Clinical outcomes and response to chemotherapy in a cohort of pancreatic cancer patients with germline variants of unknown significance (VUS) in BRCA1 and BRCA2 genes.

PURPOSE: The clinical outcome and the efficacy of chemotherapy in pancreatic cancer patients with BRCA1/2 Variants of Unknown Significance (VUS) is unknown. We explored the effects of chemotherapy with or without Platinum in non metastatic and metastatic pancreatic cancer patients with BRCA1/2 VUS. METHODS: A retrospective analysis of non-metastatic or metastatic pancreatic cancer patients with gBRCA1/2 VUS treated in 13 Italian centers between November 2015 and December 2020 was performed. All patients were assessed for toxicity and RECIST 1.1 response. Metastatic patients were evaluated for survival outcome. RESULTS: 30 pancreatic cancer patients with gBRCA1/2 VUS were considered: 20 were M+ and 10 were non-M+. Pl-CT was recommended to 16 patients: 10 M+ (6 FOLFIRINOX and 4 PAXG) and 6 non-M+ (3 FOLFIRINOX and 3 PAXG); 11 patients received Nabpaclitaxel-Gemcitabine (AG; 8 M+) and 3 patients (2 M+) were treated with Gemcitabine (G). The RECIST 1.1 response rate was 27% for AG and 44% for Pl-CT (22% for (m) FOLFIRINOX and 71% PAXG). 1 year Progression-Free Survival was 37.5% for patients treated with AG and 33% in the Pl-CT subgroup. Median Overall Survival (OS) was 23.5 months for patients treated with AG and 14 months for the Pl-CT subgroup. 1 Year and 2 Year OS were numerically better for AG (1 Year OS: 75% vs 60% and 2 Year OS: 50% and 20% in AG and Pl-CT subgroups, respectively) as well. CONCLUSIONS: Pl-CT does not seem to be associated with a better outcome compared to AG chemotherapy in PDAC patients with BRCA 1/2 VUS.

Second-line therapy in pancreatic ductal adenocarcinoma (PDAC) patients with germline BRCA1-2 pathogenic variants (gBRCA1-2pv).

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) harbouring germline BRCA1-2 pathogenic variants (gBRCA1-2pv) is a distinct nosological entity. Information on second-line therapy (2LT) outcome in this setting is lacking. METHODS: Data of gBRCA1-2pv metastatic PDAC patients treated with chemotherapy were collected. A primary analysis of 2LT RECIST response, median progression-free survival (mPFS2) and overall survival (mOS2), was performed. A secondary analysis addressed the impact of timing of platinum introduction on the outcome of patients receiving at least a first-line combination chemotherapy (1LT). RESULTS: Eighty-four gBRCA1-2pv metastatic PDAC patients were enrolled. The primary analysis, including 43 patients, highlighted a significant improvement of mPFS2 and a doubled response rate, in the platinum-based 2LT subgroup as compared to the platinum-free (8.8 versus 3.7 months, p = 0.013). Seventy-seven patients were included in the secondary analysis. Median PFS1 of 3- and 4-drug platinum-based 1LT significantly outperformed both platinum-free combinations and platinum-based doublets (11.4 versus 6.4 versus 7.9 months, p = 0.01). Albeit still immature, data on mOS paralleled those on mPFS. CONCLUSIONS: This study highlighted the beneficial role of platinum agents in gBRCA1-2pv PDAC patients also in second-line treatment setting. However, our data suggest that early use of 3- and 4-drug platinum-based chemotherapy combinations provides a survival outcome advantage.

Epidemiology and geographic distribution of BRCA1-2 and DNA Damage response genes pathogenic variants in pancreatic ductal adenocarcinoma patients.

Incidence of pancreatic ductal adenocarcinoma (PDAC) is increasing over the last years, while patients prognosis remains grim. Recently germline BRCA1 and 2 pathogenic variants (gBRCA1-2) have emerged as risk factors for PDAC development, as well as new predictors of response to specific therapeutic interventions. However, data on gBRCA1-2 incidence in PDAC are currently sparse and limited to selected categories of patients, as for positive cancer history cases, for patients affected only by early or late stages of disease and mainly from the North-American population, thus generating incomplete information about the gBRCA1/2 epidemiology. In Western Countries gBRCA1-2 incidence ranges between 4.5% and 8% in unselected PDAC patients, raising up to 26% in cohorts with positive family cancer history. To date a limited number of studies from Asian countries are available, reporting a 10% as highest incidence of gBRCA1-2 in familiar PDAC, claiming at least in part a role of ethnicity in the gBRCA1-2 incidence and in other genes potentially implicated in the therapeutic decisions. Drawing a better defined map for the incidence of gBRCA1-2 and other germline pathogenic variants of DNA Damage Response genes (gDDR) might help assessing the therapeutic strategies for mutated patients according to the geographic areas. These informations may enhance the chance to predict efficacy and toxicity of selected chemotherapy regimens, fostering the development and implementation of the pharmaco-ethnicity knowledge in the routine-clinical practice, and increasing the awareness of the potential incorrect generalization of trials results outside of the geographic area where they are conducted.

Treatment opportunities and future perspectives for pancreatic cancer patients with germline BRCA1-2 pathogenic variants.

Personalized treatments and predictive biomarkers of pancreatic cancer (PDAC) are still lacking. Recently germline mutations in BRCA 1 and 2 genes, leading to homologous repair deficiency, have emerged as new targets for more specific and effective therapies, exploiting the increased susceptibility to platinum salts and PARP inhibitors. In addition to BRCA, pathogenic variants in PALB2 and in other genes involved in the DNA damage response pathway (DDR) represent potential targets, as well as their respective somatic alterations. This enlarged molecularly-selected population sharing the BRCAness phenotype, is expected to show a higher sensibility to a number of DNA damaging agents and DDR inhibitors. However, the possibility of new therapeutic opportunities for DDR defective PDAC patients has to face the lack of solid evidence about the proper type and timing of targeted-treatments, the potential combination strategies and most importantly, the lack of informations on the functional impact of each specific pathogenic variant on the DDR pathway. This review summarizes the current and near-future options for the clinical management of PDAC patients harboring a DDR deficiency, analyzing the state of the art of the indications of platinum salts and other cytotoxic agents in the advanced and early stage PDAC, the development of PARP inhibitors and the rational for new combinations with immunotherapy and cycle checkpoint inhibitors, as well as the strategy to overcome the development of resistance over treatments.

Mechanism of Action and Clinical Efficacy of CDK4/6 Inhibitors in BRCA-Mutated, Estrogen Receptor-Positive Breast Cancers: Case Report and Literature Review.

Sensitivity to endocrine therapy of patients with estrogen receptor (ER)-positive metastatic breast cancer and germline BRCA1/2 mutations is not yet fully elucidated. Furthermore, the registration trials of CDK 4/6 inhibitors in combination with endocrine therapy lacked of a pre-specified subgroup analysis in BRCA1/2 mutation carriers. We report clinical history of two patients with BRCA-mutated, ER-positive metastatic breast cancer treated with letrozole plus the CDK 4/6 inhibitor palbociclib. Biological and clinical implications of the treatment outcome observed in the two cases are discussed with the knowledge of scientific evidence to date available. Overall, biological rationale, preclinical, and clinical data support the prominent role of CDK 4/6 inhibitors plus endocrine therapy, even in combination with PARP inhibitors, in the treatment of BRCA-mutated, ER-positive breast cancers. However, the interaction between Cyclin/CDK pathway, ER and BRCA is complex and evidences reported so far, albeit reliable, await confirmation in the context of future randomized clinical trials.