Abstract P1-07-17: The SCAN-B study: 5-year summary of a large-scale population-based prospective breast cancer translational genomics platform covering a wide geography of Sweden (NCT02306096)

Background:

Breast cancer exhibits significant molecular, pathological, and clinical heterogeneity. Current clinicopathological evaluation is imperfect for predicting outcome, which results in overtreatment for many patients, and for others, leads to death from recurrent disease. Therefore, additional criteria are needed to better personalize care and maximize treatment effectiveness and survival. To address these challenges, large-scale population-based studies are needed to develop and evaluate new predictive biomarker tests under real-world conditions.

Methods:

In 2010 we initiated the Sweden Cancerome Analysis Network - Breast (SCAN-B) multicenter prospective study (ClinicalTrials.gov identifier NCT02306096) with longsighted aims to 1) analyze breast cancers with next-generation genomic technologies for translational research in a population-based manner and integrated with healthcare; 2) decipher fundamental tumor biology from these analyses; 3) utilize genomic data to develop and validate new clinically-actionable biomarker assays; and 4) establish real-time clinical implementation of molecular diagnostic and treatment-predictive tests. Eligibility criteria are suspicion or confirmed diagnosis of primary breast cancer. Eligibility will be extended to recurrent breast cancer in late 2016. For all patients, tumor biopsy and/or surgical tumor specimen and baseline blood samples are collected, as well as follow-up blood samples at defined intervals, and clinical data are obtained from regional and national databases. From all samples, DNA, RNA, and protein fractions are isolated, and tissue arrays are constructed. In the first phase, we focus on molecular profiling of tumor tissue by next-generation RNA-sequencing.

Results:

From August 2010 through May 2016, we have consented and enrolled 8,669 patients with primary breast cancer at 9 hospital sites in Sweden, representing approximately 85% of eligible patients in the catchment area. Preoperative blood samples have been collected for 8,288 (96%) patients and primary fresh-frozen tumor specimens collected for 6,129 (71%) patients. All tumors have been RNA-sequenced, and newly enrolled cases are analyzed in “real-time” within an average of 7 days after biopsy/surgery. Herein we describe the study infrastructure and protocols and present initial proof of concept results from prospective RNA-sequencing including tumor molecular subtyping, detection of driver gene mutations, and determination of ER, PgR, HER2, Ki67, and tumor grade from RNA-seq data. Prospective patient enrollment is ongoing and pilot clinical reports are being evaluated at multidisciplinary breast cancer conferences.

Conclusions:

We demonstrate that population-based collection and real-time RNA-sequencing analysis of breast cancer is feasible at large-scale. The SCAN-B Study should significantly reduce the time to discovery, validation, and clinical implementation of novel molecular diagnostic and predictive tests. We welcome the participation of additional comprehensive cancer treatment centers.

Citation Format: Saal LH, Hegardt C, Vallon-Christersson J, Häkkinen J, Ehinger A, Manjer J, Larsson C, Loman N, Rydén L, Malmberg M, Borg Å. The SCAN-B study: 5-year summary of a large-scale population-based prospective breast cancer translational genomics platform covering a wide geography of Sweden (NCT02306096) [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 P1-07-17.

Abstract P3-09-01: BRCAsearch - results of population-based screening of BRCA1 and BRCA2 germline mutations in incident breast cancer in South Sweden

Increasing evidence supports the benefit of identifying the BRCA1 and BRCA2 germline mutation status in early breast cancer. Germline mutations in these two genes are treatment predictive for the benefit of risk reducing surgical interventions of the contralateral breast and the ovaries and fallopian tubes, in early breast cancer (Metcalf 2014; Domchek 2010). Furthermore, they may possibly also be treatment predictive for the effect of certain types of medical interventions (Tutt SABCS 2014).

In order to provide the patient with the opportunity to take BRCA test results into account already when planning primary treatment, BRCA testing and cancer genetic counseling needs to be initiated and performed early during the diagnostic and treatment related process in newly diagnosed breast cancer cases. Special attention needs to be taken to the fact that the test results may affect not only the patient, but also her or his relatives. We have observed that the clinical efficacy of BRCA-screening criteria may be surprisingly low, leaving a substantial number of BRCA-carriers undetected in spite of intense contacts with health care providers (Unpublished results).

BRCAsearch (ClinicalTrials.gov Identifier: NCT02557776) is a population based study including new invasive breast cancer cases at three hospitals in the South of Sweden. Patients are invited to perform BRCA1 and BRCA2 germline mutation analysis at time of primary treatment after written study information and written genetic counseling, irrespective of family history, age or clinical phenotype. The primary end-points of the study include the rate of BRCA mutations in newly diagnosed breast cancer in South Sweden, the fraction of patients that accept inclusion in the study, and the rate of mutation positive patients that do not fulfill clinical criteria for BRCA mutation screening. Secondary end-points include the perception among patient of the intervention and testing procedures, the types of questions the patients present during the process and psychosocial outcome among carriers and non-carriers.

In May 2016 about 400 patients have been included in the study, whereof 333 have been analyzed for BRCA germline mutations. The accrual target of the study is 500 patients, which will be reached during the fall of 2016. At the meeting, the BRCA1 and BRCA2 mutation rates will be presented, as well as the acceptance rate of the study among patients approached, and the fraction of mutation positive patients that do not fulfill current BRCA1 and BRCA2 mutation screening criteria, and whose positive mutation status therefore would have been missed if clinical selection criteria had been applied.

The results of the study will be used to define selection criteria for BRCA-mutation screening in new breast cancer cases, and the design of screening procedures with an appropriate clinical effectiveness.Increasing evidence supports the benefit of identifying the BRCA1 and BRCA2 germline mutation status in early breast cancer. Germline mutations in these two genes are treatment predictive for the benefit of risk reducing surgical interventions of the contralateral breast and the ovaries and fallopian tubes, in early breast cancer (Metcalf 2014; Domchek 2010). Furthermore, they may possibly also be treatment predictive for the effect of certain types of medical interventions (Tutt SABCS 2014).

In order to provide the patient with the opportunity to take BRCA test results into account already when planning primary treatment, BRCA testing and cancer genetic counseling needs to be initiated and performed early during the diagnostic and treatment related process in newly diagnosed breast cancer cases. Special attention needs to be taken to the fact that the test results may affect not only the patient, but also her or his relatives. We have observed that the clinical efficacy of BRCA-screening criteria may be surprisingly low, leaving a substantial number of BRCA-carriers undetected in spite of intense contacts with health care providers (Unpublished results).

BRCAsearch (ClinicalTrials.gov Identifier: NCT02557776) is a population based study including new invasive breast cancer cases at three hospitals in the South of Sweden. Patients are invited to perform BRCA1 and BRCA2 germline mutation analysis at time of primary treatment after written study information and written genetic counseling, irrespective of family history, age or clinical phenotype. The primary end-points of the study include the rate of BRCA mutations in newly diagnosed breast cancer in South Sweden, the fraction of patients that accept inclusion in the study, and the rate of mutation positive patients that do not fulfill clinical criteria for BRCA mutation screening. Secondary end-points include the perception among patient of the intervention and testing procedures, the types of questions the patients present during the process and psychosocial outcome among carriers and non-carriers.

In May 2016 about 400 patients have been included in the study, whereof 333 have been analyzed for BRCA germline mutations. The accrual target of the study is 500 patients, which will be reached during the fall of 2016. At the meeting, the BRCA1 and BRCA2 mutation rates will be presented, as well as the acceptance rate of the study among patients approached, and the fraction of mutation positive patients that do not fulfill current BRCA1 and BRCA2 mutation screening criteria, and whose positive mutation status therefore would have been missed if clinical selection criteria had been applied.

The results of the study will be used to define selection criteria for BRCA-mutation screening in new breast cancer cases, and the design of screening procedures with an appropriate clinical effectiveness.

Citation Format: Loman N, Borg Å, Henriksson K, Kristoffersson U, Kvist A, Silfverberg B, Törngren T, Brandberg Y, Nilsson M. BRCAsearch - results of population-based screening of BRCA1 and BRCA2 germline mutations in incident breast cancer in South Sweden [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 P3-09-01.

Association of breast cancer risk in BRCA1 and BRCA2 mutation carriers with genetic variants showing differential allelic expression: identification of a modifier of breast cancer risk at locus 11q22.3

PURPOSE

Cis-acting regulatory SNPs resulting in differential allelic expression (DAE) may, in part, explain the underlying phenotypic variation associated with many complex diseases. To investigate whether common variants associated with DAE were involved in breast cancer susceptibility among BRCA1 and BRCA2 mutation carriers, a list of 175 genes was developed based of their involvement in cancer-related pathways.

METHODS

Using data from a genome-wide map of SNPs associated with allelic expression, we assessed the association of ~320 SNPs located in the vicinity of these genes with breast and ovarian cancer risks in 15,252 BRCA1 and 8211 BRCA2 mutation carriers ascertained from 54 studies participating in the Consortium of Investigators of Modifiers of BRCA1/2.

RESULTS

We identified a region on 11q22.3 that is significantly associated with breast cancer risk in BRCA1 mutation carriers (most significant SNP rs228595 p = 7 × 10-6). This association was absent in BRCA2 carriers (p = 0.57). The 11q22.3 region notably encompasses genes such as ACAT1, NPAT, and ATM. Expression quantitative trait loci associations were observed in both normal breast and tumors across this region, namely for ACAT1, ATM, and other genes. In silico analysis revealed some overlap between top risk-associated SNPs and relevant biological features in mammary cell data, which suggests potential functional significance.

CONCLUSION

We identified 11q22.3 as a new modifier locus in BRCA1 carriers. Replication in larger studies using estrogen receptor (ER)-negative or triple-negative (i.e., ER-, progesterone receptor-, and HER2-negative) cases could therefore be helpful to confirm the association of this locus with breast cancer risk.

Inheritance of deleterious mutations at both BRCA1 and BRCA2 in an international sample of 32,295 women

BACKGROUND

Most BRCA1 or BRCA2 mutation carriers have inherited a single (heterozygous) mutation. Transheterozygotes (TH) who have inherited deleterious mutations in both BRCA1 and BRCA2 are rare, and the consequences of transheterozygosity are poorly understood.

METHODS

From 32,295 female BRCA1/2 mutation carriers, we identified 93 TH (0.3 %). "Cases" were defined as TH, and "controls" were single mutations at BRCA1 (SH1) or BRCA2 (SH2). Matched SH1 "controls" carried a BRCA1 mutation found in the TH "case". Matched SH2 "controls" carried a BRCA2 mutation found in the TH "case". After matching the TH carriers with SH1 or SH2, 91 TH were matched to 9316 SH1, and 89 TH were matched to 3370 SH2.

RESULTS

The majority of TH (45.2 %) involved the three common Jewish mutations. TH were more likely than SH1 and SH2 women to have been ever diagnosed with breast cancer (BC; p = 0.002). TH were more likely to be diagnosed with ovarian cancer (OC) than SH2 (p = 0.017), but not SH1. Age at BC diagnosis was the same in TH vs. SH1 (p = 0.231), but was on average 4.5 years younger in TH than in SH2 (p < 0.001). BC in TH was more likely to be estrogen receptor (ER) positive (p = 0.010) or progesterone receptor (PR) positive (p = 0.013) than in SH1, but less likely to be ER positive (p < 0.001) or PR positive (p = 0.012) than SH2. Among 15 tumors from TH patients, there was no clear pattern of loss of heterozygosity (LOH) for BRCA1 or BRCA2 in either BC or OC.

CONCLUSIONS

Our observations suggest that clinical TH phenotypes resemble SH1. However, TH breast tumor marker characteristics are phenotypically intermediate to SH1 and SH2.

Targeted sequencing of BRCA1 and BRCA2 across a large unselected breast cancer cohort suggests that one-third of mutations are somatic

We carried out targeted sequencing of BRCA1/2 in an unselected cohort of patients diagnosed with primary breast cancer within a population without strong founder mutations. Eleven percent of cases harbored a germline or somatic BRCA1/2 mutation, and the ratio of germline versus somatic mutation was 2 : 1. This has implications for treatment, genetic counseling, and interpretation of tumor-only testing.

Background

A mutation found in the BRCA1 or BRCA2 gene of a breast tumor could be either germline or somatically acquired. The prevalence of somatic BRCA1/2 mutations and the ratio between somatic and germline BRCA1/2 mutations in unselected breast cancer patients are currently unclear.

Patients and methods

Paired normal and tumor DNA was analyzed for BRCA1/2 mutations by massively parallel sequencing in an unselected cohort of 273 breast cancer patients from south Sweden.

Results

Deleterious germline mutations in BRCA1 (n = 10) or BRCA2 (n = 10) were detected in 20 patients (7%). Deleterious somatic mutations in BRCA1 (n = 4) or BRCA2 (n = 5) were detected in 9 patients (3%). Accordingly, about 1 in 9 breast carcinomas (11%) in our cohort harbor a BRCA1/2 mutation. For each gene, the tumor phenotypes were very similar regardless of the mutation being germline or somatically acquired, whereas the tumor phenotypes differed significantly between wild-type and mutated cases. For age at diagnosis, the patients with somatic BRCA1/2 mutations resembled the wild-type patients (median age at diagnosis, germline BRCA1: 41.5 years; germline BRCA2: 49.5 years; somatic BRCA1/2: 65 years; wild-type BRCA1/2: 62.5 years).

Conclusions

In a population without strong germline founder mutations, the likelihood of a BRCA1/2 mutation found in a breast carcinoma being somatic was ∼1/3 and germline 2/3. This may have implications for treatment and genetic counseling.

Abstract OT2-05-01: BRCAsearch: A population based prospective study on screening for BRCA1 and BRCA2 germline mutations in patients with newly diagnosed breast cancer treated in southern Sweden

The overall purpose of the study BRCAsearch is to evaluate a new method for offering mutation analysis of BRCA1 and BRCA2 to all patients with newly diagnosed breast cancer.

Patients with breast cancer in southern Sweden are offered inclusion in the SCAN-B study at the time of diagnosis pre-surgery. If they consent, a part of the tumor is sent to a lab in Lund, Sweden, for research purposes (RNA sequencing etc.). Patients that are included in the SCAN-B study are eligible for inclusion in BRCAsearch.

Summary of study procedure for BRCAsearch:

1.An envelope with written information is given to the patient at the visit to the surgeon the week after surgery. This envelope contains a written genetic counseling, information about the study, an informed consent form, psychosocial questionnaires and contact information to a genetic counsellor and psycisians responsible for the study (telephone, e-mail). The patient can contact a genetic counselor for pre-test telephone genetic counseling if she wishes to.

2.BRCA1 and BRCA2 are analyzed.

3.Non-carriers are informed about the test result with a letter. Mutation carriers and VUS (variants of uncertain significance) are telephoned and given a time for an appointment at the Department of Clinical Genetics.

4.Psychosocial self-reported questionnaires are delivered at 3 times over a year.

Inclusion criteria (all):

1.The patient is included in the SCAN-B study.

2.The patient is recently diagnosed with an invasive breast cancer or a ductal cancer in situ.

3.The patient has signed an informed consent form for BRCAsearch.

Exclusion criteria (any of):

1.The patient is unable to understand the written information in Swedish.

2.The patient is a psychological state, due to chronic och temporary reasons, where one could suspect that information about the study substantially could be detrimental to the psychological well-beeing.

Primary outcome measures:

• Prevalence of BRCA1/2 mutations in an unselected breast cancer cohort in southern Sweden

• Uptake of genetic testing

• Proportion of the mutation carriers that do not fulfil current criteria for genetic testing

Secondary outcome measures:

• How many of the patients that contact us for questions and what type of questions they have

• How uptake of genetic testing varies with patient, treatment, and tumor characteristics

• The patients' attitudes towards the method used for identifying mutation carriers

• The economic cost per QALY (quality-adjusted life year)

• Psychosocial comparisons between mutation carriers and non-carriers

Targeted accrual is 500 patients included in the study, which is expected to be reached by the end of 2016.

The study enrolls patients from two hospitals in southern Sweden:

1.Helsingborg Hospital (study start: Febuary 2, 2015)

2.Kristianstad Hospital (study start: March 2, 2015).

Citation Format: Nilsson MP, Borg Å, Henriksson K, Kristoffersson U, Kvist A, Silfverberg B, Törngren T, Loman N. BRCAsearch: A population based prospective study on screening for BRCA1 and BRCA2 germline mutations in patients with newly diagnosed breast cancer treated in southern Sweden. [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 OT2-05-01.

Abstract OT3-02-10: Nordic trip, a randomized phase 3 study in early triple negative breast cancer

Background: Adjuvant treatment among the heterogeneous group of triple negative breast cancers (TNBC) is still a challenge. Recently published data indicate that platinum salts may have a role in the treatment of TNBC (v Minckwitz 2014), especially in BRCA-associated cases (Tutt 2014). Subgroup analyses from two large adjuvant studies indicate that also oral capecitabine may add a significant value in this subset of BC (Lindman 2010, O'Shaughnessy, 2010).

As a planned collaboration between the nordic countries, we are currently preparing a three-armed randomized phase 3 study of the addition of carboplatin and capecitabine respectively to a chemo backbone consisting of a taxane-antracycline based treatment in both the adjuvant and the neoadjuvant setting.

Objectives: The primary endpoint will be invasive disease-free survival (IDFS). Secondary endpoints will include IDFS in subsets of TNBC, eg according to gene-expression-based subtypes of TNBC(Lehmann 2011), and BRCA-mutation status. In the cohort treated neoadjuvant, biomarkers predicting pathological response will be identified with the purpose to validate them in the adjuvant cohort.

Method: 1800 patients (pts) with early TNBC stage 1 (&gt;10 mm) - 3 will be randomized 1:1:1 to three treatment arms.

A: nab-paclitaxel (nP) followed by epirubicine-cyclophosphamide (EC)

B: nP-capecitabine followed by EC-capecitabine.

C: nP-carboplatin followed by EC

Treatment will be given either in the adjuvant or in the neoadjuvant setting, the primary endpoint will include all randomized pts from both cohorts.

Statistical considerations: We assume a 75% five-year IDFS with standard treatment (A), and that a relative reduction of the event incidence of 30% for each of the two experimental treatments (B and C) would be a clinically relevant finding (HR=0.7). In order to achieve 80% power at a 0.05 significance level for each of the two comparisons A vs. B and A vs. C, 600 patients need to be evaluated in each of the three treatment arms. Stratification factors: pre- vs postoperative treatment, nodal status and treatment site.

Citation Format: Loman N, Linderholm B, Joensuu H, Ejlertsen B, Johannsson OT, Geisler J, Bendahl P-O, Ahlgren J, Lindman H. Nordic trip, a randomized phase 3 study in early triple negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-02-10.

Efficacy and safety of olaparib monotherapy in germline BRCA1/2 mutation carriers with advanced ovarian cancer and three or more lines of prior therapy

OBJECTIVE

The efficacy and safety of olaparib, an oral poly(ADP-ribose) polymerase (PARP) inhibitor, was investigated in a subgroup of patients with germline BRCA1/2 mutated (gBRCA1/2m) advanced ovarian cancer who had received ≥3 prior lines of chemotherapy. Primary data from this Phase II study (Study 42, ClinicalTrials.govNCT01078662) have been reported previously.

METHODS

Eligible patients were treated with oral olaparib 400mg bid capsule monotherapy until disease progression according to RECIST v1.1. Objective response rate (ORR) and duration of response (DoR) were assessed for patients with measurable disease at baseline. Safety and tolerability were assessed for all patients by adverse event (AE) incidence and changes in laboratory parameters. Platinum resistance status was obtained retrospectively, and responses to olaparib evaluated.

RESULTS

In patients with gBRCA1/2m ovarian cancer, 154/193 (80%) had received ≥3 prior lines of chemotherapy, of whom 137/154 (89%) had measurable disease at baseline. ORR was 34% (46/137; 95% confidence interval [CI] 26-42) and median DoR was 7.9 (95% CI 5.6-9.6) months. ORR in platinum-resistant tumors was 30%. Median DoR for platinum-sensitive and platinum-resistant disease was similar: 8.2months (95% CI 5.6-13.5) compared with 8.0months (4.8-14.8), respectively. Six of the 193 (3%) patients had an AE with an outcome of death. None of these AEs at time of occurrence was considered causally related to olaparib.

CONCLUSION

Following ≥3 prior lines of chemotherapy, olaparib 400mg bid (capsule form) monotherapy demonstrated notable antitumor activity in patients with gBRCA1/2m advanced ovarian cancer. No new safety signals were identified.

Clinical and molecular complexity of breast cancer metastases

Clinical oncology is advancing toward a more personalized treatment orientation, making the need to understand the biology of metastasis increasingly acute. Dissecting the complex molecular, genetic and clinical phenotypes underlying the processes involved in the development of metastatic disease, which remains the principal cause of cancer-related deaths, could lead to the identification of more effective prognostication and targeted approaches to prevent and treat metastases. The past decade has witnessed significant progress in the field of cancer metastasis research. Clinical and technological milestones have been reached which have tremendously enriched our understanding of the complex pathways undertaken by primary tumors to progress into lethal metastases and how some of these processes might be amenable to therapy. The aim of this review article is to highlight the recent advances toward unraveling the clinical and molecular complexity of breast cancer metastases. We focus on genes mediating breast cancer metastases and organ-specific tropism, and discuss gene signatures for prediction of metastatic disease. The challenges of translating this information into clinically applicable tools for improving the prognostication of the metastatic potential of a primary breast tumor, as well as for therapeutic interventions against latent and active metastatic disease are addressed.

Transcriptional Profiling of Breast Cancer Metastases Identifies Liver Metastasis-Selective Genes Associated with Adverse Outcome in Luminal A Primary Breast Cancer

PURPOSE

The complete molecular basis of the organ-specificity of metastasis is elusive. This study aimed to provide an independent characterization of the transcriptional landscape of breast cancer metastases with the specific objective to identify liver metastasis-selective genes of prognostic importance following primary tumor diagnosis.

EXPERIMENTAL DESIGN

A cohort of 304 women with advanced breast cancer was studied. Associations between the site of recurrence and clinicopathologic features were investigated. Fine-needle aspirates of metastases (n = 91) were subjected to whole-genome transcriptional profiling. Liver metastasis-selective genes were identified by significance analysis of microarray (SAM) analyses and independently validated in external datasets. Finally, the prognostic relevance of the liver metastasis-selective genes in primary breast cancer was tested.

RESULTS

Liver relapse was associated with estrogen receptor (ER) expression (P = 0.002), luminal B subtype (P = 0.01), and was prognostic for an inferior postrelapse survival (P = 0.01). The major variation in the transcriptional landscape of metastases was also associated with ER expression and molecular subtype. However, liver metastases displayed unique transcriptional fingerprints, characterized by downregulation of extracellular matrix (i.e., stromal) genes. Importantly, we identified a 17-gene liver metastasis-selective signature, which was significantly and independently prognostic for shorter relapse-free (P < 0.001) and overall (P = 0.001) survival in ER-positive tumors. Remarkably, this signature remained independently prognostic for shorter relapse-free survival (P = 0.001) among luminal A tumors.

CONCLUSIONS

Extracellular matrix (stromal) genes can be used to partition breast cancer by site of relapse and may be used to further refine prognostication in ER positive primary breast cancer.

Abstract P6-08-03: Transcriptional profiling of breast cancer metastases identifies liver metastasis-selective genes associated with adverse outcome in luminal A primary breast cancer

Background: The site of relapse is associated with the prognosis of metastatic breast cancer, but our understanding of the molecular determinants of organ-specificity of metastasis is incomplete. This study aimed to provide additional insight into the biology of breast cancer liver metastases and to identify liver metastasis-selective genes associated with outcome in primary breast cancer.

Methods: A cohort of 304 women with locally advanced and metastatic breast cancer was studied. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki67 expression were quantified in primary tumors (N=217) by immunohistochemistry and in situ hybridization on tissue microarrays, and molecular subtypes were assigned according to the 2013 St Gallen guidelines. In addition, fine-needle aspirates of metastases (N=91) were subjected to whole genome transcriptional profiling.

Results: Liver relapse was significantly associated with ER positivity (P&lt;0.002) and the luminal B-like subtype (P&lt;0.01) and was prognostic of an inferior post-relapse survival (P&lt;0.001). Transcriptional profiling revealed that the major variation in the transcriptional landscape of breast cancer metastases was associated with the expression of hormone receptors and the tumor molecular subtype. However, liver metastases displayed unique transcriptional fingerprints, characterized by down-regulation of extracellular matrix (i.e. stromal) genes involved in adhesion and skeletal development. Importantly, we identified a subset of 17 liver metastasis-selective genes that displayed significantly decreased expression in primary tumors of high histological grade (grade 3) and of the luminal B and basal subtypes (P&lt;0.001). This 17-gene signature was significantly and independently prognostic of shorter relapse-free (P =0.001) and overall (P=0.03) survival among patients with ER positive primary tumors. Remarkably, the 17-gene signature remained an independent predictor of shorter relapse-free survival (P=0.004) among patients with luminal A primary tumors.

Conclusion: These results highlight a possible role of stroma-related genes in breast cancer liver metastasis biology and validate the prognostic relevance of extracellular matrix/stromal genes in hormone receptor positive primary breast cancer, specifically of the luminal A subtype.

Citation Format: Siker Kimbung, Ida Johansson, Anna Danielsson, Srinivas Veerla, Suzanne Egyhazi, Jonas Bergh, Zakaria Einbeigi, Barbro Linderholm, Elisabet Lidbrink, Niklas Loman, Per Malmström, Martin Söderberg, Thomas M Walz, Mårten Fernö, Thomas Hatschek, Ingrid Hedenfalk, the TEX Study Group. Transcriptional profiling of breast cancer metastases identifies liver metastasis-selective genes associated with adverse outcome in luminal A primary breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-03.

Abstract P3-11-14: Is pathologic complete response (pCR) a valid marker of outcome even in large breast cancer? Clinical results from a neoadjuvant trial using a combination of epirubicin, docetaxel and bevacizumab (PROMIX)

Background: Several randomized trials have proven that preoperative chemotherapy is equivalent to adjuvant treatment, and allows for clinical and radiological assessment of efficacy in vivo. Recent results show that response-guided neoadjuvant therapy is a favorable policy for hormone receptor positive tumors, while pCR predicts prognosis for triple-negative (TNBC) and HER2 positive breast cancer (von Minckwitz 2013; Cortazar 2014). Since 2012 the FDA accepts pCR (ypT0 ypN0) as endpoint for accelerated drug approval.

Methods: In total, 150 women 18 years or older with verified HER2 negative breast cancer suitable for primary medical treatment were included in the trial between September 2008 and December 2011. The patients received two courses of epirubicin and docetaxel (Taxotere®), both 75mg/m2 for the 1st two courses, followed by the same treatment with addition of bevacizumab (Avastin®) 15 mg/kg for 4 additional courses. Clinical and radiological evaluations with mammography and ultrasound were performed before start and after courses 2, 4 and 6. Core biopsies were taken before start, after 2 courses, and at time of surgery. Blood samples were drawn before and 24 hours after the first 4 courses.

Results: Median age was 49 years, range: 27 to 70 years; 73% were reported as ductal, 15% as lobular, and 12% as rare histological types. Mean tumor size was 59 mm, median 55 mm, range: 20-180 mm; 3 tumors (2.0%) were reported as inflammatory, and 13 (8.7%) presented with skin involvement (T4b). Enlarged axillary nodes were found in 102 patients (68%) before start of treatment, 77 of these (64%) verified as metastatic. SNB in cases of normal axillary status was performed in 16 cases, in 9 cases (8%) with positive finding. Supra- or infraclavicular node involvement was verified in 20 cases (13%). 25% of all tumors were ER- and/or PR-negative, tumor grade based on a diagnostic biopsy was evaluable in only 83 cases. Of these, 4 (5%) were grade I, 46 (55%) grade II, and 33 (40%) grade III. Mean proliferation count (Ki67) was 37%, median 30%, range 1-90%. Breakdown into intrinsic subtypes based on immunohistochemistry defined 68 (46%) as luminal A-like, 36 (24%) as luminal B-like, and 44 (30%) as TNBC. pCR was achieved in 20 cases, 3 (2%) luminal A-like, 5 (3.4%) luminal B-like and 12 (8.2%) TNBC. After 2.2 years of follow-up, 35 patients (23.3%) have experienced recurrence and 18 of these (12%) have deceased due to breast cancer, among these 6 despite pCR, 2 classified as luminal B-like, and 4 as TNBC. The molecular subtype of the tumor predicted outcome, but pCR was not in our material, even after adjustment for tumor size at diagnosis, a predictor of favorable outcome. The number of events in relation to molecular subtypes is however limited. Updated outcome data will be presented.

Conclusions: The present trial does not confirm previously reported observations that pCR is a marker of favorable prognosis. One possible explanation is that unfavorable biological characteristics, particularly heterogeneity, may increase with tumor burden. Genomic and proteomic analyses are currently ongoing.

Citation Format: Thomas Hatschek, Judith Bjöhle, Elisabet Lidbrink, Tobias Lekberg, Niklas Loman, Anna von Wachenfeldt Väppling, Martin Söderberg, Zakaria Einbeigi, Lena Carlsson, Henrik Lindman, Irma Fredriksson, Jan Frisell, Lars Löfgren, Lisa Rydén, Mats Hellström, Mårten Fernö, Jonas Bergh. Is pathologic complete response (pCR) a valid marker of outcome even in large breast cancer? Clinical results from a neoadjuvant trial using a combination of epirubicin, docetaxel and bevacizumab (PROMIX) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-11-14.

Abstract P2-05-02: Preliminary translational results from PROMIX, a phase II trial of preoperative chemotherapy with the addition of bevacizumab in large operable and locally advanced HER2-negative breast cancer

Background: Preoperative chemotherapy in breast cancer (bc) provides unique possibilities to evaluate effects of therapy by studying response and changes in the tumor during the course of treatment. A pathologic complete response (pCR) correlates positively with long term prognosis in high-proliferating bc. In triple negative bc (TNBC) the prognosis was still relatively serious in cases with pCR in one large meta-analysis (Cortazar Lancet 2014).

Methods: 150 cases were included in this multicenter study, and treated with six cycles of epirubicin and docetaxel, adding bevacizumab from cycle 3, before surgery. Core needle biopsies were collected at free hand or with ultrasound (US) guidance and snap frozen at base-line and after cycle 2, tissue was also collected at surgery. Subtyping was performed using immunohistochemistry (IHC) of ER, Ki67 and HER2 according to modified St Gallen criteria; and using bead array gene expression profiling (GEX) according to PAM50.

Results: Biopsies were successfully retrieved from 145/150 pts at baseline, 138 after cycle 2 and 139 at surgery. The mRNA yield was adequate for GEX from 123/145 (85%) at baseline, 82/138 (59%) at cycle 2 and 71/139 (51%) at surgery, the decrease being a result of tumor shrinkage during treatment.

Initial PAM50 subtypes were as follows: luminal A (LA) 20%, luminal B (LB) 45%, HER2 5 %, basal like (BL) 22% and normal like (NL) 8%. PAM50 at baseline differed compared to IHC subtypes. Among IHC defined LA-like cases 15/33 (45%) were classified as LB by PAM50. Similarly, among IHC LB-like 22/57 (39%) were classified as non-LB (6 basal, 8 LA, 3 HER2 and 5 NL), while among IHC TNBC 7/28 (25%) were classified as non-BL subtypes (1 LA, 3 HER2 and 3 NL).

Of the pts with a baseline GEX analysis, 17 (14%) achieved a pCR. The observed pCR rates among PAM50 subtypes were: LA 8%, LB 5%, HER2 17%, BL 53% and NL 20%. For non-pCR cases, 39/52 (75%) of the tumors changed PAM50 subtype between baseline and surgery. The majority changed to the NL subtype. 33% of the LB tumors changed to the LA subtype.

Currently, after 2.2 years of follow-up, 16 pts are deceased due to bc. Among BL cases, 6/9 pts with a pCR at surgery remain alive; while 3/9 have died from bc. Exploratory analyses using functional gene modules (Desmedt Clin Cancer Res 2008) suggest that patients with BL tumors who have died have higher scores for PLAU/invasion and lower scores for STAT1/immune response compared with those who are still alive. Tumor size at baseline did not obviously correlate with outcome.

Conclusion: We show that biological material can be retrieved from a substantial fraction of cases treated within a multicenter study of preoperative chemotherapy. The success rate may be ameliorated by routine use of US guidance. The distribution of subtypes differs between modified IHC St Gallen criteria and PAM50, especially within the luminal subtypes. The pCR rate is highest among cases with a BL tumor at baseline. Shift of the gene signature between different subtypes during the course of treatment is frequent. In this set of relatively large tumors, the prognosis among BL bc appears to be adverse in spite of a pCR.

Citation Format: Niklas Loman, Ida Johansson, Judith Bjöhle, Jan Frisell, Tobias Lekberg, Lisa Rydén, Anna von Wachenfeldt, Jonas Bergh, Thomas Hatschek, Ingrid Hedenfalk. Preliminary translational results from PROMIX, a phase II trial of preoperative chemotherapy with the addition of bevacizumab in large operable and locally advanced HER2-negative breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-05-02.

An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

INTRODUCTION

Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers.

METHODS

We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals.

RESULTS

We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk.

CONCLUSIONS

This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.

Association of type and location of BRCA1 and BRCA2 mutations with risk of breast and ovarian cancer

IMPORTANCE

Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists.

OBJECTIVE

To identify mutation-specific cancer risks for carriers of BRCA1/2.

DESIGN, SETTING, AND PARTICIPANTS

Observational study of women who were ascertained between 1937 and 2011 (median, 1999) and found to carry disease-associated BRCA1 or BRCA2 mutations. The international sample comprised 19,581 carriers of BRCA1 mutations and 11,900 carriers of BRCA2 mutations from 55 centers in 33 countries on 6 continents. We estimated hazard ratios for breast and ovarian cancer based on mutation type, function, and nucleotide position. We also estimated RHR, the ratio of breast vs ovarian cancer hazard ratios. A value of RHR greater than 1 indicated elevated breast cancer risk; a value of RHR less than 1 indicated elevated ovarian cancer risk.

EXPOSURES

Mutations of BRCA1 or BRCA2.

MAIN OUTCOMES AND MEASURES

Breast and ovarian cancer risks.

RESULTS

Among BRCA1 mutation carriers, 9052 women (46%) were diagnosed with breast cancer, 2317 (12%) with ovarian cancer, 1041 (5%) with breast and ovarian cancer, and 7171 (37%) without cancer. Among BRCA2 mutation carriers, 6180 women (52%) were diagnosed with breast cancer, 682 (6%) with ovarian cancer, 272 (2%) with breast and ovarian cancer, and 4766 (40%) without cancer. In BRCA1, we identified 3 breast cancer cluster regions (BCCRs) located at c.179 to c.505 (BCCR1; RHR = 1.46; 95% CI, 1.22-1.74; P = 2 × 10(-6)), c.4328 to c.4945 (BCCR2; RHR = 1.34; 95% CI, 1.01-1.78; P = .04), and c. 5261 to c.5563 (BCCR2', RHR = 1.38; 95% CI, 1.22-1.55; P = 6 × 10(-9)). We also identified an ovarian cancer cluster region (OCCR) from c.1380 to c.4062 (approximately exon 11) with RHR = 0.62 (95% CI, 0.56-0.70; P = 9 × 10(-17)). In BRCA2, we observed multiple BCCRs spanning c.1 to c.596 (BCCR1; RHR = 1.71; 95% CI, 1.06-2.78; P = .03), c.772 to c.1806 (BCCR1'; RHR = 1.63; 95% CI, 1.10-2.40; P = .01), and c.7394 to c.8904 (BCCR2; RHR = 2.31; 95% CI, 1.69-3.16; P = .00002). We also identified 3 OCCRs: the first (OCCR1) spanned c.3249 to c.5681 that was adjacent to c.5946delT (6174delT; RHR = 0.51; 95% CI, 0.44-0.60; P = 6 × 10(-17)). The second OCCR spanned c.6645 to c.7471 (OCCR2; RHR = 0.57; 95% CI, 0.41-0.80; P = .001). Mutations conferring nonsense-mediated decay were associated with differential breast or ovarian cancer risks and an earlier age of breast cancer diagnosis for both BRCA1 and BRCA2 mutation carriers.

CONCLUSIONS AND RELEVANCE

Breast and ovarian cancer risks varied by type and location of BRCA1/2 mutations. With appropriate validation, these data may have implications for risk assessment and cancer prevention decision making for carriers of BRCA1 and BRCA2 mutations.

Assessing associations between the AURKA-HMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers

While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood approach. The association of HMMR rs299290 with breast cancer risk in BRCA1 mutation carriers was confirmed: per-allele hazard ratio (HR) = 1.10, 95% confidence interval (CI) 1.04-1.15, p = 1.9 x 10(-4) (false discovery rate (FDR)-adjusted p = 0.043). Variation in CSTF1, located next to AURKA, was also found to be associated with breast cancer risk in BRCA2 mutation carriers: rs2426618 per-allele HR = 1.10, 95% CI 1.03-1.16, p = 0.005 (FDR-adjusted p = 0.045). Assessment of pairwise interactions provided suggestions (FDR-adjusted pinteraction values > 0.05) for deviations from the multiplicative model for rs299290 and CSTF1 rs6064391, and rs299290 and TUBG1 rs11649877 in both BRCA1 and BRCA2 mutation carriers. Following these suggestions, the expression of HMMR and AURKA or TUBG1 in sporadic breast tumors was found to potentially interact, influencing patients' survival. Together, the results of this study support the hypothesis of a causative link between altered function of AURKA-HMMR-TPX2-TUBG1 and breast carcinogenesis in BRCA1/2 mutation carriers.

The Sweden Cancerome Analysis Network - Breast (SCAN-B) Initiative: a large-scale multicenter infrastructure towards implementation of breast cancer genomic analyses in the clinical routine

BACKGROUND

Breast cancer exhibits significant molecular, pathological, and clinical heterogeneity. Current clinicopathological evaluation is imperfect for predicting outcome, which results in overtreatment for many patients, and for others, leads to death from recurrent disease. Therefore, additional criteria are needed to better personalize care and maximize treatment effectiveness and survival.

METHODS

To address these challenges, the Sweden Cancerome Analysis Network - Breast (SCAN-B) consortium was initiated in 2010 as a multicenter prospective study with longsighted aims to analyze breast cancers with next-generation genomic technologies for translational research in a population-based manner and integrated with healthcare; decipher fundamental tumor biology from these analyses; utilize genomic data to develop and validate new clinically-actionable biomarker assays; and establish real-time clinical implementation of molecular diagnostic, prognostic, and predictive tests. In the first phase, we focus on molecular profiling by next-generation RNA-sequencing on the Illumina platform.

RESULTS

In the first 3 years from 30 August 2010 through 31 August 2013, we have consented and enrolled 3,979 patients with primary breast cancer at the seven hospital sites in South Sweden, representing approximately 85% of eligible patients in the catchment area. Preoperative blood samples have been collected for 3,942 (99%) patients and primary tumor specimens collected for 2,929 (74%) patients. Herein we describe the study infrastructure and protocols and present initial proof of concept results from prospective RNA sequencing including tumor molecular subtyping and detection of driver gene mutations. Prospective patient enrollment is ongoing.

CONCLUSIONS

We demonstrate that large-scale population-based collection and RNA-sequencing analysis of breast cancer is feasible. The SCAN-B Initiative should significantly reduce the time to discovery, validation, and clinical implementation of novel molecular diagnostic and predictive tests. We welcome the participation of additional comprehensive cancer treatment centers.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02306096.

Molecular subtype and tumor characteristics of breast cancer metastases as assessed by gene expression significantly influence patient post-relapse survival

BACKGROUND

We and others have recently shown that tumor characteristics are altered throughout tumor progression. These findings emphasize the need for re-examination of tumor characteristics at relapse and have led to recommendations from ESMO and the Swedish Breast Cancer group. Here, we aim to determine whether tumor characteristics and molecular subtypes in breast cancer metastases confer clinically relevant prognostic information for patients.

PATIENTS AND METHODS

The translational aspect of the Swedish multicenter randomized trial called TEX included 111 patients with at least one biopsy from a morphologically confirmed locoregional or distant breast cancer metastasis diagnosed from December 2002 until June 2007. All patients had detailed clinical information, complete follow-up, and metastasis gene expression information (Affymetrix array GPL10379). We assessed the previously published gene expression modules describing biological processes [proliferation, apoptosis, human epidermal receptor 2 (HER2) and estrogen (ER) signaling, tumor invasion, immune response, and angiogenesis] and pathways (Ras, MAPK, PTEN, AKT-MTOR, PI3KCA, IGF1, Src, Myc, E2F3, and β-catenin) and the intrinsic subtypes (PAM50). Furthermore, by contrasting genes expressed in the metastases in relation to survival, we derived a poor metastasis survival signature.

RESULTS

A significant reduction in post-relapse breast cancer-specific survival was associated with low-ER receptor signaling and apoptosis gene module scores, and high AKT-MTOR, Ras, and β-catenin module scores. Similarly, intrinsic subtyping of the metastases provided statistically significant post-relapse survival information with the worst survival outcome in the basal-like [hazard ratio (HR) 3.7; 95% confidence interval (CI) 1.3-10.9] and HER2-enriched (HR 4.4; 95% CI 1.5-12.8) subtypes compared with the luminal A subtype. Overall, 25% of the metastases were basal-like, 32% HER2-enriched, 10% luminal A, 28% luminal B, and 5% normal-like.

CONCLUSIONS

We show that tumor characteristics and molecular subtypes of breast cancer metastases significantly influence post-relapse patient survival, emphasizing that molecular investigations at relapse provide prognostic and clinically relevant information. CLINICALTRIALS.GOV: This is the translational part of the Swedish multicenter and randomized trial TEX, clinicaltrials.gov identifier nct01433614 (http://www.clinicaltrials.gov/ct2/show/nct01433614).

Associations of common breast cancer susceptibility alleles with risk of breast cancer subtypes in BRCA1 and BRCA2 mutation carriers

INTRODUCTION

More than 70 common alleles are known to be involved in breast cancer (BC) susceptibility, and several exhibit significant heterogeneity in their associations with different BC subtypes. Although there are differences in the association patterns between BRCA1 and BRCA2 mutation carriers and the general population for several loci, no study has comprehensively evaluated the associations of all known BC susceptibility alleles with risk of BC subtypes in BRCA1 and BRCA2 carriers.

METHODS

We used data from 15,252 BRCA1 and 8,211 BRCA2 carriers to analyze the associations between approximately 200,000 genetic variants on the iCOGS array and risk of BC subtypes defined by estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and triple-negative- (TN) status; morphologic subtypes; histological grade; and nodal involvement.

RESULTS

The estimated BC hazard ratios (HRs) for the 74 known BC alleles in BRCA1 carriers exhibited moderate correlations with the corresponding odds ratios from the general population. However, their associations with ER-positive BC in BRCA1 carriers were more consistent with the ER-positive associations in the general population (intraclass correlation (ICC) = 0.61, 95% confidence interval (CI): 0.45 to 0.74), and the same was true when considering ER-negative associations in both groups (ICC = 0.59, 95% CI: 0.42 to 0.72). Similarly, there was strong correlation between the ER-positive associations for BRCA1 and BRCA2 carriers (ICC = 0.67, 95% CI: 0.52 to 0.78), whereas ER-positive associations in any one of the groups were generally inconsistent with ER-negative associations in any of the others. After stratifying by ER status in mutation carriers, additional significant associations were observed. Several previously unreported variants exhibited associations at P <10(-6) in the analyses by PR status, HER2 status, TN phenotype, morphologic subtypes, histological grade and nodal involvement.

CONCLUSIONS

Differences in associations of common BC susceptibility alleles between BRCA1 and BRCA2 carriers and the general population are explained to a large extent by differences in the prevalence of ER-positive and ER-negative tumors. Estimates of the risks associated with these variants based on population-based studies are likely to be applicable to mutation carriers after taking ER status into account, which has implications for risk prediction.

Olaparib monotherapy in patients with advanced cancer and a germline BRCA1/2 mutation

PURPOSE

Olaparib is an oral poly (ADP-ribose) polymerase inhibitor with activity in germline BRCA1 and BRCA2 (BRCA1/2) -associated breast and ovarian cancers. We evaluated the efficacy and safety of olaparib in a spectrum of BRCA1/2-associated cancers.

PATIENTS AND METHODS

This multicenter phase II study enrolled individuals with a germline BRCA1/2 mutation and recurrent cancer. Eligibility included ovarian cancer resistant to prior platinum; breast cancer with ≥ three chemotherapy regimens for metastatic disease; pancreatic cancer with prior gemcitabine treatment; or prostate cancer with progression on hormonal and one systemic therapy. Olaparib was administered at 400 mg twice per day. The primary efficacy end point was tumor response rate.

RESULTS

A total of 298 patients received treatment and were evaluable. The tumor response rate was 26.2% (78 of 298; 95% CI, 21.3 to 31.6) overall and 31.1% (60 of 193; 95% CI, 24.6 to 38.1), 12.9% (eight of 62; 95% CI, 5.7 to 23.9), 21.7% (five of 23; 95% CI, 7.5 to 43.7), and 50.0% (four of eight; 95% CI, 15.7 to 84.3) in ovarian, breast, pancreatic, and prostate cancers, respectively. Stable disease ≥ 8 weeks was observed in 42% of patients (95% CI, 36.0 to 47.4), including 40% (95% CI, 33.4 to 47.7), 47% (95% CI, 34.0 to 59.9), 35% (95% CI, 16.4 to 57.3), and 25% (95% CI, 3.2 to 65.1) of those with ovarian, breast, pancreatic, or prostate cancer, respectively. The most common adverse events (AEs) were fatigue, nausea, and vomiting. Grade ≥ 3 AEs were reported for 54% of patients; anemia was the most common (17%).

CONCLUSION

Responses to olaparib were observed across different tumor types associated with germline BRCA1/2 mutations. Olaparib warrants further investigation in confirmatory studies.