Laura Cortesi

Lifestyle and environmental factors in women carrying BRCA pathogenic variants with and without cancer

Abstract Background In the development of breast cancer and ovarian cancer there may be an influence of lifestyle and environmental factors. This influence could be relevant also in patients with genetic predisposition such as in carriers of germline pathogenic variants in the BRCA genes. However, this issue has been addressed in only a few studies so far. Methods In this retrospective, multicenter case-control study, we enrolled participants with a pathogenic variant BRCA gene and divided into 2 groups: group 1, patients with breast cancer and/or ovarian cancer, and group 2, subjects without cancer. We compared these groups regarding demographic data as age, body mass index, smoking habits, estroprogestinic use, Mediterranean diet, and physical activity. Multivariable analyses were used to identify predisposing factors. All evaluations were 2-tailed and considered statistically significant if the P value was less than .05. Results We enrolled 281 participants, 135 (79.4%) with breast cancer, 32 (18.8%) with ovarian cancer, 3 (1.8%) with both, and 111 unaffected (39.5%) women. Independent risk factors associated with cancer were age (P < .0001); body mass index (P = .007); family history (P = .002); occupation (P = .003); smoking habits (P = .012), number of cigarettes smoked (P = .016), and pack-year index (P = .022); and estroprogestinic use (P = .032) and years of estroprogestinic use (P = .029). At multivariate analysis, age (odds ratio [OR] = 1.062; P < .0001), family history (OR = 0.129; P = .001), number of cigarettes smoked (P = .014), and estroprogestinic use (OR = 2.009; P = .025) were statistically significant risk factors associated with cancer development. Conclusions In the development of breast cancer and ovarian cancer, lifestyle and environmental factors seem to play a statistically significant role in the presence of genetic predisposition associated with BRCA1 and BRCA2 gene mutations.

Atypical cancer risk profile in carriers of Italian founder BRCA1 variant p.His1673del: Implications for classification and clinical management

Abstract Background BRCA1 :c.5017_5019del (p.His1673del) is a founder variant relatively frequent in Northern Italy. Despite previous suggestion of pathogenicity, variant classification in public databases is still conflicting, needing additional evidence. Methods Maximum likelihood penetrance of breast/ovarian and other cancer types was estimated using full pedigree data from 53 informative Italian families. The effect of the variant on BRCA1‐ABRAXAS1 interaction was assessed using a GFP‐fragment reassembly‐based PPI assay. Results were combined with additional data from multiple sources to classify the variant according to ACMG/AMP classification rules specified for BRCA1/2 . Results Variant‐carriers displayed increased risk for ovarian cancer (HR = 33.0, 95% CI = 7.0–155.0; cumulative risk at age 70 = 27.6%, 95% CI = 12.6–40.0%) but not for breast cancer (HR = 0.7, 95% CI = 0.2–2.2). An increased risk of uterine cancer (HR = 8.0, 95% CI = 1.03–61.6) emerged, warranting further evaluation. Likelihood‐ratio in favor of pathogenicity was 98898642.82 under assumption of standard BRCA1 breast and ovarian penetrance, and 104240832.84 after excluding breast cancer diagnoses (based on penetrance results). Functional analysis demonstrated that the variant abrogates the BRCA1‐ABRAXAS1 binding, supporting the PS3 code assignment within the ACMG/AMP rule‐based model. Collectively, these findings allowed to classify the variant as pathogenic. Conclusion Pathogenicity of BRCA1 :c.5017_5019del(p.His1673del) has been confirmed; however, breast cancer risk in Italian families is not increased, unlike in families from other countries and in carriers of most BRCA1 pathogenic variants. The knowledge of atypical risk profiles for this and other variants will pave the way for personalized management based on specific genotype.

Platinum-based chemotherapy and PARP inhibitors for patients with a germline BRCA pathogenic variant and advanced breast cancer (LATER-BC): retrospective multicentric analysis of post-progression treatments

Patients with breast cancer (BC) harbouring a germinal BRCA pathogenic variant (gBRCA-PV) may have an enhanced sensitivity to platinum-based chemotherapy (PBC) and PARP inhibitors (PARPi). As reported in ovarian cancer, however, sensitivity and resistance to these treatments could partially overlap. In patients with a gBRCA-PV and advanced BC (aBC), it remains unclear whether prior exposure to PARPi/PBC affects tumour response to subsequent PBC/PARPi, respectively. We conducted a retrospective, multicentric study to investigate the clinical benefit of post-PBC PARPi and vice versa in patients with a gBRCA-PV and aBC. Patients included had received (neo)adjuvant PBC and then PARPi in advanced setting (group 1), PBC followed by PARPi (group 2) or PARPi followed by PBC (group 3), both in advanced setting. We reported median progression-free survival (mPFS) and disease control rate (DCR) in each group. A total of 67 patients from six centres were included. PARPi-mPFS in advanced setting was 6.1 months in patients in group 1 (N = 12), while PARPi-DCR was 67%. In group 2 (N = 36), PARPi-mPFS was 3.4 months and PARPi-DCR was 64%. Age  6 months were associated with longer PARPi-PFS; previous PBC-PFS > 6 months and PBC in first to second line were associated with longer PARPi-DCR. Patients in group 3 (N = 21) reported a PBC-mPFS of 1.8 months and a PBC-DCR of 14%. PARPi-PFS ≥ 9 months and PARPi-FI ≥ 6 months were associated with better PBC-DCR. Sensitivity and resistance to PARPi and PBC partially overlap in patients with a gBRCA-PV and aBC. Evidence of PARPi activity emerged in patients who progressed on previous PBC.