Abstract P3-08-66: Metaplastic breast cancer in patients older than 65 years

Abstract

Abstract Background: Metaplastic breast cancer (MBC) is a rare histologic subtype of breast cancer. It comprises less than 1% of all breast cancers. We evaluated the clinical characteristics and outcomes of MBC in geriatric patients older than age 65. Methods: We reviewed the chart of the pathologically proven MBC cases from 2000-2017. Only patients with age more than 65 years were included in the study for analysis. Results: A total of 48 MBC patients were included in the study. Thirty-six (76%) were white and 11 (23%) black. The number of patients in stages I, II, III, and IV were 12, 26, 6, and 4, respectively; 39 (81%) had nuclear grade III. Three (6%) had progesterone receptor positive, 3 (6%) were Her2 positive, and 4 (10%) were estrogen receptor positive. The most common distant metastases were lung (20%), followed by bone (12%). Fifty percent had a lumpectomy, 11% had hormonal therapy, and 60% had radiation therapy. Only 50% of patients received chemotherapy, out of which 46% received anthracycline. On univariable analysis, stage of the MBC and metastasis to the lung, bone, and brain were associated with worse overall survival (OS). There was no statistical significance in OS when stage II was compared with stage I MBC. Stage III had median OS of 18 months with HR of 3.25 (95% CI 0.85, 12.44) (p=0.086) and stage IV had 10 months median OS with HR of 11.17, (95% CI 2.37, 52.62) (p=0.002). Hormonal therapy, radiation therapy, and type of chemotherapy (anthracycline vs. non-anthracycline) did not show any statistical significance in regards to OS and progression-free survival. Conclusion: In our study, MBC demonstrated overall poor survival and progression-free survival. Only stage of the MBC and metastasis to brain bone and lung proved to predict worse survival. Citation Format: Johnny Chahine, Bicky Thapa, Xuefei Jia, Abdo Haddad. Metaplastic breast cancer in patients older than 65 years [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-66.