Abstract
Breast cancer is the most commonly diagnosed cancer and the leading cause of death in women worldwide. Yet the racial/ethnic disparity in incidences and distributions of breast cancer remains largely unknown. To examine the racial/ethnic patterns associated with the incidence of the subtypes of breast cancer and distribution of patients across clinicopathological variables. This population-based cohort study analyzed data from the Surveillance, Epidemiology, and End Results (SEER) database, which collected data from 18 SEER cancer registries that identified patients with breast cancer in the US diagnosed between January 1, 2010, and December 31, 2015. The inclusion criteria were (1) female patients with primary unilateral breast cancer who underwent surgical treatment; (2) record of estrogen receptor, progesterone receptor, and ERBB2 status; (3) record of medical history and histological subtype of the specified tumor location; and (4) data on patient race/ethnicity, lateral tumor position, tumor size, tumor TNM stage, and number of tumors. Incidence and distribution rates were identified and compared for different molecular subtypes, histological grades, pathological patterns, T stages, TNM stages, and tumor sites of breast cancers for each racial/ethnic group. Patient race/ethnicity was classified as follows: non-Hispanic White, Hispanic White, Black, Asian/Pacific Islander, American Indian/Alaskan Native, and unknown. Data were analyzed from January 1, 2010, to December 31, 2015. Incidence rates of 4 molecular subtypes: hormone receptor (HR)-positive and ERBB2-negative, HR-positive and ERBB2-positive, HR-negative and ERBB2-positive, and triple-negative breast cancer (TNBC). Data on distribution by histological grades (grades 1-4 and unknown), pathological patterns, T stages, TNM stages, and tumor sites was also extracted. Annual age-standardized incidence rates and incidence rate ratios (IRRs) were calculated with 95% CIs. Race/ethnicity case-to-case odds ratios were estimated using polytomous regression. A total of 239 211 women with breast cancer were analyzed (median [interquartile range]) age, 60 [50-69] years). The annual incidence rate of all breast cancers was 31.3 (95% CI, 31.2- 31.5) per 100 000 people in non-Hispanic White women (the reference group), which was higher compared with the incidence among Black women (IRR, 1.04; 95% CI, 1.02-1.05; P < .001). The incidence rates were also lower in Asian/Pacific Islander (IRR, 0.90; 95% CI, 0.89-0.92; P < .001), American Indian/Alaskan native (IRR, 0.82; 95% CI, 0.81-0.83; P < .001), and Hispanic White women (IRR, 0.79; 95% CI, 0.75-0.83; P < .001). In Black patients, the incidences of the HR-positive and ERBB2-positive (IRR, 1.12; 95% CI, 1.08-1.16; P < .001), HR-negative and ERBB2-positive (IRR, 1.46; 95% CI, 1.38-1.54; P < .001), and TNBC (IRR, 2.07; 95% CI, 2.01-2.14; P < .001) subtypes were higher than those in non-Hispanic White patients, but the incidence of the HR-positive and ERBB2-negative subtype in Black women was lower (IRR, 0.86; 95% CI, 0.84-0.87; P < .001). The incidences of histological grade 1 (IRR, 0.75; 95% CI, 0.73-0.78; P < .001) and grade 2 (IRR, 0.91; 95% CI, 0.89-0.93; P < .001) were lower in Asian/Pacific Islander vs non-Hispanic White patients. Non-Hispanic White patients had a higher proportion of lobular carcinoma (9.7% [n = 15 718]) and tubular adenocarcinoma (0.6% [n = 997]) than Black (7.2% [n = 1933]; 0.3% [n = 81]), Asian/Pacific Islander (5.7% [n = 1202]; 0.3% [n = 55]), Hispanic White (7.2% [n = 1985]; 0.3% [n = 88]), and American Indian/Alaskan Native patients (7.2% [n = 101]; 0.4% [n = 5]). This cohort study found notable disparities in incidences and proportions of different molecular subtypes, histological grades, pathological patterns, T stages, TNM stages, and tumor sites associated with race/ethnicity. The findings suggest that combining epidemiologic with genomic and molecular profiling data warrants further research.
Highlights
Breast cancer is the most commonly diagnosed cancer and the leading cause of death in women worldwide.1,2 Despite recent advances in treatment and prognosis of this disease, the racial/ethnic gap in incidence and death rates has widened
The annual incidence rate of all breast cancers was 31.3 per 100 000 people in non-Hispanic White women, which was higher compared with the incidence among Black women (IRR, 1.04; 95% CI, 1.02-1.05; P < .001)
The incidence rates were lower in Asian/Pacific Islander (IRR, 0.90; 95% CI, 0.89-0.92; P < .001), American Indian/Alaskan native (IRR, 0.82; 95% CI, 0.81-0.83; P < .001), and Hispanic White women (IRR, 0.79; 95% CI, 0.75-0.83; P < .001)
Summary
Breast cancer is the most commonly diagnosed cancer and the leading cause of death in women worldwide. Despite recent advances in treatment and prognosis of this disease, the racial/ethnic gap in incidence and death rates has widened. In the United States, the incidence of breast cancer is higher among Black and White individuals younger than 45 years, whereas the rate in White women between the ages of 60 and 84 years is substantially higher than in Black women.. The incidence in Black women is lower, the mortality rate is higher in Black women than in White women.. A propensity-matched study using the National Cancer Data Base reported that, among female patients with hormone receptor (HR)–positive breast cancer, Black women had twice the risk of death compared with White women.. Miller et al reported that, in a study of more than 1.3 million women in the US who were diagnosed with breast cancer between 2001 and 2009, the survival rate for Black women was consistently 10 percentage points lower than for White women, and this disparity persisted over time In the United States, the incidence of breast cancer is higher among Black and White individuals younger than 45 years, whereas the rate in White women between the ages of 60 and 84 years is substantially higher than in Black women. the incidence in Black women is lower, the mortality rate is higher in Black women than in White women. A propensity-matched study using the National Cancer Data Base reported that, among female patients with hormone receptor (HR)–positive breast cancer, Black women had twice the risk of death compared with White women. Miller et al reported that, in a study of more than 1.3 million women in the US who were diagnosed with breast cancer between 2001 and 2009, the survival rate for Black women was consistently 10 percentage points lower than for White women, and this disparity persisted over time
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.