Overall survival differences between patients with inflammatory and noninflammatory breast cancer presenting with distant metastasis at diagnosis

Inflammatory breast cancer (IBC) is a rare and aggressive disease. Previous studies have shown that among patients with stage III breast cancer, IBC is associated with a worse prognosis than noninflammatory breast cancer (non-IBC). Whether this difference holds true among patients with stage IV breast cancer has not been studied. We tested the hypothesis that overall survival (OS) is worse in patients with IBC than in those with non-IBC among patients with distant metastasis at diagnosis (stage IV disease). We reviewed the records of 1504 consecutive patients with stage IV breast cancer (IBC: 206; non-IBC: 1298) treated at our institution from 1987 through 2012. Survival curves for IBC and non-IBC subcohorts were compared. The Cox proportional hazards model was used to determine predictors of OS. The median follow-up period was 4.7 years. IBC was associated with shorter median OS time than non-IBC (2.27 vs. 3.40 years; P = 0.0128, log-rank test). In a multicovariate Cox model that included 1389 patients, the diagnosis of IBC was a significant independent predictor of worse OS (hazard ratio = 1.431, P = 0.0011). Other significant predictors of worse OS included Black (vs. White) ethnicity, younger age at diagnosis, negative HER2 status, and visceral (vs. nonvisceral) site of metastasis. IBC is associated with shorter OS than non-IBC in patients with distant metastasis at diagnosis. The prognostic impact of IBC should be taken into consideration among patients with stage IV breast cancer.