Paul Basilio, MDLinx | November 22, 2017
While male breast cancer (MBC) shares some features with female breast cancer, its rare nature precludes a thorough characterization. A recent study in the journal Clinical Breast Cancer represented the largest analysis of stage IV MBC to date of this small subset of a rare disease.
It has been reported that MBC carries a worse prognosis than breast cancer in women, most likely due to delayed diagnosis or differences in cancer cell biology. Male breast cancer represents <1% of all breast cancers, so relatively few studies have been published about its presentation, epidemiology, and prognosis
Using data obtained from the National Cancer Institute’s Surveillance Epidemiology, and End Results (SEER) database, data on tumor location, grade, and histology were gathered from patients diagnosed with stage IV MBC between 1988 and 2012. Prognostic factors for overall survival (OS) and cause-specific survival (CSS) were evaluated. In all, 394 patients were included in the analysis.
Results showed a 5-year OS and CSS of 21.1% and 38.3%, respectively. Patients with progesterone receptor- (PR) positive disease had better OS and CSS. Those who underwent surgery saw a longer median CSS vs those who did not receive surgical intervention.
While stage IV MBC has poor OS and CSS overall, there were some bright points in the study. Overall survival and CSS were improved in men with PR-positive disease, those who are younger than 65 years of age, those who have tumor sizes smaller than 2 cm, and those who undergo surgery of the primary tumor.
“Although there is some preliminary evidence supporting the use of primary surgical resection in stage IV disease, our findings only add to the growing debate about the role of local therapy in the setting of metastatic disease,” the authors conclude.
The authors acknowledged several limitations of the study. The retrospective design is inherently associated with some bias. In addition, chemotherapy or systemic therapies are not recorded in the SEER database, so the effect of these missing data to the differences in survival based on prognostic factors is unknown.
BRCA mutation status and androgen-receptor positivity were also not recorded, and Her2 status has only been reported since 2010.
To read more about this study, click here.