Influential Factors on Risk-reduction Mastectomy in a High-risk Breast Cancer Population With Genetic Predispositions

Demographics and Clinical Decision Making in Patients with Germline Moderate Penetrance Non-BRCA Mutations in Breast Cancer Related Genes

BACKGROUND

Management of pathogenic variants in high penetrance genes related to breast cancer (BC), such as BRCA1 and BRCA2, are well established. However, moderate penetrance mutations are understudied. We aim to compare risk reduction decision-making patterns in patients with a moderate penetrance BC-related genetic mutations, without a prior BC diagnosis.

PATIENTS AND METHODS

Female patients aged ≥ 18 years who tested positive for a BRCA1/2, high penetrance, or moderate penetrance mutation related to BC between 1996 and 2023 without a concurrent or prior BC diagnosis were retrospectively identified from a single academic center's database. Groups were stratified by mutation type: BRCA1/2 mutations (BRCA1, BRCA2), high penetrance mutations (HPM; CDH1, PALB2, PTEN, STK11, TP53), or moderate penetrance mutations (MPM; ATM, BARD1, CHEK2, NF1, RAD51C, RAD51D). Demographics and clinical outcomes were compared.

RESULTS

A total of 528 patients met the inclusion criteria, with 66% (n = 350) having a BRCA1/2 mutation, 8% (n = 44) having HPM, and 25% (n = 134) having MPM; the median follow-up was 56.0 months. In our cohort, 20.9% of patients with BRCA mutations, 9.1% with HPM, and 7.5% with MPM chose to undergo risk-reducing mastectomies (RRM). Within the moderate penetrance cohort, patients who chose to undergo RRM were younger at the time of genetic testing (39.4 vs. 47.5 years, p = 0.03) and had a higher number of family members with BC (2 vs. 1, p = 0.05).

CONCLUSIONS

Our findings provide insights into the demographic characteristics and family history of patients with moderate penetrance mutations and those who pursue risk-reducing surgery.

Differences among a Portuguese cohort of BRCA pathogenic/likely pathogenic variants carriers choosing risk-reducing mastectomy or intensive breast surveillance

PURPOSE

Women with BRCA1 and BRCA2 (BRCA1/2) pathogenic/likely pathogenic (P/LP) variants have a higher risk to develop breast and ovarian cancer. In structured high-risk clinics, risk-reducing measures are adopted. This study aimed at characterizing these women and identify factors that may have influenced their choice between risk reduction mastectomy (RRM) and intensive breast surveillance (IBS).

METHODS

This study reviewed retrospectively 187 clinical records of affected and unaffected women with P/LP variants of the BRCA1/2 genes, from 2007 to 2022, of which 50 chose RRM, while 137 chose IBS. The research focused on personal and family history and tumor characteristics and their relation with the preventive option chosen.

RESULTS

Among women with personal history of breast cancer, a higher proportion opted for RRM compared to those asymptomatic (34.2% vs 21.3%, p = 0.049), with younger age determining the option for RRM (38.5 years vs 44.0 years, p < 0.001). Among women with personal history of ovarian cancer, a higher proportion opted for RRM compared to those without that history (62.5% vs 25.1%, p = 0.033), with younger age determining the option for RRM (42.6 years vs 62.7 years, p = 0.009). Women who had bilateral salpingo-oophorectomy were more likely to choose RRM than those who did not (37.3% vs 18.3%, p = 0.003). Family history was not associated with preventive option (33.3% vs 25.3, p = 0.346).

CONCLUSIONS

The decision for the preventive option is multifactorial. In our study, personal history of breast or ovarian cancer, younger age at diagnosis, and previous bilateral salpingo-oophorectomy were associated with the choice of RRM. Family history was not associated with the preventive option.

The Breast Cancer Screening and Timing of Breast MRI—Experience in a Genetic High-Risk Screening Clinic in a Comprehensive Cancer Center

For women with genetic risk of breast cancer, the addition of screening breast MRI to mammography has become a standard. The order and interval of annual imaging can be variable among providers. To evaluate the clinical implications related to the timing, we conducted a chart review on a cohort of women (N = 276) with high-risk (BRCA1, BRCA2, CDH1, PTEN and TP53) and moderate high-risk (ATM and CHEK2) predisposition to breast cancer in a 48-month follow up. The estimated MRI detection rate in the entire group is 1.75% (18 per 1000 MRI tests). For the high-risk group, the estimated rate is 2.98% (30 per 1000 MRI tests). Many women discovered their genetic risk at an age much older (average age of the high-risk group was 48 years) than the age recommended to initiate enhanced screening (age 20 to 25 years). In total, 4 of the 11 primary breast cancers detected were identified by screening MRI within the first month after initial visit, which were not detected by previous mammography, suggesting the benefit of initiating MRI immediately after the discovery of genetic risk. Breast screening findings for women with Lynch syndrome and neurofibromatosis type 1 were also included in this report.