Abstract P3-14-10: Breast cancer patterns, behavior and survival among American Indians in the west north central region and the other regions of the U.S.

Abstract

Abstract Purpose: American Indians (AIs) constitute the single largest racial minority in North Dakota and South Dakota. There are no studies looking at what sociodemographic or biological factors may play a role in affecting outcomes and mortality of breast cancer (BC) among AIs in the United States. Our study compared the BC patterns, behavior, and survival of AIs living in the West North Central Region (WNCR) of the U.S (which includes ND, SD, MN, NE, IO, KS, MO) to the AI BC patients in the remainder of the country. Methods: We used the records of all AI BC patients diagnosed between the years 2004-2016 from The National Cancer Database participant user files. All analyses were conducted using SPSS software (version 25). Results: Records were available for 6,466 AI BC patients, 798 were in the WNCR. There was no difference between WNCR and other regions in the stage distribution, mean age at diagnosis, morphology, hormonal/HER2 status, tumor size, lymph node status, or second cancers. The WNCR patients had less private insurance, lived in zip codes with lower median income, had more co-morbidities, and traveled longer distances for care (p<0.001 for each). They had higher grade cancers (p<0.001) at diagnosis. The WNCR patients were less likely to have received radiation therapy (p=0.015) but more likely to have received chemotherapy (p<0.001) and hormonal therapy (p=0.009) and had longer inpatient stay days after surgery (p<0.001). Time to first treatment and first treatment within 90 days (88.0% vs. 79.7%, p<0.001) was significantly better in the WNCR than in other regions of the country. Five year mortality rate was higher (16.3% vs. 11.1%, p<0.001) and cumulative survival was lower (p<0.001) in the WNCR as compared to AIs in other regions of the country. Univariate/multivariate analysis failed to identify variables that could explain the differences in 5 year mortality or cumulative survival between WNCR and other regions. Conclusion:AIs with BC in the WNCR had worse 5 year mortality and cumulative survival as compared to AIs in other regions in the US. Our analysis could not identify variables that explained the differences in mortality or cumulative survival between WNCR and other regions. Citation Format: Anu G Gaba, Li Cao, Rebecca Renfrew, Deann Witte, Janet Wernisch, Denise Lutkemeier, Kristi Egland, Ross Crosby. Breast cancer patterns, behavior and survival among American Indians in the west north central region and the other regions of the U.S. [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 P3-14-10.