Abstract P5-12-21: The utility of antiestrogen therapy in early-stage, pure mucinous carcinomas of the breast

Le résumé fourni par la source

Abstract Background: Pure mucinous breast tumors are rare and characterized by cluster-like hyperplasia of tumor cells floating in extracellular mucous fluid, comprising 90% of the tumor mass. Despite their generally favorable prognosis, optimal management, particularly regarding antiestrogen therapy, in small (less than or equal to 3 cm), node-negative breast cancers, remains uncertain. Methods: We conducted a retrospective review of 77 women treated between 2010 to 2018 and diagnosed with node-negative, pure mucinous breast tumors less than or equal to 3 cm, with a follow-up period of at least 5 years. Factors including age, type of surgery, margin status, adjuvant therapies, and treatment outcomes were analyzed. Patients with non-pure mucinous histology were excluded. Results: Of the 163 patients identified, 86 were excluded due to non-pure mucinous histology, nodal involvement, tumors >3 cm, or less than 5 years of follow-up. The median age at diagnosis was 70 years (range 40-88), with a median follow-up of 93 months (range 60-158). Average tumor size was 1.42 cm (range 0.10-3.0 cm). Surgical management included lumpectomy alone in 4 patients (5.2%), lumpectomy with lymph node evaluation in 53 patients (68.8%), and mastectomy with or without lymph node evaluation in 20 patients (26.0%). Adjuvant treatments included radiation in 38 patients (49.4%) and endocrine therapy with aromatase inhibitor or tamoxifen in 45 patients (58.5%). Of these, 2 patients received chemotherapy followed by endocrine therapy (2.6%). 36 patients (46.8%) completed at least 5 years of endocrine therapy. Only 3 (3.9%) local recurrences were seen and no distance recurrences. Of the patients with a local recurrence, none of them completed 5 years of antiestrogen therapy following breast conservation and 2 received radiation. The average time to recurrence was 69 months (range 30-120). Overall survival was 88.3%, and breast cancer-specific survival was 100%. Conclusions: Our findings call attention to reconsidering the necessity of antiestrogen therapy for pure mucinous breast tumors less than or equal to 3 cm with node-negative status, given the very low local recurrence rate observed overall. Despite fewer than half of patients completing a 5-year course of antiestrogen therapy, no distant recurrences or breast cancer related deaths were observed with a median follow-up exceeding 7 years, suggesting a limited benefit with antiestrogen therapy. These results underscore the favorable prognosis of mucinous carcinomas, supporting a more personalized approach for adjuvant endocrine therapy recommendations, such as considering patient comorbidities and life expectancy. Further research with larger cohorts and extended follow-up would be beneficial to further refine treatment guidelines for early stage mucinous breast carcinomas. Citation Format: The utility of antiestrogen therapy in early-stage, pure mucinous carcinomas of the breast. The utility of antiestrogen therapy in early-stage, pure mucinous carcinomas of the breast [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P5-12-21.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.