Inflammatory versus grade III and IV breast cancer and effect of mammogram

Abstract

1545 Background: Inflammatory breast cancer (IBC) is an aggressive manifestation of primary breast cancer. Demographic characteristics and survivality were compared between IBC and grade III and IV breast cancer using SEER data. Methods: SEER dataset were generated according to the manual. After excluding male gender, missing information, sarcomas, lymphoma and/or breast malignancy with different histologic origin, 1,430 IBC and 32,752 non-IBC grade III and IV breast cancer patients were used in the final analysis. In a subpopulation analysis IBC patients were dichotomized into patient who were diagnosed before and after year 2000. Results: There were no significant difference in mean age and white population between IBC and non-IBC patients. In IBC group 45% of patients were married whereas 56%of non-IBC patients were married (p value <0.001). Prevalence of estrogen and progesterone receptor status where very similar between the two groups. Prevalence of metastasis in IBC is much more higher (95.2%) than non-IBC (4.5%) patients. 5-year survivality was 29% for IBC and 74% for non-IBC patients. In a Cox regression model adjusted for age (continuous), race (white vs. non-white), marital status (married vs. not married), estrogen receptor status (positive vs. negative) and progesterone receptor status (positive vs. negative), IBC remained the only significant risk factor with hazard ratio of 4.12 (95% CI: 3.86, 4.41). There is no difference in the 5 year survivality among the IBC patients who were diagnosed before (N=884) and after (N=546) year 2000 (29% and 32% respectively and log-rank p value of 0.85). In a separate Cox regression model, for this sub-population, adjusted for same variables, risk of dying due to IBC was same (hazard ratio 1.00, 95% CI: 0.86, 1.16) between patients who were diagnosed before and after year 2000. Conclusions: IBC has significantly low 5-year survivality as compared to grade III and IV breast cancer patient. Mammogram in this population failed to increase survivality by early diagnosis. No significant financial relationships to disclose.