BRCA1/2 alterations and reversion mutations in the area of PARP inhibitors in high grade ovarian cancer: state of the art and forthcoming challenges.

BRCA1/2 genes are part of homologous recombination (HR) DNA repair pathways in charge of error-free double-strand break (DSB) repair. Loss-of-function mutations of BRCA1/2 genes have been associated for a long time with breast and ovarian cancer hereditary syndrome. Recently, polyadenosine diphosphate-ribose polymerase inhibitors (PARPi) have revolutionized the therapeutic landscape of BRCA1/2-mutated tumors, especially of BRCA1/2 high-grade serous ovarian cancer (HGSC), taking advantage of HR deficiency through the synthetic lethality concept. However, PARPi efficiency differs among patients, and most of them will develop resistance, particularly in the relapse setting. In the current proposal, we aim to review primary and secondary resistance to PARPi in HGSC owing to BRCA1/2 alterations. Of note, as several mechanisms of primary or secondary resistance to PARPi have been described, BRCA1/2 reversion mutations that restore HR pathways are by far the most reported. First, the type and location of the BRCA1/2 primary mutation have been associated with PARPi and platinum-salt sensitivity and impact the probability of the occurrence and the type of secondary reversion mutation. Furthermore, the presence of multiple reversion mutations and the variation of allelic frequency under treatment underline the role of intratumor heterogeneity (ITH) in treatment resistance. Of note, circulating tumor DNA might help us to detect and characterize reversion mutations and ITH to finally refine the treatment strategy. Importantly, forthcoming therapeutic strategies, including combination with antiangiogenics or with targeted therapies, may help us delay and overcome PARPi resistance secondary to BRCA1/2 reversion mutations. Also, progression despite PARPi therapy does not preclude PARPi rechallenge in selected patients.

Gynecological carcinosarcomas: Overview and future perspectives.

Gynecologic carcinosarcoma (CS) are rare and aggressive tumors composed of high-grade carcinoma and sarcoma. Carcinosarcoma account for less than 5% of uterine and ovarian carcinoma and patients have poor outcome with a 5-year overall survival of less than 30%. In early-stage setting, the treatment mainstay is surgery and adjuvant chemoradiotherapy or adjuvant chemotherapy in uterine (UCS) and ovarian CS (OCS), respectively. In metastatic or advanced stage disease, chemotherapy is the rule with a lower response rate and poorer prognosis compared to other high-grade carcinomas. Although very few treatment options are available, CS are often excluded from the clinical trials precluding therapeutic improvement. However, recent molecular advances are paving the way for new therapeutic strategies. In the current proposal, we extensively review the uterine and ovarian carcinosarcomas including epidemiology, pathology, genomic landscape, as well as current therapies and future perspectives.

Efficacy of second-line chemotherapy or immune checkpoint inhibitors for patients with a prolonged objective response (≥ 6 months) after first-line therapy for recurrent or metastatic head and neck squamous cell carcinoma: a retrospective study.

BACKGROUND: Patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M-HNSCC) have a poor prognosis and limited therapeutic options. Immune checkpoint inhibitors (ICIs) are effective in patients with tumor progression < 6 months following first-line, platinum-based chemotherapy (PBC), but data are missing for patients with progression ≥ 6 months after the last platinum dose. METHODS: Retrospective analysis (six French centers, 2008-2019) of all consecutive R/M-HNSCC patients. treated first-line with PBC and tumor progression ≥ 6 months after the last platinum dose. PRIMARY ENDPOINT: progression-free survival after second-line therapy (PFS2). Additional endpoints: overall survival from Day 1 of first-line (OS1) and second-line (OS2) therapy. RESULTS: R/M-HNSCC patients (n = 144) received cisplatinum (n = 67, 47%) or carboplatinum (n = 77, 53%) first-line. Response after first-line: complete response (CR; n = 16, 11%); partial response (PR; n = 77, 53%); stable disease (n = 22, 15%). Second-line therapy: PBC (n = 95, 66%); platinum-free regimen (PFR) (n = 25, 17%); ICI (n = 24, 17%). Median [95% confidence interval] PFS (months): PBC 5.0 [3.8-6.2]; PFR 4.0 [1-7.0]; ICI 2.0 [0.4-3.6] (p = 0.16). For PBC, PFR, and ICI, respectively: OS1 30, 23, and 29 months (p = 1.02); OS2 14, 10, and 16 months (p = 0.25); PR, 26%, 16%, and 21% patients; CR, 0%, 8%, and 4% patients. For subsequent lines, ICIs were administered for PBC (n = 11, 12%) and PFR (n = 2, 8%). No predictive factor for efficacy (PFS, OS) was identified. CONCLUSIONS: Our retrospective study suggests similar efficacy regarding OS2 for second-line chemotherapy or ICI in R/M-HNSCC patients with progression ≥ 6 months after the last first-line platinum dose.

Predictive Biomarkers for Response to Immunotherapy in Triple Negative Breast Cancer: Promises and Challenges.

Triple negative breast cancer (TNBC) is a highly heterogeneous disease with a poor prognosis and a paucity of therapeutic options. In recent years, immunotherapy has emerged as a new treatment option for patients with TNBC. However, this therapeutic evolution is paralleled by a growing need for biomarkers which allow for a better selection of patients who are most likely to benefit from this immune checkpoint inhibitor (ICI)-based regimen. These biomarkers will not only facilitate a better optimization of treatment strategies, but they will also avoid unnecessary side effects in non-responders, and limit the increasing financial toxicity linked to the use of these agents. Huge efforts have been deployed to identify predictive biomarkers for the ICI, but until now, the fruits of this labor remained largely unsatisfactory. Among clinically validated biomarkers, only programmed death-ligand 1 protein (PD-L1) expression has been prospectively assessed in TNBC trials. In addition to this, microsatellite instability and a high tumor mutational burden are approved as tumor agnostic biomarkers, but only a small percentage of TNBC fits this category. Furthermore, TNBC should no longer be approached as a single biological entity, but rather as a complex disease with different molecular, clinicopathological, and tumor microenvironment subgroups. This review provides an overview of the validated and evolving predictive biomarkers for a response to ICI in TNBC.

Clinical outcome of patients with isolated central nervous system progression on first-line pertuzumab and trastuzumab treatment for HER2-positive metastatic breast cancer in a real-life cohort.

BACKGROUND: More than 10% of HER2-positive metastatic breast cancer (mBC) will develop Central Nervous System (CNS) metastases as first and isolated site of relapse on trastuzumab and pertuzumab first-line therapy. However, few clinical data are available to guide the best strategy in this setting. METHODS: Patients experiencing isolated CNS progression on trastuzumab and pertuzumab first-line therapy were retrospectively identified from the French Epidemiological Strategy and Medical Economics (ESME) real-life database between 2008 and 2016. RESULTS: Among 995 patients treated with first-line trastuzumab and pertuzumab for HER2-positive mBC, 132 patients (13%) experienced isolated CNS progression with a median time of 12 months after mBC diagnosis. Twelves patients did not receive any treatment and were excluded from the analysis. Among the 120 patients considered, 76 (63%) received CNS-directed local therapy, 73 (60%) continued trastuzumab and pertuzumab, whereas 47 (39%) started another systemic treatment. After a median follow-up of 21 months, there was no difference in progression-free survival for patient who continued trastuzumab-pertuzumab or switched to another systemic treatment. In multivariate analysis, trastuzumab-pertuzumab continuation was associated with longer OS (HR 0,28 IC 95%: 0,14-0,54 p < 0,001). mOS was not reached (95% 37.6-NE) and was 23.2 months (95% CI 15.5-53.6) in patients who continued trastuzumab and pertuzumab therapy and in patients who switched for another systemic therapy, respectively. CONCLUSION: In this real-life cohort, trastuzumab-pertuzumab continuation after local treatment for isolated CNS progression did not negatively impact PFS and OS. Prospective trials and assessment of new strategies are warranted in this specific situation.

Predominance of BRCA2 Mutation and Estrogen Receptor Positivity in Unselected Breast Cancer with BRCA1 or BRCA2 Mutation.

BACKGROUND: Poly(ADP-ribose) polymerase 1 inhibitor (PARPi) agents can improve progression-free survival of patients with breast cancer who carry a germline BRCA1 or BRCA2 pathogenic or likely pathogenic variant (gBRCA) in both the metastatic and adjuvant setting. Therefore, we need to reassess the frequency of gBRCA1 and gBRCA2 in order to redefine the criteria for women and tumor phenotype that should be tested. OBJECTIVE: We studied the relative distribution of gBRCA1 and gBRCA2 in unselected populations of women with breast cancer and in unaffected individuals. We also analyzed the proportion of estrogen receptor (ER)-positive (ER+) tumors in unselected breast cancer patients with gBRCA. DESIGN: We performed a meta-analysis of studies of unselected breast cancer that analyzed the relative contribution of gBRCA1 versus gBRCA2 among unselected breast cancer cases in gBRCA carriers. We then performed a meta-analysis of gBRCA carriage in unaffected individuals from genome-wide population studies, the gnomAD databank, and case-control studies. RESULTS: The BRCA2 gene was involved in 54% of breast cancer cases in unselected patients with gBRCA (n = 108,699) and 60% of unaffected individuals (n = 238,973) as compared with 38% of the largest gBRCA family cohort (n = 29,700). The meta-analysis showed that 1.66% (95% CI 1.08-2.54) and 1.71% (95% CI 1.33-2.2) of unselected breast cancer patients carried gBRCA1 and gBRCA2, respectively. In a population of unaffected individuals, the frequency of heterozygosity for gBRCA1 and gBRCA2 was estimated at 1/434 and 1/288, respectively. Nearly 0.5% of unaffected individuals in the studied populations carried a gBRCA. Carriage of a gBRCA was 2.5% for patients with ER+ tumors (95% CI 1.5-4.1) and 5.7% (95% CI 5.1-6.2) for those with ER- tumors. Overall, 58% of breast tumors occurring in women carrying a gBRCA were ER+ (n = 86,870). CONCLUSIONS: This meta-analysis showed that gBRCA2 carriage is predominant in unselected breast cancer patients and unaffected individuals. ER+ tumors among women with gBRCA-related breast cancer are predominant and have been underestimated. Because PARPi agents improve progression-free survival with ER+ gBRCA breast cancer in most clinical trials, breast cancer should be considered, regardless of ER status, for BRCA1/2 screening for therapeutic purposes.

PARP Inhibitors: A Major Therapeutic Option in Endocrine-Receptor Positive Breast Cancers.

Recently, OlympiAD and EMBRACA trials demonstrated the favorable efficacy/toxicity ratio of PARPi, compared to chemotherapy, in patients with HER2-negative metastatic breast cancers (mBC) carrying a germline BRCA mutation. PARPi have been largely adopted in triple-negative metastatic breast cancer, but their place has been less clearly defined in endocrine-receptor positive, HER2 negative (ER+/ HER2-) mBC. The present narrative review aims at addressing this question by identifying the patients that are more likely benefit from PARPi. Frequencies of BRCA pathogenic variant (PV) carriers among ER+/HER2- breast cancer patients have been underestimated, and many experts assume than 50% of all BRCA1/2 mutated breast cancers are of ER+/HER2- subtype. Patients with ER+/HER2- BRCA-mutated mBC seemed to have a higher risk of early disease progression while on CDK4/6 inhibitors and PARPi are effective especially when prescribed before exposure to chemotherapy. The OLYMPIA trial also highlighted the utility of PARPi in patients with early breast cancers at high risk of relapse and carrying PV of BRCA. PARPi might also be effective in patients with HRD diseases, representing up to 20% of ER+/HER2- breast cancers. Consequently, the future implementation of early genotyping strategies for identifying the patients with high-risk ER+/HER2- HRD breast cancers likely to benefit from PARPi is of high importance.

Biological and clinical features of triple negative Invasive Lobular Carcinomas of the breast. Clinical outcome and actionable molecular alterations.

BACKGROUND: We report here for the first time, a comprehensive characterization of biological and clinical features of early-stage triple negative Invasive Lobular Carcinomas(TN-ILCs) METHODS: We analyzed all consecutive patients with early-stage TN-ILC operated at two reference cancer-centers between 1994 and 2012. Primary objective was to assess the invasive disease-free survival(iDFS). Co-primary objective was to assess biological features of TN-ILCs, including molecular intrinsic subtypes based on PAM-50 assay, expression of androgen receptor (AR) and mutational status of ERBB2-gene. Additionally, DNA mutational status of an independent cohort of 45 TN-ILCs from three databases were analyzed, to confirm mutations in ERBB2-gene and to identify other recurrently mutated genes. RESULTS: Among 4152 ILCs, 74(1.8%) were TN and were analyzed. The iDFS at 5 and 10 years of FUP were 50.4%(95%CI,38.0-61.6) and 37.2%(95%CI,25.5-48.8), respectively. The molecular subtype was defined through PAM50-classifier for 31 out of 74 TN-ILCs: 48% were Luminal-A(15/31), 3% luminal-B(1/31), 32% HER2-enriched (10/31), and only 16% basal-like(5/31). Luminal tumors expressed AR more frequently than non-luminal tumors (AR≥1% in 94% of luminal tumors versus 53% in non-luminal tumors; p-value = 0.001). 20% of TN-ILCs analyzed(7/35), harbored a pathogenetic and actionable mutation in the ERBB2-gene. Analysis of the independent cohort of 45 TN-ILCs from three different databases, confirmed similar percentage of pathogenetic and actionable mutations in ERBB2-gene(20%; 9/45). Among the top 10 molecular pathways significantly enriched for recurrently mutated genes in TN-ILCs(FDR<0.05), there were ErbB-signaling and DNA-damage-response pathways. CONCLUSIONS: TN-ILCs are rare tumors with poor prognosis. Their specific biological features require newly defined targeted therapeutic strategies.

Analyses of the Rationale and Implementation of Research Biopsies in Oncology Clinical Trials at a Tertiary Cancer Center.

BACKGROUND: Biomarkers in clinical trials have led to massive incorporation of research biopsies, with potentially risks and no direct benefit for patients. In 2018, the American Society of Clinical Oncology (ASCO) released an ethical framework to provide guidance on incorporating research biopsies in cancer clinical trials. MATERIALS AND METHODS: We collected biopsy requirements of cancer clinical trials conducted at Institut Jules Bordet (IJB) between 2015 and 2019 to examine adherence with the ASCO Ethical Framework. We used logistic regression models to test the association between the request for biopsy, the request for tissue, and the adherence to the ASCO framework as well as some trial characteristics. RESULTS: Between January 2015 and December 2019, 178 oncological studies were conducted at IJB. Of these, 138 (78%) were sponsored by industry, 132 (74%) were phase II and III studies, and 141 (79%) concerned metastatic disease. Tissue was required for inclusion for 119 (67%) studies, among which 59 required at least one new biopsy. Adherence to ASCO's Ethical Framework was 67% for studies requiring tissue and went down to 39% for studies requiring at least one new biopsy. In multivariate analysis, requests for tissue or new biopsies increased in early-phase studies (p < .001, p < .001, respectively) and in studies investigating innovative treatments (immunotherapy or targeted therapies; p < .01, p = .02). Compliance to the ASCO framework significantly decreased with time (p < .001) and in early-phase studies (p < .001). CONCLUSION: Numerous studies required tissue or new biopsies for exploratory objectives of unknown clinical utility. Requests for tissue increased over the years, whereas compliance to ASCO's Ethical Framework decreased. IMPLICATIONS FOR PRACTICE: In 2019, the American Society of Clinical Oncology (ASCO) developed an ethical framework to provide guidance on incorporating research biopsies in clinical trials. This study underlines the growing request for tissue in clinical trials with potentially no impact on drug development and no benefit to actual or future patients. Adherence to ASCO's Ethical Framework decreases through time. These results highlight the importance of improving the ethics of research biopsies. ASCO's Ethical Framework offers an opportunity to improve quality of care in clinical research by maximizing scientific utility and allowing for clinically meaningful correlative science and safe access to innovative treatments for a maximum number of patients.

Association between Body Mass Index and Survival Outcome in Metastatic Cancer Patients Treated by Immunotherapy: Analysis of a French Retrospective Cohort.

The response to immunotherapy has been little investigated in overweight and obese cancer patients. We evaluated the relationships between BMI, toxicity, and survival in patients treated by immunotherapy for metastatic cancer. We included metastatic cancer patients treated by immunotherapy between January 2017 and June 2020 at the Centre Léon Bérard. In total, 272 patients were included: 64% men and 36% women, with a median age of 61.4 years. BMI ≥ 25 in 34.2% and 50% had non-small cell lung cancer (n = 136). Most received monotherapy, with nivolumab in 41.9% and pembrolizumab in 37.9%. Toxicity, mostly dysthyroiditis, occurred in 41%. Median overall survival (OS), estimated by Kaplan-Meier analysis, was significantly longer for patients with a BMI ≥ 25 than for those with a BMI < 25 (24.8 versus 13.7 months HR = 0.63; 95% CI 0.44-0.92, p = 0.015), and for patients experiencing toxicity than for those without toxicity (NR versus 7.8 months, HR = 0.22; 95% CI 0.15-0.33, p < 0.001). Adjusted OS was associated with toxicity, and the occurrence of toxicity was associated with sex and histological features but not with BMI. Thus, being overweight and experiencing toxicity was associated with longer overall survival in patients treated by immunotherapy. More attention should be paid to body composition in the care of cancer patients.