Longitudinal profiling identifies co-occurring BRCA1/2 reversions, TP53BP1, RIF1 and PAXIP1 mutations in PARP inhibitor-resistant advanced breast cancer.

BACKGROUND: Resistance to therapies that target homologous recombination deficiency (HRD) in breast cancer limits their overall effectiveness. Multiple, preclinically validated, mechanisms of resistance have been proposed, but their existence and relative frequency in clinical disease are unclear, as is how to target resistance. PATIENTS AND METHODS: Longitudinal mutation and methylation profiling of circulating tumour (ct)DNA was carried out in 47 patients with metastatic BRCA1-, BRCA2- or PALB2-mutant breast cancer treated with HRD-targeted therapy who developed progressive disease-18 patients had primary resistance and 29 exhibited response followed by resistance. ctDNA isolated at multiple time points in the patient treatment course (before, on-treatment and at progression) was sequenced using a novel >750-gene intron/exon targeted sequencing panel. Where available, matched tumour biopsies were whole exome and RNA sequenced and also used to assess nuclear RAD51. RESULTS: BRCA1/2 reversion mutations were present in 60% of patients and were the most prevalent form of resistance. In 10 cases, reversions were detected in ctDNA before clinical progression. Two new reversion-based mechanisms were identified: (i) intragenic BRCA1/2 deletions with intronic breakpoints; and (ii) intragenic BRCA1/2 secondary mutations that formed novel splice acceptor sites, the latter being confirmed by in vitro minigene reporter assays. When seen before commencing subsequent treatment, reversions were associated with significantly shorter time to progression. Tumours with reversions retained HRD mutational signatures but had functional homologous recombination based on RAD51 status. Although less frequent than reversions, nonreversion mechanisms [loss-of-function (LoF) mutations in TP53BP1, RIF1 or PAXIP1] were evident in patients with acquired resistance and occasionally coexisted with reversions, challenging the notion that singular resistance mechanisms emerge in each patient. CONCLUSIONS: These observations map the prevalence of candidate drivers of resistance across time in a clinical setting, information with implications for clinical management and trial design in HRD breast cancers.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer.

BACKGROUND: The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety. PATIENTS AND METHODS: One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015. RESULTS: With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome. CONCLUSION: With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Post-hematopoietic stem cell transplant squamous cell carcinoma in patients with Fanconi anemia: a dreadful enemy.

INTRODUCTION: Hematopoietic stem cell transplantation (HSCT) is a curative option for patients with Fanconi anemia (FA) and hematological manifestations but it does not prevent solid tumors, especially squamous cell carcinomas (SCC). METHODS: Retrospective study in 22 FA patients who had received HSCT and had been followed up beyond 2 years after HSCT. RESULTS: The median follow-up was 15 years. Six patients developed head-and-neck SCC after transplantation. The cumulative incidence of SCC at 15 and 30 years from the HSCT was 14.2% and 71.2%, respectively. One patient was diagnosed in stage IV and the rest, who were being followed up in cancer screening programs, in stage I. Treatment of SCC consisted of surgery in all patients; radiotherapy and chemotherapy were used in two patients and were poorly tolerated. CONCLUSION: FA patients have high risk of head-and-neck SCC. Multi-disciplinary programs for early cancer detection are of special relevance in these patients.

Safety of assisted reproductive techniques in young women harboring germline pathogenic variants in BRCA1/2 with a pregnancy after prior history of breast cancer.

BACKGROUND: Knowledge is growing on the safety of assisted reproductive techniques (ART) in cancer survivors. No data exist, however, for the specific population of breast cancer patients harboring germline BRCA1/2 pathogenic variants. PATIENTS AND METHODS: This is a multicenter retrospective cohort study across 30 centers worldwide including women diagnosed at ≤40 years with stage I-III breast cancer, between January 2000 and December 2012, harboring known germline BRCA1/2 pathogenic variants. Patients included in this analysis had a post-treatment pregnancy either achieved through use of ART (ART group) or naturally (non-ART group). ART procedures included ovulation induction, ovarian stimulation for in vitro fertilization or intracytoplasmic sperm injection, and embryo transfer under hormonal replacement therapy. RESULTS: Among the 1424 patients registered in the study, 168 were eligible for inclusion in the present analysis, of whom 22 were in the ART group and 146 in the non-ART group. Survivors in the ART group conceived at an older age compared with those in the non-ART group (median age: 39.7 versus 35.4 years, respectively). Women in the ART group experienced more delivery complications compared with those in the non-ART group (22.1% versus 4.1%, respectively). No other apparent differences in obstetrical outcomes were observed between cohorts. The median follow-up from pregnancy was 3.4 years (range: 0.8-8.6 years) in the ART group and 5.0 years (range: 0.8-17.6 years) in the non-ART group. Two patients (9.1%) in the ART group experienced a disease-free survival event (specifically, a locoregional recurrence) compared with 40 patients (27.4%) in the non-ART group. In the ART group, no patients deceased compared with 10 patients (6.9%) in the non-ART group. CONCLUSION: This study provides encouraging safety data on the use of ART in breast cancer survivors harboring germline pathogenic variants in BRCA1/2, when natural conception fails or when they opt for ART in order to carry out preimplantation genetic testing.

Association of RAD51 with homologous recombination deficiency (HRD) and clinical outcomes in untreated triple-negative breast cancer (TNBC): analysis of the GeparSixto randomized clinical trial.

BACKGROUND: Current genetic and genomic tests measuring homologous recombination deficiency (HRD) show limited predictive value. This study compares the performance of an immunohistology-based RAD51 test with genetic/genomic tests to identify patients with HRD primary triple-negative breast cancer (TNBC) and evaluates its accuracy to select patients sensitive to platinum-based neoadjuvant chemotherapy (NACT). PATIENTS AND METHODS: This is a retrospective, blinded, biomarker analysis from the GeparSixto randomized clinical trial. TNBC patients received neoadjuvant paclitaxel plus Myocet®-nonpegylated liposomal doxorubicin (PM) or PM plus carboplatin (PMCb), both arms including bevacizumab. Formalin-fixed paraffin-embedded (FFPE) tumor samples were laid on tissue microarrays. RAD51, BRCA1 and γH2AX were quantified using an immunofluorescence assay. The predictive value of RAD51 was assessed by regression models. Concordance analyses were carried out between RAD51 score and tumor BRCA (tBRCA) status or genomic HRD score (Myriad myChoice®). Associations with pathological complete response (pCR) and survival were studied. Functional HRD was predefined as a RAD51 score ≤10% (RAD51-low). RESULTS: Functional HRD by RAD51-low was evidenced in 81/133 tumors (61%). RAD51 identified 93% tBRCA-mutated tumors and 45% non-tBRCA mutant cases as functional HRD. The concordance between RAD51 and genomic HRD was 87% [95% confidence interval (CI) 79% to 93%]. In patients with RAD51-high tumors, pCR was similar between treatment arms [PMCb 31% versus PM 39%, odds ratio (OR) 0.71, 0.23-2.24, P = 0.56]. Patients with RAD51-low tumors benefited from PMCb (pCR 66% versus 33%, OR 3.96, 1.56-10.05, P = 0.004; interaction test P = 0.02). This benefit maintained statistical significance in the multivariate analysis. Carboplatin addition showed similar disease-free survival in the RAD51-high [hazard ratio (HR) 0.40, log-rank P = 0.11] and RAD51-low (0.45, P = 0.11) groups. CONCLUSIONS: The RAD51 test identifies tumors with functional HRD and is highly concordant with tBRCA mutation and genomic HRD. RAD51 independently predicts clinical benefit from adding Cb to NACT in TNBC. Our results support further development to incorporate RAD51 testing in clinical decision-making.

Olaparib monotherapy as primary treatment in unselected triple negative breast cancer.

BACKGROUND: The antitumor efficacy of PARP inhibitors (PARPi) for breast cancer patients harboring germline BRCA1/2 (gBRCA1/2) mutations is well established. While PARPi monotherapy was ineffective in patients with metastatic triple negative breast cancer (TNBC) wild type for BRCA1/2, we hypothesized that PARPi may be effective in primary TNBCs without previous chemotherapy exposure. PATIENTS AND METHODS: In the phase II PETREMAC trial, patients with primary TNBC >2 cm received olaparib for up to 10 weeks before chemotherapy. Tumor biopsies collected before and after olaparib underwent targeted DNA sequencing (360 genes) and BRCA1 methylation analyses. In addition, BRCAness (multiplex ligation-dependent probe amplification), PAM50 gene expression, RAD51 foci, tumor-infiltrating lymphocytes (TILs) and PD-L1 analyses were performed on pretreatment samples. RESULTS: The median pretreatment tumor diameter was 60 mm (range 25-112 mm). Eighteen out of 32 patients obtained an objective response (OR) to olaparib (56.3%). Somatic or germline mutations affecting homologous recombination (HR) were observed in 10/18 responders [OR 55.6%, 95% confidence interval (CI) 33.7-75.4] contrasting 1/14 non-responders (OR 7.1%; CI 1.3-31.5, P = 0.008). Among tumors without HR mutations, 6/8 responders versus 3/13 non-responders revealed BRCA1 hypermethylation (P = 0.03). Thus, 16/18 responders (88.9%, CI 67.2-96.9), in contrast to 4/14 non-responders (28.6%, CI 11.7-54.7, P = 0.0008), carried HR mutations and/or BRCA1 methylation. Excluding one gPALB2 and four gBRCA1/2 mutation carriers, 12/14 responders (85.7%, CI 60.1-96.0) versus 3/13 non-responders (23.1%, CI 8.2-50.3, P = 0.002) carried somatic HR mutations and/or BRCA1 methylation. In contrast to BRCAness signature or basal-like subtype, low RAD51 scores, high TIL or high PD-L1 expression all correlated to olaparib response. CONCLUSION: Olaparib yielded a high clinical response rate in treatment-naïve TNBCs revealing HR deficiency, beyond germline HR mutations. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02624973.

SEOM clinical guidelines in hereditary breast and ovarian cancer (2019).

Mutations in BRCA1 and BRCA2 high penetrance genes account for most hereditary breast and ovarian cancer, although other new high-moderate penetrance genes included in multigene panels have increased the genetic diagnosis of hereditary breast and ovarian cancer families by 50%. Multigene cancer panels provide new challenges related to increased frequency of variants of uncertain significance, new gene-specific cancer risk assessments, and clinical recommendations for carriers of mutations of new genes. Although clinical criteria for genetic testing continue to be largely based on personal and family history with around a 10% detection rate, broader criteria are being applied with a lower threshold for detecting mutations when there are therapeutic implications for patients with breast or ovarian cancer. In this regard, new models of genetic counselling and testing are being implemented following the registration of PARP inhibitors for individuals who display BRCA mutations. Massive sequencing techniques in tumor tissue is also driving a paradigm shift in genetic testing and potential identification of germline mutations. In this paper, we review the current clinical criteria for genetic testing, as well as surveillance recommendations in healthy carriers, risk reduction surgical options, and new treatment strategies in breast cancer gene-mutated carriers.

A decade of clinical development of PARP inhibitors in perspective.

Genomic instability is a hallmark of cancer, and often is the result of altered DNA repair capacities in tumour cells. DNA damage repair defects are common in different cancer types; these alterations can also induce tumour-specific vulnerabilities that can be exploited therapeutically. In 2009, a first-in-man clinical trial of the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib clinically validated the synthetic lethal interaction between inhibition of PARP1, a key sensor of DNA damage, and BRCA1/BRCA2 deficiency. In this review, we summarize a decade of PARP inhibitor clinical development, a work that has resulted in the registration of several PARP inhibitors in breast (olaparib and talazoparib) and ovarian cancer (olaparib, niraparib and rucaparib, either alone or following platinum chemotherapy as maintenance therapy). Over the past 10 years, our knowledge on the mechanism of action of PARP inhibitor as well as how tumours become resistant has been extended, and we summarise this work here. We also discuss opportunities for expanding the precision medicine approach with PARP inhibitors, identifying a wider population who could benefit from this drug class. This includes developing and validating better predictive biomarkers for patient stratification, mainly based on homologous recombination defects beyond BRCA1/BRCA2 mutations, identifying DNA repair deficient tumours in other cancer types such as prostate or pancreatic cancer, or by designing combination therapies with PARP inhibitors.

A narrative overview of the patients' outcomes after multigene cancer panel testing, and a thorough evaluation of its implications for genetic counselling.

Massively parallel sequencing is being implemented in clinical practice through the use of multigene panel testing, whole exome sequencing and whole genome sequencing. In this manuscript we explore how the use of massively parallel sequencing, and in particular multigene cancer panel testing, is potentially changing the process of genetic counselling and how patients cope with pre-test genetic counselling and results. We found that the main challenges are around uncertainty, hopes and expectations and the amount and complexity of information that needs to be discussed. This may impact the process of genetic counselling, although genetic counsellors can still use their core skills and enhance some of them in order to evolve and meet patients' needs in the genomics era. Available data suggests that patients can cope with multigene cancer panels although more research is needed to fully understand the psychosocial implications of multigene cancer panels for patients, especially for those who have variants of unknown significance or moderate penetrance variants. Research is also needed to explore and develop communication models that maximize patients' understanding and empower them to make informed decisions.

Quality of life with talazoparib after platinum or multiple cytotoxic non-platinum regimens in patients with advanced breast cancer and germline BRCA1/2 mutations: patient-reported outcomes from the ABRAZO phase 2 trial.

BACKGROUND: Talazoparib (1 mg/day) exhibited promising efficacy and safety in patients with advanced breast cancer during ABRAZO (NCT02034916); this study evaluated patient-reported outcomes (PROs). PATIENTS AND METHODS: ABRAZO is a two-cohort, two-stage, phase 2 study of talazoparib in patients with advanced breast cancer after a response to prior platinum-based therapy (cohort 1 [C1], n = 49) or ≥3 platinum-free cytotoxic-based regimens (cohort 2 [C2], n = 35). PROs were assessed on day 1 (baseline), every 6 weeks for an initial 24 weeks, and every 12 weeks thereafter until progression, using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (QLQ-C30) and its breast cancer module, QLQ-BR23. RESULTS: Global health status/quality of life (GHS/QoL) was maintained from baseline across all time points for both C1 and C2. For C1 and C2, median time to deterioration (TTD) of GHS/QoL (95% confidence interval [CI]) was 2.8 (2.1, 3.0) and 5.5 (4.2, 5.7) months, respectively. Median TTD for all QLQ-C30 functional scales for C1 and C2 ranged 2.1-3.1 months and 4.2-5.6 months, respectively; median TTD for all QLQ-BR23 symptom scales ranged 2.6-4.0 months and 4.2-5.6 months, respectively. There were no statistically significant differences in estimated overall change from baseline in the GHS/QoL scale for both cohorts (C1: -2.6 [95% CI, -7.8, 2.5]; C2: 1.2 [95% CI, -5.5, 8.0]). Significant overall improvements in the breast symptoms and arm symptoms and the future perspective of patients in C1 and C2 were observed, despite the statistically significant and clinically meaningful overall deterioration among patients regarding their role functioning (in C1) and dyspnoea symptoms (in C2). CONCLUSION: Despite the statistically significant and clinically meaningful overall deterioration among patients regarding their role functioning (in C1) and dyspnoea symptoms (in C2), patients in both C1 and C2 reported significant overall improvements in their breast symptoms, arm symptoms and future perspective, and their GHS/QoL was maintained from baseline.

RAD51 foci as a functional biomarker of homologous recombination repair and PARP inhibitor resistance in germline BRCA-mutated breast cancer.

Background: BRCA1 and BRCA2 (BRCA1/2)-deficient tumors display impaired homologous recombination repair (HRR) and enhanced sensitivity to DNA damaging agents or to poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi). Their efficacy in germline BRCA1/2 (gBRCA1/2)-mutated metastatic breast cancers has been recently confirmed in clinical trials. Numerous mechanisms of PARPi resistance have been described, whose clinical relevance in gBRCA-mutated breast cancer is unknown. This highlights the need to identify functional biomarkers to better predict PARPi sensitivity. Patients and methods: We investigated the in vivo mechanisms of PARPi resistance in gBRCA1 patient-derived tumor xenografts (PDXs) exhibiting differential response to PARPi. Analysis included exome sequencing and immunostaining of DNA damage response proteins to functionally evaluate HRR. Findings were validated in a retrospective sample set from gBRCA1/2-cancer patients treated with PARPi. Results: RAD51 nuclear foci, a surrogate marker of HRR functionality, were the only common feature in PDX and patient samples with primary or acquired PARPi resistance. Consistently, low RAD51 was associated with objective response to PARPi. Evaluation of the RAD51 biomarker in untreated tumors was feasible due to endogenous DNA damage. In PARPi-resistant gBRCA1 PDXs, genetic analysis found no in-frame secondary mutations, but BRCA1 hypomorphic proteins in 60% of the models, TP53BP1-loss in 20% and RAD51-amplification in one sample, none mutually exclusive. Conversely, one of three PARPi-resistant gBRCA2 tumors displayed BRCA2 restoration by exome sequencing. In PDXs, PARPi resistance could be reverted upon combination of a PARPi with an ataxia-telangiectasia mutated (ATM) inhibitor. Conclusion: Detection of RAD51 foci in gBRCA tumors correlates with PARPi resistance regardless of the underlying mechanism restoring HRR function. This is a promising biomarker to be used in the clinic to better select patients for PARPi therapy. Our study also supports the clinical development of PARPi combinations such as those with ATM inhibitors.

Psychological impact of multigene cancer panel testing in patients with a clinical suspicion of hereditary cancer across Spain.

OBJECTIVE: Patients' psychological reactions to multigene cancer panel testing might differ compared with the single-gene testing reactions because of the complexity and uncertainty associated with the different possible results. Understanding patients' preferences and psychological impact of multigene panel testing is important to adapt the genetic counselling model. METHODS: One hundred eighty-seven unrelated patients with clinical suspicion of hereditary cancer undergoing a 25-gene panel test completed questionnaires after pretest genetic counselling and at 1 week, 3 months, and 12 months after results to elicit their preferences regarding results disclosure and to measure their cancer worry and testing-specific distress and uncertainty. RESULTS: A pathogenic variant was identified in 38 patients (34 high penetrance and 4 moderate penetrance variants), and 54 patients had at least one variant of uncertain significance. Overall, cancer panel testing was not associated with an increase in cancer worry after results disclosure (P value = .87). Twelve months after results, carriers of a moderate penetrance variant had higher distress and uncertainty scores compared with carriers of high penetrance variants. Cancer worry prior to genetic testing predicted genetic testing specific distress after results, especially at long term (P value <.001). Most of the patients reported the wish to know all genetic results. CONCLUSIONS: Our results suggest that patients can psychologically cope with cancer panel testing, but distress and uncertainty observed in carriers of moderate penetrance cancer variants in this cohort warrant further research.

Germline BRCA testing is moving from cancer risk assessment to a predictive biomarker for targeting cancer therapeutics.

PURPOSE: Originally, BRCA testing was used for risk assessment and prevention strategies for breast and ovarian cancer. Nowadays, BRCA status may influence therapeutic decision making at cancer diagnosis. Our objective was to analyze whether the medical advances have changed the burden and pattern of referral, and the pathogenic mutation detection rate. METHODS: We included 969 probands from our hereditary cancer registry who undertook a full BRCA analysis between 2006 and 2014. Chi-square tests were used to compare categorical variables. RESULTS: The number of genetic tests have raised from 28 to 170, representing a sixfold increase. In 2006, we tested 1.6 relatives/proband while this proportion was four in 2014. Overall, 20 % harbored a deleterious mutation and 11 % had a variant of unknown significance (VUS). There has been a downward trend in the detection rate of VUS. Testing patients with breast cancer during neoadjuvancy has raised from 4 to 25 % (p = 0.002), while testing them during remission has decreased from 79 to 29 % (p < 0.001). The proportion of patients assessed during the first 6 months after their cancer diagnosis has increased from 3 to 34 % (p = 0.001). Risk reducing mastectomy and salpingoophorectomy have raised from 0 to 24 %, and from 36 to 65 %, respectively. CONCLUSIONS: BRCA testing has experienced a sixfold increase, the number of relatives being tested has doubled, and the test is being performed at earlier phases of the disease. It is necessary to adequate the health resources to preserve the BRCA genetic counseling quality while incorporating BRCA testing for therapeutic decision making.

SEOM clinical guidelines in Hereditary Breast and ovarian cancer.

Approximately, 7 % of all breast cancers (BC) and 11-15 % of ovarian cancers (OC) are associated with inherited predisposition, mainly related to germline mutations in high penetrance BRCA1/2 genes. Clinical criteria for genetic testing are based on personal and family history to estimate a minimum 10 % detection rate. Selection criteria are evolving according to new advances in this field and the clinical utility of genetic testing. Multiplex panel testing carries its own challenges and we recommend inclusion of genes with clinical utility. We recommend screening with annual mammography from age 30 and breast MRI from age 25 for BRCA1 and BRCA2 mutation carriers. Bilateral salpingo-oophorectomy should be offered to women with a BRCA1 or BRCA2 mutation, between 35 and 40 years and after completion of childbearing, or individualise based on the earliest age of ovarian cancer diagnosed in the family. Bilateral risk-reducing mastectomy is an option for healthy BRCA1 and BRCA2 mutation carriers, as well as contralateral mastectomy for young patients with a prior BC diagnosis. BRCA genetic testing in patients with BC and OC may influence their locoregional and systemic treatment.

Detailed characterization of MLH1 p.D41H and p.N710D variants coexisting in a Lynch syndrome family with conserved MLH1 expression tumors.

Lynch syndrome (LS) is an autosomal dominant cancer-susceptibility disease caused by inactivating germline mutations in mismatch repair (MMR) genes. Variants of unknown significance (VUS) are often detected in mutational analysis of MMR genes. Here we describe a large family fulfilling Amsterdam I criteria carrying two rare VUS in the MLH1 gene: c.121G > C (p.D41H) and c.2128A > G (p.N710D). Collection of clinico-pathological data, multifactorial analysis, in silico predictions, and functional analyses were used to elucidate the clinical significance of the identified MLH1 VUS. Only the c.121G > C variant cosegregated with LS-associated tumors in the family. Diagnosed colorectal tumors were microsatellite unstable although immunohistochemical staining revealed no loss of MMR proteins expression. Multifactorial likelihood analysis classified c.2128A > G as a non-pathogenic variant and c.121G > C as pathogenic. In vitro functional tests revealed impaired MMR activity and diminished expression of c.121G > C. Accordingly, the N710 residue is located in the unconserved MLH1 C-terminal domain, whereas D41 is highly conserved and located in the ATPase domain. The obtained results will enable adequate genetic counseling of c.121G > C and c.2128A > G variant carriers and their families. Furthermore, they exemplify how cumulative data and comprehensive analyses are mandatory to refine the classification of MMR variants.

Phase I trial of olaparib in combination with cisplatin for the treatment of patients with advanced breast, ovarian and other solid tumors.

BACKGROUND: To establish the maximum tolerated dose, determine safety/tolerability and evaluate the pharmacokinetics and preliminary efficacy of olaparib in combination with cisplatin in patients with advanced solid tumors. PATIENTS AND METHODS: Patients aged ≥ 18 years with advanced solid tumors, who had progressed on standard treatment, were assigned to a treatment cohort and received oral olaparib [50-200 mg twice daily (bid); 21-day cycle] continuously or intermittently (days 1-5 or 1-10) in combination with cisplatin (60-75 mg/m(2) intravenously) on day 1 of each cycle. RESULTS: Dose-limiting toxicities (DLTs) of grade 3 neutropenia (cisplatin 75 mg/m(2) with continuous olaparib 100 mg bid or 200 mg bid; n = 1 each) and grade 3 lipase elevation (cisplatin 75 mg/m(2) with olaparib 100 mg bid days 1-10 or 50 mg bid days 1-5; n = 1 each) were reported. Olaparib and cisplatin doses were subsequently reduced to 50 mg bid days 1-5 and 60 mg/m(2), respectively; no DLTs were reported for patients receiving this regimen. The most frequent grade ≥ 3 adverse events were neutropenia (16.7%), anemia (9.3%) and leucopenia (9.3%). Thirty patients (55.6%) received colony-stimulating factors for hematologic support. The overall objective response rate was 41% for patients with measurable disease, and 43% and 71% among patients with a BRCA1/2 mutation who had ovarian and breast cancer, respectively. CONCLUSIONS: Olaparib in combination with cisplatin 75 mg/m(2) was not considered tolerable; intermittent olaparib (50 mg bid, days 1-5) with cisplatin 60 mg/m(2) improved tolerability. Promising antitumor activity in patients with germline BRCA1/2 mutations was observed and warrants further investigation.

Association of BRCA1 germline mutations in young onset triple-negative breast cancer (TNBC).

BACKGROUND: BRCA1-associated breast cancers have been associated to a triple-negative phenotype. The prevalence of BRCA1 germline mutations in young onset TNBC based on informativeness of family history has not been reported. PATIENTS AND METHODS: From January 2008 to May 2009 were collected blood and tumor samples from patients with TNBC younger than 50 years and without a family history of breast and ovarian cancer in first- and second-degree relatives. Analysis of BRCA1 germline mutations was made. Age at diagnosis and informativeness of family history (presence of female in first- and second-degree relatives alive until age 45) was collected in all cases. Immunohistochemistry of basal-like features was performed centrally in all available tumors. RESULTS: Seven pathogenic mutations were detected in 92 patients (7.6 %), two of them in patients younger than 35 years (28.6 %) (Fisher's exact test, p = 0.631). Three non-classified variants were detected (3.2 %). Family history was informative in two patients with a pathogenic mutation (28.6 %) and not informative in five (71.4 %) (Fisher's exact test, p = 0.121). Of the seven patients with a pathogenic mutation, four had a basal-like phenotype. CONCLUSION: Patients with apparently sporadic TNBC younger than 50 years and a non-informative family history are candidates for germline genetic testing of BRCA1.