Clinicopathologic Characteristics and Outcome Descriptors of Metaplastic Breast Carcinoma

Abstract

Context.— Metaplastic breast carcinoma is an aggressive form of breast cancer that accounts for 0.5% to 3% of all breast cancers. Objective.— To study the clinicopathologic characteristics and outcomes of this rare disease. Design.— Retrospective study of patients with a diagnosis of metaplastic breast carcinoma between 2000 and 2019. Hematoxylin-eosin–stained slides were reviewed and additional clinical data were obtained from electronic medical records. Univariable and multivariable Cox proportional hazard regression analyses were used to determine associations between overall survival and several clinicopathologic variables. Results.— Of the 125 patients with metaplastic breast carcinoma identified, only patients with high-grade disease (N = 115) were included in the data analysis. A total of 38 participants (33%) were white, 66 (57%) were African American, and 11 (10%) belonged to other ethnicities. The median age at diagnosis was 57 years. The median tumor size was 3 cm. Heterologous histology was seen in 30% of cases. Multivariable analyses showed that patients with a larger tumor size had worse overall survival (hazard ratio [HR], 1.25; 95% CI, 1.10–1.44; P < .001). Distant metastatic disease was also associated with worse overall survival on multivariable analysis (HR, 10.27; 95% CI, 2.03–55.54; P = .005). In addition to treatment with either partial or complete mastectomies, 84 patients (73%) received chemotherapy. Multivariable analyses showed that chemotherapy had no effect on overall survival (HR, 0.53; 95% CI, 0.09–6.05; P = .55). Conclusions.— A larger tumor size and distant metastatic disease are associated with worse overall survival in patients with metaplastic breast carcinoma. Additional studies are needed to further characterize our findings.

Establishment of prognostic model for postoperative patients with metaplastic breast cancer: Based on a retrospective large data analysis and Chinese multicenter study

“…These emphasizes that we might need to consider to the effect of non-biologic stressors on the disease in the future. However, additional multicenter studies are needed to further characterize these findings ( Abada et al, 2022 ).…”

The mixed subtype has a worse prognosis than other histological subtypes: a retrospective analysis of 217 patients with metaplastic breast cancer

“…Multiple reports, including our study, have found the mixed subtype to be an unfavorable factor [ 12 , 13 , 15 , 16 ]. Many authors regarded tumor size was correlated with survival [ 12 , 13 , 15 , 23 , 24 ]. However, one multi-center research indicated that only lymph node status and lymphovascular invasion influenced prognosis, not tumor size and histological grade [ 9 ].…”

“…MpBC has little response to NAC, with previous studies showing the pCR rate in the range of 0–17% [ 7 , 15 , 16 , 23 , 24 , 39 ]. A recent prospective trial (NCT02276443) showed the pCR rate reaching 23% [ 40 ].…”

Estrogen receptor status has no prognostic relevance in metaplastic breast carcinoma

“…We have previously described our experience with MBC as a rare subtype of breast cancer. [ 10 ] However, in the current study, we have provided additional clinical information on the relevance of ER status in MBC, given that most cases are triple-negative. Following our review, the median age at diagnosis for all MBC patients was 57 years and this finding is similar to what has been previously reported in other studies.…”

“…We searched our institution’s database between January 2000 and April 2019 to identify patients diagnosed with MBC during this time. As previously reported, search terms used included “metaplastic breast carcinoma”, “carcinosarcoma”, “breast carcinoma with metaplasia”, “squamous cell carcinoma”, “spindle cell carcinoma”, “carcinoma with sarcomatoid metaplasia”, “carcinoma with osseous or bony metaplasia”, “carcinoma with chondroid metaplasia”, and “breast carcinoma with osteoclastic giant cells.” [ 10 ] We reviewed patient’s demographic information, tumor characteristics (tumor size, histologic differentiation, tumor focality, histologic grade, lymphovascular invasion, lymph node metastasis, distant metastasis, estrogen receptor [ER], progesterone receptor [PR], human epidermal receptor-2[(HER-2], Ductal Carcinoma in situ [DCIS], and fibrocystic breast disease), comorbidity (obesity, smoking, history of prior cancers), treatment received, and OS. [ 10 ] Clinical tumor size was based on the largest size recorded by gross pathologic examination.…”