Identifying factors that impact survival among women with inflammatory breast cancer

Abstract

The objective of this retrospective study was to determine factors impacting survival among women with inflammatory breast cancer (IBC). The Surveillance, Epidemiology and End Results Registry (SEER) was searched to identify women with stage III/IV IBC diagnosed between 2004 and 2007. IBC was identified within SEER as T4d disease as defined by the sixth edition of the American Joint Committee on Cancer. The Kaplan-Meier product-limit method was used to describe inflammatory breast cancer-specific survival (IBCS). Cox models were fitted to assess the multivariable relationship of various patient and tumor characteristics and IBCS. Two thousand three hundred and eighty-four women with stage IIIB/C and IV IBC were identified. Two-year IBCS among women with stage IIIB, IIIC and IV disease was 81%, 67% and 42%, respectively (P < 0.0001). In the multivariable model, patients with stage IIIB disease and those with stage IIIC disease had a 63% [hazard ratio (HR) 0.373, 95% confidence interval (CI) 0.296-0.470, P < 0.001] and 31% (HR 0.691, 95% CI 0.512-0.933, P = 0.016) decreased risk of death from IBC, respectively, compared with women with stage IV disease. Other factors significantly associated with decreased risk of death from IBC included low-grade tumors, being of white/other race, undergoing surgery, receiving radiation therapy and hormone receptor-positive disease. Among women with stage IV disease, those who underwent surgery of their primary had a 51% decreased risk of death compared with those who did not undergo surgery (HR = 0.489, 95% CI 0.339-0.704, P < 0.0001). Although IBC is an aggressive subtype of locally advanced breast cancer, it is heterogeneous with various factors affecting survival. Furthermore, our results indicate that a subgroup of women with stage IV IBC may benefit from aggressive combined modality management.