Comparison of Rare Types of Breast Cancer

Aims: Mucinous, medullary, and papillary carcinomas are rarely encountered types of breast cancer. This study aims to contribute to the literature by comparing the clinical and prognostic features and treatment alternatives of rare breast carcinomas.
Study Design: Thirty-four patients with rare breast cancer out of a total of 1368 patients who underwent surgery for breast cancer in our clinic between January 2011 and December 2020 were included in the study.
Methodology: The patients were assigned into three groups, i.e., medullary carcinoma group (Group 1), mucinous carcinoma group (Group 2) and papillary carcinoma group (Group 3). Demographic and clinical features, treatment modalities used, surgical approaches, pathological features of tumors and survival were compared between the groups.
Results: Thirty-four patients were included in the study. The mean age of the patients in Group 3 was higher, though it was not statistically significant. Modified radical mastectomy was more frequently performed in all the groups. The number of the lymph nodes removed through axillary dissections and the number of the positive lymph nodes were similar in all the groups. The tumors in all the groups were also of comparable sizes (30 mm in Group 1, 42.5 mm in Group 2 and 30 mm in Group 3; p:0.464). Estrogen receptors were negative in a significantly higher rate of Group 1(66.7% of Group 1, p<0,001). A significantly higher rate of Group 1 received postoperative chemotherapy (93,3% of Group 1,p:0.001), but the rate of the patients receiving hormonotherapy in this group was significantly lower (26.7% of Group, p<0,001). The patients with medullary cancer had significantly longer survival than those with mucinous cancer and those with papillary cancer (76.2 in Group 1, 54.5 in Group 2 and 58.4 in Group 3; p:0.005).
Conclusion: While rare subtypes of breast carcinoma did not affect opting for surgical treatment, selection of oncological therapy was affected depending on the hormone receptor status of these tumors. The long-term survival differed between rare breast tumors. In view of the unique clinical pictures of the tumors, the patients should be evaluated individually, and the evaluation should be associated with theevidence-based principles available for more common breast carcinomas.