Development of CNS metastases and survival in patients with inflammatory breast cancer

BACKGROUND: Inflammatory breast cancer (IBC) is associated with a poor prognosis and high risk of central nervous system (CNS) metastases. METHODS: We retrospectively reviewed stage III-IBC patients compared with noninflammatory invasive ductal carcinoma (NI-IDC) patients treated between January 1, 1984, and December 31, 2011, who began primary treatment within 1 year of diagnosis and had been followed up for at least 1 year before the development of CNS metastasis or death. Cumulative CNS metastasis incidence and post-CNS metastasis overall survival (OS) estimates were computed. Multivariable Cox proportional hazard models explored factors for post-CNS metastasis survival. RESULTS: A total of 2323 patients were identified (589-IBC/1734-NI-IDC). Eighty-one IBC patients developed CNS metastasis, versus 154 NI-IDC patients. The 2-, 5-, and 10-year cumulative CNS metastasis incidence rates in IBC and NI-IDC were 9.8%, 15.8%, 17.4% and 6.5%, 10.1%, and 12.7%, respectively. This was significantly different between IBC and NI-IDC patients (P =.0037). Multicovariate competing risk regression models in IBC and NI-IDC patients showed no statistically significant associations with the risk of developing CNS metastasis, except neoadjuvant taxane use in NI-IDC patients (hazard ratio, 0.45; 95% confidence interval, 0.24-0.83; P =.011). The median follow-up was 7.2 years, and the median post-CNS metastasis OS was not significantly different between IBC (7.6 months) and NI-IDC (5.6 months) patients. One hundred ninety patients with CNS metastasis died. HER2-positive patients had better OS, with a median 14.1 versus 4.3 months (P <.0001). Age >50 years (P =.012) but not IBC status was a significant predictor of post-CNS metastasis survival. CONCLUSION: IBC patients demonstrated higher CNS metastasis incidence rates but OS following CNS metastases is similar in both groups. HER2 status and age may play prognostic roles. Cancer 2018;124:2299-305.