Increase in postmenopausal women with distant stage breast cancer in the United States over the last 18 years: Who is the most at risk?
Authors: Aliabadi Arya , Liao Cheng-I , Eakin Cortney , Johnson Caitlin Ruth , Chan Chloe , Kapp Daniel Stuart , Cohen Joshua Garrett , Chan John K 
Published: June 2022

10537 Background: In the United States, Asian women have traditionally been considered at low risk for breast cancer; yet it is unknown how distant stage disease has trended by geographic, demographic, and modifiable risk factors since 2001. Methods: Data were obtained from the United States Cancer Statistics (USCS) program from 2001-2018, the Behavioral Risk Factor Surveillance System (BRFSS) from 2000-2018. SEER*Stat 8.3.9.2 and the Joinpoint regression program 4.9.0.0 were used to calculate the incidences and trends of distant stage breast cancer per 100,000 women. The trend was presented as average annual or biennial percent change (AAPC or ABPC). Results: Using the USCS program, the overall incidence of postmenopausal breast cancer decreased from 367.90 to 345.07 (per 100,000); however, the incidence of distant stage cancer increased from 16.75 to 19.77 (per 100,000) over 18 years. The incidence is the highest for Black, followed by White, Hispanic, and Asian women at 27.14, 19.86, 14.15, and 11.98 (per 100,000) in 2018, respectively. The annual increase is highest in Asian, followed by Black, White, and Hispanic women at 2.28%, 1.44%, 1.17%, and 0.87% (P < 0.001), respectively. On intersection analysis, postmenopausal Asian women living in the Northeast have the highest annual rise at 2.54% (P = 0.004). BRFSS data revealed that the proportion of women non-compliant with screening mammograms decreased from 36.03% in 2000 to 20.93% in 2018. In 2018, Asian women were the most non-compliant followed by Hispanic, Black, and White women at 40.99%, 40.06%, 21.67%, and 18.17%, respectively. Over time, White, Black, and Hispanic women improved on compliance by 3.43%, 3.32%, and 1.24% (p < 0.05) on screening rates biennially; however, Asian women have not made any improvement (ABPC 0.80%, p = 0.410). On intersectional analysis, the most non-compliant group in 2018 were Asian women in the Midwest at 54.48%. We then evaluated upstream social determinants of breast cancer, such as obesity. While the baseline incidence of obesity in Asian Americans is low compared to other racial groups, it has increased from 9.22 in 2001 to 13.67 (per 100,000) in 2016. Specifically, the incidence of obesity increased the most in postmenopausal Asian 65 to 74-year-olds at 3% compared to White, Hispanic, and Black Americans of the same age group at 2.5%, 2.2%, and 1.1% (p < 0.05), respectively. Conclusions: Although the incidence of breast cancer has decreased in the United States since 2001, the rate of distant stage breast cancer continues to rise. Postmenopausal Asian women with distant stage breast cancer are increasing at the highest rate compared to other racial groups. Further, Asian women are more non-compliant with screening mammograms and have an increased rate of obesity. Tailored interventions are warranted to enhance primary and secondary prevention and decrease distant stage cancer in this high-risk group.