Trends in inflammatory breast carcinoma incidence and survival: The surveillance, epidemiology, and end results program at the National Cancer Institute

Abstract

Background: Inflammatory breast carcinoma (IBC) appears to be a clinicopathologic entity distinct from noninflammatory locally advanced breast cancer (LABC). We examined incidence and survival trends for IBC in Surveillance, Epidemiology, and End Results (SEER) Program data with a case definition designed to capture many of its unique clinical and pathologic characteristics. Methods: We analyzed breast cancer cases diagnosed in the SEER 9 Registries (n 180 224), between 1988 and 2000. Breast cancer cases were categorized using SEER's "Extent of Disease" codes in combination with International Classification of Diseases for Oncology morphology code 8530/3 and classified as IBC (n = 3648), LABC (n = 3636), and non-T4 breast cancer (n = 172 940). We compared changes in incidence rates over 3-year intervals by breast cancer subtype and race using SEER*Stat. Survival differences by breast cancer subtype and race were assessed using Kaplan-Meier curves and log-rank statistics. All statistical tests were two-sided. Results: Between 1988 and 1990 and 1997 and 1999, IBC incidence rates (per 100 000 woman-years) increased from 2.0 to 2.5 (P 10 years, P