Second Primary Cancer Risk by Race and Ethnogeographic Region Among Asian American and Pacific Islander Breast Cancer Survivors in the United States
Cody Ramin, Jessica P. Li, Lan Zhang, Kekoa Taparra, Lene H. S. Veiga, Amy Berrington de Gonzalez, Gretchen L. Gierach, Jaimie Z. Shing, Jacqueline B. VoABSTRACT
Background
Second primary cancer (SPC) risk differs by race and ethnicity among U.S. breast cancer survivors, yet limited data disaggregate Asian American (AA) and Pacific Islander (PI) women.
Methods
We identified 64,277 AA and 5455 PI women diagnosed with invasive unilateral breast cancer between 2000 and 2019 (followed through 2020) and survived ≥ 1 year in the Surveillance, Epidemiology, and End Results database. We examined SPC risk (all SPCs, non‐breast SPCs, and site‐specific SPCs) by race (AA, PI) and Asian ethnogeographic regions (East, South, and Southeast). Subdistribution hazard ratios (SHRs) and cumulative incidence of SPCs were estimated, accounting for competing risks.
Results
Over 6.13 median years of follow‐up, 4083 AA women (East = 1922; South = 312; Southeast = 1579; Other/Unknown = 270) and 498 PI women developed SPCs. Overall, PI women had higher SPC risk than AA women (SHR = 1.44, 95% CI = 1.31–1.58), driven by contralateral breast, lung/bronchus, ovarian, and digestive system cancers. Among AA women, South AA women had lower SPC risk than East AA women (SHR = 0.85, 95% CI = 0.75–0.96), driven by lower lung/bronchus, digestive system, and colorectal cancer risk. Southeast AA women had similar SPC risk to East AA women, but lower digestive system cancer risk (SHR = 0.77, 95% CI = 0.66–0.89), and higher uterine (SHR = 1.29, 95% CI = 1.02–1.63) and thyroid cancer risk (SHR = 1.97, 95% CI = 1.47–2.64). One in 10 PI women developed an SPC within 10‐years (10.32%) compared with one in 14 AA women (AA = 6.91%; East AA = 7.66%; South AA = 6.25%; Southeast AA = 7.26%).
Conclusions
SPC risks were highest among PI breast cancer survivors and differed across Asian ethnogeographic regions. These findings highlight the need to understand factors associated with SPC risks and develop tailored interventions to address these disparities.