Abstract 170: Racial differences in stage at diagnosis and survival for premenopausal breast cancer patients.
Authors: Akolkar Namita , Obirieze Augustine , Frederick Wayne , Wilson Lori 
Published: August 2014

BACKGROUND: There are racial/ ethnic disparities in breast cancer survival rates in the US. Tumor stage at diagnosis has long been a prognostic factor in breast cancer. Our objective was to determine whether there are racial disparities in tumor stage at diagnosis of breast cancer in pre-menopausal women, using a large national cancer registry.

METHODS: We conducted a retrospective analysis using data from the Surveillance Epidemiology and End Results database for 1996-2006. Premenopausal (≤50 years) women with primary diagnosis of breast cancer were identified using appropriate ICD-O-3 codes (C500-C509). Comparing racial/ethnic groups, with white race as the reference, multivariate logistic regression was used to assess the odds of late stage (stage III or IV) versus early stage (stage I or II) diagnosis at presentation, adjusting for prognostic factors, tumor characteristics, and year differences. All statistical tests were two-sided.

RESULTS: A total of 86,570 women met our inclusion criteria. Of those, 56,811 (65.62%) were White, 10,789 (12.46%) were Hispanic, 9,896 (11.43%) were Black, 8,115 (9.37%) were Asian or Pacific Islanders, 544 (0.63%) were Native American and for 415 (0.48%) women the race was unknown. A majority of patients were 46-50 years old (43%) and married (65%) at the time of diagnosis. Most were diagnosed with stage II (46%), invasive ductal (93%) histology, 1.1-2cm (36%) in size, poorly differentiated (45%), and without distant metastasis (96%). On multivariate analysis, compared to white women, Black women had 58% higher adjusted odds (OR: 1.58; 95% CI: 1.49-1.68) and Hispanic women had 37% higher odds (OR: 1.37; 95%CI: 1.29-1.46) of having late stage versus early stage breast cancer at time of diagnosis. Figure 1 shows the race specific percent of women diagnosed with late stage cancer across the years. Cancer-specific mortality rates were 10.1% for whites, 21.1% for blacks, 13.4% for Hispanics, 17.6% for Native Americans, and 9.6 % for Asians (p value &lt;.001).

CONCLUSIONS: Utilizing a large cohort of premenopausal women diagnosed with breast cancer our study showed African-American and Hispanic women have higher incidence of diagnosis of late stage breast cancer as compared to their white counterparts. They as well as Native Americans also have higher cancer specific mortality rates as compared to their white and Asian counterparts. This study provides evidence that premenopausal African-American and Hispanic women represent a high-risk group that will benefit from identification of factors that contribute to late stage at presentation.

Figure 1: Percent of women in each race diagnosed with late stage breast cancer over time.

Citation Format: Namita Akolkar, Augustine Obirieze, Wayne Frederick, Lori Wilson. Racial differences in stage at diagnosis and survival for premenopausal breast cancer patients. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 170. doi:10.1158/1538-7445.AM2013-170