Abstract P2-05-01: Whole genome sequencing reveals enrichment of mutations in mucin gene family in breast cancer diagnosed during pregnancy

Background

Pregnancy is known to modulate breast cancer (BC) risk. Different reproductive behaviors have been shown to impact not only the risk of developing BC but also the phenotypes of these tumors. Breast cancer diagnosed during pregnancy (BCP) is a rare disease but could serve as a good model to understand how pregnancy modulates BC biology. In this project, we aim to interrogate the effect of pregnancy on the biology of BC by performing whole genome sequencing (WGS) using a unique series of BC patients diagnosed during pregnancy (BCP).

Method

Whole genome sequencing was performed for 35 BCP and 20 non-pregnant controls matched for age and stage with available clinic-pathological data. DNA extracted from primary tumor and matched adjacent normal FFPE tissues was assessed using WGS on Illumina HiSeqXTen platform targeting 60x and 30x coverage for tumor and normal DNA respectively. Briefly, 2x150bp paired end sequence data were generated, cleaned, trimmed and aligned to the reference genome (hg19) using bwa-mem. Somatic mutations were detected using Strelka and annotated using SnpEff. Mutational signatures were extracted using deconstructSigs. Differences on mutational profiles between BCP and case controls were assessed using Wilcoxon test for continuous variables and Fisher exact test for categorical variables.

Result

No difference in clinic-pathological features was observed between BCP and control patients. A median of 10084 and 13829 SNVs and of 26 and 21 indels were identified in the BCP and controls respectively, no significant difference between the two groups being observed (p = 0.703 and p = 0.851). Of interest, a significantly higher number of mutations was found in the BCP as compared to the control group when considering only mutations associated with a deleterious effect (median: 20 vs. 12, p = 0.027). As expected, TP53 and PIK3CA were the most frequently mutated genes both in BCP and control cases without any significant difference between the groups (34.3% vs. 22.2%, p = 0.53 and 20.0% vs. 16.7%, p = 1, respectively). Interestingly, there was a significant enrichment of non-silent mutations in the mucin genes family (MUC2, MUC4, MUC12, MUC16, MUC17, MUC20) in the BCP group: 45.7% of BCP vs. 11.1% of control cases had at least one such mutation (p = 0.015). A similar significant result (45.7% vs. 23.1%, p = 0.034) was found when comparing BCP with BC control cases from the TCGA dataset (selected to have similar age, ER and PR distribution, N = 56). When comparing the distribution of the twelve BC mutational signatures, a borderline significant enrichment with a signature depicting mismatch-repair deficiency (signature 20) was observed in the BCP patients (p = 0.059).

Conclusion

This is the first study reporting the mutational landscape of breast cancer diagnosed during pregnancy using WGS. We found that BCP are associated with a higher number of putative driver mutations including mutations in mucin genes, shown to be implicated in tumorigenesis. Furthermore, BCP were enriched with a mismatch-repair deficiency signature. These results could open new avenues for the development of targeted therapeutic approaches for patients diagnosed with breast cancer during pregnancy.

Citation Format: Nguyen B, Venet D, Desmedt C, Pruneri G, Peccatori F, Mardis ER, Azim HA, Rothé F, Sotiriou C. Whole genome sequencing reveals enrichment of mutations in mucin gene family in breast cancer diagnosed during pregnancy [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 P2-05-01.

Regional Nodal Irradiation After Breast Conserving Surgery for Early HER2-Positive Breast Cancer: Results of a Subanalysis From the ALTTO Trial

Background

Two randomized trials recently demonstrated that regional nodal irradiation (RNI) could reduce the risk of recurrence in early breast cancer; however, these trials were conducted in the pretrastuzumab era. Whether these results are applicable to human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients treated with anti-HER2-targeted therapy is unknown.

Methods

This retrospective analysis was performed on patients with node-positive breast cancer who were enrolled in the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization phase III adjuvant trial and subjected to BCS. The primary objective of the present study was to examine the effect of RNI on disease-free survival (DFS). A multivariable cox regression analysis adjusted for number of positive lymph nodes, tumor size, grade, age, hormone receptors status, presence of macrometastatis, treatment arm, and chemotherapy timing was carried out to investigate the relationship between RNI and DFS.

Results

One thousand six hundred sixty-four HER2-positive breast cancer patients were included, of whom 878 (52.8%) had received RNI to the axillary, supraclavicular, and/or internal mammary lymph nodes. Patients in the RNI group had higher nodal burden and more frequently had tumors larger than 2 cm. At a median follow-up of 4.5 years, DFS was 84.3% in the RNI group and 88.3% in the non-RNI group. No differences in regional recurrence (0.9 % vs 0.6 %) or in overall survival (93.6% vs 95.3%) were observed between the two groups. After adjustment in multivariable analysis, there was no statistically significant association between RNI and DFS (hazard ratio = 0.96, 95% confidence interval = 0.71 to 1.29).

Conclusions

Our analysis did not demonstrate a DFS benefit of RNI in HER2-positive, node-positive patients treated with adjuvant HER2-targeted therapy. The benefit of RNI in HER2-positive breast cancer needs further testing within randomized clinical trials.

Abstract 1452: Interrogating the impact of pregnancy on breast cancer biology using DNA copy number profiling

Background

Epidemiological evidence indicates a clear relationship between pregnancy and breast cancer (BC) risk. However, little is known regarding the impact of pregnancy on BC biology. DNA copy number aberrations (CNAs) play an important role in breast carcinogenesis. BC during pregnancy is a rare disease, however it can be used as a model to study the impact of pregnancy on BC biology.

Methods

We retrospectively included 54 pregnant and 113 non-pregnant BC patients matched for age and stage with complete clinic-pathological, gene expression and 5-year follow-up data. CNAs were assessed using Affymetrix OncoScan FFPE arrays. First, we filtered genes whose expression was driven by CNAs. Then, we identified genes that were differentially affected by pregnancy both at the CNA and the gene expression level.

Results

After quality control, CNA profiles were obtained for 38 pregnant and 87 non-pregnant BC patients. There were no significant differences in classical clinic-pathological features (pT, pN, grade, PAM50). We selected 1981 genes whose expression was correlated with CNAs (ρ ≥ 0.4). Among these, 77 genes were altered at the expression level (p ≤ 0.01) between pregnant and control patients, whereas 171 genes were altered at the CNA level (p ≤ 0.05). Twenty-eight genes were concomitantly altered at the expression and CNA levels which was significantly higher than expected (p = 0.021, permutation test). These genes were mapped on three different chromosomes. Genes located on chr7q and chr11q were associated with copy number gains and were up-regulated in pregnant patients whereas genes located on chr22q were associated with copy number loss in control patients. Of interest we identified 6 putative oncogenes (CDK6, ESRRA, S6K2, LIMK2, MKL1) that were up-regulated in pregnant patients. A ‘pregnancy-associated breast cancer signature’ was computed from the expression of the 28 genes. There was a negative relationship between the signature and the expression of ESR1 and PGR genes. This signature was significantly more correlated with the proliferation-associated AURKA gene in pregnant patients as compared to control (ρ = 0.73 vs ρ = 0.24, p = 0.001).

Conclusions

In this study, we were able to identify several genomic alterations associated with pregnancy that could help elucidate the impact of pregnancy on BC risk. Moreover, by combining CNAs with gene expression, we were able to identify genes that could be responsible for the poorer prognosis seen in pregnancy-associated breast cancer and could be potential drivers of this rare disease.

Citation Format: Bastien Nguyen, David Venet, Françoise Rothé, Christine Desmedt, Samira Majjaj, Giancarlo Pruneri, David Brown, Fedro Peccatori, Hatem A. Azim, Christos Sotiriou. Interrogating the impact of pregnancy on breast cancer biology using DNA copy number profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1452. doi:10.1158/1538-7445.AM2017-1452

Safety of pregnancy in patients (pts) with history of estrogen receptor positive (ER+) breast cancer (BC): Long-term follow-up analysis from a multicenter study

LBA10066

The full, final text of this abstract will be available at abstracts.asco.org at 7:30 AM (EDT) on Saturday, June 3, 2017, and in the Annual Meeting Proceedings online supplement to the June 20, 2017, issue of the Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

Impact of Diabetes, Insulin, and Metformin Use on the Outcome of Patients With Human Epidermal Growth Factor Receptor 2-Positive Primary Breast Cancer: Analysis From the ALTTO Phase III Randomized Trial

Purpose Previous studies have suggested an association between metformin use and improved outcome in patients with diabetes and breast cancer. In the current study, we aimed to explore this association in human epidermal growth factor receptor 2 (HER2 ) -positive primary breast cancer in the context of a large, phase III adjuvant trial. Patients and Methods The ALTTO trial randomly assigned patients with HER2-positive breast cancer to receive 1 year of either trastuzumab alone, lapatinib alone, their sequence, or their combination. In this substudy, we evaluated whether patients with diabetes at study entry-with or without metformin treatment-were associated with different disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) compared with patients without diabetes. Results A total of 8,381 patients were included in the current analysis: 7,935 patients (94.7%) had no history of diabetes at diagnosis, 186 patients (2.2%) had diabetes with no metformin treatment, and 260 patients (3.1%) were diabetic and had been treated with metformin. Median follow-up was 4.5 years (0.16 to 6.31 years), at which 1,205 (14.38%), 929 (11.08%), and 528 (6.3%) patients experienced DFS, DDFS, and OS events, respectively. Patients with diabetes who had not been treated with metformin experienced worse DFS (multivariable hazard ratio [HR], 1.40; 95% CI, 1.01 to 1.94; P = .043), DDFS (multivariable HR, 1.56; 95% CI, 1.10 to 2.22; P = .013), and OS (multivariable HR, 1.87; 95% CI, 1.23 to 2.85; P = .004). This effect was limited to hormone receptor-positive patients. Whereas insulin treatment was associated with a detrimental effect, metformin had a salutary effect in patients with diabetes who had HER2-positive and hormone receptor-positive breast cancer. Conclusion Metformin may improve the worse prognosis that is associated with diabetes and insulin treatment, mainly in patients with primary HER2-positive and hormone receptor-positive breast cancer.

Abstract OT3-02-01: POSITIVE: A study evaluating pregnancy and disease outcome and safety of interrupting endocrine therapy for young women with endocrine-responsive breast cancer who desire pregnancy (IBCSG 48-14/BIG 8-13)

Background

Young breast cancer (BC) patients often face the disease before completing their family planning. The best available retrospective evidence suggests that pregnancy after BC does not negatively impact disease outcomes in patients with endocrine-responsive BC and is safe for offspring. However, given the possibility of prolonged adjuvant endocrine therapy (ET) (5-10 yrs), it is not feasible to wait until completion of therapy in many of these women and thus there is a need to explore the safety of temporary interruption of ET to allow pregnancy. To date, no prospective study has been conducted in young women attempting future pregnancy.

Trial Design

Young patients with endocrine-responsive early BC and pregnancy desire will interrupt ET for up to 2 yrs to attempt pregnancy. As resumption of menses and conception depends on many factors, e.g. patient's age and adjuvant treatment received, the 2-yr interruption period is approximate, intended to include treatment wash-out (3 mos) conception (∼3-6 mos), delivery (∼9 mos), breast feeding (∼6 mos). Patients will be strongly advised to resume ET as soon as pregnancy attempts are concluded and to complete the planned 5-10 yrs ET.

Major Eligibility Criteria

* Histologically-proven stage I-III endocrine-responsive BC.

* Age ≥ 18 and ≤ 42 years at enrollment.

* Adjuvant ET (SERM alone, GnRH analogue plus SERM or AI) for ≥18 mos but ≤30 mos, stopped within 1 mo prior to enrollment.

* Patient wishes to become pregnant.

* Premenopausal status at BC diagnosis.

Specific Aim

To assess the risk of BC relapse associated with temporary interruption of ET to permit pregnancy and to evaluate pregnancy success and offspring outcome.

Statistical Methods

A true risk of BC recurrence of 2% per year is assumed for patients who do not interrupt ET. With 500 patients enrolled in 4.0 yrs and an additional 1.6 yrs of follow up, there will be approximately 1600 patient-yrs of follow up and a median follow up of approximately 3 yrs at the time of the primary analysis, anticipated to occur 5.6 yrs after enrolment of the first patient. If the true risk of BC recurrence is 2% per yr, we anticipate 31 BC recurrences and an estimated 3-yr breast cancer free interval (BCFI) event of 5.6% (95% CI 4.0% to 7.9%).

Translational Research will investigate different ovarian function and uterine parameters; and circulating tumour DNA. FFPE tissue of the primary tumour will be collected to integrate different parameters related to biology of BC arising in young women. All material will be banked centrally.

Psycho-oncological Companion Study on fertility concerns, psychological well-being and decisional conflicts is mandatory in the US and open to interested centers elsewhere.

Accrual: Target: 500; Actual: 39 (30 Apr 2016)

Psycho-oncological Companion Study Accrual: Target: 200; Actual: 29 (30 Apr 2016)

Contact Information

POSITIVE is conducted and sponsored by the International Breast Cancer Study Group. The Alliance for Clinical Trials in Oncology is the US sponsor for NCTN network. Contact Monica Ruggeri, IBCSG Coordinating Center, monica.ruggeri@ibcsg.org, or Trial Coordinators at ibcsg48_positive@fstrf.org.

Citation Format: Pagani O, Partridge AH, Azim Jr. HA, Peccatori F, Ruggeri M, Sun Z. POSITIVE: A study evaluating pregnancy and disease outcome and safety of interrupting endocrine therapy for young women with endocrine-responsive breast cancer who desire pregnancy (IBCSG 48-14/BIG 8-13) [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 OT3-02-01.

Abstract P1-05-17: Interrogating the impact of pregnancy on breast cancer biology using DNA copy number profiling

Background

Epidemiological evidence indicates a clear relationship between pregnancy and breast cancer (BC) risk. However, little is known regarding the impact of pregnancy on BC biology. DNA copy number aberrations (CNAs) play an important role in breast carcinogenesis. BC during pregnancy is a rare disease but yet could serve as a good model to study the impact of pregnancy on BC biology.

Methods

We retrospectively included 54 pregnant and 113 non-pregnant BC patients matched for age and stage with complete clinico-pathological, gene expression and 5-year follow-up data. CNAs were assessed using Affymetrix OncoScan FFPE arrays. We identified the CNAs associated with pregnancy using a multivariate logistic regression adjusted for classical clinico-pathological features. We further evaluated their impact on gene expression.

Results

After quality control, CNA profiles were obtained for 38 pregnant and 87 non-pregnant BC patients. We identified 13 regions with copy number gains, 11 of which were more frequently gained in pregnant compared to non-pregnant controls and 5 regions with copy number loss, 3 of which were more frequently lost in pregnant patients (p≤0.05). Of interest, we identified 4 genes previously identified as driver event associated with CNAs in breast cancer (S. Nik-Zainal et al, Nature 2016). AKT1 and CDKN2A/B were more frequently gained in the pregnant compared to the non-pregnant (23.7% vs. 8.0%, p=0.068 and 18.4% vs. 4.6% p=0.036) and ARID1B was less frequently gained in the pregnant cohort (2.6% vs. 13.8%, p=0.02). Interestingly, PAPPA which had been previously identified as a pregnancy-dependent oncogene (Takabatake Y. et al, EMBO Mol Med. 2016) was also more frequently gained in the pregnant compared to the non-pregnant patients (21.1% vs 5.8%, p=0.03). We next evaluated the effect of these CNAs on their own gene expression levels and found that AKT1 and CDKN2A/B CNAs were affected by gene-dosage effect.

Conclusions

In this study, we were able to identify several genomic alterations associated with pregnancy that could further elucidate the impact of pregnancy on BC risk. Moreover, by combining CNAs with gene expression, we were able to identify genes whose expression were associated with CNAs and therefore could be considered potential drivers of this rare disease.

Citation Format: Nguyen B, Brown DN, Rothé F, Desmedt C, Majjaj S, Pruneri G, Peccatori F, Azim Jr HA, Sotiriou C. Interrogating the impact of pregnancy on breast cancer biology using DNA copy number profiling [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 P1-05-17.

RNA Sequencing to Predict Response to Neoadjuvant Anti-HER2 Therapy: A Secondary Analysis of the NeoALTTO Randomized Clinical Trial

Importance

In neoadjuvant trials, treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancers with dual HER2 blockade resulted in increased pathologic complete response (pCR) rates compared with each targeted agent alone. Amplification and/or overexpression of HER2 currently remains the only biomarker for therapeutic decisions, but it is insufficient to explain the heterogeneous response to anti-HER2 agents.

Objective

To investigate the ability of clinically and biologically relevant genes and gene signatures (GSs) measured by RNA sequencing to predict the efficacy of anti-HER2 agents.

Design, Setting, and Participants

The neoadjuvant NeoALTTO trial randomized 455 women with HER2-positive early-stage breast cancer to trastuzumab, lapatinib, or the combination for 6 weeks followed by the addition of weekly paclitaxel for 12 weeks, followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide after surgery. The present substudy, which was planned in the NeoALTTO main protocol, evaluated the association of pretreatment gene expression levels defined using RNA sequencing with pCR and event-free survival (EFS).

Main Outcomes and Measures

Gene expression-based biomarkers using RNA sequencing were examined for their association with response to anti-HER2 therapy and long-term outcome.

Results

Sequencing data were available for 254 (56%) of the NeoALTTO participants (mean [SD] age of substudy participants, 48.8 [11.2] years). The expression of ERBB2/HER2 was the most significant predictor of pCR, followed by HER2-enriched subtype, ESR1, treatment arm, ER immunohistochemical analysis scores, Genomic Grade Index, immune, proliferation, and AKT/mTOR GSs. Adjusting for clinicopathological variables and treatment arms, ERBB2/HER2, HER2-enriched subtype, ESR1, and Genomic Grade Index remained significant. Immune GSs were associated with higher pCR only in the combination arm (odds ratio, 2.1; 95% CI, 1.2-4.0; interaction test P = .01), while the stroma GSs were significantly associated with higher pCR in the single arms and with lower pCR in the combination arm (odds ratio, 0.46; 95% CI, 0.25-0.84; P = .009). None of the evaluated variables was associated with EFS after correction for multiple testing, but this analysis was underpowered.

Conclusions and Relevance

High levels of ERBB2/HER2 and low levels of ESR1 were associated with pCR in all treatment arms. In the combination arm, high expression of immune and stroma GSs were significantly associated with higher and lower pCR rates, respectively, and should be further explored as candidate predictive markers.

Trial Registration

clinicaltrials.gov Identifier: NCT00553358.

Challenges in Treating Premenopausal Women with Endocrine-Sensitive Breast Cancer

For the hundreds of thousands of premenopausal women who are diagnosed annually with endocrine-sensitive breast cancer, treatment strategies are complex. For many, chemotherapy may not be necessary, and endocrine therapy decision making is paramount. Options for adjuvant endocrine regimens include tamoxifen for 5 years, tamoxifen for 10 years, ovarian function suppression (OFS) plus tamoxifen for 5 years, and OFS plus an aromatase inhibitor for 5 years. There are modest differences in efficacy between these regimens, with a benefit from OFS most obvious among patients with higher-risk disease; therefore, choosing which should be used for a given patient requires consideration of expected toxicities and patient preferences. An aromatase inhibitor cannot be safely prescribed without OFS in this setting. Additional research is needed to determine whether genomic tests such as Prosigna and Endopredict can help with decision making about optimal duration of endocrine therapy for premenopausal patients. Endocrine therapy side effects can include hot flashes, sexual dysfunction, osteoporosis, and infertility, all of which may impair quality of life and can encourage nonadherence with treatment. Ovarian function suppression worsens menopausal side effects. Hot flashes tend to be worse with tamoxifen/OFS, whereas sexual dysfunction and osteoporosis tend to be worse with aromatase inhibitors/OFS. Pregnancy is safe after endocrine therapy, and some survivors can conceive naturally. Still, embryo or oocyte cryopreservation should be considered at the time of diagnosis for patients with endocrine-sensitive disease who desire future childbearing, particularly if they will undergo chemotherapy.

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

IMPORTANCE

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

INTERVENTIONS

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

MAIN OUTCOMES AND MEASURES

Distant recurrence-free interval (DRFI).

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: NCT00004205 and NCT00004205.

Lapatinib-Related Rash and Breast Cancer Outcome in the ALTTO Phase III Randomized Trial

BACKGROUND

Previously we have shown that early development of rash is associated with a higher chance of achieving pathological complete response to neoadjuvant lapatinib. In the current analysis, we investigate its impact on survival in the ALTTO phase III adjuvant trial.

METHODS

In ALTTO, patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer were randomly assigned to adjuvant trastuzumab, lapatinib, their sequence, or their combination for a total duration of one year. We evaluated whether the development of early lapatinib-related rash (ie, within 6 weeks) is associated with disease-free (DFS) and overall survival (OS). Landmark analysis at eight weeks and time-dependent analysis were tested in a multivariable model stratifying on trial's stratification factors. All statistical tests were two-sided.

RESULTS

Out of 6098 lapatinib-treated patients, 3973(65.2%) were included in the landmark analysis, of whom 1389 (35.0%) had developed early rash. After median follow-up of 4.5 years, the development of early rash was associated with a trend of improved DFS (multivariable: hazard ratio [HR] = 0.87, 95% confidence interval [CI] = 0.73 to 1.03,P= .10) and statistically significantly improved OS (multivariable: HR = 0.63, 95% CI = 0.48 to 0.82,P< .001) compared with subjects without early rash. Compared with patients randomly assigned to trastuzumab (n = 2051), patients who were randomly assigned to trastuzumab/lapatinib combination and developed early rash (n = 692) had superior DFS (multivariable: HR = 0.72, 95% CI = 0.55 to 0.92,P= .01) and OS (multivariable: HR = 0.59, 95% CI = 0.39 to 0.90,P= .01). Time-dependent analysis suggests that the occurrence of rash is predictive of lapatinib benefit, both when given in combination or sequential to trastuzumab.

CONCLUSIONS

Our results indicate that early development of rash identifies patients who derive superior benefit from lapatinib-based therapy.

Adjuvant chemotherapy in elderly patients with breast cancer: key challenges

Elderly women with early breast cancer (BC) form a heterogeneous and large subgroup (41.8% of women with BC are over 65). Decision making in this subgroup is made more difficult by lack of familiarity with their physical, cognitive and social issues. Adequate management depends on biological factors and accurate clinical evaluation through comprehensive geriatric assessment (CGA). CGA can help to better select and determine potential risks factors for patients who are candidates for adjuvant chemotherapy. It is still recently introduced in geriatric oncology and there is a lack of awareness of its importance. Available data on adjuvant chemotherapy for BC is limited but suggests it can be of benefit for well selected patients, though the risk of short and long-term toxicity is significant. Here we provide a discussion of the key practical issues in decision making in the setting of adjuvant chemotherapy for elderly BC patients.

The current use and attitudes towards tumor genome sequencing in breast cancer

There is increasing availability of technologies that can interrogate the genomic landscape of an individual tumor; however, their impact on daily practice remains uncertain. We conducted a 28-item survey to investigate the current attitudes towards the integration of tumor genome sequencing in breast cancer management. A link to the survey was communicated via newsletters of several oncological societies, and dedicated mailing by academic research groups. Multivariable logistic regression modeling was carried out to determine the relationship between predictors and outcomes. 215 physicians participated to the survey. The majority were medical oncologists (88%), practicing in Europe (70%) and working in academic institutions (66%). Tumor genome sequencing was requested by 82 participants (38%), of whom 21% reported low confidence in their genomic knowledge, and 56% considered tumor genome sequencing to be poorly accessible. In multivariable analysis, having time allocated to research (OR 3.37, 95% CI 1.84–6.15, p < 0.0001), working in Asia (OR 5.76, 95% CI 1.57 – 21.15, p = 0.01) and having institutional guidelines for molecular sequencing (OR 2.09, 95% 0.99–4.42, p = 0.05) were associated with a higher probability of use. In conclusion, our survey indicates that tumor genome sequencing is sometimes used, albeit not widely, in guiding management of breast cancer patients.

Abstract OT2-01-08: POSITIVE: A study evaluating pregnancy and disease outcome and safety of interrupting endocrine therapy for young women with endocrine responsive breast cancer who desire pregnancy (IBCSG 48-14/BIG 8-13)

Background

Young breast cancer (BC) patients often face the disease before completing their family planning. The best available retrospective evidence suggests that pregnancy after BC does not negatively impact disease outcome in patients with endocrine sensitive BC and is safe for the offspring. However, given the need for prolonged adjuvant endocrine therapy for 5-10 years, it is not feasible to wait until completion of therapy in most of these women and thus there is a need to explore the safety of temporary interruption of endocrine therapy to allow pregnancy. To date, no definitive prospective study has been conducted in young women desiring future pregnancy.

Trial Design

Young patients with endocrine responsive early BC and pregnancy desire will interrupt endocrine treatment for up to 2 yrs to attempt pregnancy. As resumption of menses and conception depends on many factors, e.g. patient's age and adjuvant treatment received, the 2-yr interruption period is approximate, intended to include treatment wash-out (3 mos) conception (∼3-6 mos), delivery (∼9 mos), breast feeding (∼6 mos). Patients will be strongly advised to resume ET as soon as pregnancy attempts are concluded, and to complete 5-10 yrs ET at the local investigator discretion.

Major Eligibility Criteria

-Histologically-proven stage I-III endocrine-responsive BC.

-Age ≥ 18 and ≤ 42 years at enrollment.

-Adjuvant endocrine therapy (SERM alone, GnRH analogue plus SERM or AI) for ≥18 months but ≤30 months, stopped within 1 month prior to enrollment.

-Patient wishes to become pregnant.

-Premenopausal status at BC diagnosis.

Specific Aim

To assess the risk of BC relapse associated with temporary interruption of ET to permit pregnancy and to evaluate pregnancy success.

Statistical Methods

A true risk of BC recurrence of 2% per year is assumed for patients who do not interrupt endocrine treatment. With 500 patients enrolled in 4.0 yrs and an additional 1.6 yrs of follow up, there will be approximately 1600 patient-yrs of follow up and a median follow up of approximately 3 yrs at the time of the primary analysis, anticipated to occur 5.6 yrs after enrollment of the first patient. If the true risk of BC recurrence is 2% per yr, we anticipate 31 BC recurrences and an estimated 3-yr breast cancer free interval (BCFI) failure of 5.6% (95% CI 4.0% to 7.9%).

Translational Research will investigate different ovarian function parameters; uterine evaluation; and circulating tumor DNA. FFPE tissue of the primary tumor will be collected to integrate different parameters related to biology of BC arising in young women. All material will be banked centrally.

Psycho-oncological Companion Study on fertility concerns, psychological well-being and decisional conflicts is mandatory in the United States and open to interested centers elsewhere.

Accrual: Target: 500; Actual: 4 (31 May 2015)

Contact Information

POSITIVE is conducted and sponsored by the International Breast Cancer Study Group. Alliance for Clinical Trials in Oncology is US sponsor for NCTN network. Contact Trial Coordinators at ibcsg48_positive@fstrf.org.

Citation Format: Pagani O, Partridge A, Azim Jr HA, Peccatori FA, Ruggeri M, Sun Z. POSITIVE: A study evaluating pregnancy and disease outcome and safety of interrupting endocrine therapy for young women with endocrine responsive breast cancer who desire pregnancy (IBCSG 48-14/BIG 8-13). [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 OT2-01-08.

Abstract PD5-07: The impact of early lapatinib-induced rash on disease-free and overall survival in patients treated within the ALTTO phase III randomized trial

Background: We have previously shown in a phase III neoadjuvant trial that early development of lapatinib-induced rash (i.e. within 6 weeks after lapatinib initiation) is independently associated with a higher chance of obtaining a pathological complete response (Azim et al; JCO 2013). In the current study, we aimed to investigate whether early lapatinib-induced rash is associated with improved survival in the context of a large phase III adjuvant trial.

Methods: This analysis is based on the ALTTO trial (BIG 2-06, Alliance N063D), in which patients with HER2-positive early breast cancer were randomized to adjuvant trastuzumab, lapatinib, their sequence or their combination for a total duration of 1 year. In this sub-study, we evaluated whether the development of rash (any grade) within 6 weeks of lapatinib initiation was associated with disease-free (DFS) and overall survival (OS). All analyses were tested in a multivariate model adjusted for treatment arm, treatment completion and trial stratification factors.

Results: A total of 6,098 lapatinib-treated patients were included in the current analysis; of whom 2,006 patients (32.9%) developed early lapatinib-induced rash, 1,025 (16.8%) developed rash after 6 weeks and 3,067 (50.3%) did not develop rash. No differences in patient characteristics were observed between the three groups apart from a higher frequency of younger patients (≤ 50) in the early rash group (54% vs. 47% and 44%, p&lt;0.0001). At a median follow-up of 4.5 years, 876 (14.37%) and 377 (6.18%) patients in the lapatinib containing arms experienced a DFS and OS event, respectively. In a multivariate analysis confined to patients randomized to the lapatinib containing arms, the development of early rash was associated with improved DFS (HR: 0.80; 95%CI: 0.69-0.93, p=0.004) and OS (HR: 0.61; 95%CI: 0.48 - 0.78, p&lt;0.001) compared to patients who did not develop early rash, with no interaction according to patient's age (p=0.9). No significant association was observed between the development of rash after 6 weeks of lapatinib initiation and survival. Compared to patients randomized to the trastuzumab alone arm (n=2,076), patients who developed early rash in the sequence (n=580) or combination (n=704) arms of trastuzumab/lapatinib had superior DFS (Sequence: HR 0.75 [95% CI: 0.58 – 0.98], p=0.034; Combination: HR 0.69 [95% CI: 0.54 – 0.89], p=0.005) and OS (Sequence: HR 0.57 [95%CI: 0.36 – 0.88], p=0.012; Combination: HR 0.59 [95% CI: 0.39 – 0.89], p=0.011). On the other hand, patients randomized to the lapatinib only arm who developed early rash (n=722) still had inferior DFS (HR 1.28 [95% CI: 1.04 – 1.59], p=0.02) with no difference in OS (HR: 0.95; 95%CI: 0.67 – 1.35, p=0.79) compared to patients randomized to the trastuzumab alone arm.

Conclusions: The results support our previous findings in the neoadjuvant setting that early development of skin rash within the first 6 weeks can identify patients who derive superior benefit of lapatinib treatment.

Citation Format: Azim Jr HA, Sonnenblick A, Agbor-Tarh D, Bradbury I, Daly F, Huang Y, Dueck AC, Pritchard K, Wolff AC, Jackisch C, Lang I, Untch M, Smith I, Boyle F, Xu B, Gomez H, Perez E, Piccart M, de Azambuja E. The impact of early lapatinib-induced rash on disease-free and overall survival in patients treated within the ALTTO phase III randomized trial. [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 PD5-07.

Abstract P6-04-13: The role of precision medicine in "real-life" management of breast cancer patients: A survey assessing the current use and attitudes towards tumor molecular sequencing in clinical practice

Background: Personalized medicine is a rising paradigm in cancer care. The identification of pathways involved in carcinogenesis along with the development of targeted therapies has revolutionized cancer treatment. There is increasing availability of technologies that can interrogate the genomic landscape of the tumor; however, it is still uncertain whether such platforms are used in clinical practice.

Methods: We conducted a 28-item survey to investigate the current use of tumor molecular sequencing in the management of breast cancer patients. A link to the online survey was communicated via various platforms such as the European Society for Medical Oncology (ESMO) and European School of Oncology (ESO) newsletter, and via a dedicated mailing by the Breast International Group (BIG) and other academic groups. Descriptive statistical analysis and Fisher's exact tests were applied to explore potential association between the demographic characteristics and responses.

Results: A total of 211 physicians from 35 countries participated to the study between the 9 March and 3 June 2015, with 92% fully completed questionnaires. The mean age of the participants was 45 years (range 27-77). The majority of responders were medical oncologists (88%), practicing in Europe (69%) and working in academic institutions (66%). 62% (130/211) of participants had never requested tumor molecular sequencing for breast cancer patients. Working in academic institutions and having more time allocated to research were associated with the use of tumor molecular sequencing (p = 0.007 and 0.009, respectively). For the 81 participants that used tumor molecular sequencing in the past (Table 1), there was a significant association between accessibility and frequency of use (p=0.02). 92% (181/211) of participants claimed that they would probably use tumor molecular sequencing more often if it was more accessible. Lack of funding and lack of access to the technology were the main reasons for poor endorsement. 89% of participants believe that tumor molecular sequencing will play a major role in the management of breast cancer patients in the future. Current weak evidence and poor access to matched targeted therapy are the main concerns against a wider use of these platforms in clinical practice.

Table 1. Summary of replies from the 81 participants that used tumor molecular sequencing for breast cancer patientsQuestionResponseN (%)In what percentage of your breast cancer patients has tumor molecular sequencing been performed at least once?≤5%55 (68%) &gt;5%26 (32%)How often do the results lead to enrollment in a clinical trial?≤10%53 (65%) &gt;10%28 (35%)How confident are you in interpreting tumor sequencing results?Not at all/A little17 (21%) Somewhat/Highly64 (79%)Do you consider molecular sequencing platforms accessible?Not at all/A little45 (55%) Somewhat/Highly36 (45%)

Conclusion: Our survey indicates that molecular sequencing platforms are sometimes used, albeit not widely in guiding management of breast cancer patients. Poor accessibility may contribute to the low frequency of use, but lack of evidence and poor access to matched targeted therapy are also major concerns.

Citation Format: Gingras I, Sonnenblick A, Dolci S, de Azambuja E, Paesmans M, Delaloge S, Piccart MJ, Sotiriou C, Michail I, Azim Jr HA. The role of precision medicine in "real-life" management of breast cancer patients: A survey assessing the current use and attitudes towards tumor molecular sequencing in clinical practice. [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 P6-04-13.

Cancer and fertility preservation: international recommendations from an expert meeting

In the last years, thanks to the improvement in the prognosis of cancer patients, a growing attention has been given to the fertility issues. International guidelines on fertility preservation in cancer patients recommend that physicians discuss, as early as possible, with all patients of reproductive age their risk of infertility from the disease and/or treatment and their interest in having children after cancer, and help with informed fertility preservation decisions. As recommended by the American Society of Clinical Oncology and the European Society for Medical Oncology, sperm cryopreservation and embryo/oocyte cryopreservation are standard strategies for fertility preservations in male and female patients, respectively; other strategies (e.g. pharmacological protection of the gonads and gonadal tissue cryopreservation) are considered experimental techniques. However, since then, new data have become available, and several issues in this field are still controversial and should be addressed by both patients and their treating physicians.In April 2015, physicians with expertise in the field of fertility preservation in cancer patients from several European countries were invited in Genova (Italy) to participate in a workshop on the topic of "cancer and fertility preservation". A total of ten controversial issues were discussed at the conference. Experts were asked to present an up-to-date review of the literature published on these topics and the presentation of own unpublished data was encouraged. On the basis of the data presented, as well as the expertise of the invited speakers, a total of ten recommendations were discussed and prepared with the aim to help physicians in counseling their young patients interested in fertility preservation.Although there is a great interest in this field, due to the lack of large prospective cohort studies and randomized trials on these topics, the level of evidence is not higher than 3 for most of the recommendations highlighting the need of further research efforts in many areas of this field. The participation to the ongoing registries and prospective studies is crucial to acquire more robust information in order to provide evidence-based recommendations.

Genomic aberrations in young and elderly breast cancer patients

BACKGROUND

Age at breast cancer diagnosis is a known prognostic factor. Previously, several groups including ours have shown that young age at diagnosis is associated with higher prevalence of basal-like tumors and aggressive tumor phenotypes. Yet the impact of age at diagnosis on the genomic landscape of breast cancer remains unclear. In this study, we examined the pattern of somatic mutations, chromosomal copy number variations (CNVs) and transcriptomic profiles in young and elderly breast cancer patients.

METHODS

Analyses were performed on The Cancer Genome Atlas (TCGA) dataset. Patients with metastatic disease at diagnosis, classified as normal-like by PAM50 or had missing clinical information were excluded. Young patients were defined as ≤45 years of age, while elderly patients were those ≥70 years of age at breast cancer diagnosis. The remaining patients were classified as "intermediate". We evaluated the association between age at diagnosis and somatic mutations, CNV and gene expression in a logistic regression model adjusting for tumor size, nodal status, histology and breast cancer subtype. All analyses were corrected for multiple testing using the Benjamini-Hochberg approach.

RESULTS

In this study, 125, 486 and 169 patients were ≤45, 46-69 and ≥70 years of age, respectively. Older patients had more somatic mutations (n = 44 versus 35 versus 31; P = 0.0009) and more CNVs, especially in ductal tumors (P = 0.02). Eleven mutations were independently associated with age at diagnosis, of which only GATA3 was associated with young age (15.2% versus 8.2% versus 9%; P = 0.003). Only two CNV events were independently associated with age, with more chr18p losses in older patients and more chr6q27 deletions in younger ones. Younger age at diagnosis was associated with higher expression of gene signatures related to proliferation, stem cell features and endocrine resistance.

CONCLUSIONS

Age adds a layer of biological complexity beyond breast cancer molecular subtypes, classic pathological and clinical variables, worthy of further consideration in future drug development as we seek to refine therapeutic strategies in the era of personalized medicine.

Ovarian suppression using luteinizing hormone-releasing hormone agonists during chemotherapy to preserve ovarian function and fertility of breast cancer patients: a meta-analysis of randomized studies

BACKGROUND

The role of temporary ovarian suppression with luteinizing hormone-releasing hormone agonists (LHRHa) in the prevention of chemotherapy-induced premature ovarian failure (POF) is still controversial. Our meta-analysis of randomized, controlled trials (RCTs) investigates whether the use of LHRHa during chemotherapy in premenopausal breast cancer patients reduces treatment-related POF rate, increases pregnancy rate, and impacts disease-free survival (DFS).

METHODS

A literature search using PubMed, Embase, and the Cochrane Library, and the proceedings of major conferences, was conducted up to 30 April 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) for POF (i.e. POF by study definition, and POF defined as amenorrhea 1 year after chemotherapy completion) and for patients with pregnancy, as well hazard ratios (HRs) and 95% CI for DFS, were calculated for each trial. Pooled analysis was carried out using the fixed- and random-effects models.

RESULTS

A total of 12 RCTs were eligible including 1231 breast cancer patients. The use of LHRHa was associated with a significant reduced risk of POF (OR 0.36, 95% CI 0.23-0.57; P < 0.001), yet with significant heterogeneity (I(2) = 47.1%, Pheterogeneity = 0.026). In eight studies reporting amenorrhea rates 1 year after chemotherapy completion, the addition of LHRHa reduced the risk of POF (OR 0.55, 95% CI 0.41-0.73, P < 0.001) without heterogeneity (I(2) = 0.0%, Pheterogeneity = 0.936). In five studies reporting pregnancies, more patients treated with LHRHa achieved pregnancy (33 versus 19 women; OR 1.83, 95% CI 1.02-3.28, P = 0.041; I(2) = 0.0%, Pheterogeneity = 0.629). In three studies reporting DFS, no difference was observed (HR 1.00, 95% CI 0.49-2.04, P = 0.939; I(2) = 68.0%, Pheterogeneity = 0.044).

CONCLUSION

Temporary ovarian suppression with LHRHa in young breast cancer patients is associated with a reduced risk of chemotherapy-induced POF and seems to increase the pregnancy rate, without an apparent negative consequence on prognosis.