Clinicopathological features and prognostic analysis of Her-2-negative breast mucinous adenocarcinoma: A SEER database analysis

Background: Breast mucinous adenocarcinoma is a group of malignant tumors of epithelial origin of the breast with a good prognosis; however, whether its treatment regimen should be consistent with that of non-specific types of breast cancer remains to be investigated. Methods: In this study, the clinicopathological information, treatment modalities, and prognosis of 10,466 patients with mucinous adenocarcinoma of the breast from the Surveillance, Epidemiology, and End Results (SEER) database were analyzed. Results: After adjusting for other factors, radiotherapy showed a favorable benefit in most subgroups; although this may be associated with a higher proportion of breast-conserving surgery in early cases, chemotherapy did not show any benefit. In particular, estrogen receptor-negative subgroup patients who received chemotherapy had a poorer prognosis. Conclusions: Although derived from retrospective studies, the results of these analyses revealed trends that may warrant further study.