Male breast cancer: Results of the treatments and prognostic factors in 690 cases

Male breast cancer

Male breast cancer (MaleBC) is a rare disease, accounting for <1% of all male tumors. During the last few years, there has been an increase in the incidence of this disease, along with the increase in female breast cancer (FBC). Little is known about the etiology of MaleBC: hormonal, environmental and genetic factors have been reported to be involved in its pathogenesis. Major risk factors include clinical disorders carrying hormonal imbalances, radiation exposure and, in particular, a positive family history (FH) for BC, the latter suggestive of genetic susceptibility. Rare mutations in high-penetrance genes (BRCA1 and BRCA2) confer a high risk of BC development; low-penetrance gene mutations (i.e. CHEK-2) are more common but involve a lower risk increase. About 90% of all male breast tumors have proved to be invasive ductal carcinomas, expressing high levels of hormone receptors with evident therapeutic returns. The most common clinical sign of BC onset in men is a painless palpable retroareolar lump, which should be evaluated by means of mammography, ultrasonography and core biopsy or fine needle aspiration (FNA). To date, there are no published data from prospective randomized trials supporting a specific therapeutic approach in MaleBC. Tumor size together with the number of axillary nodes involved are the main prognostic factors and should guide the treatment choice. Locoregional approaches include surgery and radiotherapy (RT), depending upon the initial clinical presentation. When systemic treatment (adjuvant, neoadjuvant and metastatic) is delivered, the choice between hormonal and or chemotherapy (CT) should depend upon the clinical and biological features, according to the FBC management guidelines. However great caution is required because of high rates of age-related comorbidities.

Strategies in treating male breast cancer

Male breast cancer is rare. Median age at diagnosis is approximately 65 years, and > 35% of male breast cancers occur in elderly men. Retroareolar lump is the most frequent symptom, and 25-30% of tumours are T(4) lesions. Infiltrating ductal carcinoma represents almost 90% of the cases, and 10% are ductal carcinoma in situ. Axillary nodal involvement is present in 50-60% of the cases. Estrogen and progesterone receptors are positive in 75-92% and 54-77% of the cases. Mastectomy with axillary dissection remains the standard treatment. Sentinel lymph node biopsy could be proposed in small tumours (< or = 2 cm). Locoregional radiotherapy is very often indicated. Tamoxifen is the standard adjuvant treatment, but chemotherapy is proposed in young men with axillary nodal involvement and/or negative hormone receptors. Tumour size and, more particularly, histopathological axillary involvement are the strongest predictive factors for both locoregional recurrence and metastasis. Globally, the prognosis is similar to that in women (at identical stage), but the intercurrent death rate is higher due to the important impact of comorbidities and second neoplasm.