Development of a noninvasive HIFU treatment for breast adenocarcinomas using a toroidal transducer based on preliminary attenuation measurements

Breast cancer is the most commonly diagnosed type of cancer among women. For the last fifteen years, treatments that are less invasive than lumpectomy, such as high-intensity focused ultrasound (HIFU) therapy, have been developed, with encouraging results. In this study, a toroidal HIFU transducer was used to create lesions of at least 2 cm in diameter within less than one minute of treatment. The toroidal HIFU transducer created two focal zones that led to large, fast and homogeneous ablations (10.5 cc/min). The experiments were conducted in 30 human samples of normal breast tissues recovered from mastectomies to measure acoustic attenuation (N = 30), and then, HIFU lesions were created (N = 15). Eight HIFU ablations were performed to evaluate the reproducibility of the lesions. HIFU lesions were created in 45 s with a toroidal HIFU transducer working at 2.5 MHz. The longest and shortest axes of the HIFU lesions were 21.7 ± 3.1 mm and 23.5 ± 3.3 mm respectively, corresponding to an average volume of 7.3 ± 1.4 cm³. These HIFU lesions were performed at an average depth of 19.0 ± 1.5 mm, while the integrity of the skin was preserved. The HIFU-treated breast tissues had a higher level of attenuation (0.57 ± 0.11 Np.cm^-1.MHz^-1) when compared to the untreated tissues (0.21 ± 0.04 Np.cm^-1.MHz^-1). This study shows the feasibility of a fast and fully noninvasive treatment using a toroidal transducer for breast tumors measuring up to 15 mm in diameter.

Need for risk-adapted therapy for malignant ovarian germ cell tumors: A large multicenter analysis of germ cell tumors' patients from French TMRG network

BACKGROUND

Malignant ovarian germ cell tumors are rare tumors, affecting young women with a generally favorable prognosis. The French reference network for Rare Malignant Gynecological Tumors (TMRG) aims to improve their management. The purpose of this study is to report clinicopathological features and long-term outcomes, to explore prognostic parameters and to help in considering adjuvant strategy for stage I patients.

PATIENTS AND METHODS

Data from patients with MOGCT registered among 13 of the largest centers of the TMRG network were analyzed. We report clinicopathological features, estimated 5-year event-free survival (5y-EFS) and 5-year overall survival (5y-OS) of MOGCT patients.

RESULTS

We collected data from 147 patients including 101 (68.7%) FIGO stage I patients. Histology identifies 40 dysgerminomas, 52 immature teratomas, 32 yolk sac tumors, 2 choriocarcinomas and 21 mixed tumors. Surgery was performed in 140 (95.2%) patients and 106 (72.1%) received first line chemotherapy. Twenty-two stage I patients did not receive chemotherapy. Relapse occurred in 24 patients: 13 were exclusively treated with upfront surgery and 11 received surgery and chemotherapy. 5y-EFS was 82% and 5y-OS was 92.4%. Stage I patients who underwent surgery alone had an estimated 5y-EFS of 54.6% and patients receiving adjuvant chemotherapy 94.4% (P < .001). However, no impact on estimated 5y-OS was observed: 96.3% versus 97.8% respectively (P = .62). FIGO stage, complete primary surgery and post-operative alpha fetoprotein level significantly correlated with survival.

CONCLUSION

Adjuvant chemotherapy does not seem to improve survival in stage I patients. Active surveillance can be proposed for selected patients with a complete surgical staging.

JS1.1 Specific genetic alterations of breast tumors lead to Yo paraneoplastic cerebellar syndromes

BACKGROUND

Paraneoplastic cerebellar degenerations with anti-Yo antibodies (Yo-PCD) are rare syndromes associated with ovarian or breast cancers and caused by an auto-immune response against neuronal antigens expressed by tumor cells. We previously demonstrated in Yo-PCD ovarian cancers an association between massive infiltration of ovarian tumors by activated immune effector cells and recurrent gains and/or mutations of onconeural Yo genes (CDR2L and CDR2), suggesting that such genetic alterations in ovarian tumor cells may trigger immune tolerance breakdown and initiation of the auto-immune reaction against Purkinje cells.

MATERIAL AND METHODS

We pursued the characterization of Yo-PCD tumors and specifically studied breast cancer by IHC, FISH, CGH array and RNA sequencing analysis of 17 breast Yo-PCD tumors and by comparing their genetic characteristics with 10 sporadic breast tumors and public databases.

RESULTS

We confirmed that specific genetic alterations were also present in breast cancers associated with Yo-PCD. Moreover, this study provides additional evidence for a role of tumor cell specificities in PCD immunopathology by revealing peculiarities in Yo-PCD breast tumors compared to Yo-PCD ovarian cancer. Indeed, not only the CDR2L Yo gene was amplified in 8/9 breast Yo-PCD cancers but also the Erb2/Her2 gene in 15/16 (both genes are on chromosome 17q). In addition to this original Her2 and Yo antigen amplification confirmed by FISH, we observed an overexpression of these proteins by IHC analysis. These Yo-PCD breast cancers are also all negative for hormone receptors (HR). Thus, Yo-PCD breast tumors seem to belong to the molecularly and clinically distinct class of HR-negative and Her2-enriched breast cancers, which represents less than 10 % of breast cancers in the general population. Transcriptomic analysis confirmed that breast Yo-PCD tumors differ by their expression programs from classical breast cancers molecular subtypes.

CONCLUSION

Understanding the tumor genetic features leading to the immune breakdown and anti-tumor immune response as well as nervous tissue attack remains challenging and seems to be specific according to the tumor subtypes. Herein, our results suggest that, despite sharing common genetic alterations (copy number variations and mutations affecting Yo genes), the Yo-PCD immunopathogenesis of breast and ovarian cancers differ by involving different tumor-specific molecular pathways.

Abstract P5-12-05: Phenotypic discordance between primary and metastatic breast cancer (MBC) in a large scale real-life multicentre French cohort

Background: Therapeutic options at diagnosis for metastatic breast cancers (MBC) differ largely according to cancer phenotype (namely, hormone receptor (HR) and HER2 status). Reported discordance rates between primary tumor and metastasis vary widely in literature, with a median of 18% for estrogen receptor, 31% for progesterone receptor and 10% for HER2. The present study aimed to compare phenotypic profiles between primary and MBC in the real-life setting.

Patients (pts) and methods:

Epidemio-Strategy and Medical Economics (ESME)MBC data platform (NCT03275311) is a French national, multicenter, observational cohort using clinical trials' methodology for data capture, monitoring and quality controls. At the time of analysis, it comprised data of 16703 consecutive newly diagnosed MBC pts (1/01/08-31/12/14) treated in 18 French comprehensive cancer centres. The primary endpoint was the discordance rate of HR and HER2 status between primary tumor and MBC (biopsy of metastatic site done within 6 months of MBC diagnosis). Only patients with both histological reports available were considered. Potential factors associated with phenotype discordance were assessed in a multivariate logistic regression.

Results: 2933 out of 16703 (17.6%) had a biopsy in the first 6 months of metastatic disease. HR and/or HER2 status was available in 1677 pts. The discordance rate between primary and matched MBC was 14.2% (222/1566) for HR: loss of expression in 72.5%, gain in 27.5%. For HER2, the discordance rate was 7.8% (84/1076): 45.2% of losses and 54.8% of gains of expression. The primary HR+/HER2+ subgroup had the highest rate of changes: 53% (49/92) with either a loss of HR (43%), loss of HER2 (43%) or a loss of both (14%). 18% (33/181) of primary triple-negative breast cancer (TNBC) had a phenotypic change with a majority of HR gain (79%). In multivariate analysis, administration of adjuvant chemotherapy +/- targeted therapy was the sole independent predictor of HR status modification (OR: 1.73, 95%CI 1.27-2.36, p=0.001). The presence of a mixed histology was the only predictor of HER2 discordance (OR =2.57, 95%CI 1.19-5.55, p=0.016).

Patient characteristics Total population (n=16703)Pts with primary and MBC phenotype available (n=1677)Age at metastatic diagnosis Median (range)61 (19-99)60 (24-93)De novo MBC4507 (27.1%)221 (13.2%)Number of metastatic sites Median (range)1 (1-9)2 (1-7)MBC sites  Brain1200 (7.2%)138 (8.2%)Visceral7755 (46.4%)928 (55.3%)Non-visceral7748 (46.4%)611 (36.4%)Phenotypic profileN = 2933N=1677TNBC356 (18.5%)272 (19.3%)HR+/HER2-1251 (65.0%)917 (65.2%)HR-/HER2+150 (7.8%)105 (7.5%)HR+/HER2+168 (8.7%)112 (8%)Missing1008271Metastatic site samplingN=2933N=1677Bone692 (24.2%)419 (25.5%)Liver514 (18.0%)355 (21.6%)Skin379 (13.3%)203 (12.4%)Node306 (10.7%)169 (10.3%)Lung258 (9.0%)168 (10.2%)Pleura283 (9.9%)121 (7.4%)CNS/CSF*132 (4.6%)42 (2.6%)Other or multiple296 (10.3%)165 (10.0%)Missing7335* CNS= central nervous system, CSF=cerebro-spinal fluid

Conclusion: Biopsy and phenotype re-evaluation of MBC early in the disease course has a confirmed potential significant therapeutic impact in this large scale real life setting and should be proposed as often as possible.

Citation Format: Lefevre S, Lusque A, Joyon N, Arnould L, Penault-Llorca F, MacGrogan G, Treilleux I, Vincent-Salomon A, Haudebourg J, Maran-Gonzalez A, Charafe-Jauffret E, Courtinard C, Franchet C, Verriele V, Brain E, Tas P, Delaloge S, Filleron T, LaCroix-Triki M. Phenotypic discordance between primary and metastatic breast cancer (MBC) in a large scale real-life multicentre French cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-12-05.

Abstract P3-13-08: Preclinical validation of a new tumor imaging agent targeting αvβ3 to detect breast tumor using NIR-light imaging

Surgery is still a essential step for breast cancer treatment. Complete tumor removal during surgery rely on surgeon's ability to differentiate tumor from normal tissue. To date, no intra operative method is available and reliable enough to help the surgeon delineate precisely tumor extension in the adjacent normal tissue. Thus, surgeons rely solely on pre operative imaging techniques to delineate tumor margins. Recent advances made in the field of non-invasive imaging and vectorized nano-size particles have revealed a remarkable potential for improved tumor-margin detection. AngiostampTM is a new fluorescent agent for intra operative imaging. This system provides strong binding on αvβ3 integrin-rich tumor neoangiogenesis. Our general hypothesis is that targeting αvβ3 integrin-rich breast carcinoma neoangiogenesis should provide improved delivery of diagnostic compounds and assist surgeons intra operatively using near-infrared imaging techniques.

We conducted preclinical studies to evaluate the distribution of angiostampTM in vivo in murine breast tumor model and to determine the expression of αvβ3 integrin on human breast specimens.

The capacity of AngiostampTM to target αvβ3 integrin was assessed in 4T1 breast tumor model. After tumor implantation, mices were injected with AngiostampTM or a saline solution. Detection of the tumors was performed at different timepoints (early, progressive and established tumors, N= 24 mices/timepoint) using near infrared (NIR) imaging system (FluobeamTM) to detect fluorescence in tumor tissue.

In parallel, the expression of αvβ3 integrins in normal breast tissue, benign lesions (N=20) and various tumors subtypes (N=120) was assessed by immunohistochemistry.

In mice injected with AngiostampTM, fluorescence was observed only within the tumors with low background. AngiostampTM labeled tumors at all timepoint. No false negative fluorescence was found as confirmed by histopathological analyses.

In humans, the αvβ3 integrin are expressed in normal breast epithelial cells and benign metaplastic or proliferative epithelial lesions. However, due to the density of carcinomatous cells, the level of expression was much higher in breast cancer: 94% of invasive ductal carcinomas and 100% of invasive lobular carcinomas had a membranous staining (moderate to high intensity). Expression in breast cancer was not restricted to tumor subtypes neither hormone receptor expression nor SBR grade.

Based on this preclinical demonstration, AngiostampTM could allow a better intra-operative detection of tumor bed in breast cancer, increasing the efficiency of surgical procedure especially for infraclinic disease and decreasing the rate of second surgery. Preclinical development is ongoing and the first clinical trial is expected in 2017.

Citation Format: Beurrier F, Dutour A, Chen Y, Froc E, Gayet P, Guillermet S, Rizo P, Chopin N, Faure C, Dammaco MA, Klinger S, Ferraioli D, Garin G, Treilleux I. Preclinical validation of a new tumor imaging agent targeting αvβ3 to detect breast tumor using NIR-light imaging [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 P3-13-08.

Abstract P6-07-13: New insights on HER2 amplification from the constitutional and somatic standpoints: Results from the ICGC and SIGNAL/Phare studies

Background: HER2-positive (HER2+) breast cancers are defined by the amplification and/or overexpression of the human epidermal growth factor receptor (HER2/ERBB2) gene on chromosome region 17q12. Although anti-HER2 targeted therapies have greatly improved treatment of HER2+ breast cancer, the magnitude of benefit varies widely between patients. Deciphering the genomic and genetic heterogeneity of HER2+ breast cancer may provide a basis to better understand their natural history, opening new avenues of treatment.

Methods: As part of the ICGC Breast Cancer Working Group effort, we combined whole genome sequencing and transcriptomic analyses of 64 HER2+ primary invasive carcinomas, and a genome wide association study (GWAS) of over 9.836 breast cancer patients in the prospective SIGNAL/PHARE cohort (NCT00381901 – RECF1098).

Results: Using WGS data we precisely delineate the ERBB2 amplicon as a 106 kb region involving six genes and show that the amplification mechanism was consistent with breakage-fusion-bridge (BFB) cycles. Four RNA expression-based groups were identified, displaying specific genomic alterations in terms of amplification, rearrangements and mutations. On other hand, GWAS analyses failed to identify any constitutional variants associated with HER2 amplification.

Discussion: By combining whole genome sequencing and expression analysis, we provide evidence showing that HER2+ tumours display considerably more molecular heterogeneity than previously reported. These results are reinforced with the lack of association between any genetic variants and HER2 amplification from GWAS analyses. Taken as a whole, these results suggest that HER2+ breast cancers do not represent per se a homogeneous subtype, but are distributed along the whole breast cancer spectrum, from ER-positive luminal to ER-negative basal phenotype. Genome alterations present in HER2+ tumors are in accordance with these phenotypes, and it is likely that the HER2 amplification is a secondary event in the course of tumorigenesis, not favored by any particular constitutional or somatic genetic variants.

Citation Format: Vincent-Salomon A, Ferrari A, Pivot X, Macgrogan G, Arnould L, Treilleux I, Romieux G, Sertier A-S, Thomas E, Tonon L, Boyault S, Kielbassa J, Letexier V, Pauporte I, Birbaum D, Saintigny P, Cox D, Viari A. New insights on HER2 amplification from the constitutional and somatic standpoints: Results from the ICGC and SIGNAL/Phare studies. [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 P6-07-13.

[Axillary lymph node metastases with an occult breast: About 16 cases from a cohort of 7770 patients]

OBJECTIVES

Isolated axillary lymph node metastases is an unusual clinical presentation of breast carcinoma. We studied its different issues.

METHODS

This study is a follow-up study of 16patients, treated between 1996 and 2012, presenting with axillary metastases with an occult breast carcinoma, which could not be identified by physical examination nor by a conventional imaging or a breast MRI. Clinical characteristics, histological analysis, treatment, monitoring and five-year survival rate were studied.

RESULTS

The incidence of this kind of breast cancer was 0.20%. A breast MRI was performed in 75% of the patients. The histology of these tumors showed a rate of hormono-sensibility of 50% and an HER2 overexpression of 44%. Sixty-nine percent of the patients had no breast surgery or radiotherapy; global five-year survival rate for these women was 77.4%±11.5.

CONCLUSION

The survival rates of this study should lead the practitioner to choose a less aggressive breast therapy. Moreover, the histological characteristics explain the high metastatic potential of these tumors, and relate them to the HER2+ subclass of gene expression patterns of breast carcinomas.

Translational studies within the TAMRAD randomized GINECO trial: evidence for mTORC1 activation marker as a predictive factor for everolimus efficacy in advanced breast cancer

BACKGROUND

Everolimus is an agent frequently associated with specific toxicities. Predictive markers of efficacy are needed to help define which patients could benefit from it. The goal of this exploratory study was to identify potential predictive biomarkers in the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) activation pathway using primary tumor samples collected during the phase II tamoxifen plus everolimus (TAMRAD) trial.

PATIENTS AND METHODS

Tumor tissues were collected retrospectively from the TAMRAD trial. Immunohistochemistry was carried out using specific antibodies directed toward proteins that result in mTORC1 activation [canonical phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mTOR or alternative pathways]. DNA was extracted from the tumor tissue; mutation screening in the PIK3CA gene (exons 9 and 20) and the KRAS gene (exons 2 and 3) was first carried out using Sanger direct sequencing, and then completed by next-generation sequencing for PIK3CA. An exploratory analysis of everolimus efficacy in terms of a time-to-progression (TTP) increase was carried out in each biomarker subgroup (high versus low expression referring to the median percentage of marked cells).

RESULTS

A total of 55 primary tumor samples from the TAMRAD trial—25 from the tamoxifen-alone group and 30 from the tamoxifen/everolimus group—were evaluated for biomarkers. The subgroups most likely to have an improvement in TTP with tamoxifen/everolimus therapy, compared with tamoxifen alone, were patients with high p4EBP1, low 4EBP1, low liver kinase B1, low pAkt, and low PI3K. Among the 45 samples screened for mutation status, nine samples (20%; 95% CI 9.6-34.6) had a PIK3CA mutation. KRAS mutation was observed in one patient.

CONCLUSIONS

A positive correlation between late effectors of mTORC1 activation, a positive correlation between Akt-independent mTORC1 activation, and an inverse correlation between canonical PI3K/Akt/mTOR pathway and everolimus efficacy were observed in this exploratory analysis. However, these correlations need to be validated in larger studies before applying the findings to routine clinical practice.

[Spontaneous regression of breast cancer after biopsy. About two cases]

We report two cases of spontaneous regression of breast cancer occurred in our institution. It was about a 34- and an 82-year-old patient. The examination revealed a palpable nodule. In both cases, biopsy revealed a negative immunohistochemical staining for estrogen and progesterone receptors, and HER-2 negative. Histological analysis of the surgical specimen found fibrous tissue rearrangement without carcinoma. In the first case, a sarcoidosis was diagnosed at the same time, the mediastinal nodes mimicked a metastatic cancer. These cases illustrate a rare phenomenon. The main hypothesis is a carcinoma- directed immune response triggered by the biopsy.

Abstract P1-08-27: Quantitative analysis of tumor expression of phosphoproteins from PI3-kinase and MAP-kinase signaling pathways as biomarkers of the biological and clinical activity of trastuzumab and everolimus in breast cancer: Unicancer RADHER phase II trial results

Background: PI3-kinase (PI3K) and MAP kinase (MAPK) are the main signaling pathways implicated in molecular oncogenesis. In breast cancer, inhibition of these signaling pathways has been largely envisaged by means of targeted therapy. Unicancer RADHER study aimed at evaluating the efficacy of adding everolimus (E) to trastuzumab (T) as preoperative therapy for primary HER2+ operable breast cancer patients and to evaluate molecular response biomarkers. We report here the investigation of the expression of phosphoproteins from PI3K and MAPK signaling pathways as predictive biomarkers of clinical and pathological response as well as pharmacodynamic markers of treatment activity.

Methods: 82 eligible patients were randomized to receive T alone (loading dose 4 mg/kg, then 2 mg/kg/week), or T+E (10 mg/day) for a 6-week pre-operative treatment. Clinical response rate (cRR) was determined from OMS criteria with complete and partial responses being considered as “ responders “ and stable and progressive diseases as “ non responders “. Pathological response rate was evaluated according to Sataloff classification, with Ta and Tb being considered as “ responders “ and, Tc and Td as “ non responders “. The expression levels of phosphorylated-AKT (p-AKT), p-GSK3b, p-S6 kinase, p-MEK1, p-ERK1/2, p-P90RSK, p-IGF1R as well as p-P38MAPK were quantitatively assessed using multiplex bead immuno-assay. All patients had baseline needle frozen biopsies taken before initiation of the treatment, at cycle 4 as an option and at surgery. Before being submitted to total protein extraction, all biopsies were validated by a senior pathologist after HE slide examination to ensure a tumor content &gt;50%. 36 pairs associating baseline + surgery tumor specimens and 4 pairs of baseline + cycle 4 biopsies were eligible for protein extraction. Results: No statistically significant relationship was observed between the expression level of any of the phosphoproteins in the initial biopsies and neither the clinical nor the pathological response, overall. After treatment, as compared to the level of expression measured in the initial biopsies, a significant increase of p-GSK3β, p-MEK1, p-ERK1/2, p-P38MAPK was observed in T+E arm and a significant decrease in p-S6 kinase expression in the global patient population. No significant variation was observed in T arm. Additional analysis with immunohistochemistry data is planned and will be presented.

Conclusion: In the present study, measuring phosphoproteins expression showed that combining E with T, altered the regulation of signaling proteins from PI3-Kinase and MAP-kinase pathways. No response predictive biomarker could be identified among the phosphoproteins analyzed tending to show that the clinical and pathological response to T and T+E should be driven by additional mechanisms. As a whole, these results validate the use of multiplex bead immuno-analysis for determination of phosphorylated signaling proteins in clinical needle biopsies from breast cancer specimens and its prospective evaluation as biomarker for the activity of targeted therapies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-27.

Abstract S6-07: Genomic characterisation of metastatic samples from breast cancer patients using next generation sequencing

Background: Although several studies have reported genomic characterisation of primary breast tumors, little is known about the genomic alterations of the metastatic tissues. Breast cancer patients who were prospectively enrolled in a trial (SAFIR01) underwent a biopsy of metastasis. The primary aim of this biopsy was to drive the treatment according to the results of whole genome CGH arrays and sanger sequencing on two genes (PIK3CA and AKT1). The results of the clinical trial were previously reported (André et al ASCO 2013). The secondary goal of the biopsies was to perform genomic characterisation of metastases in breast cancer patients. Here we report the analyses of such metastatic samples using next generation sequencing (NGS) approaches.

Patients and methods: Two approaches were applied. In order to describe the incidence of targetable genomic alterations, we performed in depth targeted sequencing on 100 genes (200x coverage) using Illumina HiSeq 2000 (DNA vision). This analysis was performed on 240 metastatic samples. The second approach was more exploratory and aimed at discovering new genes involved in the metastatic process and/or resistance to therapies. In order to achieve this goal, we performed whole exome sequencing in 100 pairs of metastatic tissue (100x) and normal DNA (Integragen Inc, Hiseq platform). Finally, phosphor-S6K staining was performed in 300 samples in order to explore the activation status of mTOR pathway in metastatic disease, and to correlate with genomic data.

Results: Targeted sequencing was performed on 240 metastatic samples in order to report the prevalence of targetable genomic alterations in metastatic breast cancer. Results are available for the first 159 samples. In addition to the already reported PIK3CA (26%) and AKT1 mutations (4%), NGS identified mutations of PTEN (4%), ERBB2 (2%), K-Ras (1%), ATM (2%), CDH1 (2%), GATA3 (2%), PTPN11 (1%), PTPRD (1%), ROS1 (1%). Results on the 81 samples, together with whole exome sequencing (n = 100) and phosphoproteins are being analysed and results will be available mid-november 2013.

Conclusion: This is the first large study that aims at defining the genomic landscape of metastatic samples. Results will provide insights into the prevalence of targetable genomic alterations in metastatic tissue, together with candidate genes involved in the metastatic process and resistance to therapies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S6-07.

Abstract P3-14-13: eIF4E/4EBP1 axis and response to neoadjuvant trastuzumab-based treatment in HER2+ breast cancer – Results of a multicentre French retrospective cohort

Background

Despite a growing number of studies exploring the underlying mechanisms, resistance to trastuzumab (TTZ) in HER2+ breast cancer (BC) remains elusive and an important issue in clinical practice. Among the proposed mechanisms, involvement of the PI3K/Akt/mTOR pathway is one of the best characterized. In a previous preclinical and clinical study (n = 54) (Bergé Y et al, SABCS 2009 and [1]), we have shown a significant correlation between eIF4E (a downstream effector of the PI3K/Akt/mTOR pathway) expression level as determined by immunohistochemistry (IHC) on initial tumor biopsy and pathological complete response (pCR) in patients with HER2+ BC treated with a neoadjuvant TTZ-containing regimen. The aim of this study was to validate these findings on an independent and larger cohort of HER2+ BC treated in neoadjuvant setting.

Method

In this multicenter (n = 9) study, 274 patients (pts) with HER2+ BC treated were included. All pts received neoadjuvant chemotherapy regimen containing TTZ, consisting mostly of 3-4 cycles of FEC (5FU, Epirubicin, Cyclophosphamid) followed by 3-4 cycles of TTZ–Docetaxel (n = 116). 74 pts received 6 cycles of TTZ–Docetaxel, 18 received 6 cycles of TTZ–Docetaxel-Cyclophosphamid, 12 received 6 cycles of TTZ–Docetaxel-carbolpatine, and the remaining 54 pts received other regimens. Pathological response was assessed according to Sataloff and Chevallier criteria. Unstained slides from the initial tumor biopsy were centrally collected for biomarkers analysis. Expression levels of eIF4E, p-4EBP1 and pS6 were determined by IHC. An immunoreactive score (IRS) combining the percentage of stained tumor cells and staining intensity was assessed by two pathologists.

Results

Median age at diagnosis was 50 years [range 22–84]. Most pts presented with T2 (52.6%), N1 (53.9%) stage, with a median tumor size of 40mm [range 0-150mm] as determined on clinical examination. Tumors were mainly invasive ductal of no special type (93.8%), of histological grade III (50%) and II (45%), ER+ (54.4%). Breast conserving surgery with free margins was achieved in 50.9% of pts. pCR (breast Sataloff TA) was observed in 53% of pts, and in 47.6% when considering both breast and lymph node response. Out of the 274 pts, 257 had sufficient tumor on the initial biopsy for biomarker analysis. Preliminary results showed a median eIF4E IRS of 6 [range 1-12], with 52.1% of cases displaying a low eIF4E expression level (IRS£6). The agreement for inter-observer assessment of eIF4E status was good (k = 0.618, 95% CI [0.523-0.713]). Scoring of p-4EBP1 and pS6 are ongoing and correlations of pCR with eIF4E/4EBP1 axis will be presented.

Conclusion

In this large multicentre retrospective study, the rate of pCR obtained in neoadjuvant setting of HER2+ BC is similar to those described in the literature. Thorough tumor collection allows biomarkers analysis, which has been specifically focused on downstream effectors of the PI3K/Akt/mTOR pathway.

Reference[1] Zindy P, Bergé Y, Allal B et al. Formation of the eIF4F translation-initiation complex determines sensitivity to anticancer drugs targeting the EGFR and HER2 receptors. Cancer Res. 2011;71(12):4068-73.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-13.

Lysyl oxidase activity regulates oncogenic stress response and tumorigenesis

Cellular senescence, a stable proliferation arrest, is induced in response to various stresses. Oncogenic stress-induced senescence (OIS) results in blocked proliferation and constitutes a fail-safe program counteracting tumorigenesis. The events that enable a tumor in a benign senescent state to escape from OIS and become malignant are largely unknown. We show that lysyl oxidase activity contributes to the decision to maintain senescence. Indeed, in human epithelial cell the constitutive expression of the LOX or LOXL2 protein favored OIS escape, whereas inhibition of lysyl oxidase activity was found to stabilize OIS. The relevance of these in vitro observations is supported by in vivo findings: in a transgenic mouse model of aggressive pancreatic ductal adenocarcinoma (PDAC), increasing lysyl oxidase activity accelerates senescence escape, whereas inhibition of lysyl oxidase activity was found to stabilize senescence, delay tumorigenesis, and increase survival. Mechanistically, we show that lysyl oxidase activity favors the escape of senescence by regulating the focal-adhesion kinase. Altogether, our results demonstrate that lysyl oxidase activity participates in primary tumor growth by directly impacting the senescence stability.

Methylation, a key step for nongenomic estrogen signaling in breast tumors

Estrogen receptor alpha (ERalpha) is a member of a large conserved superfamily of steroid hormone nuclear receptors which regulates many physiological pathways by acting as a ligand-dependent transcription factor. Evidence is emerging that estrogens also induce rapid signaling to the downstream kinase cascades; however the mechanisms underlying this nongenomic function remain poorly understood. We have recently shown that ERalpha is methylated specifically by the arginine methyltransferase PRMT1 at arginine 260 in the DNA-binding domain of the receptor. This methylation event is required for mediating the extra-nuclear function of the receptor which would thereby interact with Src/FAK and p85 and propagate the signal to downstream transduction cascades that orchestrate cell proliferation and survival. Of particular interest, a possible role of methylated ERalpha in mammary tumorigenesis is also evident by the fact that, as demonstrated by immunohistochemical studies on a cohort of breast cancer patients, ERalpha is methylated in normal epithelial breast cells and is hypermethylated in a subset of breast cancers. Hypermethylation of ERalpha in breast cancer might cause hyperactivation of cellular kinase signaling, notably of Akt, described as a selective survival advantage for primary tumor cells even in the presence of anti-estrogens. A detailed understanding of the molecular mechanisms that control estrogen signaling in breast cancer is a crucial step in identifying new effective therapies.

Prognostic value of Dicer expression in human breast cancers and association with the mesenchymal phenotype

BACKGROUND

Dicer, a ribonuclease, is the key enzyme required for the biogenesis of microRNAs and small interfering RNAs and is essential for both mammalian development and cell differentiation. Recent evidence indicates that Dicer may also be involved in tumourigenesis. However, no studies have examined the clinical significance of Dicer at both the RNA and the protein levels in breast cancer.

METHODS

In this study, the biological and prognostic value of Dicer expression was assessed in breast cancer cell lines, breast cancer progression cellular models, and in two well-characterised sets of breast carcinoma samples obtained from patients with long-term follow-up using tissue microarrays and quantitative reverse transcription-PCR.

RESULTS

We have found that Dicer protein expression is significantly associated with hormone receptor status and cancer subtype in breast tumours (ER P=0.008; PR P=0.019; cancer subtype P=0.023, luminal A P=0.0174). Dicer mRNA expression appeared to have an independent prognostic impact in metastatic disease (hazard ratio=3.36, P=0.0032). In the breast cancer cell lines, lower Dicer expression was found in cells harbouring a mesenchymal phenotype and in metastatic bone derivatives of a breast cancer cell line. These findings suggest that the downregulation of Dicer expression may be related to the metastatic spread of tumours.

CONCLUSION

Assessment of Dicer expression may facilitate prediction of distant metastases for patients suffering from breast cancer.

Fluorescence in situ hybridization (FISH) technique by reference centers for HER2 status determination in metastatic breast cancer: quality assurance results of FISH 2002 study

Abstract #2069

Background: Concordance between IHC and FISH in local and regional centers was evaluated in the FISH 2002 Study. Primary metastatic breast cancer (MBC) tumor samples were tested by IHC for HER2 status according to in-house techniques at 18 regional (n=871) and 81 peripheral (n=670) centers in France between 2002 and 2006. All samples were tested by FISH at regional centers [Penault-Llorca et al. SABCS 2006]. This second part of the study comprises quality assurance evaluation of FISH techniques.&#x2028; Methods: 464 cases were selected according to the protocol and were either re-assessed using archived pictures or retested by 3 reference centers (Clermont-Ferrand, Strasbourg, Paris-Curie). 246 samples were re-assessed and 166 were retested.&#x2028; Results:Global discordance combining re-assessment and retesting results was 10.7% in the first half of the study and 5.1% in the second part (p=0.041).&#x2028; &#x2028; Discussion: Concordance was excellent for negative (100%) and IHC 2+ cases (97%). Among low amplification cases (≥6 and &lt;8 copies), 70% were concordant: discordant cases were mainly interpretation pitfalls of polysomic cases, emphasizing the importance of double-stained FISH analyses. These quality assurance results demonstrate that overall concordance and quality of HER2 status determined by FISH has improved significantly over time. This improvement is likely to be related to introduction of rigorous quality control procedures, training, and education, all of which should be continued.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2069.

Netrin-1: a promising therapeutic target in metastatic breast cancer. Expression analysis in localized and metastatic breast tumors and preclinical validation

Abstract #3075

Netrin-1, an axon navigation cue was proposed to play a crucial role during colorectal tumorigenesis by regulating apoptosis. The netrin-1 receptors DCC and UNC5H belong to the family of dependence receptors that share the ability to induce apoptosis in the absence of their ligand. Cells expressing one of these dependence receptors are thus dependent on ligand availability to survive. Such a trait confers on these receptors a tumor suppressor activity by preventing uncontrolled cell proliferation.&#x2028; We have previously shown in breast cancer that gaining autocrine expression of the ligand netrin-1 would represent for cancer cells a selective advantage. Human and murine netrin-1-expressing mammary metastatic cell lines undergo apoptosis when netrin-1 expression is experimentally decreased or when decoy soluble receptor ectodomains are used. Such treatments prevent metastasis formation in a syngenic mouse model of lung colonization by a mammary cancer cell line (Fitamant et al., PNAS 2008, vol 105).&#x2028; In order to assess the clinical importance of netrin-1 expression in human breast cancer, we quantified by Q-RT-PCR the mRNA levels of netrin-1 in primary breast cancer biopsies and studied their correlation to pathological and clinical data. We used frozen tumor samples from 120 breast cancer patients treated in our institution between 1993 and 2000. At diagnosis, median age was 50, median tumor size was 40 mm. 11% of the patients had SBR1 tumor, 46% had SBR2 tumor and 43% had SBR3 tumor. Estrogen receptor was positive for 62% of the patients. 17% of the patients were pN0, M0; 71% were pN+, M0 and 12% already had distant metastasis (M+) at time of diagnosis. Although there is no correlation between netrin-1 expression and tumor size, histological SBR grade or hormone receptor status, there is a strong correlation between high netrin-1 expression and the presence of nodal involvement (p=0,007) or distant metastasis at the time of diagnosis (p&lt;0,0001). We hypothesize that high netrin-1 expression allows an early and rapid metastatic dissemination during tumor development. We are currently exploring netrin-1 expression levels at different metastatic sites and are completing survival analysis of our cohort of patients.&#x2028; In parallel, preclinical mice models of xenografts either of human breast cancer cell lines or fresh human breast tumors were used to evaluate netrin-1 targeting strategy. The preliminary results show that disrupting netrin-1 activity appears to be more efficient than a conventional Adryamicin-Cyclophosphamide treatment in decreasing tumor sizes and suppressing lung metastasis.&#x2028; These results support netrin-1 as a marker of metastatic dissemination and as a promising therapeutic target in breast cancer progression.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3075.

The molecular causes of low ATM protein expression in breast carcinoma; promoter methylation and levels of the catalytic subunit of DNA-dependent protein kinase

AIMS

To investigate whether aberrant methylation of the ATM promoter or loss of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) may be the underlying causes of reduced ATM protein levels often seen in breast tumours.

METHODS AND RESULTS

Methylation-specific polymerase chain reaction was used to determine the ATM promoter status and DNA-PKcs levels were measured by immunohistochemistry. None of the 74 invasive carcinomas (ICs) studied showed ATM promoter hypermethylation, whereas promoter methylation of CDKN2A/p16 (1.8%) and GSTP1 (15.8%) was detected. Of 92 ICs examined, 68 had reduced DNA-PKcs levels, supporting previous findings that alterations in double-strand break repair are associated with breast cancer pathogenesis. Although no association was found between the DNA-PKcs and ATM scores for the series of 92 tissues and 22/24 tissues with normal DNA-PKcs had reduced ATM, 29 tumours showed low expression of both DNA-PKcs and ATM compared with normal tissues.

CONCLUSIONS

No evidence was found that the reduction in ATM protein levels seen in breast carcinoma is the result of epigenetic silencing. However, cross-regulation between DNA-PKcs and ATM may be a possible cause in a subset of tumours and warrants further investigation.

BCIRG 001 molecular analysis: Identification of prognostic factors in patients (pts) receiving adjuvant therapy for node- positive (N+) breast cancer (BC)

525

Background: BCIRG 001 (1,491 pts) demonstrated significant superiority of docetaxel/doxorubicin/cyclophosphamide (TAC) over fluorouracil/doxorubicin/cyclophosphamide (FAC) given as adjuvant therapy for N+ operable BC in terms of disease-free survival (DFS) and overall survival (OS) (Martin et al, N Eng J Med, 2005). This ancillary study was aimed to identify tumor-associated factors related to DFS and OS. Methods: Formalin-fixed primary tumors from pts in BCIRG 001 were analysed by immunohistochemistry. Protocol- specified assessment of histological grade (GR), tumor size (TS), estrogen (ER) and progesterone receptors (PR), lymph node status (LN), HER2, MUC1, Mib, p53, Bcl-2, Bax, Bcl-X, Bag-1, tubulin β isotypes II, III and IV, tau protein and detyrosinated a tubulin was performed. Parameters were scored as the percentage of positive cells and analysed as lower or greater than median values. The samples were randomly split into training (2/3) and validation (1/3) sets. Associations between selected parameters and DFS or OS were tested through univariate analyses using the Kaplan Meier method (log-rank test) on the training set. A backward stepwise Cox regression analysis was performed to identify the final model of prognostic factors on the training set. Multivariate analyses were applied to the validation set. Results: 1,350 samples were split into a training (n=906) and a validation (n=444) set. In univariate GR, TS, LN, ER and PR, Mib, tau protein and HER2 were correlated with DFS in both sets. In multivariate ER, PR, TS, LN, Mib (all p<0.01) and tau (p=0.043) were significantly associated with DFS in the training set. In univariate GR, TS, LN, ER and PR, Mib, MUC1, Bcl-2, tubulin III and IV and tau were correlated with OS in both sets, with a trend for p53. In multivariate ER, TS, LN, Mib, p53 (all p<0.01) and PR (p=0.028) were independently correlated with OS in the training set. Conclusions: These data suggest that tau and p53 are independent markers of DFS and OS, respectively, while Mib is correlated with both DFS and OS in pts receiving these forms of adjuvant chemotherapy for N+ BC. Complementary analyses will be presented.

No significant financial relationships to disclose.

Malignant teratoma 32 years after treatment of germ cell tumor confined to testis

After the first 2 years of follow-up, the prognosis of testicular cancer confined to the testis is traditionally considered excellent. We report on a man who presented with a psoas mass, corresponding to a very late relapse of his left testicular cancer initially confined to the testis and confirmed by negative retroperitoneal lymph node dissection. Histologic analysis of the mass revealed malignant teratoma. The patient's history was remarkable because of the very long interval to relapse (32 years) associated with this malignant teratoma. This clinical case illustrates the possibility of late relapses throughout life, whatever the initial stage.

Expression of ATM, p53, and the MRE11-Rad50-NBS1 complex in myoepithelial cells from benign and malignant proliferations of the breast

AIMS

To analyse the expression of proteins involved in DNA double strand break detection and repair in the luminal and myoepithelial compartments of benign breast lesions and malignant breast tumours with myoepithelial differentiation.

METHODS

Expression of the ataxia telangiectasia (ATM) and p53 proteins was immunohistochemically evaluated in 18 benign and malignant myoepithelial tumours of the breast. Fifteen benign breast lesions with prominent myoepithelial compartment were also evaluated for these proteins, in addition to those in the MRE11-Rad50-NBS1 (MRN) complex, and the expression profiles were compared with those seen in eight independent non-cancer (normal breast) samples and in the surrounding normal tissues of the benign and malignant tumours examined.

RESULTS

ATM expression was higher in the myoepithelial compartment of three of 15 benign breast lesions and lower in the luminal compartment of eight of these lesions compared with that found in the corresponding normal tissue compartments. Malignant myoepithelial tumours overexpressed ATM in one of 18 cases. p53 was consistently negative in benign lesions and was overexpressed in eight of 18 malignant tumours. In benign breast lesions, expression of the MRN complex was significantly more reduced in myoepithelial cells (up to 73%) than in luminal cells (up to 40%) (p=0.0005).

CONCLUSIONS

Malignant myoepithelial tumours rarely overexpress ATM but are frequently positive for p53. In benign breast lesions, expression of the MRN complex was more frequently reduced in the myoepithelial than in the luminal epithelial compartment, suggesting different DNA repair capabilities in these two cell types.