Clinicopathological study of non-palpable familial breast cancer detected by screening mammography and diagnosed as DCIS

Background Recent widespread use of screening mammography has led to increased detection rates of non-palpable breast cancer. This study aimed to evaluate the clinicopathological features of non-palpable ductal carcinomas in situ of the breast that were detected by screening mammography of patients with a family history of breast cancer. Methods We selected 6 Japanese patients diagnosed with non-palpable breast cancer with self-reported family history of breast cancer. Mutations in BRCA1 and BRCA2 were evaluated with germ line genetic testing and immunohistochemistry (IHC) using resected specimens. Pathological features, such as estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, were also evaluated. Results The patients (ages 41–67 years; mean 53.5) had 7 tumors with one patient having synchronous bilateral breast cancer. Breast cancer was suspected from the microcalcification in 5 tumors and the distortion in 2 tumors by mammography and diagnosed by biopsy. Breast-conserving surgery was performed in 2 patients and mastectomy was performed in 4 patients. Genetic testing revealed BRCA2 gene germ line mutation in three patients. IHC of BRCA was consistent with BRCA2 mutation status. Conclusions The family history of breast cancer patients may lead one to suspect familial breast cancer and screening mammography is useful for the early detection of these cancers. IHC of BRCA showed staining results that were consistent with BRCA genetic testing, suggesting that it has the potential to be a useful tool in clinical practice.