to detect remnant tumor cells in scar tissue.

METHODS

Patients with PM from ovarian cancer admitted for CS were included. ICG, at 0.25 mg per kg of patient weight, was injected intraoperatively after explorative laparotomy before CS.

RESULTS

A total of 108 peritoneal lesions, including 25 scars, were imaged in 20 patients. Seventy-three were malignant (67.6%) and 35 benign (32.4%). The mean Tumor to Background Ratio (ex vivo) was 1.8 (SD 1.3) in malignant and 1.0 (SD 0.79) in benign nodules (P = 0.007). Of 25 post-NAC scars, the mean Tumor to Background Ratio (TBR) (in vivo) was 2.06 (SD 1.15) in malignant and 1.21 (SD 0.50) in benign nodules (P = 0.26). The positive predictive value of ICG-FI to detect tumor cells in scars was 57.1%.

CONCLUSIONS

ICG-FI is accurate to demonstrate PM in ovarian cancer but unable to discriminate between benign and malignant post-NAC.

DNA methylation-based immune response signature improves patient diagnosis in multiple cancers

BACKGROUND

The tumor immune response is increasingly associated with better clinical outcomes in breast and other cancers. However, the evaluation of tumor-infiltrating lymphocytes (TILs) relies on histopathological measurements with limited accuracy and reproducibility. Here, we profiled DNA methylation markers to identify a methylation of TIL (MeTIL) signature that recapitulates TIL evaluations and their prognostic value for long-term outcomes in breast cancer (BC).

METHODS

MeTIL signature scores were correlated with clinical endpoints reflecting overall or disease-free survival and a pathologic complete response to preoperative anthracycline therapy in 3 BC cohorts from the Jules Bordet Institute in Brussels and in other cancer types from The Cancer Genome Atlas.

RESULTS

The MeTIL signature measured TIL distributions in a sensitive manner and predicted survival and response to chemotherapy in BC better than did histopathological assessment of TILs or gene expression-based immune markers, respectively. The MeTIL signature also improved the prediction of survival in other malignancies, including melanoma and lung cancer. Furthermore, the MeTIL signature predicted differences in survival for malignancies in which TILs were not known to have a prognostic value. Finally, we showed that MeTIL markers can be determined by bisulfite pyrosequencing of small amounts of DNA from formalin-fixed, paraffin-embedded tumor tissue, supporting clinical applications for this methodology.

CONCLUSIONS

This study highlights the power of DNA methylation to evaluate tumor immune responses and the potential of this approach to improve the diagnosis and treatment of breast and other cancers.

FUNDING

This work was funded by the Fonds National de la Recherche Scientifique (FNRS) and Télévie, the INNOVIRIS Brussels Region BRUBREAST Project, the IUAP P7/03 program, the Belgian "Foundation against Cancer," the Breast Cancer Research Foundation (BCRF), and the Fonds Gaston Ithier.

Abstract 3694: FOXP1 suppresses immune cell migration in breast tumors

Tumor infiltrating lymphocytes (TIL) play an essential role in mediating response to chemotherapy and improving clinical outcomes in breast cancer (BC). Extensive TIL infiltration is characterized by their organized into tertiary lymphoid structures (TLS). TIL infiltration and TLS formation may be regulated, in part, by transcription factors (TF) controlling cytokine/chemokine production within the tumor microenvironment. The forkhead box protein 1 (FOXP1) is a TF shown to be abnormally expressed in a variety of human tumors and play an important role in T cell cytokine production. Therefore we aimed to study FOXP1-mediated regulation of TIL in BC. Investigation of FOXP1 expression in public microarray data from untreated BC patients, BC cell lines [Luminal A (MCF7), HER2+ (BT474) and triple negative (TN; MDA-MB231)] and prospectively collected formalin-fixed paraffin-embedded (FFPE) primary breast tissues showed that FOXP1 is repressed at transcript and protein level in HER2+ or TN breast tumors compared to estrogen receptor positive tumors (Luminal A and B). Moreover HER2+ and TN subtypes, which showed decreased FOXP1 levels, are 2 well known highly infiltrated BC. Based on our hypothesis that FOXP1 could play a role on immune cell infiltration in breast tumors, data analysis of the prospective BC cohort showed that high FOXP1 (FOXP1hi) expression is significantly associated with a lower percentage of TIL and number of TLS compared to FOXP1 low (FOXP1lo) tumors. To investigate the impact on specific cytokines/chemokines involved in TIL recruitment and/or TLS formation, FOXP1 was silenced in MCF7 (FOXP1hi tumor cell line) or upregulated in MDA-MB-231 (FOXP1lo tumor cell line) followed by gene expression analysis using a RT-qPCR based human cytokine/chemokine array. FOXP1 repression upregulated major T and B cell chemoattractant chemokines and overexpression repressed most of these molecules in the cell line experiments. Next we analyzed major chemoattractant molecule expression in FOXP1lo and FOXP1hi prospective breast tumors and found that FOXP1hi tumors having a significant decrease in CXCL9, CXCL10, CXCL11, CXCL13, CX3CL, CCL20, IL2, and IL21. A migration assay (Transwell chambers) done using healthy donor (HD) PBMC showed a significant increase in total lymphocytes migrated towards FOXP1 repressed tumor conditioned media (TCM) of MCF7 compared to the TCM of control or medium alone. Finally analysis of lymphocyte migration to FOXP1lo and FOXP1hi tumor supernatants (SN) from primary tumors that we consistently prepare without enzymatic digestion, showed that there was a significant decrease in number of lymphocytes migrated towards FOXP1hi tumor SN including the migration rates of individual T and B lymphocytes populations compared to FOXP1lo tumor SN. These data suggest that FOXP1 could play a critical role in establishing effective anti-tumor immune responses by negative regulation of TIL via suppression of cytokine/chemokine expression in breast tumors.

Citation Format: Pushpamali De Silva, Soizic Garaud, Roland de Wind, Gert Van den Eynden, Anaïs Boisson, Cinzia Solinas, Edoardo Migliori, Hugues Duvillier, Denis Larsimont, Martine Piccart-Gebhart, Karen Willard-Gallo. FOXP1 suppresses immune cell migration in breast tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3694. doi:10.1158/1538-7445.AM2017-3694

CXCL13-producing TFH cells link immune suppression and adaptive memory in human breast cancer

T follicular helper cells (TFH cells) are important regulators of antigen-specific B cell responses. The B cell chemoattractant CXCL13 has recently been linked with TFH cell infiltration and improved survival in human cancer. Although human TFH cells can produce CXCL13, their immune functions are currently unknown. This study presents data from human breast cancer, advocating a role for tumor-infiltrating CXCL13-producing (CXCR5-) TFH cells, here named TFHX13 cells, in promoting local memory B cell differentiation. TFHX13 cells potentially trigger tertiary lymphoid structure formation and thereby generate germinal center B cell responses at the tumor site. Follicular DCs are not potent CXCL13 producers in breast tumor tissues. We used the TFH cell markers PD-1 and ICOS to identify distinct effector and regulatory CD4+ T cell subpopulations in breast tumors. TFHX13 cells are an important component of the PD-1hiICOSint effector subpopulation and coexpanded with PD-1intICOShiFOXP3hi Tregs. IL2 deprivation induces CXCL13 expression in vitro with a synergistic effect from TGFβ1, providing insight into TFHX13 cell differentiation in response to Treg accumulation, similar to conventional TFH cell responses. Our data suggest that human TFHX13 cell differentiation may be a key factor in converting Treg-mediated immune suppression to de novo activation of adaptive antitumor humoral responses in the chronic inflammatory breast cancer microenvironment.

Indocyanine green fluorescence-guided surgery after IV injection in metastatic colorectal cancer: A systematic review

OBJECTIVE

Indocyanine green fluorescence-guided surgery (ICG-FGS) has emerged as a potential new imaging modality for improving the detection of hepatic, lymph node (LN), and peritoneal metastases in colorectal cancer (CRC) patients. The aim of this paper is to review the available literature in the clinical setting of ICG-FGS for tumoral detection in various fields of metastatic colorectal disease.

METHODS

PubMed and Medline literature databases were searched for original articles on the use of ICG in the setting of clinical studies on colorectal cancer. The search terms used were "near-infrared fluorescence", "intraoperative imaging", "indocyanine green", "human" and "colorectal cancer".

RESULTS

ICG fluorescence imaging (ICG-FI) is clearly supported as an intraoperative technique that allows the detection of additional superficial hepatic metastases of CRC. Data on the role of ICG-FI in the intraoperative detection of peritoneal metastases and LN metastases are scarce but encouraging and ICG-FI could potentially improve the staging and treatment of these patients.

CONCLUSION

ICG-FI is a promising imaging technique in the detection of small infraclinic LN, hepatic, and peritoneal metastatic deposits that may allow better staging and more complete surgical resection with a potential prognostic benefit for patients.

Phylogenetic analysis of metastatic progression in breast cancer using somatic mutations and copy number aberrations

Several studies using genome-wide molecular techniques have reported various degrees of genetic heterogeneity between primary tumours and their distant metastases. However, it has been difficult to discern patterns of dissemination owing to the limited number of patients and available metastases. Here, we use phylogenetic techniques on data generated using whole-exome sequencing and copy number profiling of primary and multiple-matched metastatic tumours from ten autopsied patients to infer the evolutionary history of breast cancer progression. We observed two modes of disease progression. In some patients, all distant metastases cluster on a branch separate from their primary lesion. Clonal frequency analyses of somatic mutations show that the metastases have a monoclonal origin and descend from a common 'metastatic precursor'. Alternatively, multiple metastatic lesions are seeded from different clones present within the primary tumour. We further show that a metastasis can be horizontally cross-seeded. These findings provide insights into breast cancer dissemination.

N-Acetylcysteine breaks resistance to trastuzumab caused by MUC4 overexpression in human HER2 positive BC-bearing nude mice monitored by 89Zr-Trastuzumab and 18F-FDG PET imaging

Trastuzumab remains an important drug in the management of human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer (BC). Several studies reported resistance mechanisms to trastuzumab, including impaired HER2-accessibility caused by mucin 4 (MUC4). Previously, we demonstrated an increase of Zirconium-89-radiolabeled-trastuzumab (⁸⁹Zr-Trastuzumab) accumulation when MUC4-overexpressing BC-cells were challenged with the mucolytic drug N-Acetylcysteine (NAC). Hereby, using the same approach we investigated whether tumor exposure to NAC would also enhance trastuzumab-efficacy.

Dual SKBr3 (HER2+/MUC4-, sensitive to trastuzumab) and JIMT1 (HER2+/MUC4+, resistant to trastuzumab) HER2-BC-bearing-xenografts were treated with trastuzumab and NAC. Treatment was monitored by molecular imaging evaluating HER2-accessibility/activity (⁸⁹Zr-Trastuzumab HER2-immunoPET) and glucose metabolism (¹⁸F-FDG-PET/CT), as well as tumor volume and the expression of key proteins.

In the MUC4-positive JIMT1-tumors, the NAC-trastuzumab combination resulted in improved tumor-growth control compared to trastuzumab alone; with smaller tumor volume/weight, lower 18F-FDG uptake, lower %Ki67 and pAkt-expression. NAC reduced MUC4-expression, but did not affect HER2-expression or the trastuzumab-sensitivity of the MUC4-negative SKBr3-tumors.

These findings suggest that improving HER2-accessibility by reducing MUC4-masking with the mucolytic drug NAC, results in a higher anti-tumor effect of trastuzumab. This provides a rationale for the potential benefit of this approach to possibly treat a subset of HER2-positive BC overexpressing MUC4.

Abstract A62: Investigating the role of follicular helper T cells, B cells and CXCL13 in breast cancer-associated tertiary lymphoid structures

Patient outcomes have been linked to the presence of tumor infiltrating lymphocytes (TIL) in solid tumors. In human breast cancer (BC), higher TIL infiltration is associated with a better prognosis and also predicts relevant responses to pre-operative chemotherapy. TIL are primarily composed of T cells, albeit around 20% of BC patients show significant B cell infiltration, and can organize in tertiary lymphoid structures (TLS) located in the peritumoral stroma 1, which are associated with survival in HER2+ and triple negative BC patients. Further, these studies revealed that CD4+ follicular helper T (Tfh) cells producing CXCL13 were specifically associated with peritumoral TLS. CXCL13 is an important B cell chemoattractant whose function is to recruit B cells to the germinal center (GC) in secondary lymphoid organs and TLS, where they can mature and differentiate into memory or antibody-producing B cells. Our recent efforts have focused on exploring the role of Tfh, B cells and CXCL13 play in the development and/or maintenance of GC-like structures in BC-associated TLS. We first derived a GC-B cell gene signature for integration in our published Tfh cell gene signature 1. The combined gene signature was tested for its ability to sensitively detect BC-associated TLS using a qRT-PCR-based assay and a retrospective series (n=54) of formalin-fixed paraffin-embedded (FFPE) BC tissues. These data revealed a correlation between gene signature expression and the extent of TIL and TLS scored by trained pathologists on dual-immunohistochemistry stained (CD3+CD20 for T and B cells, respectively) FFPE tissue sections. The detection of TLS using our combined GC-B cell/Tfh cell gene signature was subsequently confirmed using tissues from our prospective BC cohort (n=83). In addition, CXCL13 gene expression was well correlated with genes associated with GC-B cells and Tfh, indicating these parameters are closely related, as confirmed by immunofluorescence staining on FFPE tissues.

Further understanding the factors that promote TLS formation in vivo could provide important insight for treatment decisions in BC. CXCL13 expression was originally identified as an important signal associated with TLS that was predictive for patient outcomes 1. Factors capable of inducing CXCL13 expression in CD4+ T cells isolated from peripheral blood were investigated using flow cytometry. TGFβ1 alone or together with several cytokines (IL4, IL12, IL21, IL23 and in particular IL2 blockade) increased CXCL13 expression in activated CD4+ T cells. Similar to our characterization of Tfh TIL in fresh tumor tissues, these CXCL13-producing CD4+ T cells were CXCR5 negative and expressed the Tfh marker ICOS; however, they only had low levels of PD-1 expression compared to PD-1hi Tfh cells. CD8+ T cells were also found to produce CXCL13 albeit at low levels. The currently ongoing identification of critical genes involved in regulating CXCL13 production in treated CD4+T cells will help to elucidate the mechanism(s) underlying chemokine induction. The increased accuracy in TIL and TLS detection in BC together with a better understanding of the role Tfh and CXCL13 play in these structures (and GC) development should help to identify the critical immune components involved in BC TLS formation.

1Gu-Trantien et al. J Clin Invest. 2013

Citation Format: Edoardo Migliori, Chunyan Gu-Trantien, Soizic Garaud, Gert Van den Eynden, Alexandre De Wind, Pushpamali De Silva, Cinzia Solinas, Anais Boisson, Celine Naveaux, Denis Larsimont, Martine Piccart-Gebhart, Karen Willard-Gallo. Investigating the role of follicular helper T cells, B cells and CXCL13 in breast cancer-associated tertiary lymphoid structures. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A62.

Abstract P3-04-04: Detection of ESR1 mutations in matched primary and metastatic samples from endocrine-resistant lobular breast cancer patients

Background:

Invasive lobular breast cancer (ILBC) represents the second most common histology of breast cancer (BC) and accounts for 10-15% of all invasive cases. Since &gt;90% of ILBCs express the estrogen receptor (ER, coded by the ESR1 gene), the vast majority of these patients receive endocrine therapy. ESR1 mutations have mainly been identified in metastases from ER-positive BC at a frequency ranging from 11 to 50% and were shown to be associated with resistance to endocrine therapy. Nevertheless, ESR1 mutations have never been assessed in metastatic ILBC, hence the present study.

Patients and methods:

We aimed at interrogating the five most commonly reported ESR1 mutations (Y537S/C/N, D538G, E380Q) by droplet digital PCR (BioRad) in matched primary, axillary and metastatic ILBC samples (N=212) from 69 endocrine-resistant patients collected retrospectively from five hospitals.

Results:

We present here the results for the two most frequent ESR1 mutations (Y537S and D538G); data from the remaining mutations will be available at the time of the conference. We observed Y537S and D538G mutations in metastases from three and four patients, respectively. For one patient, the sampled metastasis harbored both the Y537S and the D538G mutations, confirming that ESR1 polyclonality can be present in the same metastasis. For another patient, two metastases were sampled and the D538G mutation was only present in one metastasis. Intriguingly, for two patients we observed D538G mutations only in the primary tumor but not in the corresponding metastasis, and for another only in an axillary lymph node. We could hypothesize that the clone carrying the mutation in the early setting has been removed either by the primary surgery or subsequent adjuvant chemotherapy. The ESR1 Y537S and D538G mutational frequencies observed in our metastatic ILC cohort (3/69, 4.35% and 4/69, 5.80%, respectively) are not statistically different from the frequencies reported in breast cancer metastases in the literature across the different studies (6.62% and 6.20%, respectively). All patients with ESR1-mutated metastases received at least 4 years of endocrine therapy and all but one were treated with an aromatase inhibitor (AI). However, half of these patients received exclusively endocrine therapy in the adjuvant setting.

Conclusion:

This is to the best of our knowledge, the first metastatic ILBC series in which the most frequently reported ESR1 mutations are being investigated, and the largest series in which ESR1 mutations are being investigated in matched metastatic, primary tumor and axillary lymph node samples. The frequencies that we found for the Y537S and D538G mutations are in line with those reported in the literature in metastatic biopsies for the general BC population. We further demonstrated using multiple samples from the primary tumor and an ultra-sensitive technology that there was no patient presenting an ESR1 mutation both in the early and metastatic disease. Data on the remaining mutations (Y537S/N, E380Q) will complete these results.

Citation Format: Desmedt C, Pingitore J, Rothé F, Rouas G, Bertucci F, Galant C, Rotmensz N, van den Eynden G, Salgado R, Larsimont D, Pruneri G, Sotiriou C. Detection of ESR1 mutations in matched primary and metastatic samples from endocrine-resistant lobular breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-04.

Abstract P2-04-04: BRCA gene mutations do not shape the extent and organization of tumor infiltrating lymphocytes in triple negative breast cancer

The remarkable responses observed in metastatic cancer patients treated with immunotherapies, including inhibitors directed to the PD-1 and PD-L1 checkpoint molecules, makes it a priority to identify critical variations in pro- and anti-tumor immune responses in breast cancer (BC). In patients with triple negative (TN) BC, an increased presence of tumor infiltrating lymphocytes (TIL) and tertiary lymphoid structures (TLS) have been associated with good clinical outcomes. However, the frequency of specific lymphocyte subpopulations, PD-1 and/or PD-L1 expression and their prognostic significance remains an open question. Our recent work found that PD-1 and PD-L1 expression are specifically associated with higher TIL densities and an increased number of TLS in BC. We further demonstrated that TIL density, TLS and PD-L1 expression were correlated with more aggressive breast tumor characteristics, including higher proliferation and hormone receptor negativity. In this project, we examined the prevalence of TIL, TLS, PD-1 and PD-L1 expression in TNBC and further compared these immune parameters between TNBC patients harboring BRCA1 or BRCA2 germline gene mutations with those carrying the wild-type (wt) genes.

A total of 1402 BC patients whose blood was genetically tested for germline BRCA1 and BRCA2 mutations were examined for inclusion in this study. Ninety-eight chemotherapy-naïve patients with primary invasive ER–, PR– and HER2– BC and demonstrated germline BRCA1 or BRCA2 wt or mutated-gene status were included in this study. Ninety-four tumors were determined to be suitable for evaluating immune cell infiltration (51 BRCA wt and 43 BRCA-mutated). FFPE tumor tissue from the surgical specimens was analyzed by immunohistochemistry (IHC) staining of full-face tissue sections. IHC was performed as a dual label using CD3 plus CD20 for T and B cells, CD4 plus CD8 for the major T cell subpopulations and PD-1 plus PD-L1 for individual or paired expression of these receptors. The stained slides were independently scored by two experienced pathologists for TIL, TIL subpopulations, TLS and checkpoint molecule expression.

These analyses revealed that 87% of our TNBC cohort was TIL-positive (≥10% TIL) with 35% classified as lymphocyte predominant BC (LPBC; ≥50% TIL). T cells were the principal component of the lymphocytic infiltrate with no significant differences between the BRCA wt and BRCA-mutated groups detected in total T cells (CD3+), helper T cells (CD4+), cytotoxic T cells (CD8+) or B cells (CD20+). TLS were identified in 73% of tumors with again no significant differences between the BRCA groups. Examination of checkpoint molecule expression identified 33% tumors as PD-1 positive and 40% as PD-L1 positive. PD-1 expression was correlated with PD-L1 expression and both with TIL positivity and the level of immune infiltration but not BRCA mutational status.

Overall, our analyses revealed that BRCA wt and BRCA-mutated TNBC are remarkably similar in terms of TIL heterogeneity, a TLS presence and checkpoint molecule expression. These data suggest that BRCA gene mutations are not immunogenic nor do they directly drive immune infiltration in TNBC.

Citation Format: Willard-Gallo K, Solinas C, Marcoux D, t'Kint de Roodenbeke D, Garaud S, Van den Eynden G, de Wind A, Boisson A, Larsimont D, Piccart M. BRCA gene mutations do not shape the extent and organization of tumor infiltrating lymphocytes in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-04-04.

Abstract P6-07-02: CDK4 phosphorylation status and corresponding gene expression profile predict sensitivity to Palbociclib

Although the specific CDK4/6 inhibitor PD0332991 (Palbociclib) was recently approved by the FDA to treat advanced ER+ breast tumors, there is yet no reliable sensitivity prediction tool. Cyclin D-CDK4/6 are the first CDK complexes to be activated in G1 phase in response to oncogenic pathways. They phosphorylate and inactivate the central cell cycle/tumor suppressor pRb. CDK4 activity requires its binding to a cyclin D (CCND1-3 genes) with which INK4 CDK4 inhibitors such as p16 (CDKN2A-D genes) compete. Although the assembly of the CDK4-cyclin D complexes was considered to be the main level of CDK4 activity control, we have shown that the activating T172-phosphorylation of CDK4 is actually the central rate-limiting event that initiates the cell cycle decision and signals the presence of active CDK4.

Here, using 2D-gel electrophoresis to separate the modified forms of CDK4, we found in breast cancer cell lines that only the CDK4 T172-phosphorylation correlates with the sensitivity to PD0332991. The only exception was in the rare case of combined CCNE1 amplification and CDKN2A loss wherein combination of PD0332991 with a CDK2 inhibitor is required to block entry in the cell cycle. Additionally, three types of CDK4 modification profile were identified by 2D-gel electrophoresis in 56 breast tumors. In the first profile, the phosphorylated CDK4 was undetectable as in normal breast samples despite a high KI67 index. In the second and third profiles, the CDK4 phosphorylation was detectable and its intensity was either above or below 90% of the intensity of a second yet unidentified form of CDK4, respectively. The proportions of these profiles differ among breast tumors according to their clinic-pathological characteristics, molecular subtypes and risk. Finally, we identified a 11-gene expression signature that faithfully predicted the CDK4 modification profiles of breast tumors and cell lines (concordance rates of 84% and 100% in the 56 analyzed breast tumor samples or cell lines respectively). All three CDK4 modification profiles were evaluated in a merged independent dataset of 4034 published gene expression profiles. In these 4034 patients, 70% of triple-negative tumors, 18% of HER2-positive tumors and 5% of ER-positive tumors were predicted to have the first CDK4 profile wherein CDK4 phosphorylation is undetectable and to be completely unresponsive to CDK4 inhibitors. The phosphorylated CDK4 was predicted to be the major modified form in 26% of triple-negative tumors, 48% of HER2- positive tumors and 56% of ER-positive tumors. These patients should benefit the most from treatment with CDK4 inhibitors. Therefore, prediction of the CDK4 modification profile may allow extending treatment with Palbociclib to presently ineligible patients. As tumors with the third CDK4 modification profile generally present low grade and low OncotypeDX risks, the added value of including CDK4 inhibitors in their treatment compared to surgery and hormone therapy alone is questionable.

In conclusion, we identified CDK4 phosphorylation as the most direct biomarker of CDK4 inhibitor sensitivity in breast cancer and developed a promising 11-gene based surrogate marker to guide their use in the clinic.Although the specific CDK4/6 inhibitor PD0332991 (Palbociclib) was recently approved by the FDA to treat advanced ER+ breast tumors, there is yet no reliable sensitivity prediction tool. Cyclin D-CDK4/6 are the first CDK complexes to be activated in G1 phase in response to oncogenic pathways. They phosphorylate and inactivate the central cell cycle/tumor suppressor pRb. CDK4 activity requires its binding to a cyclin D (CCND1-3 genes) with which INK4 CDK4 inhibitors such as p16 (CDKN2A-D genes) compete. Although the assembly of the CDK4-cyclin D complexes was considered to be the main level of CDK4 activity control, we have shown that the activating T172-phosphorylation of CDK4 is actually the central rate-limiting event that initiates the cell cycle decision and signals the presence of active CDK4.

Here, using 2D-gel electrophoresis to separate the modified forms of CDK4, we found in breast cancer cell lines that only the CDK4 T172-phosphorylation correlates with the sensitivity to PD0332991. The only exception was in the rare case of combined CCNE1 amplification and CDKN2A loss wherein combination of PD0332991 with a CDK2 inhibitor is required to block entry in the cell cycle. Additionally, three types of CDK4 modification profile were identified by 2D-gel electrophoresis in 56 breast tumors. In the first profile, the phosphorylated CDK4 was undetectable as in normal breast samples despite a high KI67 index. In the second and third profiles, the CDK4 phosphorylation was detectable and its intensity was either above or below 90% of the intensity of a second yet unidentified form of CDK4, respectively. The proportions of these profiles differ among breast tumors according to their clinic-pathological characteristics, molecular subtypes and risk. Finally, we identified a 11-gene expression signature that faithfully predicted the CDK4 modification profiles of breast tumors and cell lines (concordance rates of 84% and 100% in the 56 analyzed breast tumor samples or cell lines respectively). All three CDK4 modification profiles were evaluated in a merged independent dataset of 4034 published gene expression profiles. In these 4034 patients, 70% of triple-negative tumors, 18% of HER2-positive tumors and 5% of ER-positive tumors were predicted to have the first CDK4 profile wherein CDK4 phosphorylation is undetectable and to be completely unresponsive to CDK4 inhibitors. The phosphorylated CDK4 was predicted to be the major modified form in 26% of triple-negative tumors, 48% of HER2- positive tumors and 56% of ER-positive tumors. These patients should benefit the most from treatment with CDK4 inhibitors. Therefore, prediction of the CDK4 modification profile may allow extending treatment with Palbociclib to presently ineligible patients. As tumors with the third CDK4 modification profile generally present low grade and low OncotypeDX risks, the added value of including CDK4 inhibitors in their treatment compared to surgery and hormone therapy alone is questionable.

In conclusion, we identified CDK4 phosphorylation as the most direct biomarker of CDK4 inhibitor sensitivity in breast cancer and developed a promising 11-gene based surrogate marker to guide their use in the clinic.

Citation Format: Raspe ES, Coulonval K, Pita J, Paternot S, Rothé F, Larsimont D, Van Laere S, Piccart M, Ignatiadis M, Sotiriou C, Roger PP. CDK4 phosphorylation status and corresponding gene expression profile predict sensitivity to Palbociclib [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-07-02.

Sentinel Lymph Node Detection by Blue Dye Versus Indocyanine Green Fluorescence Imaging in Colon Cancer

BACKGROUND/AIM

Nodal staging is used in colorectal cancer (CRC) to determine which patients should receive adjuvant chemotherapy. The aim of this study was to evaluate the role of indocyanine green fluorescence imaging (ICG-FI) in sentinel lymph node (SLN) detection compared to the standard technique.

MATERIALS AND METHODS

Twenty patients with CRC admitted for elective colectomy were included (NCT01995591). Ex vivo SLN detection was performed using patent blue (PB) and free ICG injected around the tumor.

RESULTS

Identification rates were 95% (19/20) for both techniques. Sensitivity was 43% for PB and 57% for ICG. Correlation between the techniques was 83%. FI was more sensitive in patients with body mass index (BMI) >25 kg/m(2) Serial section analysis did not allow for up-staging of patients.

CONCLUSION

The use of ICG-FI is superior to the blue dye technique in patients with a BMI >25 kg/m(2) However, the sensitivity of ICG-FI in SLN detection remains low, with a high rate of false-negative results.

Tumor-infiltrating lymphocyte composition, organization and PD-1/ PD-L1 expression are linked in breast cancer

The clinical relevance of tumor-infiltrating lymphocytes (TIL) in breast cancer (BC) has been clearly established by their demonstrated correlation with long-term positive outcomes. Nevertheless, the relationship between protective immunity, observed in some patients, and critical features of the infiltrate remains unresolved. This study examined TIL density, composition and organization together with PD-1 and PD-L1 expression in freshly collected and paraffin-embedded tissues from 125 patients with invasive primary BC. Tumor and normal breast tissues were analyzed using both flow cytometry and immunohistochemistry. TIL density distribution is a continuum with 25% of tumors identified as TIL-negative at a TIL density equivalent to normal breast tissues. TIL-positive tumors (75%) were equally divided into TIL-intermediate and TIL-high. Tumors had higher mean frequencies of CD4⁺ T cells and CD19⁺ B cells and a lower mean frequency of CD8⁺ T cells compare with normal tissues, increasing the CD4⁺/CD8⁺ T-cell ratio. Tertiary lymphoid structures (TLS), principally located in the peri-tumoral stroma, were detected in 60% of tumors and correlated with higher TIL infiltration. PD-1 and PD-L1 expression were also associated with higher TIL densities and TLS. TIL density, TLS and PD-L1 expression were correlated with more aggressive tumor characteristics, including higher proliferation and hormone receptor negativity. Our findings reveal an important relationship between PD-1/PD-L1 expression, increased CD4⁺ T and B-cell infiltration, TIL density and TLS, suggesting that evaluating not only the extent but also the nature and location of the immune infiltrate should be considered when evaluating antitumor immunity and the potential for benefit from immunotherapies.

Langerhans cell number is a strong and independent prognostic factor for head and neck squamous cell carcinomas

OBJECTIVES

Head and neck squamous cell carcinomas (HNSCCs) exhibit great biological heterogeneity and relatively poor prognosis. Tobacco and alcohol consumption is involved in the cause of the majority of these cancers, but over the last several years, Human Papilloma Virus (HPV) infection has increased specifically in oropharyngeal cancers and become an additional risk factor. Here, we evaluated the number of Langerhans cells (LCs) in HNSCC and reporting its prognostic power in comparison to other risk factors.

MATERIALS AND METHODS

Our clinical series was composed of 25 tumor-free peritumoral epithelium, 64 low-grade dysplasia, 54 high-grade dysplasia and 125 carcinoma samples. HPV was detected by E6/E7 qPCR and p16 immunohistochemistry. CD1a-positive LCs were counted in intra-tumoral and stromal compartments as well as lymph nodes. MIP-3α was assessed in carcinomas using immunohistochemistry.

RESULTS

Univariate Cox regression analyses demonstrated that high LC number is associated with longer recurrence-free survival in both intra-tumoral and stromal compartments and longer overall survival in stromal compartment. Tobacco and alcohol habits, but not HPV status, are also correlated with poor prognoses in terms of recurrence. Multivariate analyses reported stromal LC number as a strong prognostic factor independent of tobacco, alcohol and HPV status. Moreover, LC number is higher in tumors and invaded lymph nodes than dysplastic lesions but it decreases in HPV-positive cancer patients. Further, LC number correlates with MIP-3α expression.

CONCLUSION

These findings suggest that LC number is a significant and independent prognostic factor for HNSCC. LC infiltration is increased in cancer lesions but decrease with HPV infection.

Feasibility Study of EndoTAG-1, a Tumor Endothelial Targeting Agent, in Combination with Paclitaxel followed by FEC as Induction Therapy in HER2-Negative Breast Cancer

Background

EndoTAG-1, a tumor endothelial targeting agent has shown activity in metastatic triple-negative breast cancer (BC) in combination with paclitaxel.

Methods

HER2-negative BC patients candidates for neoadjuvant chemotherapy were scheduled to receive 12 cycles of weekly EndoTAG-1 22mg/m² plus paclitaxel 70mg/m² followed by 3 cycles of FEC (Fluorouracil 500mg/m², Epirubicin 100mg/m², Cyclophosphamide 500mg/m²) every 3 weeks followed by surgery. Primary endpoint was percent (%) reduction in Magnetic Resonance Imaging (MRI) estimated Gadolinium (Gd) enhancing tumor volume at the end of EndoTAG-1 plus paclitaxel administration as compared to baseline. Safety, pathological complete response (pCR) defined as no residual tumor in breast and axillary nodes at surgery and correlation between % reduction in MRI estimated tumor volume and pCR were also evaluated.

Results

Fifteen out of 20 scheduled patients were included: Six patients with estrogen receptor (ER)-negative/HER2-negative and 9 with ER-positive/HER2-negative BC. Nine patients completed treatment as per protocol. Despite premedication and slow infusion rates, grade 3 hypersensitivity reactions to EndoTAG-1 were observed during the 1^st, 2^nd, 3^rd and 6^th weekly infusion in 4 patients, respectively, and required permanent discontinuation of the EndoTAG-1. Moreover, two additional patients stopped EndoTAG-1 plus paclitaxel after 8 and 9 weeks due to clinical disease progression. Two patients had grade 3 increases in transaminases and 1 patient grade 4 neutropenia. pCR was achieved in 5 of the 6 ER-/HER2- and in none of the 9 ER+/HER2- BC patients. The mean % reduction in MRI estimated tumor volume at the end of EndoTAG-1 plus paclitaxel treatment was 81% (95% CI, 66% to 96%, p<0.001) for the 15 patients that underwent surgery; 96% for patients with pCR and 73% for patients with no pCR (p = 0.04).

Conclusions

The EndoTAG-1 and paclitaxel combination showed promising preliminary activity as preoperative treatment, especially in ER-/HER2- patients. Further studies are warranted with need of premedication optimization.

Trial Registration

ClinicalTrials.gov NCT01537536

Abstract 4139: TfhX13 cells link breast cancer immune suppression and adaptive memory

Background:

Previously, we identified PD-1hiCD200hiCD4+ follicular helper T (Tfh) cells infiltrating human breast cancer (BC TIL) as principal producers of the B cell chemoattractant CXCL13 and correlated their presence with improved patient outcome. Our recent efforts have focused on understanding the relationship between Tfh, Th1 and Treg BC TIL, investigating the role(s) that CXCL13+CD4+ TIL play in tumor immunity and determining the condition(s) that favor their differentiation.

Methods:

Ten-color flow cytometry was used to characterize CD4+ TIL subpopulations in fresh tissues. Confocal microscopy was employed to study the in situ interaction between CXCL13+CD4+ T cells and B cells. CXCL13 was induced in normal PBMC in vitro.

Results:

Our data reveal that an exacerbated Treg response accompanies high CXCL13 expression within the activated CD4+ TIL compartment in BC. Th1 responses, using IFN-γ expression as a barometer, are limited. CXCL13+CD4+ TIL display both similar and distinct characteristics compared to their tonsillar counterparts. Tumor bed-localized CXCL13+ TIL, external to tertiary lymphoid structure (TLS) germinal centers (GC), are abundant in some tumors with extensive lymphoid infiltrates. Based on our observations, we designate the CXCL13+CD4+ TIL as TfhX13 cells.

A combination of PD-1 and ICOS can clearly segregate the CD4+ TIL into three distinct subpopulations: PD-1loICOSlo, PD-1hiICOSint and PD-1intICOShi. The PD-1hiICOSint TIL are enriched in TfhX13 and Th1 cells while the PD-1intICOShi TIL are principally FoxP3hi Treg. A linear correlation is observed between these two TIL subpopulations in 90% of BC while the remaining 10% contain an unbalanced, higher level of PD-1intICOShi Treg. qRT-PCR data confirmed the significant positive prognostic value of CXCL13 gene expression with ICOS expression signaling the adverse effects of Treg cell dominance observed in some BC. TfhX13 TIL abundance appears to parallel both a GC and post-TLS memory B cell presence. Confocal microscopy revealed TfhX13 TIL interact directly with B cells and plasma cells, potentially guiding B cell migration through the tumor and promoting TLS formation with functional GC. Finally, we show that IL-2 deprivation is critical for inducing CXCL13 while TGF-β1 treatment reduces IFN-γ and increases FoxP3 expression in normal CD4+ T cells.

Conclusion:

IL-2 consumption by Treg cells was shown to be essential for murine Tfh cell development and a subsequent GC response. Supported by this observation, our data indicate that TfhX13 cell differentiation is an important element of the Tfh cell program and suggests their propagation in BC occurs in response to Treg accumulation. CXCL13 expression may activate adaptive memory responses dependent upon in situ B cell maturation and thereby initiate a secondary attempt at protective anti-tumor immunity in the face of Treg-mediated immune suppression.

Citation Format: Chunyan Gu-Trantien, Edoardo Migliori, Denis Larsimont, Karen Willard-Gallo. TfhX13 cells link breast cancer immune suppression and adaptive memory. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4139.

Classical risk factors, but not HPV status, predict survival after chemoradiotherapy in advanced head and neck cancer patients

Purpose

Despite the advent of concomitant chemoradiotherapy (CCRT), the prognosis of advanced head and neck squamous cell carcinoma (HNSCC) patients remains particularly poor. Classically, HNSCC, especially oropharyngeal carcinomas, associated with human papillomavirus (HPV) exhibits better treatment outcomes than HNSCCs in non-infected patients, eliciting a call for the de-escalation of current therapies. To improve the management of HNSCC patients, we aimed to determine the impact of active HPV infection on patient response, recurrence and survival after CCRT in a population of heavy tobacco and alcohol consumers.

Methods

Paraffin-embedded samples from 218 advanced HNSCC patients, mostly smokers and/or drinkers treated by CCRT, were tested for the presence of HPV DNA by surrogate type-specific E6/E7 qPCR and p16 immunohistochemistry. Associations between the response to CCRT and patient outcomes according to HPV status and clinical data were evaluated by Kaplan–Meier analysis and both univariate and multivariate Cox regression.

Results

Type-specific E6/E7 PCR demonstrated HPV positivity in 20 % of HNSCC. Regarding HPV status, we did not find any significant relation with response to therapy in terms of progression-free survival or overall survival. However, we observed a significantly worse prognosis for consumers of alcohol and tobacco compared to nondrinkers (p = 0.003) and non-smokers (p = 0.03). Survival analyses also revealed that the outcome is compromised in stage IV patients (p = 0.007) and, in particular, for oral cavity, hypopharynx and oropharynx carcinoma patients (p = 0.001).

Conclusion

The risk of death from HNSCC significantly increases when patients are exposed to tobacco and alcohol during their therapy, regardless of HPV status.

The Genomic Grade Assay Compared With Ki67 to Determine Risk of Distant Breast Cancer Recurrence

IMPORTANCE

The Genomic Grade Index (GGI) was previously developed, evaluated on frozen tissue, and shown to be prognostic in early breast cancer. To test the GGI in formalin-fixed, paraffin-embedded breast cancer tumors, a quantitative reverse transcriptase polymerase chain reaction assay was developed and named the Genomic Grade (GG). The GG assay has the potential to increase the clinical application of the GGI, but robust demonstration of the clinical validity of the GG assay is required.

OBJECTIVE

To evaluate the prognostic ability of the GG assay to detect breast cancer recurrence compared with centrally reviewed immunohistochemical testing of Ki67 antigen proliferation.

DESIGN, SETTING, AND PARTICIPANTS

This is an internationally collaborative substudy of a large phase 3 4-arm adjuvant trial. Patients had endocrine receptor-positive, node-positive, or node-negative nonmetastatic primary breast cancer. Patients included in this study had available formalin-fixed, paraffin-embedded samples of their primary tumors and were randomized to either a 5-year tamoxifen monotherapy arm or a 5-year letrozole monotherapy arm. Associations between either GG assay results or log2-transformed Ki67 data and survival end points were evaluated using Cox regression models stratified for chemotherapy use; the 2 vs 4 arm randomization option; and endocrine therapy assignment with and without adjustment for clinicopathological parameters, including centrally reviewed histological grade, hormone receptors, and ERBB2 (formerly HER2 or HER2/neu). The likelihood ratio statistic was used to assess the added prognostic value.

INTERVENTIONS

Central evaluation and comparison, blinded for clinical information, of the GG assay, breast cancer histological grade, and Ki67.

MAIN OUTCOMES AND MEASURES

Distant recurrence-free interval (DRFI).

RESULTS

Genomic Grade assay data were obtained in 883 breast cancer samples (62%). At a median follow-up of 8.1 years, 84 (10%) had distant recurrences. Increasing GG or Ki67 were both significantly associated with lower DRFI and added independent prognostic information to the clinicopathological prognostic factors. In patients with early node-negative breast cancer who were endocrine-only treated, 38% were GG1 with a 10-year DRFI of 99% (95% CI, 97%-100%), and 18% were histological grade 1 with a 10-year DRFI of 100% (95% CI, 100%-100%). For GG equivocal patients, the 10-year DRFI was 94% (95% CI, 90%-98%), and for GG3 patients, the 10-year DRFI was 87% (95% CI, 80%-94%).

CONCLUSIONS AND RELEVANCE

Either the GG assay or centrally reviewed Ki67 significantly improves clinicopathological models to determine distant recurrence of breast cancer. Compared with the histological grade, the GG assay can identify a higher proportion of endocrine-only treated patients with very low risk of distant recurrence at 10 years.

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: NCT00004205 and NCT00004205.

Ex vivo detection of tumoral lymph nodes of colorectal origin with fluorescence imaging after intraoperative intravenous injection of indocyanine green

BACKGROUND AND OBJECTIVES

The aim of this study was to investigate the potential role of indocyanine green (ICG) fluorescence imaging after intraoperative intravenous (IV) injection for the "ex vivo" detection of metastatic lymph nodes (mLNs) of colorectal cancer origin.

METHODS

Fresh-fixed LNs in cassettes and/or paraffin-embedded LNs of patients included in a study that evaluated the role of ICG in the detection of peritoneal metastases of colorectal origin (Protocol NCT-01995591) were further explored with a dedicated near-infrared camera system for their fluorescence. An IV injection of ICG was delivered intraoperatively at 0.25 mg/kg. Signal to background ratios (SBRs) were calculated.

RESULTS

LNs on operative specimens were evaluated for 12 patients (5 males, 7 females). A total of 182 LNs were analyzed. The mean LN number per patient was 15.2 (median: 15.5; range 3-22). SBRs of mLNs were significantly more fluorescent than benign LNs, 1.41 versus 1.04 arbitrary units (P < 0.0002). On univariate analysis, fluorescence was statistically correlated with LN surface area (>20 mm(2) ) (P < 0.0004).

CONCLUSION

Ex vivo ICG fluorescence imaging after intraoperative IV injection represents a potential method for detecting invaded LN's of colorectal cancer origin on operative specimens. Further clinical studies are needed to better define optimal techniques. J. Surg. Oncol. 2016;114:348-353. © 2016 Wiley Periodicals, Inc.

Genomic Characterization of Primary Invasive Lobular Breast Cancer

Purpose

Invasive lobular breast cancer (ILBC) is the second most common histologic subtype after invasive ductal breast cancer (IDBC). Despite clinical and pathologic differences, ILBC is still treated as IDBC. We aimed to identify genomic alterations in ILBC with potential clinical implications.

Methods

From an initial 630 ILBC primary tumors, we interrogated oncogenic substitutions and insertions and deletions of 360 cancer genes and genome-wide copy number aberrations in 413 and 170 ILBC samples, respectively, and correlated those findings with clinicopathologic and outcome features.

Results

Besides the high mutation frequency of CDH1 in 65% of tumors, alterations in one of the three key genes of the phosphatidylinositol 3-kinase pathway, PIK3CA, PTEN, and AKT1, were present in more than one-half of the cases. HER2 and HER3 were mutated in 5.1% and 3.6% of the tumors, with most of these mutations having a proven role in activating the human epidermal growth factor receptor/ERBB pathway. Mutations in FOXA1 and ESR1 copy number gains were detected in 9% and 25% of the samples. All these alterations were more frequent in ILBC than in IDBC. The histologic diversity of ILBC was associated with specific alterations, such as enrichment for HER2 mutations in the mixed, nonclassic, and ESR1 gains in the solid subtype. Survival analyses revealed that chromosome 1q and 11p gains showed independent prognostic value in ILBC and that HER2 and AKT1 mutations were associated with increased risk of early relapse.

Conclusion

This study demonstrates that we can now begin to individualize the treatment of ILBC, with HER2, HER3, and AKT1 mutations representing high-prevalence therapeutic targets and FOXA1 mutations and ESR1 gains deserving urgent dedicated clinical investigation, especially in the context of endocrine treatment.

Abstract S1-02: Lymphocytic infiltration in invasive lobular breast cancer

Background: The presence and prognostic value of tumor infiltrating lymphocytes (TILs) in invasive breast carcinoma has been demonstrated in several studies, especially in the triple-negative and HER2-positive subtypes. So far, TILs have not been investigated with sufficient detail in invasive lobular breast cancer (ILBC). Here we therefore aimed at: first, assessing the distribution of stromal TILs in ILBC; second, correlating the presence of TILs with standard clinical and pathological markers; third, exploring associations of TILs with recurrent genomic alterations; and, fourth, comparing the lymphocytic composition of ER-positive/HER2-negative lobular to ER-positive/HER2-negative ductal tumors.

Material and methods: The percentage of stromal TILs was independently assessed according to Salgado et al. (Ann Oncol 2015) by three pathologists on full-face hematoxylin and eosin slides in a well-annotated retrospective series of 614 primary ILBCs previously characterized at the genomic level. The median value of TILs was used for the analyses. For the association analyses, we focused on the more homogeneous group of ER-positive/HER2-negative ILBC (555/614). Breast cancer-free interval was used as survival endpoint and the analyses were censored at 12 years of follow-up. The comparison of the lymphocytic composition (relative percentage of CD45+ TILs which are CD4+, CD8+ or CD19+) was assessed by FACS in a separate prospective cohort of 51 ER-positive/HER2-negative lobular and 112 ER-positive/HER2-negative ductal tumors.

Results: The intraclass correlation coefficient between the three pathologists was 0.71 (95%CI:0.65-0.76). The median percentage of stromal TILs was 5% and the interquartile range 5-10%, with only 9% of the samples having ≥ 20%. Greater numbers of TILs were significantly associated with younger age at diagnosis, axillary lymph node involvement, high proliferative tumors as assessed by Ki67, and with the mixed non-classic ILBC subtypes. Greater numbers of TILs were associated with worse prognosis (HR=1.22; 95%CI:1.07-1.38, p=0.003) only in the unadjusted analysis, as it lost significance after adjustment for standard clinical and pathological variables. Greater numbers of TILs were observed in tumors harboring ARID1A, BRCA2, KMT2C and TP53 mutations, as well as chr3p21.31 and chr8q24.23 (PTK2) loss; whereas lower numbers were observed in tumors with ERBB3 mutations as well as chr7p and chr11q14.1 (PAK1) gains. There were no significant differences in the relative proportion of CD4+, CD8+ or CD19+ lymphocytes between ER-positive/HER2-negative lobular and ductal tumors.

Conclusion: In this work, which reports to our knowledge on the largest series of ILBC ever assessed for TILs, we showed that most ILBCs were characterized by low lymphocytic infiltration. Besides the association of TILs with clinical and pathological features of ILBC patients, we found that higher TIL levels were observed in the presence of specific mutations and copy number alterations. Higher numbers of TILs were associated with worse prognosis at the univariate analysis. Finally, based on the assessed markers, we have no evidence of differential lymphocytic composition between ER-positive/HER2-negative lobular and ductal tumors.

Citation Format: Desmedt C, Salgado R, Buisseret L, Zoppoli G, Fornili M, Van den Eynden G, Garaud S, Gundem G, Rothé F, Brown D, Kheddoumi N, Rouas G, Galant C, Bertucci F, Piccart M, Campbell P, Viale G, Larsimont D, Willard-Gallo K, Biganzoli E, Pruneri G, Sotiriou C. Lymphocytic infiltration in invasive lobular breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S1-02.

Abstract A124: Tertiary lymphoid structures: Predictors of effective antitumor immunity in human breast cancer?

The clinical relevance of tumor infiltrating lymphocytes (TIL) in breast cancer (BC) is now broadly accepted; however, the relationship between protective immunity, observed in some patients, and critical features of lymphoid subset composition and organization are largely unknown. Our recent work revealed that tertiary lymphoid structures (TLS), principally composed of T and B cells, present in the peri-tumoral regions of BC are associated with increased TIL infiltration in the tumor bed and good clinical outcomes in both the neo-adjuvant and adjuvant settings. To gain insight into the immune components linked with a significant TIL and TLS presence, we initiated a prospective study of T and B cell TIL. Breast tissues from tumors (current n=483) and matched non-adjacent non-tumor tissues (NANT) as well as normal tissue from mammary reductions (n=49) were systematically immunophenotyped by flow cytometry on the day of surgery. Primary tumor supernatants derived from the tissue homogenates (non-enzymatic) and plasma from all patients were stored for cytokine/chemokine and immunoglobulin analysis. TIL organization and spatial distribution was analyzed on paraffin sections using immunohistochemistry (IHC) and immunofluorescence (IF). The fresh tissue analyses revealed that TIL distribution in BC forms a continuum. The infiltration levels detected in normal tissue and NANT were used to define cutoffs that discriminate between TIL positive (TILpos) and negative (TILneg) tumors. TILneg tumors are defined as those with a TIL density &lt;99th percentile of the lymphocyte density in normal breast tissue. TILpos tumors include TIL-high (TILhi) where TIL density is &gt;99th percentile of lymphocyte density in NANT and TIL-intermediate (TILint). Applying these thresholds to the TIL infiltration levels identified approximately 25% of tumors as TILneg with infiltrating lymphocytes similar to normal breast tissue. The TILpos tumors (75%) are subdivided into 36% TILint and 39% TILhi tumors. TILpos tumors are characterized by an increase in CD4+ T cells and CD19+/CD20+ B cells. The median CD4/CD8 ratio was &gt;1 in TILpos compared to &lt;1 in TILneg tumors and NANT. CD4+ and CD8+ T cells were predominantly CD45RO+ memory cells with a significant proportion expressing PD-1. All stages of B cell differentiation were detected in the infiltrate; however, memory B cells were significantly increased in BC (50%) compared to normal tissues (&lt;15%) with the highest levels seen in TILhi tumors. An increase in centroblasts and centrocytes, the germinal center (GC) B cells, was associated with Tfh cells, both resident in peri-tumoral TLS. Their presence was positively correlated with antibody-secreting cells, suggesting local humoral immune responses are generated in TLS, which is supported by the increased immunoglobulin levels detected in tumor supernatants compared to NANT/normal tissue supernatants. Closer examination of Tfh cells infiltrating BC indicates that CXCL13-producing Tfh TIL vary from Tfh cells in secondary lymphoid organs such as tonsils. Tfh TIL express the highest levels of some GC Tfh cell markers (PD-1, CD200 and TIGIT) but intermediate levels of others (ICOS and BCL6) and are essentially negative for CXCR5. Closer examination of Tfh cells in the tumor bed revealed that they directly contact CD20+ B cells, IgG+ and IgA+ plasma cells as well as CXCL13–CD8+ TIL. Taken together, our data suggest that active cross-talk between adaptive immune cells in the tumor microenvironment may be key to establishing immunological memory sufficiently robust to control residual BC over the long term. These data further signify that TLS and/or the presence of GC-associated Tfh and B cells may be important biomarkers that identify effective anti-tumor immunity, which can ultimately be used to independently grade therapeutic responses.

Citation Format: Soizic Garaud, Laurence Buisseret, Chunyan Gu-Trantien, Gert Van den Eynden, Alexandre de Wind, Edoardo Migliori, Roberto Salgado, Denis Larsimont, Martine Piccart, Karen Willard-Gallo. Tertiary lymphoid structures: Predictors of effective antitumor immunity in human breast cancer? [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A124.

Retrospective Rescreening of Negative Cervical Cytology Samples Preceding Histologically Proven CIN2-3 and Squamous Cell Carcinoma: An Educational Opportunity to Understand and Prevent Laboratory Errors

OBJECTIVES

We aimed to analyze the false-negative (FN) liquid-based cytology diagnoses from the 5 years preceding all the 2013 histologically proven cervical intraepithelial neoplasia (CIN)2-3 and squamous cell carcinoma (SCC) and to propose corrective actions.

STUDY DESIGN

This was a retrospective, blinded rescreening ('5-year look-back') of liquid-based cytology samples with negative categorizations, which occurred before histologically proven CIN2-3 and SCC.

RESULTS

The FN rate was 7.8% (21/256 samples preceding CIN2-3 and 0/13 samples preceding SCC). Slides confirmed as 'negative', 'interpretation error' and 'screening error', respectively, were 3.3% (9/269), 2.6% (7/269) and 1.9% (5/269). In 9/12 cases, error was associated with small atypical cells. In 7/12 cases, these diagnostic cells were less than 5/10 HPF. Inflammation and prominent reactive changes were present in 5/12 cases. Five patients had a positive clinical history. In 2 cases, there were multiple-cell-layer artifacts. Dense groups of small blue atypical cells were missed in 2 other cases. Dotting was imprecise in 6/7 samples.

CONCLUSION

Considering the above results, we specifically reoriented our continuous education activities, focusing rapid rescreening on scanty, isolated, small, atypical cells and dense cell groups. Prior to final diagnosis, pathologists should systematically review the entire surface of the dotted slides, with special attention being devoted to slides with multiple cell layers and tridimensional groups.

Abstract 3891: Tackling the obstacles facing the implementation of a molecular screening program in an early drug development unit: The Jules Bordet Institute Program for Molecular Profiling of Metastatic Lesions - feasibility (Precision-f)

Introduction

The identification of pathways involved in carcinogenesis, the emergence of high-throughput technologies enabling tumor molecular analysis and the development of targeted therapies have led to the concept of precision medicine. Higher response rates and longer survivals have been achieved in recent genomic-driven clinical trials. However, genomic-driven cancer medicine is hindered by multiple obstacles. Our aim was to assess the feasibility of incorporating real-time targeted gene sequencing (TGS) of DNA derived from metastatic biopsies into daily clinical practice.

Experimental procedures

Precision-f (NCT01932489) is a pilot trial conducted at the Jules Bordet Institute. Patients with metastatic colorectal cancer (CRC), melanoma or non-small cell lung (NSCLC) cancer were enrolled. Two FFPE blocks and one fresh frozen sample embedded in OCT were collected from newly performed metastatic biopsies as well as one whole blood sample. The FFPE samples were checked for tumor cellularity and 5×5 μm sections were cut and sent to 2 laboratories. Targeted gene sequencing was performed on DNA extracted for the same sample using the Illumina TruSeq Amplicon Cancer Panel performed on a MiSeq Desktop Sequencer, and the Life Technologies Ion AmpliSeq Cancer Hotspot Panel performed on an Ion Personal Genome Machine. Results were reported to the institutional sequencing tumor board for discussion, annotation and treatment assignment. The main objectives were the evaluation of biopsy quality, turnaround time, the presence of “actionable” alterations, technology cross-validity and treatment assignments.

Results

Thirty-four patients were enrolled between December 2013 and August 2014: 13 NSCLC patients, 11 CRC patients, 10 melanoma patients. Successful molecular results were achieved from 32/34 biopsies (94%). The most frequent site of biopsy was the liver (10) followed by the lung (7), the skin (5) and lymph nodes (5). 27/34 (79%) samples had ≥ 20% tumor cells. 31/34 (91%) of samples had &gt; 10 ng of DNA for TGS. The median turnaround time for results reporting was 15 calendar days [8-22]. “Actionable” mutations were found for 66% (21/32) of patients, 76% (16/21) of which were treated with therapy according to the identified molecular alteration. Reasons for non-targeted therapy were: non-eligibility (2), unavailable drugs (2) and patient refusal (1). The results of the comparison of TGS data across the 2 platforms is ongoing and will be presented at the meeting.

Conclusion

The precision-f pilot trial has demonstrated the feasibility and clinical relevance of a molecular screening program in a clinical pharmacology unit. A Belgian national initiative will follow in order to enhance patient participation in genomic-driven clinical trials.

Citation Format: Philippe G. Aftimos, Marion Maetens, Catherine Sibille, Jean-François Laes, Sylvain Brohée, Thierry Berghmans, Joseph Kerger, Alain Hendlisz, Alexandre Irrthum, Olivier De Henau, Amélie Deleporte, Stylianos Drisis, Denis Larsimont, Jalal Vakili, Christos Sotiriou, Martine Piccart, Ahmad Awada. Tackling the obstacles facing the implementation of a molecular screening program in an early drug development unit: The Jules Bordet Institute Program for Molecular Profiling of Metastatic Lesions - feasibility (Precision-f). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3891. doi:10.1158/1538-7445.AM2015-3891

Abstract CT135: Uncovering the genomic heterogeneity of multifocal breast cancer

Background: Multifocal breast cancer (MFBC), defined as multiple synchronous unilateral lesions of invasive breast cancer, is relatively frequent and has been associated with more aggressive features than unifocal cancer. Here, we aimed to investigate the genomic heterogeneity between MFBC lesions sharing similar histo-pathological parameters.Material and methods: The characterization of different lesions from 36 patients with ductal MFBC involved the identification of non-silent coding mutations in 360 protein-coding genes (171 tumour and 36 matched normal samples). We selected only patients with lesions presenting the same grade, ER and HER2 status. Mutations were classified as ‘oncogenic’ in case of recurrent substitutions reported in COSMIC or truncating mutations affecting tumour suppressor genes. All mutations identified in a given patient were further interrogated in all samples from that patient through deep re-sequencing using an orthogonal platform. Whole genome rearrangement screen was further conducted in 8/36 patients.Results: Twenty-four patients (67%) had substitutions/indels shared by all their lesions, of which 11 carried the same mutations in all lesions, and 13 had lesions with both common and private mutations. Three-quarters of those 24 patients shared oncogenic variants. The remaining 12 patients (33%) did not share any substitution/indels, with inter-lesion heterogeneity observed for oncogenic mutation(s) in genes such as PIK3CA, TP53, GATA3 and PTEN. Genomically heterogeneous lesions tended to be further apart in the mammary gland than the homogeneous ones. Genome-wide analysis of a limited number of MFBC nevertheless identified a common somatic background in all studied MFBC, including those with no mutation in common between the lesions.

Conclusion and perspectives: As the number of molecular targeted therapies increases and trials driven by genomic screening are ongoing, our findings, based on the targeted sequencing of cancer genes in 36 MFBC tumors, highlight the presence of genomic inter-lesion heterogeneity in one-third of the cases despite similar pathological features. This implies that deeper molecular characterization of all MFBC lesions is warranted for the adequate management of those cancers.

[CD, DF, and EP contributed equally to this work. PJC and CS contributed equally to this work.]

Citation Format: Christine Desmedt, Debora Fumagalli, Elisabetta Pietri, Gabriele Zoppoli, Serena Nik-Zainal, Gunes Gundem, David Brown, Francois Rothe, Samira Majjaj, Anna Garuti, Enrico Carminati, Sherene Loi, Thomas Van Brussel, Marion Maetens, Laura Mudie, Delphine Vincent, Naima Kheddoumi, Luigi Serra, Ilaria Massa, Alberto Ballestrero, Dino Amadori, Roberto Salgado, Alexandre de Wind, Diether Lambrechts, Martine Piccart, Denis Larsimont, Peter J. Campbell, Christos Sotiriou. Uncovering the genomic heterogeneity of multifocal breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT135. doi:10.1158/1538-7445.AM2015-CT135

Abstract 1287: Characterization of B cells infiltrating human breast cancer

Recent advances in tumor immunology have shown that an important link exists between tumor infiltrating lymphocytes (TIL) and patient outcome. In human breast cancer (BC), more extensive lymphocyte infiltration is associated with a better prognosis and also predicts responses to pre-operative chemotherapy. TIL are principally composed of T cells; however, approximately 20% of BC patients have a significant B cell infiltration, which can be diffuse and/or aggregated in stroma-located tertiary lymphoid structures (TLS). B cell infiltration in human BC has been associated with better survival and a longer disease-free interval, although the pro-/anti-tumor activities of B cells remain under debate. We undertook this study to more fully characterize the B cell infiltrate in human BC and the role humoral immunity potentially plays in generating effective anti-tumor immune responses.

Flow cytometric analysis of fresh breast tissue homogenates detected an increased density of infiltrating B cells in all untreated primary BC (n = 223) compared with normal (mammary reductions; n = 53) and non-tumor non-adjacent (NANT; n = 198) breast tissues. This increase is not observed in BC tissue from metastatic and recurrent BC nor neoadjuvant-treated primary tumors. Potential correlations between infiltrating B cell density and clinicopathological parameters were examined, revealing that B cell density was associated with Ki67, ER and PgR status but not with age, tumor size, nodal status, grade, vascular invasion, HER-2 status, stage, histotype, subtype or in situ lesions. B cell infiltration was also correlated with the number of infiltrating CD4+ and CD8+ T cells and CD14+ monocytes. All stages of B cell differentiation were detected in the infiltrate; however, memory B cells significantly increased in BC compared to normal breast tissues. An increase in centroblasts and centrocytes, the germinal center B cells, was associated with a TFH cell presence (our data previously demonstrating that TFH cells predict good clinical outcomes). Furthermore, the presence of centroblasts-centrocytes and TFH cells was positively correlated with antibody-secreting cells, suggesting local humoral immune responses are generated in TLS. This hypothesis is supported by the increased immunoglobulin secretion detected in primary supernatants from tumors compared with normal breast tissues. Embedded BC tissues, examined by confocal microscopy, confirm that infiltrating B cells are principally located in TLS, which are composed of marginal, follicular mantle and germinal center zones surrounded by T cells.

These data show that B cell infiltration is correlated with the overall extent of TIL and their presence likely functions to generate a humoral immune response adjacent to the tumor bed. B cells in extensively infiltrated tumors potentially play other important functional roles in generating effective anti-tumor immune responses, an aspect currently under investigation.

Citation Format: Soizic Garaud, Laurence Buisseret, Céline Naveaux, Anaïs Boisson, Jean-Nicolas Lodewyckx, Hugues Duvillier, Ligia Craciun, Denis Larsimont, Karen Willard-Gallo. Characterization of B cells infiltrating human breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1287. doi:10.1158/1538-7445.AM2015-1287

Subclonal diversification of primary breast cancer revealed by multiregion sequencing

Sequencing cancer genomes may enable tailoring of therapeutics to the underlying biological abnormalities driving a particular patient’s tumor. However, sequencing-based strategies rely heavily on representative sampling of tumors. To understand the subclonal structure of primary breast cancer, we applied whole genome and targeted sequencing to multiple samples from each of 50 patients’ tumors (total 303). The extent of subclonal diversification varied among cases and followed spatial patterns. No strict temporal order was evident, with point mutations and rearrangements affecting the most common breast cancer genes, including PIK3CA, TP53, PTEN, BRCA2 and MYC, occurring early in some tumors and late in others. In 13/50 cancers, potentially targetable mutations were subclonal. Landmarks of disease progression, such as resisting chemotherapy and acquiring invasive or metastatic potential, arose within detectable subclones of antecedent lesions. These findings highlight the importance of including analyses of subclonal structure and tumor evolution in clinical trials of primary breast cancer.

SNPs at miR-155 binding sites of TYRP1 explain discrepancy between mRNA and protein and refine TYRP1 prognostic value in melanoma

Background:

We previously demonstrated an inverse correlation between tyrosinase-related protein 1 (TYRP1) mRNA expression in melanoma metastases and patient survival. However, TYRP1 protein was not detected in half of tissues expressing mRNA and did not correlate with survival. Based on a study reporting that 3′ untranslated region (UTR) of TYRP1 mRNA contains two miR-155-5p (named miR-155) binding sites exhibiting single-nucleotide polymorphisms (SNPs) that promote (matched miRNA–mRNA interaction) mRNA decay or not (mismatched), we aimed to investigate the role of miR-155 in the regulation of TYRP1 mRNA expression and protein translation accounting for these SNPs.

Methods:

The effect of miR-155 on TYRP1 mRNA/protein expression was evaluated in two melanoma cell lines harbouring matched or mismatched miR-155–TYRP1 mRNA interaction after transfection with pre-miR-155. In parallel, 192 skin and lymph node melanoma metastases were examined for TYRP1 mRNA/protein, miR-155 and SNPs and correlated with patient survival. TYRP1 mRNA, SNPs at its 3′UTR and miR-155 were analysed by RT–qPCR, whereas TYRP1 protein was evaluated by western blot in cell lines and by immunohistochemistry in metastatic tissues.

Results:

The miR-155 induced a dose-dependent TYRP1 mRNA decay and hampered its translation into protein in the line with the ‘match' genotype. In melanoma metastases, TYRP1 mRNA inversely correlated with miR-155 expression but not with TYRP1 protein in the ‘match' group, whereas it positively correlated with protein but not with miR-155 in the ‘mismatch' group. Consequently, in the latter group, TYRP1 protein inversely correlated with survival.

Conclusion:

Polymorphisms in 3′UTR of TYRP1 mRNA can affect TYRP1 mRNA regulation by miR-155 and its subsequent translation into protein. These SNPs can render TYRP1 mRNA and protein expression nonsusceptible to miR-155 activity and disclose a prognostic value for TYRP1 protein in a subgroup of melanoma patients. These data support the interest in the prognostic value of melanogenic markers and propose TYRP1 to refine prognosis in patients with advanced disease.