Abstract C017: Breast cancer trends and disparities in an urban setting
Authors: Juon Hee-Soon , McIntire Russell , Keith Scott , Zeigler-Johnson Charnita 
Published: August 2020

Background: Although efforts have been made to decrease breast cancer disparities, recent changes in breast cancer screening recommendations can influence cancer trends by race/ethnicity. The goal of this descriptive study was to determine how recent trends in breast cancer vary by race/ethnicity in a multiethnic, urban setting.

Methods: We obtained PA cancer registry data and female breast cancer rates of patients residing in Philadelphia County (2005-2014). Race was categorized based upon data in the Cancer Registry as all cases (all races), and the most prevalent groups of cases, including white/Caucasian (47%), black/African American (46%), Hispanic (4%) and Asian (3%). Our sample of the 4 major race/ethnic groups included 10,801 women. We conducted descriptive analyses using chi-square tests for categorical variables and Kruskal-Wallis tests for continuous variables. Patient characteristics included incidence, advanced tumor stage (regional and distant disease), and advanced tumor grade (poorly differentiated or undifferentiated). We also calculated the percent change in incidence and mortality rates by race/ethnicity. A cut-point of 50 years were used to examine trends in incidence among younger vs. older patients.

Results: The median age at breast cancer diagnosis differed significantly by race/ethnicity (p&lt;0.001). White women were among the oldest at diagnosis (median age 65). Asian women were among the youngest (median age 53). More black women (18%) died from breast cancer compared to white (13%), Hispanic (12%) and Asian women (11%, p&lt;0.001). Advanced tumor grade was most common among Asian women (51%) and lowest among white women (33%, p&lt;0.001). Distant stage was most common among black women (10%) and compared to each of the other groups of women (8%, p&lt;0.001). Breast cancer rates were not available across many of the years for Asian and Hispanic women. However, trends in breast cancer incidence showed that Hispanic women had lower incidence at every point in time than black or white women. Percent change in incidence rates increased by 17% in Hispanics vs. 11% in white and 4% in black women. Among older women (age 50+), breast cancer incidence increased by 17% among black women and 10% among white women. Among young women (&lt;age 50), the incidence increased by 32% among white women but decreased by 16% among black women. Among older women, advanced-stage breast cancer was consistently most common among blacks. However, among younger women, recent trends show that white women now have the highest rates of advanced-stage disease. Breast cancer mortality was consistently highest for black women, although mortality rates have decreased over time. The decrease in mortality was 21% in white women and 15% in black women.

Conclusion: We observed race/ethnic differences in breast cancer trends in patient age, tumor characteristics, and disease rates. Future studies should examine factors that have influenced recent shifts in breast cancer incidence and mortality among diverse populations.

Citation Format: Hee-Soon Juon, Russell McIntire, Scott Keith, Charnita Zeigler-Johnson. Breast cancer trends and disparities in an urban setting [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C017.