Response-guided neoadjuvant sacituzumab govitecan for localized triple-negative breast cancer: results from the NeoSTAR trial

BACKGROUND

Sacituzumab govitecan (SG), a novel antibody-drug conjugate (ADC) targeting TROP2, is approved for pre-treated metastatic triple-negative breast cancer (mTNBC). We conducted an investigator-initiated clinical trial evaluating neoadjuvant (NA) SG (NCT04230109), and report primary results.

PATIENTS AND METHODS

Participants with early-stage TNBC received NA SG for four cycles. The primary objective was to assess pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) to SG. Secondary objectives included overall response rate (ORR), safety, event-free survival (EFS), and predictive biomarkers. A response-guided approach was utilized, and subsequent systemic therapy decisions were at the discretion of the treating physician.

RESULTS

From July 2020 to August 2021, 50 participants were enrolled (median age = 48.5 years; 13 clinical stage I disease, 26 stage II, 11 stage III). Forty-nine (98%) completed four cycles of SG. Overall, the pCR rate with SG alone was 30% [n = 15, 95% confidence interval (CI) 18% to 45%]. The ORR per RECIST V1.1 after SG alone was 64% (n = 32/50, 95% CI 77% to 98%). Higher Ki-67 and tumor-infiltrating lymphocytes (TILs) were predictive of pCR to SG (P = 0.007 for Ki-67 and 0.002 for TILs), while baseline TROP2 expression was not (P = 0.440). Common adverse events were nausea (82%), fatigue (76%), alopecia (76%), neutropenia (44%), and rash (48%). With a median follow-up time of 18.9 months (95% CI 16.3-21.9 months), the 2-year EFS for all participants was 95%. Among participants with a pCR with SG (n = 15), the 2-year EFS was 100%.

CONCLUSIONS

In the first NA trial with an ADC in localized TNBC, SG demonstrated single-agent efficacy and feasibility of response-guided escalation/de-escalation. Further research on optimal duration of SG as well as NA combination strategies, including immunotherapy, are needed.

MacroH2A restricts inflammatory gene expression in melanoma cancer-associated fibroblasts by coordinating chromatin looping

MacroH2A has established tumour suppressive functions in melanoma and other cancers, but an unappreciated role in the tumour microenvironment. Using an autochthonous, immunocompetent mouse model of melanoma, we demonstrate that mice devoid of macroH2A variants exhibit increased tumour burden compared with wild-type counterparts. MacroH2A-deficient tumours accumulate immunosuppressive monocytes and are depleted of functional cytotoxic T cells, characteristics consistent with a compromised anti-tumour response. Single cell and spatial transcriptomics identify increased dedifferentiation along the neural crest lineage of the tumour compartment and increased frequency and activation of cancer-associated fibroblasts following macroH2A loss. Mechanistically, macroH2A-deficient cancer-associated fibroblasts display increased myeloid chemoattractant activity as a consequence of hyperinducible expression of inflammatory genes, which is enforced by increased chromatin looping of their promoters to enhancers that gain H3K27ac. In summary, we reveal a tumour suppressive role for macroH2A variants through the regulation of chromatin architecture in the tumour stroma with potential implications for human melanoma.

Spatial Positioning and Matrix Programs of Cancer-Associated Fibroblasts Promote T-cell Exclusion in Human Lung Tumors

It is currently accepted that cancer-associated fibroblasts (CAF) participate in T-cell exclusion from tumor nests. To unbiasedly test this, we used single-cell RNA sequencing coupled with multiplex imaging on a large cohort of lung tumors. We identified four main CAF populations, two of which are associated with T-cell exclusion: (i) MYH11+αSMA+ CAF, which are present in early-stage tumors and form a single cell layer lining cancer aggregates, and (ii) FAP+αSMA+ CAF, which appear in more advanced tumors and organize in patches within the stroma or in multiple layers around tumor nests. Both populations orchestrate a particular structural tissue organization through dense and aligned fiber deposition compared with T cell-permissive CAF. Yet they produce distinct matrix molecules, including collagen IV (MYH11+αSMA+ CAF) and collagen XI/XII (FAP+αSMA+ CAF). Hereby, we uncovered unique molecular programs of CAF driving T-cell marginalization, whose targeting should increase immunotherapy efficacy in patients bearing T cell-excluded tumors.

SIGNIFICANCE

The cellular and molecular programs driving T-cell marginalization in solid tumors remain unclear. Here, we describe two CAF populations associated with T-cell exclusion in human lung tumors. We demonstrate the importance of pairing molecular and spatial analysis of the tumor microenvironment, a prerequisite to developing new strategies targeting T cell-excluding CAF. See related commentary by Sherman, p. 2501. This article is highlighted in the In This Issue feature, p. 2483.

TBCRC 030: a phase II study of preoperative cisplatin versus paclitaxel in triple-negative breast cancer: evaluating the homologous recombination deficiency (HRD) biomarker

BACKGROUND

Cisplatin and paclitaxel are active in triple-negative breast cancer (TNBC). Despite different mechanisms of action, effective predictive biomarkers to preferentially inform drug selection have not been identified. The homologous recombination deficiency (HRD) assay (Myriad Genetics, Inc.) detects impaired double-strand DNA break repair and may identify patients with BRCA1/2-proficient tumors that are sensitive to DNA-targeting therapy. The primary objective of TBCRC 030 was to detect an association of HRD with pathologic response [residual cancer burden (RCB)-0/1] to single-agent cisplatin or paclitaxel.

PATIENTS AND METHODS

This prospective phase II study enrolled patients with germline BRCA1/2 wild-type/unknown stage I-III TNBC in a 12-week randomized study of preoperative cisplatin or paclitaxel. The HRD assay was carried out on baseline tissue; positive HRD was defined as a score ≥33. Crossover to an alternative chemotherapy was offered if there was inadequate response.

RESULTS

One hundred and thirty-nine patients were evaluable for response, including 88 (63.3%) who had surgery at 12 weeks and 51 (36.7%) who crossed over to an alternative provider-selected preoperative chemotherapy regimen due to inadequate clinical response. HRD results were available for 104 tumors (74.8%) and 74 (71.1%) were HRD positive. The RCB-0/1 rate was 26.4% with cisplatin and 22.3% with paclitaxel. No significant association was observed between HRD score and RCB response to either cisplatin [odds ratio (OR) for RCB-0/1 if HRD positive 2.22 (95% CI: 0.39-23.68)] or paclitaxel [OR for RCB-0/1 if HRD positive 0.90 (95% CI: 0.19-4.95)]. There was no evidence of an interaction between HRD and pathologic response to chemotherapy.

CONCLUSIONS

In this prospective preoperative trial in TNBC, HRD was not predictive of pathologic response. Tumors were similarly responsive to preoperative paclitaxel or cisplatin chemotherapy.

Author Correction: A conserved dendritic-cell regulatory program limits antitumour immunity

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Dietary Intake Regulates the Circulating Inflammatory Monocyte Pool

Caloric restriction is known to improve inflammatory and autoimmune diseases. However, the mechanisms by which reduced caloric intake modulates inflammation are poorly understood. Here we show that short-term fasting reduced monocyte metabolic and inflammatory activity and drastically reduced the number of circulating monocytes. Regulation of peripheral monocyte numbers was dependent on dietary glucose and protein levels. Specifically, we found that activation of the low-energy sensor 5'-AMP-activated protein kinase (AMPK) in hepatocytes and suppression of systemic CCL2 production by peroxisome proliferator-activator receptor alpha (PPARα) reduced monocyte mobilization from the bone marrow. Importantly, we show that fasting improves chronic inflammatory diseases without compromising monocyte emergency mobilization during acute infectious inflammation and tissue repair. These results reveal that caloric intake and liver energy sensors dictate the blood and tissue immune tone and link dietary habits to inflammatory disease outcome.

A conserved dendritic-cell regulatory program limits antitumour immunity

Checkpoint blockade therapies have improved cancer treatment, but such immunotherapy regimens fail in a large subset of patients. Conventional type 1 dendritic cells (DC1s) control the response to checkpoint blockade in preclinical models and are associated with better overall survival in patients with cancer, reflecting the specialized ability of these cells to prime the responses of CD8⁺ T cells^1-3. Paradoxically, however, DC1s can be found in tumours that resist checkpoint blockade, suggesting that the functions of these cells may be altered in some lesions. Here, using single-cell RNA sequencing in human and mouse non-small-cell lung cancers, we identify a cluster of dendritic cells (DCs) that we name 'mature DCs enriched in immunoregulatory molecules' (mregDCs), owing to their coexpression of immunoregulatory genes (Cd274, Pdcd1lg2 and Cd200) and maturation genes (Cd40, Ccr7 and Il12b). We find that the mregDC program is expressed by canonical DC1s and DC2s upon uptake of tumour antigens. We further find that upregulation of the programmed death ligand 1 protein-a key checkpoint molecule-in mregDCs is induced by the receptor tyrosine kinase AXL, while upregulation of interleukin (IL)-12 depends strictly on interferon-γ and is controlled negatively by IL-4 signalling. Blocking IL-4 enhances IL-12 production by tumour-antigen-bearing mregDC1s, expands the pool of tumour-infiltrating effector T cells and reduces tumour burden. We have therefore uncovered a regulatory module associated with tumour-antigen uptake that reduces DC1 functionality in human and mouse cancers.

Abstract ES6-1: Who should have germline testing for hereditary breast cancer?

Who should have germline testing for hereditary breast cancer?

Several guidelines exist for who should be offered germline testing for mutations in breast and ovarian cancer susceptibility genes. NCCN guidelines currently recommend germline BRCA testing for all patients with epithelial ovarian /fallopian tube/primary peritoneal cancer, pancreatic cancer, metastatic/advanced prostate cancer. Testing is also recommended for anyone for whom a BRCA mutation has been identified in the family or for whom a tumor somatic BRCA mutation has been identified (in any tumor type). Among breast cancer patients, NCCN testing criteria include: young age at diagnosis, triple negative disease, Ashkenazi Jewish heritage, male gender, and a personal or family history of ovarian, pancreatic cancer, aggressive prostate cancer or other breast cancer. This year, USPSTF updated their genetic testing guidelines for BRCA1/2. These updates will be reviewed. It is important not to forget testing for germline mutations in other high-penetrance breast cancer susceptibility genes and to retest individuals who previously had BRCA genetic testing and may be appropriate candidates for multi-gene testing.

Recently, the American Society of Breast Surgeons has endorsed germline testing for mutations in BRCA1/2 and PALB2 for all breast cancer patients. Data that led to this recommendation will be reviewed as well as arguments for and against this recommendation. It is noteworthy that only 0.6% of breast cancer patients who did not meet current NCCN guidelines for genetic testing were found to have a germline mutation in BRCA1 or BRCA2 and 0.8% in any high-penetrance breast cancer susceptibility gene.

It is important for oncologists to be able to recognize which findings on a tumor genomic profile should prompt a recommendation for germline testing. This includes the ability to recognize cancer susceptibility genes amongst the list of actionable findings endorsed by the ACMG, as well as cancer susceptibility genes for which there are published management recommendations.

Recently, it has been recommended that germline BRCA testing be offered to all Ashkenazi Jewish individuals regardless of personal or family history of cancer since one in forty Ashkenazi individuals have a mutation in one of three BRCA founder mutations. BRCA mutations are 10 times more common in people with Ashkenazi Jewish ancestry, and up to half of BRCA mutations in this population occur in individuals without a known family history. Three-site Ashkenazi BRCA testing allows streamlined inexpensive BRCA testing without variants of unknown significance (VUS). One concern relates to how large population testing can be carried out, highlighting the need for new genetic testing service models.

Finally, arguments for and against population genetic testing for non-Ashkenazi individuals will be discussed. As the likelihood of identifying a mutation and the penetrance of the mutations identified decreases, and the frequency of VUS increases, the potential for causing harm through unnecessary screening and prevention strategies can outweigh the benefit of providing cancer risk information through testing.

Citation Format: N Tung. Who should have germline testing for hereditary breast cancer? [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr ES6-1.

Overexpression of BLM promotes DNA damage and increased sensitivity to platinum salts in triple-negative breast and serous ovarian cancers

Background

Platinum-based therapy is an effective treatment for a subset of triple-negative breast cancer and ovarian cancer patients. In order to increase response rate and decrease unnecessary use, robust biomarkers that predict response to therapy are needed.

Patients and methods

We performed an integrated genomic approach combining differential analysis of gene expression and DNA copy number in sensitive compared with resistant triple-negative breast cancers in two independent neoadjuvant cisplatin-treated cohorts. Functional relevance of significant hits was investigated in vitro by overexpression, knockdown and targeted inhibitor treatment.

Results

We identified two genes, the Bloom helicase (BLM) and Fanconi anemia complementation group I (FANCI), that have both increased DNA copy number and gene expression in the platinum-sensitive cases. Increased level of expression of these two genes was also associated with platinum but not with taxane response in ovarian cancer. As a functional validation, we found that overexpression of BLM promotes DNA damage and induces sensitivity to cisplatin but has no effect on paclitaxel sensitivity.

Conclusions

A biomarker based on the expression levels of the BLM and FANCI genes is a potential predictor of platinum sensitivity in triple-negative breast cancer and ovarian cancer.

CSF-1 controls cerebellar microglia and is required for motor function and social interaction

Microglia, the brain resident macrophages, critically shape forebrain neuronal circuits. However, their precise function in the cerebellum is unknown. Here we show that human and mouse cerebellar microglia express a unique molecular program distinct from forebrain microglia. Cerebellar microglial identity was driven by the CSF-1R ligand CSF-1, independently of the alternate CSF-1R ligand, IL-34. Accordingly, CSF-1 depletion from Nestin⁺ cells led to severe depletion and transcriptional alterations of cerebellar microglia, while microglia in the forebrain remained intact. Strikingly, CSF-1 deficiency and alteration of cerebellar microglia were associated with reduced Purkinje cells, altered neuronal function, and defects in motor learning and social novelty interactions. These findings reveal a novel CSF-1-CSF-1R signaling-mediated mechanism that contributes to motor function and social behavior.

OlympiAD final overall survival and tolerability results: Olaparib versus chemotherapy treatment of physician's choice in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer

BACKGROUND

In the OlympiAD study, olaparib was shown to improve progression-free survival compared with chemotherapy treatment of physician's choice (TPC) in patients with a germline BRCA1 and/or BRCA2 mutation (BRCAm) and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (mBC). We now report the planned final overall survival (OS) results, and describe the most common adverse events (AEs) to better understand olaparib tolerability in this population.

PATIENTS AND METHODS

OlympiAD, a Phase III, randomized, controlled, open-label study (NCT02000622), enrolled patients with a germline BRCAm and HER2-negative mBC who had received ≤2 lines of chemotherapy for mBC. Patients were randomized to olaparib tablets (300 mg bid) or predeclared TPC (capecitabine, vinorelbine, or eribulin). OS and safety were secondary end points.

RESULTS

A total of 205 patients were randomized to olaparib and 97 to TPC. At 64% data maturity, median OS was 19.3 months with olaparib versus 17.1 months with TPC (HR 0.90, 95% CI 0.66-1.23; P = 0.513); median follow-up was 25.3 and 26.3 months, respectively. HR for OS with olaparib versus TPC in prespecified subgroups were: prior chemotherapy for mBC [no (first-line setting): 0.51, 95% CI 0.29-0.90; yes (second/third-line): 1.13, 0.79-1.64]; receptor status (triple negative: 0.93, 0.62-1.43; hormone receptor positive: 0.86, 0.55-1.36); prior platinum (yes: 0.83, 0.49-1.45; no: 0.91, 0.64-1.33). Adverse events during olaparib treatment were generally low grade and manageable by supportive treatment or dose modification. There was a low rate of treatment discontinuation (4.9%), and the risk of developing anemia did not increase with extended olaparib exposure.

CONCLUSIONS

While there was no statistically significant improvement in OS with olaparib compared to TPC, there was the possibility of meaningful OS benefit among patients who had not received chemotherapy for metastatic disease. Olaparib was generally well-tolerated, with no evidence of cumulative toxicity during extended exposure. Please see the article online for additional video content.

Abstract P2-09-25: Clinical and pathologic characteristics of breast cancers determined to be HER2-positive by fluorescence in-situ hybridization (FISH) using alternative chromosome 17 probes

Background:

Based on updated 2013 ASCO/CAP guideline for HER2 testing, cases with a HER2/CEP17 ratio < 2.0 but with an average HER2 copy number > 4.0 and <6.0 signals/cell are considered equivocal. In such cases, HER2 testing using alternative chromosome 17 probes was proposed as one way to resolve the equivocal FISH results. Using the alternative probe method increases the number of cancers categorized as HER2 positive but brings to question if these cancers truly represent HER2 amplified breast cancers and derive the same benefit from anti-HER2 therapies.

Methods:

Since 2013, all breast cancers at our institution that were HER2 equivocal by traditional FISH but classified as HER2 positive using the alternative probe method were assessed for clinical and pathologic features including histologic type and grade, TNM stage, HER2: alternative probe ratio, treatment, and clinical outcome.

Results:

We identified 24 invasive breast cancers considered HER2 positive by the alternative probe method: 23 (96%) were estrogen receptor-positive (ER+) and 20 (83%) were progesterone receptor- positive. Histologically, only 2 were invasive lobular carcinomas; all others were ductal or had ductal and lobular features. Most cancers (63%) had low or intermediate histologic grade: Grade 1 (n=3); Grade 2 (n=12); Grade 3 (n=9). Clinical information was available for 18 patients: 2 had metastatic disease, 1 had a local recurrence after mastectomy and 15 patients had early stage disease; 9 with node negative disease and 6 with nodal involvement. HER2 IHC was equivocal (2+) in 16 (66.7%) cases, positive (3+) in 4 (16.7%) cases, and negative (0 or 1+) in 4 (16.7%) cases. The average HER2 copy number was 4.77, the average HER22:p53 ratio was 2.61. Repeat HER2 testing on a 2nd tumor sample was performed in 8 cases: HER2-positivity was confirmed in only 2 (25%) cases and by the alternative probe only. Treatment information was available for 17 patients: 1 had T1aN0M0 lesion and did not get chemotherapy, 16 received chemotherapy and 13 received trastuzumab-based chemotherapy. Eleven patients with early stage disease received chemotherapy and trastuzumab. Of these patients, 10/11 were ER+, 7/11 were node negative and 5/11 had grade 2 tumors, yet only one tumor was assessed by oncotype recurrence score ( RS = 29). Three patients received chemotherapy and trastuzumab in the neoadjuvant setting: 1 had a complete pathologic response, 1 a partial response, and 1 has not yet gone to surgery. One additional patient received neoadjuvant chemo alone and achieved a partial response.

Conclusions:

Breast cancers considered HER2+ by the alternative probe method but not by traditional FISH are almost always ER-positive and most have low or intermediate histologic grade. Repeat HER2 testing on a subsequent tumor sample did not confirm HER2-positivity in 75% of cases. Almost all patients with early stage disease received chemotherapy and trastuzumab based on the alternative probe results without molecular assessment to predict chemotherapy response. Intrinsic molecular subtyping using PAM50 analysis on these cancers is underway to determine how many are HER2-enriched by molecular assessment.

Citation Format: Desai NV, Torous V, Cruz C, Schnitt SJ, Tung N. Clinical and pathologic characteristics of breast cancers determined to be HER2-positive by fluorescence in-situ hybridization (FISH) using alternative chromosome 17 probes [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-25.

Abstract S2-02: The landscape of somatic genetic alterations in BRCA1 and BRCA2 breast cancers

Introduction: Women carrying BRCA1 or BRCA2 germline mutations have a 45-80% lifetime risk of developing breast cancer (BC). BRCA1 and BRCA2 are perceived as bona fide tumor suppressor genes, whereby bi-allelic inactivation in tumor cells is required for tumorigenesis. Recent studies have indicated that loss of heterozygosity (LOH) of the wild-type allele of BRCA1 may be heterogeneous and constitute a late event. Therefore, additional somatic events prior to full BRCA1/2 inactivation may be required for tumorigenesis. Given that the somatic events that result in the development of BRCA1/2-BCs and their chronology are not understood, here we sought to define the genomic landscape of BRCA1/2-BCs and whether LOH of BRCA1/2 wild-type allele and/or mutations affecting additional tumor suppressor genes would be clonal or subclonal in these cancers.

Methods: We retrieved 29 BRCA1-BCs and 10 BRCA2-BCs from the Pathology Departments of the authors' institutions. DNA extracted from microdissected tumor and normal breast samples was subjected to targeted capture massively parallel sequencing using either the MSK-IMPACT assay or an assay targeting all exons of 254 genes recurrently mutated in BC or related to DNA repair. Somatic single nucleotide variants, small insertions and deletions and copy number alterations affecting genes present in both sequencing assays (111 genes) were defined using state-of-the-art bioinformatics algorithms. ABSOLUTE and FACETS were employed to define clonal (i.e. present virtually in 100% of the cancer cells of a given case) and subclonal mutations and the presence of LOH of the BRCA1 and BRCA2 wild-type alleles.

Results: Our analysis revealed bi-allelic inactivation of BRCA1 in 28 of 29 BRCA1-BCs (93% harbored LOH of the BRCA1 wild-type allele and 3% harbored a second somatic BRCA1 pathogenic mutation). The only BRCA1-BC lacking bi-allelic inactivation of BRCA1 was an estrogen receptor-positive lobular carcinoma, lacking genomic features consistent with homologous recombination DNA repair defects, diagnosed at 62 years of age. Bi-allelic inactivation of BRCA2 was found in all cases (100% of harbored LOH of the BRCA2 wild-type allele). A clonal somatic 'second hit' resulting in bi-allelic inactivation of BRCA1 or BRCA2 was detected in 76% and 100% of BRCA1-BCs and BRCA2-BCs, respectively. In BRCA1-BCs, TP53 mutations were detected in 76% of cases, and these mutations were found to be clonal in 58% of cases. The repertoire of somatic mutations affecting BRCA1-BCs included clonal somatic mutations or homozygous deletions of known tumor suppressor genes, such as PTEN, RB1, CDKN2A and NF1. In contrast, only 10% of the BRCA2-BCs harbored TP53 somatic mutations. Though clonal somatic mutations in several cancer genes were detected, 40% of BRCA2-BCs had no mutations affecting the cancer genes analyzed.

Conclusions: Bi-allelic inactivation of BRCA1 and BRCA2 are frequent events in BRCA1-BCs and BRCA2-BCs, respectively. In a subset of BRCA1-BCs, however, the second 'hit' appeared to be subclonal, whereas mutations affecting TP53 and other tumor suppressor genes were clonal, supporting the notion that at least in a subset of these tumors, loss of the wild-type allele of BRCA1 may be preceded by inactivation of another tumor suppressor gene.

Citation Format: Geyer FC, Burke KA, Macedo GS, Piscuoglio S, Ng CK, Martelotto LG, Papanastatiou AD, De Filippo MR, Schultheis AM, Brogi E, Robson M, Wen YH, Weigelt B, Schnitt SJ, Tung N, Reis-Filho JS. The landscape of somatic genetic alterations in BRCA1 and BRCA2 breast cancers [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 S2-02.

Expansion and Activation of CD103(+) Dendritic Cell Progenitors at the Tumor Site Enhances Tumor Responses to Therapeutic PD-L1 and BRAF Inhibition

Large numbers of melanoma lesions develop resistance to targeted inhibition of mutant BRAF or fail to respond to checkpoint blockade. We explored whether modulation of intratumoral antigen-presenting cells (APCs) could increase responses to these therapies. Using mouse melanoma models, we found that CD103(+) dendritic cells (DCs) were the only APCs transporting intact antigens to the lymph nodes and priming tumor-specific CD8(+) T cells. CD103(+) DCs were required to promote anti-tumoral effects upon blockade of the checkpoint ligand PD-L1; however, PD-L1 inhibition only led to partial responses. Systemic administration of the growth factor FLT3L followed by intratumoral poly I:C injections expanded and activated CD103(+) DC progenitors in the tumor, enhancing responses to BRAF and PD-L1 blockade and protecting mice from tumor rechallenge. Thus, the paucity of activated CD103(+) DCs in tumors limits checkpoint-blockade efficacy and combined FLT3L and poly I:C therapy can enhance tumor responses to checkpoint and BRAF blockade.

TLR signals induce phagosomal MHC-I delivery from the endosomal recycling compartment to allow cross-presentation

Adaptation of the endoplasmic reticulum (ER) pathway for MHC class I (MHC-I) presentation in dendritic cells enables cross-presentation of peptides derived from phagocytosed microbes, infected cells, or tumor cells to CD8 T cells. How these peptides intersect with MHC-I molecules remains poorly understood. Here, we show that MHC-I selectively accumulate within phagosomes carrying microbial components, which engage Toll-like receptor (TLR) signaling. Although cross-presentation requires Sec22b-mediated phagosomal recruitment of the peptide loading complex from the ER-Golgi intermediate compartment (ERGIC), this step is independent of TLR signaling and does not deliver MHC-I. Instead, MHC-I are recruited from an endosomal recycling compartment (ERC), which is marked by Rab11a, VAMP3/cellubrevin, and VAMP8/endobrevin and holds large reserves of MHC-I. While Rab11a activity stocks ERC stores with MHC-I, MyD88-dependent TLR signals drive IκB-kinase (IKK)2-mediated phosphorylation of phagosome-associated SNAP23. Phospho-SNAP23 stabilizes SNARE complexes orchestrating ERC-phagosome fusion, enrichment of phagosomes with ERC-derived MHC-I, and subsequent cross-presentation during infection.

Activation of toll-like receptor-2 by endogenous matrix metalloproteinase-2 modulates dendritic-cell-mediated inflammatory responses

Matrix metalloproteinase-2 (MMP-2) is involved in several physiological mechanisms, including wound healing and tumor progression. We show that MMP-2 directly stimulates dendritic cells (DCs) to both upregulate OX40L on the cell surface and secrete inflammatory cytokines. The mechanism underlying DC activation includes physical association with Toll-like receptor-2 (TLR2), leading to NF-κB activation, OX40L upregulation on DCs, and ensuing TH2 differentiation. Significantly, MMP-2 polarizes T cells toward type 2 responses in vivo, in a TLR2-dependent manner. MMP-2-dependent type 2 polarization may represent a key immune regulatory mechanism for protection against a broad array of disorders, such as inflammatory, infectious, and autoimmune diseases, which can be hijacked by tumors to evade immunity.

A prior diagnosis of breast cancer is a risk factor for breast cancer in BRCA1 and BRCA2 carriers

BACKGROUND

The risk of breast cancer in carriers of BRCA1 and BRCA2 mutations is influenced by factors other than the genetic mutation itself. Modifying factors include a woman's reproductive history and family history of cancer. Risk factors are more likely to be present in women with breast cancer than in women without breast cancer, and therefore the risk of cancer in the two breasts should not be independent. It is not clear to what extent modifying factors influence the risk of a first primary or a contralateral breast cancer in BRCA carriers.

METHODS

We conducted a matched case-control study of breast cancer among 3920 BRCA1 or BRCA2 mutation carriers. We asked whether a past history of breast cancer in the contralateral breast was a risk factor for breast cancer.

RESULTS

After adjustment for age, country of residence, and cancer treatment, a previous cancer of the right breast was found to be a significant risk factor for cancer of the left breast among BRCA1 or BRCA2 carriers (relative risk: 2.1; 95% confidence interval: 1.4 to 3.0; p < 0.0001).

CONCLUSIONS

In a woman with a BRCA1 or BRCA2 mutation who is diagnosed with breast cancer, the risk of cancer in the contralateral breast depends on the first diagnosis. That observation supports the hypothesis that there are important genetic or non-genetic modifiers of cancer risk in BRCA carriers. Discovering risk modifiers might lead to greater personalization of risk assessment and management recommendations for BRCA-positive patients.

Abstract OT1-4-01: Multicenter phase II trial of the novel compound PM01183 (P) in BRCA1/2-associated or unselected metastatic breast cancer (MBC)

Background: MBC is a clinically heterogeneous disease that cannot be cured with currently available treatment options. Selective approaches are needed to identify patient subgroups with different tumor sensitivities who will benefit the most from available therapies for MBC. PM01183 (P), also known as lurbinectedin, is a new anticancer drug that binds to the DNA minor groove inducing both double-strand breaks and transcription blocking. It has significant in vitro and in vivo activity against several tumor models, particularly breast cancer. P is more active against homologous recombination (HR)-deficient cell lines; hence, MBC patients (pts) with deleterious germline BRCA mutations might be more sensitive to P than sporadic tumors.

Methods: A multicenter, open-label, phase II study of P (7.0 mg fixed dose) as 1-hour intravenous infusion every 3 weeks in pts with MBC with or without known BRCA1/2 mutation at study entry. To be enrolled, pts must be women 18-75 years old with confirmed MBC pretreated with 1-3 chemotherapy regimens for MBC (including at least one prior trastuzumab-containing regimen for HER-2 overexpressing pts), measurable disease as per RECIST v1.1, performance status (PS) of 0-1 and adequate major organ function. Pts are excluded if pretreated with P, trabectedin, or radiotherapy (RT) on &gt;35% of bone marrow; if they have prior/concurrent malignant disease not in complete remission for &gt;5 years, clinically unstable central nervous system involvement, and other diseases/situations that might increase patient's risk; if they are pregnant or lactating women; or if they require RT.

Aims: The primary aim is to determine the antitumor activity of P, in terms of overall response rate (ORR), in two cohorts of MBC pts: BRCA+ (with known BRCA1/2 mutation), and unselected (with BRCA1/2 wild type or unknown mutation status). Secondary aims are to determine duration of response, clinical benefit (response or stable disease &gt; 3 months), PFS and one-year overall survival; to evaluate whether presence of BRCA1/2 mutation predicts response to P in MBC; to explore the activity of P in specific MBC subpopulations, safety, pharmacokinetics (PK), PK/pharmacodynamic correlations, and pharmacogenomics.

Planned enrollment is 117 evaluable pts: 53 in the BRCA+ cohort and 64 in the unselected cohort. P will be considered effective if confirmed objective response is achieved in ≥ 17 BRCA+ pts and ≥ 12 unselected patients. An ORR-based futility analysis will be conducted when 20 and 30 evaluable pts have been recruited in each cohort, respectively. If &lt;4 BRCA+ pts or &lt;3 unselected pts achieve response, recruitment into that cohort will be terminated. To date, 36 patients have been enrolled at 5 centers in 2 countries: 7 in the BRCA+ cohort and 29 in the unselected cohort. Additional sites are being recruited to participate.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-4-01.

Abstract PD4-8: Prevalence of gene mutations among hereditary breast and ovarian cancer patients using a 25 gene panel

Identifying individuals at increased risk for hereditary cancer leads to early detection and prevention opportunities with the ability to reduce both cancer incidence and mortality. Hereditary cancer syndromes have genetic heterogeneity and new susceptibility genes have been recently identified. Next generation sequencing allows testing of multiple target genes simultaneously, can reduce the time and cost of sequential gene testing, and may improve mutation detection. To date, no large scale studies have reported the mutation prevalence of multiple cancer susceptibility genes among patients referred for BRCA1/BRCA2 testing.

A study was performed to determine the mutation prevalence in 25 cancer susceptibility genes among a large U.S. patient population referred to a diagnostic laboratory for BRCA1/BRCA2 testing. DNA from 1955 prospectively accrued cases was anonymized after testing was complete. Patients with Ashkenazi Jewish heritage were excluded in order to determine the relative prevalence of mutations in a generalizable population. In addition, an independent external validation set of 405 patients, including those of Ashkenazi ancestry, with history consistent with hereditary breast and ovarian cancer (HBOC) syndrome and who had previously tested negative for BRCA1/BRCA2 mutations was assessed. Extracted genomic DNA from blood was PCR amplified with a custom amplicon library on a Raindance ThunderStorm instrument. The DNA products were sequenced on an Illumina HiSeq2500. Sequence variations and large rearrangements among the 25 genes were detected and classified for pathogenicity.

Among the 1955 anonymized patients referred for BRCA1/BRCA2 testing, 275 (14.07%) patients were mutation carriers in at least one of the 25 genes. 182 (9.31%) patients had a mutation in BRCA1 or BRCA2, and 96 of 1955 (4.91%) patients had a mutation in other genes (Table 1).

Table 1GenePatients with mutation (n = 96)%ATM1414.58%BARD177.29%BRIP177.29%CHEK23031.25%MSH222.08%MSH622.08%MUTYH11.04%NBN1414.58%PALB21313.54%PMS244.17%TP5322.08%

No mutations were found in CDH1, PTEN, STK11, RAD51C, RAD51D, BMPR1A, SMAD4, MLH1, EPCAM, CDKN2A, CDK4, or APC. 1738 of 1955 patients had a personal history of breast cancer (BC), with 63% diagnosed prior to age 50, and 37% at or after age 50. Mutation prevalence for patients with BC, ovarian cancer (OC), both BC and OC, or other HBOC cancers is listed in Table 2.

Table 2Patient Cancer HistoryPatients (n)BRCA1/2Other GeneBreast CA &lt; 50 years1091116* (10.63%)51 (4.67%)Breast CA ≥ 50 years64740** (6.18%)30 (4.64%)Ovarian CA16217 (10.49%)6 (3.70%)Breast and Ovarian CA408 (20.00%)4 (10.00%)Other HBOC Cancer151 (6.67%)2 (13.33%)*2 and **1 patients had an additional mutation in a non-BRCA1/2 gene

1902 (97.29%) patients had a variant of uncertain significance in at least one of the genes tested and an average of three variants was found per patient. As of June 11, 2013 the independent external validation cases results are pending.

Compared with BRCA1/BRCA2 testing alone, using the 25 gene panel increased the identification of mutations in cancer susceptibility genes by 4.76% (95% CI: 2.71% – 6.81%), which represents a 51.1% increase in mutation detection for this population with suspected HBOC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD4-8.

Germline mutations in CDH1 are infrequent in women with early-onset or familial lobular breast cancers

BACKGROUND

Germline mutations in CDH1 are associated with hereditary diffuse gastric cancer; lobular breast cancer also occurs excessively in families with such condition.

METHOD

To determine if CDH1 is a susceptibility gene for lobular breast cancer in women without a family history of diffuse gastric cancer, germline DNA was analysed for the presence of CDH1 mutations in 318 women with lobular breast cancer who were diagnosed before the age of 45 years or had a family history of breast cancer and were not known, or known not, to be carriers of germline mutations in BRCA1 or BRCA2. Cases were ascertained through breast cancer registries and high-risk cancer genetic clinics (Breast Cancer Family Registry, the kConFab and a consortium of breast cancer genetics clinics in the United States and Spain). Additionally, Multiplex Ligation-dependent Probe Amplification was performed for 134 cases to detect large deletions.

RESULTS

No truncating mutations and no large deletions were detected. Six non-synonymous variants were found in seven families. Four (4/318 or 1.3%) are considered to be potentially pathogenic through in vitro and in silico analysis.

CONCLUSION

Potentially pathogenic germline CDH1 mutations in women with early-onset or familial lobular breast cancer are at most infrequent.

Estrogen Rececptor (ER)-Positive Breast Cancers in BRCA1 Mutation Carriers: Mutation-Related or Sporadic?

Background: Most invasive breast cancers (IBC) in BRCA1 mutation carriers are ER negative (-) and have a basal-like phenotype by expression array analysis. These tumors also have a characteristic constellation of histologic features including high grade, high mitotic rate, prominent lymphoid infiltrate, circumscribed or pushing margins, and geographic necrosis or a central fibrotic focus and typically lack ER, PR and HER2 expression (triple negative). ER positive (+) breast cancers also occur in women with germline BRCA1 mutations, but these tumors are less frequent and less well characterized. We previously reported that ER+ BRCA1-associated IBC show a wider spectrum of histologic types and grades than ER- cancers that occur in these patients. We raised the possibility that at least some ER+ BRCA1-associated IBC may be sporadic rather than mutation-related. However, it is not known how the features of these ER+ BRCA1-associated IBC compare with those of sporadic ER+ IBC.Design: To address this issue, we performed a case-control study of 60 ER+ BRCA1-associated IBC (cases) matched on age and year of diagnosis with 174 ER+ sporadic breast cancers (controls). Histologic sections of cases and controls were reviewed and the pathologic features were compared with each other as well with those of 85 ER- IBC that developed in BRCA1 mutation carriers.Results: Histologic features are summarized in the Table. When compared with ER+ controls, ER+ BRCA1-associated IBC were significantly more likely to be invasive ductal carcinomas (78% vs 58%;p=0.005), histologic grade 3 (47% vs 27%;p=0.006), and to have a high mitotic rate (29% vs 9%;p=0.0003). However, all of these features were significantly less frequent in ER+ BRCA1-associated IBC than in ER- BRCA1-associated IBC (p&lt;0.001 for all comparisons). ER+ BRCA1-associated IBC and ER+ controls were not significantly different from each other with regard to the frequency of moderate-severe lymphoid infiltrate, the presence of geographic necrosis or the presence of a fibrotic focus, but the frequency of all of these features in both groups was significantly lower than in ER- BRCA1-associated IBC (p&lt;0.01 for all comparisons). ER+ ControlsER+ BRCA1ER- BRCA1 N=174N=60N=85Histologic Type   Invasive Ductal58%78%96%Other42%22%4%Histologic Grade   327%47%96%1 or 273%53%4%Mitotic Rate   ≥10/10 HPF9%29%93%&lt;10/10 HPF91%71%7%Tumor Margin   Invasive96%90%37%Pushing/Circumscribed4%10%63%Lymphoid Infiltrate   Moderate-Severe16%7%30%Other84%93%70%Fibrotic Focus   Present7%12%56%Absent93%88%44%Geographic Necrosis   Present2%5%50%Absent98%95%50% Conclusions: ER+ breast cancers arising in women with BRCA1 germline mutations appear to be pathologically "intermediate" between ER- BRCA1-associated breast cancers and ER+ sporadic breast cancers. This raises the possibility that some ER+ BRCA1-associated invasive breast cancers are mutation-related and others are sporadic or that there is a unique mechanism by which ER+ cancers develop in mutation carriers. Immunophenotypic and molecular studies are in progress to further characterize this interesting group of tumors.This work was supported by a grant from the Breast Cancer Research Foundation.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5162.

Determination of factors predicting for estrogen receptor positive (ER+) breast cancers in BRCA1 mutation carriers

11045

Background: Most breast cancers that occur in BRCA1 mutation carriers tend to lack ER, progesterone receptors and Her2/neu. Foulkes et al.(Clin Can Res 2004; 10: 2029) reported an increase in BRCA1-associated ER+ tumors with increasing age. Little is known about the clinical factors that predict for ER status in this population. Understanding these factors and whether ER+ cancers are sporadic may have important implications for chemoprevention and treatment strategies. Methods: BRCA1mutation carriers who developed an invasive breast cancer from 1973–2008 were identified through the Cancer Risk and Prevention programs at 4 Boston-area hospitals. Clinical characteristics were abstracted from medical and research records. ER status was obtained from pathology reports, and ER staining was repeated when data was missing or when ER was listed as “weak”. Logistic regression was used to model ER positivity for the first invasive breast cancer. Potential predictors included menopausal status, age at cancer diagnosis, prior use of hormone replacement therapy, Ashkenazi-Jewish descent, age at first live birth, tobacco use, and alcohol use. Results: 170 BRCA1 mutation carriers were identified; 56 with ER+ and 114 with ER- first invasive cancers. Menopausal status was found to be a significant predictor of ER status; 18/56 (32%) with ER+ breast cancer were postmenopausal vs.14/114 (12%) with ER- cancer (odds ratio = 0.30, p = 0.002). Age >= 50 was significant in univariate analysis, 14/ 56 (25%) ER+ vs. 11/ 114 (10%) ER- cancers (p=0.01), but not in multiple regression. Conclusions: While most breast cancers in BRCA1 carriers are ER-, we found postmenopausal BRCA1carriers significantly more likely to develop an ER+ tumor than premenopausal carriers. As mutation carriers are likely to become surgically menopausal before age 50, and menopause and age are correlated, additional data will be needed to sort out the relative contribution of each factor to ER status. An understanding of this issue could have important implications for chemoprevention strategies. Molecular analysis of the ER+ breast cancers in our BRCA1+ cohort is underway to investigate whether ER+ breast cancers are manifestations of the BRCA1 mutation or sporadic.

No significant financial relationships to disclose.

Prevalence of CDH1 germline mutations in subjects with early onset or familial lobular breast cancer, a multicenter collaboration

11042

Background: Invasive lobular breast carcinoma (LBC) is part of the hereditary diffuse gastric cancer (HDGC) syndrome, associated with germline mutations in the E-cadherin (CDH1) gene. CDH1 mutations can be identified in 80% of families ascertained by DGC. The risk of DGC in CDH1 mutation carriers is 67% in males, and 83% in females; the estimated risk of LBC in women is 39–50% to age 80. Management of HDGC includes prophylactic gastrectomy. In this study, we estimated the prevalence of germline CDH1mutations among women with LBC who were either diagnosed at young age or had family history of breast cancer (BC). Methods: Germline DNA was collected from 383 women with LBC or mixed, lobular/ductal, BC from breast cancer programs, familial cancer clinics, and population-based cohorts. Germline BRCA1or BRCA2mutations carriers were excluded. Eligible women had (1) LBC before age 45 or (2) LBC at any age with at least two 1st or 2nd degree relatives with BC of any type. Denaturing high pressure liquid chromatography was undertaken, followed by direct sequencing of exons displaying changes. Results: At the time of submission 310 of 383 samples have been fully sequenced. One previously characterized missense mutation and four novel non-synonymous variants (1.6%) were found. Three of these women had LBC before 45 years and no family history of BC; two had BC family history. No gastric cancers were reported in these families. Functional assays to assess the pathogenicity of the variants are in process. Conclusions: These results confirm that CDH1 is responsible for a small proportion of familial and early onset LBC. Given the difficulty of identifying CDH1 mutations from BC history alone and the importance of managing the gastric cancer risk in CDH1carriers, these findings should underscore the need to obtain an accurate abdominal cancer family history from women with LBC.

No significant financial relationships to disclose.

A potential role of EGFR-inhibitors for the prevention of BRCA1-related breast cancer

Abstract #1110

Background: The majority of women who develop a BRCA1-related breast cancer develop an ER-/PR-/HER2- breast cancer. Endocrine prophylaxis does not prevent these ER- breast cancers. Therefore, there is a need to develop novel chemoprevention agents in this population. 67% of BRCA1-associated ER- breast cancers also overexpress epidermal growth factor receptor (EGFR). We therefore examined EGFR as a potential target for chemoprevention&#x2028; Methods: We isolated primary mammary epithelial cells (HMECs) from women with a germline BRCA1 mutation who underwent prophylactic mastectomies and from age-matched controls without a mutation who underwent reduction mammoplasties. We used a three-dimensional matrigel-based colony formation assay to assess clonality and proliferative capacity of these cells as well as their response to EGFR-inhibition. Flow cytometry was used to determine the number of EGF binding sites per cell. As a corresponding mouse model we used conditional MMTV-Cre BRCA1-/-p53+/- mice. Results: HMECs from BRCA1 mutation carriers and from controls express EGFR to a similar extent as HCC1937 BRCA1-associated triple-negative breast cancer cells (5x103 binding sites/cell). In ex vivo 3D-cultures we observed that HMECs derived from BRCA1 mutation carriers showed greater clonal and proliferative capacity when compared to normal controls. However while the HMECs derived from BRCA1 mutation carriers and normal controls were equally sensitive to the growth-inhibitory effect of Erlotinib at concentrations as low as 0.2 μM, the ID50 for HCC1937 breast cancer cells was &gt; 10 μM. Similar findings were observed in murine MECs derived from normal control mice as well as BRCA1-/-p53+/- mice which develop breast cancer at the age of 7 to 8 months. Both groups of murine MECs were equally sensitive to Erlotinib growth inhibition. Conclusion: MECs derived from breast tissue of women and mice with a germline BRCA1 mutation express EGFR and are highly sensitive to growth inhibition with the EGFR inhibitor Erlotinib. In contrast, BRCA1-associated HCC 1937 breast cancer cells are more resistant to Erlotinib inhibition despite EGFR expression. We are now studying whether Erlotinib given via oral gavage daily has the potential to delay or prevent breast cancer in this mouse model of BRCA1-related breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1110.

Characterization of estrogen receptor-positive breast cancers in BRCA1 mutation carriers

Abstract #1105

Background: Invasive breast cancers (IBC) in BRCA1 mutation carriers are usually estrogen receptor (ER) negative (-) and more than 80% have a basal-like molecular phenotype. These tumors are typically poorly differentiated invasive ductal carcinomas with a high mitotic rate and frequently show a prominent lymphoid infiltrate, pushing or circumscribed margins, and geographic necrosis or a central fibrotic focus. However, some women with BRCA1 germline mutations develop ER positive (+) cancers; little is known about the characteristics of the ER+ tumors in this group.&#x2028; Design: We identified 41 ER+ IBC that developed in women with BRCA1 germline mutations with available pathologic material for review. The histologic features were analyzed in detail and compared with those of 45 ER- IBC that developed among BRCA1 mutation carriers.&#x2028; Results: Mean patient age was 46y for ER+ and 45y for ER- cases. Ninety percent of the ER+ cases and all the ER- cases were invasive ductal carcinomas or invasive carcinomas with ductal and lobular features. There were 2 mucinous and 2 tubular carcinomas in the ER+ group. The ER+ cancers exhibited a range of histologic grades: 12 (29.3%) were grade I, 10 (24.4%) grade II, and 18 (43.9%) grade III (1 case of microinvasive carcinoma could not be graded). In contrast, 43 of the 45 ER- cancers were grade III (95.6%) and 1 (2.2%) grade II (1 case of microinvasive carcinoma could not be graded). Histologic features commonly seen in association with ER- BRCA1 mutation-associated IBC were compared between the two groups and the results are summarized in the table.&#x2028; &#x2028; Of note, a brisk mitotic rate, pushing margin, and the presence of geographic necrosis/central fibrosis were all significantly more common in ER- than in ER+ tumors.&#x2028; Conclusions: To our knowledge, this study is the first to document in detail the histologic features of the uncommon ER+ IBC occurring in BRCA1 mutation carriers. Our observations suggest that ER+ IBC in BRCA1 mutation carriers represent a morphologically diverse group. This raises the possibility that at least some ER+ IBC that develop in women with germline BRCA1 mutations may be sporadic rather than BRCA1-associated. We are currently analyzing these lesions with a panel of biomarkers and assays for loss of heterozygosity at the BRCA1 mutation sites to further address this important issue.&#x2028; This work was supported by a grant from the Breast Cancer Research Foundation.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1105.

Dose-dense (DD) doxorubicin and cyclophosphamide (AC) followed by weekly paclitaxel (P) with trastuzumab (T) and lapatinib (L) in HER2/neu-positive breast cancer is not feasible due to excessive diarrhea: updated results

Abstract #2108

Background: DD q 2 weekly (w) AC → P + T x 1 year (y) has an acceptable safely profile w/ congestive heart failure (CHF) rate of 1/70 pts (Dang, JCO 2008). Lapatinib (L) is effective in HER2 (+) BC. We conducted a pilot study of dd AC → w P + T + L to determine its feasibility and cardiac safety.&#x2028; Methods: Enrolled pts had HER2 (+) BC; LVEF &gt; 50%. Rx consisted of AC at 60/600 mg/m2 x 4 q 2 w (w/ pegfilgrastim 6 mg day 2) → P at 80 mg/m2 x 12 q w + T x 1 y; L (1000 mg daily beginning w/ P + T and continued x 1 y). MUGA is obtained at baseline and at months (mo) 2, 6, 9, and 18. Rx is considered feasible if 1) &gt; 80% pts can complete the PTL phase without a dose delay or reduction and 2) the cardiac event rate (CHF or cardiac death) is &lt; 4%. Pts can remain on-Rx w/ one dose reduction of L (1000 mg → 750 mg) for a G 3 event or &lt; G 3 toxicity (unacceptable).&#x2028; Results: From March 2007 to April 2008, we enrolled 95 pts. Median (med) age was 45 years (range, 28-73). At a med follow-up of 7 months, 90 are evaluable. Of the 90 pts, 34 (37%) withdrew from study during the PTL phase; 29 for a 2nd event of G 3 or unacceptable &lt; G 3 toxicities (15 G 3 diarrhea, 4 G 1/2 diarrhea, 1 G 3 rash, 2 G 2 rash, 1 G 3 dyspnea and also had G 3 diarrhea, 1 G 3 ↑QTc also had G 3 diarrhea, 1 G 3 ↑ALT also had G 3 diarrhea, 1 G 3 paronychia, 1 G 3 pneumonitis, 1 asymptomatic LVEF ↓, 1 myocarditis) and 5 for other reasons (2 personal reason, 1 PCP pneumonia, 1 progression, 1 P hypersensitivity). Overall, 25/90 (27%) pts had G 3 diarrhea and 31/90 (34%) pts required a dose reduction of lapatinib. Med LVEF at baseline is 67% (N=95), at mo 2 is 68% (N=90), at mo 6 is 65% (N=53), and mo 9 is 65% (N=28). To date there are no patient drop-outs due to significant LVEF declines after dd AC; one patient dropped during PTL out due to an asymptomatic LVEF decline.&#x2028; Discussion: L at 1000 mg/day is not feasible combined w/ weekly P and T by protocol stipulation (&gt; 20% pts required L dose reduction) primarily due to excessive G 3 diarrhea. These results have led to the modification of Design 2 (Arm D) of ALTTO. We will report updated results.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2108.

Germline E-cadherin mutations in familial lobular breast cancer

BACKGROUND

The cell surface glycoprotein E-cadherin (CDH1) is a key regulator of adhesive properties in epithelial cells. Germline mutations in CDH1 are well established as the defects underlying hereditary diffuse gastric cancer (HDGC) syndrome, and an increased risk of lobular breast cancer (LBC) has been described in HDGC kindreds. However, germline CDH1 mutations have not been described in patients with LBC in non-HDGC families. This study aimed to investigate the frequency of germline CDH1 mutations in patients with LBC with early onset disease or family histories of breast cancer without DGC.

METHODS

Germline DNA was analysed in 23 women with invasive lobular or mixed ductal and lobular breast cancers who had at least one close relative with breast cancer or had themselves been diagnosed before the age of 45 years, had tested negative for a germline BRCA1 or BRCA2 mutation, and reported no personal or family history of diffuse gastric cancer. The full coding sequence of CDH1 including splice junctions was amplified using PCR and screened for mutations using DHPLC and sequencing.

RESULTS

A novel germline CDH1 truncating mutation in the extracellular portion of the protein (517insA) was identified in one woman who had LBC at the age of 42 years and a first degree relative with invasive LBC.

CONCLUSIONS

Germline CDH1 mutations can be associated with invasive LBC in the absence of diffuse gastric cancer. The finding, if confirmed, may have implications for management of individuals at risk for this breast cancer subtype. Clarification of the cancer risks in the syndrome is essential.

Tubal ligation and risk of ovarian cancer in carriers of BRCA1 or BRCA2 mutations: a case-control study

BACKGROUND

In several case-control and prospective studies, tubal ligation has been associated with a decreased risk of invasive epithelial ovarian cancer. We aimed to assess the potential of tubal ligation in reducing the risk of ovarian cancer in women who carry predisposing mutations in the BRCA1 or BRCA2 genes.

METHODS

We did a matched case-control study among women from Canada, the USA, and the UK who had undergone genetic testing and who carried a pathogenic mutation in BRCA1 or BRCA2. Cases were 232 women with a history of invasive ovarian cancer, and controls were 232 women without ovarian cancer, and who had both ovaries intact. Cases and controls were matched for year of birth, country of residence, and mutation (BRCA1 or BRCA2). The odds ratio for developing ovarian cancer was estimated for tubal ligation, adjusting for oral contraceptive use, parity, history of breast cancer, and ethnic group.

FINDINGS

In an unadjusted analysis among BRCA1 carriers, significantly fewer cases than controls had ever had tubal ligation (30 of 173 [18%] vs 60 of 173 [35%], odds ratio 0.37 [95% CI 0.21-0.63]; p=0.0003). After adjustment for oral contraceptive use, parity, history of breast cancer and ethnic group, the odds ratio was 0.39 (p=0.002). Combination of tubal ligation and past use of an oral contraceptive was associated with an odds ratio of 0.28 (0.15-0.52). No protective effect of tubal ligation was seen among carriers of the BRCA2 mutation.

INTERPRETATION

Tubal ligation is a feasible option to reduce the risk of ovarian cancer in women with BRCA1 mutations who have completed childbearing.

Phenotypic characteristics associated with the APC gene I1307K mutation in Ashkenazi Jewish patients with colorectal polyps

CONTEXT

The I1307K mutation of the APC gene is found in approximately 6% of the Ashkenazi Jewish population and is associated with elevated risk of colorectal cancer. The incidence of the mutation in patients with colorectal adenomas is unknown.

OBJECTIVES

To determine the carrier rate of the I1307K mutation in Ashkenazi Jewish patients with a history of colorectal polyps but without colorectal cancer and to compare phenotypic characteristics and family history of carriers vs noncarriers.

DESIGN, SETTING, AND PATIENTS

A total of 231 patients who had at least 1 large bowel polyp diagnosed between January 1, 1992, and January 31, 1999, at 1 of 5 centers in Boston, Mass, were included, of whom 183 were Ashkenazi Jewish. DNA was isolated from cheek swab samples.

MAIN OUTCOME MEASURES

Presence of the I1307K variant in the APC gene.

RESULTS

The I1307K variant was identified in 22 (14%) of 161 Ashkenazi Jewish patients with a history of adenomatous polyps and in 1 (5%) of 20 Ashkenazi Jewish patients with hyperplastic polyps. The phenotypic features of adenomas, family history of polyps, colorectal cancer, and other cancers were indistinguishable between I1307K carriers and noncarriers.

CONCLUSIONS

The frequency of the APC I1307K mutation is elevated in Ashkenazi Jewish patients with adenomatous polyps, but not hyperplastic polyps. The I1307K mutation represents a novel paradigm for cancer-predisposing genes, as it is associated with moderately increased risk of neoplasia without other associated distinguishing phenotypic features. JAMA. 2000;284:857-860

Phase I trial of carboplatin, paclitaxel, etoposide, and cyclophosphamide with granulocyte colony stimulating factor as first-line therapy for patients with advanced epithelial ovarian cancer

OBJECTIVES

The goal of this study was to determine the maximally tolerated doses (MTDs) of carboplatin, paclitaxel (Taxol), etoposide, and cyclophosphamide (CTEC) with granulocyte-colony stimulating factor (G-CSF, Filgrastim) support as first-line chemotherapy in women with advanced epithelial ovarian cancer (EOC).

METHODS

Newly diagnosed patients with either stage IV EOC, or stage III EOC and any amount of gross residual tumor after surgical debulking were eligible to receive six cycles of CTEC over five different dose levels in this phase I trial (planned 21-day cycle length). Paclitaxel, carboplatin, and cyclophosphamide were administered intravenously on Day 1, and oral etoposide was administered on Days 1, 2, and 3. G-CSF was administered beginning Day 4.

RESULTS

Twenty patients received a total of 98 cycles of CTEC over the five dose levels evaluated. Bone marrow suppression was the major toxic effect, with grade 4 neutropenia and thrombocytopenia being observed in 25 and 23% of cycles, respectively. The overall incidence of febrile neutropenia was 10%, and no toxic deaths occurred. No grade IV thrombocytopenia or febrile neutropenia was observed once the carboplatin dose was reduced from AUC of 7 to 5. Nonhematologic toxicity was generally mild (grade 2 or less). Dose-limiting toxicity was not observed at the highest dose level evaluated in this study, preventing assignment of the MTD. The clinical complete response rate was 92%, although 15 of 16 evaluable patients have progressed with a median progression-free interval of 4 months (range, 2-11 months). One patient remains disease-free 9 months from the completion of CTEC.

CONCLUSIONS

The CTEC regimen is well tolerated and highly active. Although the MTD was not reached in this study, the short median progression-free interval suggests that this regimen is unlikely to be superior to standard treatment with paclitaxel and carboplatin. Strategies to optimize the development of future combination chemotherapy regimens in the treatment of newly diagnosed ovarian cancer are discussed.

BRCA1 and BRCA2 mutation analysis of 208 Ashkenazi Jewish women with ovarian cancer

Ovarian cancer is a component of the autosomal-dominant hereditary breast-ovarian cancer syndrome and may be due to a mutation in either the BRCA1 or BRCA2 genes. Two mutations in BRCA1 (185delAG and 5382insC) and one mutation in BRCA2 (6174delT) are common in the Ashkenazi Jewish population. One of these three mutations is present in approximately 2% of the Jewish population. Each mutation is associated with an increased risk of ovarian cancer, and it is expected that a significant proportion of Jewish women with ovarian cancer will carry one of these mutations. To estimate the proportion of ovarian cancers attributable to founding mutations in BRCA1 and BRCA2 in the Jewish population and the familial cancer risks associated with each, we interviewed 213 Jewish women with ovarian cancer at 11 medical centers in North America and Israel and offered these women genetic testing for the three founder mutations. To establish the presence of nonfounder mutations in this population, we also completed the protein-truncation test on exon 11 of BRCA1 and exons 10 and 11 of BRCA2. We obtained a detailed family history on all women we studied who had cancer and on a control population of 386 Ashkenazi Jewish women without ovarian or breast cancer. A founder mutation was present in 41.3% of the women we studied. The cumulative incidence of ovarian cancer to age 75 years was found to be 6.3% for female first-degree relatives of the patients with ovarian cancer, compared with 2.0% for the female relatives of healthy controls (relative risk 3.2; 95% CI 1.5-6.8; P=.002). The relative risk to age 75 years for breast cancer among the female first-degree relatives was 2.0 (95% CI 1.4-3.0; P=.0001). Only one nonfounder mutation was identified (in this instance, in a woman of mixed ancestry), and the three founding mutations accounted for most of the observed excess risk of ovarian and breast cancer in relatives.

Large-cell and immunoblastic lymphoma of the mediastinum: prognostic features and treatment outcome in 57 patients

PURPOSE

A retrospective study was performed to define clinical characteristics and therapeutic outcome for patients with large-cell and immunoblastic lymphoma of the mediastinum.

PATIENTS AND METHODS

Fifty-seven patients who presented with primary, mediastinal large-cell and immunoblastic lymphoma were retrospectively studied to determine initial sites of disease, radiologic characteristics, treatment, outcome, and factors that have prognostic significance for progression-free and overall survival.

RESULTS

Fifty-six of the 57 patients had disease that was confined to sites above the diaphragm. Bulky disease and extensive intrathoracic infiltration were common in these patients. All patients were treated with intensive chemotherapy regimens, and 44% of patients received chest irradiation. The overall 5-year survival by Kaplan-Meier estimation was 50% with a freedom-from-relapse rate of 45%. Predictors of disease relapse after chemotherapy included the presence of a pleural effusion (P = .015), a number of involved extranodal sites (P < .01), and a lactic dehydrogenase (LDH) ratio > 3.0 (LDH value/upper limit of assay; P = .04) as well as an incomplete treatment response as evidenced by residual mass on chest radiograph (P = .02) or persistent gallium 67 avidity (P = .01) after chemotherapy. Predictors of decreased survival included the presence of pleural effusion (P = .001), the number of involved extranodal sites (P = .022), and a positive posttreatment 67Ga scan (P = .027).

CONCLUSION

Patients with primary mediastinal large-cell and immunoblastic lymphoma have an approximate 50% chance of surviving disease-free after initial therapy. The presence of pleural effusion at presentation was associated with an extremely poor outcome. Bulk disease per se was a negative predictive factor only in patients without pleural effusions when compared with patients who did not have bulk disease. In addition, all patients with involvement of two or more extranodal sites relapsed when treated with standard chemotherapy.

Cellular myosin heavy chain in human leukocytes: isolation of 5' cDNA clones, characterization of the protein, chromosomal localization, and upregulation during myeloid differentiation

We have isolated 5' cDNA clones encoding a member of the cellular myosin heavy chain gene family from human leukocytes. The predicted amino acid sequence shows 93% identity to a chicken cellular myosin heavy chain, 76% to chicken smooth muscle, and 40% to human sarcomeric myosin heavy chain. The mRNA is expressed as a 7.4- to 7.9-kb doublet in many nonmuscle cells, and is upregulated in myeloid cell lines on induction from a proliferating to a differentiated state. Antisera raised against a peptide made from the predicted amino acid sequence specifically reacts with a 224-Kd polypeptide in leukocyte cell lines, and the protein is also upregulated during the induction of monocytic and granulocytic differentiation in these cells. The gene for this cellular myosin heavy chain maps to chromosome 22, bands q12.3-q13.1, demonstrating that it is not located in the previously described sarcomeric gene clusters on chromosomes 14 and 17. This cellular myosin heavy chain may be a major contractile protein responsible for movement in myeloid cell lines because no mRNA for sarcomeric myosin heavy chain is detected in these cells.