Modern Demographics, Oncologic Outcomes, And Prognostic Factors In Women With Inflammatory Breast Cancer

Inflammatory breast cancer (IBC) is an aggressive subtype of breast cancer. The current treatment paradigm is trimodality approach with neoadjuvant chemotherapy, modified radical mastectomy (MRM), and post-mastectomy radiation therapy (PMRT). Advancements in systemic therapy have improved survival increasing the importance of locoregional control. Even with improving outcomes, survival rates remain unsatisfactory prompting the need to identify individuals that may benefit from treatment intensification. We report tumor characteristics, patient demographics, and oncologic outcomes of IBC in the modern era in order to identify subgroups with poor outcomes. We searched the Surveillance, Epidemiology, and End Results (SEER) database for women with breast cancer. This cohort was narrowed to women with non-metastatic [Adjusted AJCC 6th M (1988+) M0] IBC [Adjusted AJCC 6thT (1988+) T4d] with MRM [(1998+) Breast] with or without external beam PMRT. To be included, patients were treated with either ipsilateral MRM with or without reconstruction with the specified race, age, hormone receptor [ER/PR Status], grade, nodal stage [(1988+)], marital, and radiation data. A minimum of 5 years of follow-up was required. We report the actuarial 5-year cause-specific survival. We identified a cohort of 4841 women treated between 1998 and 2007. The median age of diagnosis was 55. The actuarial 5-year CSS for the whole cohort was 56% (95% CI; 54.0-57.2). Black women made up 13% while white women, other races, and unknown represented 81%, 6%, and <1% respectively. Blacks, whites, and other had 5-year CSS of 42% (37.3-46.0), 58% (55.8-59.3), and 59% (51.8-64.9) respectively. Blacks had a statistically significant (SS) lower CSS than the other groups. PMRT (n = 2903) had a SS benefit compared to no RT (n = 1439) with 5-year CSS of 59% (57.3-61.3) and 49% (46.7-52.4) respectively. Women over 70 years of age had a SS lower CSS compared to women between 50-69, but not when compared to ages 20-49. Patients with high-grade histology had a SS lower CSS than intermediate and low-risk patients with CSS of 49% (47-51.8), 68% (64.6-70.8), and 82% (71.6-89.1) respectively. Negative hormone receptor status or being divorced/widowed was also associated with SS worse survival compared to receptor positive disease and being married respectively. Our study confirms that IBC has several tumor factors are associated with worse survival and suggests some patient factors are associated with health disparity. As such, select patients (e.g. black women) may benefit from individualized treatment intensification including additional adjuvant systemic therapy and/or dose escalated PMRT. Select patients may also benefit from more intense post-treatment surveillance and support. Long-term follow-up and prospective data, if feasible, is needed to confirm our findings and conclusions.