Breast conserving surgery for non-metastatic inflammatory breast cancer: A National Cancer Database (NCDB) study

Abstract Background: Single center studies have suggested breast conserving surgery (BCS) as treatment for inflammatory breast cancer (IBC). Given its infrequency, a multi-hospital database study is useful. This study reports the characteristics, outcomes, and prognostic factors of women with non-metastatic IBC who underwent BCS. Methods: The National Cancer Database (NCDB) was queried for women ≥18 years old with cT4dN0-3M0. Outcomes were compared between treatment groups. A Cox proportional hazards model assessed the relationship of variables and the overall survival (OS). Results: A total of 12,223 women were treated as follows: no surgery (12.8%), BCS (3.3%), and mastectomy (83.9%). BCS was significantly more common in academic/research institutions, South and North-East hospitals, no special type histology, triple negative breast cancer, single quadrant tumors, and node-negative tumors. Most patients who underwent BCS received chemotherapy (86.2%) and radiation therapy (61.9%), while hormonal therapy was infrequent (37.1%). Mortality was higher with BCS than mastectomy at 30 (1.3% versus 0.3%, p<0.001) and 90 (6.8% versus 1.5%, p<0.001) days post-surgery. Three- and five-year OS post-BCS was lower compared to mastectomy but higher than no surgery. Prognostic factors of OS for patients who underwent surgery included academic/research institutions, income ≥$63,000, hormone positive tumors, and receipt of chemotherapy and radiation therapy. Conclusion: BCS is offered to select women with non-metastatic IBC across NCDB participating hospitals. Caution is necessary while studying if surgery can be de-escalated in IBC. Standardized multidisciplinary care along with mastectomy remains the norm for patients with non-metastatic IBC. Citation Format: Fernando A. Angarita, Stephen B. Edge, Kristopher Attwood, Kazuaki Takabe, Jessica Young. Breast conserving surgery for non-metastatic inflammatory breast cancer: A National Cancer Database (NCDB) study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-24-05.