Prognostic factors of primary neuroendocrine breast cancer: A population‐based study

Abstract

BackgroundPrimary neuroendocrine breast carcinomas (NEBCs) are an extremely rare and underrecognized subtype of mammalian carcinoma. The prognostic factors for NEBCs remain controversial.MethodsIn this multicenter retrospective study, the prognostic factors for patients with primary NEBCs who underwent surgery and had a pathologically confirmed diagnosis of neuroendocrine carcinoma in China and the United States were examined. The endpoints were disease‐free survival (DFS) and overall survival (OS).ResultsA total of 51 Chinese patients and 98 US patients were included. In the Chinese cohort, tumor grade and Ki‐67 levels were prognostic factors for DFS in univariate analysis (hazard ratio [HR] = 5.11 [1.67–15.60], p = 0.004; HR = 57.70 [6.36–523.40], p < 0.001, respectively) and multivariate analysis (HR = 100.52 [1.33–7570.21], p = 0.037; HR = 31.47 [1.05–945.82], p = 0.047, respectively). In the US cohort, age was an important prognostic factor for OS in univariate analysis (HR = 1.09 [1.04–1.15], p = 0.001). The random effects model for the combined cohorts revealed age and positive expression of estrogen receptor (ER) as potential prognostic factors for OS (HR = 1.08 [1.01–1.14], p = 0.015; HR = 0.10 [0.02–0.44], p = 0.003, respectively).ConclusionsTumor grade and Ki‐67 levels are important prognostic factors for DFS of patients with primary NEBCs. Age and ER status are important prognostic factors for OS of patients with primary NEBCs.