Clinicopathological and survival analysis of primary spindle cell carcinoma of the breast in Chinese patients.

ABSTRACT

Due to the low prevalence of Spindle cell carcinoma (SpCC) of the breast, the perception of the disease was limited. The aim of our study was to analyze the clinicopathological features, survival outcomes and prognostic factors of SpCC of the breast among Chinese. Patients diagnosed with SpCC of the breast in Cancer Hospital of Chinese Academy of Medical Sciences between 2004 to 2021 were retrospectively analyzed. Additionally, we searched Chinese databases and Pubmed websites for literature on breast SpCC in Chinese patients. The clinicalpathological characteristics, survival outcomes and prognostic factors were evaluated. A total of 160 eligible cases were enrolled, including 23 patients in our center and 137 cases from the literature search. The median age was 52 years old (range, 22-88). 84.8% (101/119) cases were in the early stage (stage I and II). 15.0% (20/133) had axillary lymph node involvement. The majority of patients were HR-HER2- (85.4%, 98/137). 77.5% (79/102) patients received adjuvant chemotherapy. 36.9% (31/84) of patients received adjuvant radiation. Of 126 patients available for a median follow-up with 38 (range, 1-211) months, 58 cases (46.0%, 58/126) recurred, including 31.0% (18/58) who had local recurrence and 69.0% (40/58) who had distant metastasis. The most common distant metastatic site was the lung (41.4%, 24/58). Most patients (91.5%) had recurrence within 3 years. The Kaplan-Meier curves showed that the 3-year and 5-year disease-free survival (DFS) were 55.9% and 46.8%, and the 3-year and 5-year overall survival (OS) were 67.0% and 54.9%, respectively. T stage was an independent prognostic factor for OS (T1-2 vs T3-4, HR=0.362, 95% CI 0.139-0.945, P=0.038). Although SpCC of the breast was often diagnosed in the early stage with low lymph node involvement, the prognosis was poor. T stage was an indicator of prognosis for OS. Better treatments need to be explored to prevent recurrence and improve survival.