NCCN Guidelines recommend BRCA genetic testing in individuals with a probability
>5% of being a carrier. Nonetheless, the cost-effectiveness of testing individuals with no tumor
family history is still debated, especially when BRCA testing is offered by the national health
service. Our analysis evaluated the rate of BRCA pathogenic or likely-pathogenic variants in 159
triple-negative breast cancer (TNBC) patients diagnosed ≤60 years, and 109 luminal-like breast cancer
(BC) patients diagnosed ≤35 without breast and/or ovarian family histories. In TNBC patients, BRCA
mutation prevalence was 22.6% (21.4% BRCA1). Mutation prevalence was 64.2% ≤30 years, 31.8%
in patients aged 31–40, 16.1% for those aged 41–50 and 7.9% in 51–60 s. A total of 40% of patients
with estrogen receptors (ER) 1–9% were BRCA1 carriers. BRCA detection rate in early-onset BCs was
6.4% (4.6% BRCA2). Mutation prevalence was 0% between 0–25 years, 9% between 26–30 years and
6% between 31–35 years. In conclusion, BRCA testing is recommended in TNBC patients diagnosed
≤60 years, regardless of family cancer history or histotype, and by using immunohistochemical
staining <10% for both ER and/PR. In luminal-like early-onset BC, a lower BRCA detection rate was
observed, suggesting a role for other predisposing genes along with BRCA genetic testing.