Racial/ethnic differences in breast cancer survival by inflammatory status and hormonal receptor status: an analysis of the Surveillance, Epidemiology, and End Results data

Abstract

Background Compared to non-inflammatory breast cancer (non-IBC), inflammatory breast cancer (IBC) has less favorable survival and is more likely to be estrogen receptor (ER) and progesterone receptor (PR) negative. ER+/PR+ tumors, regardless of histology, have less favorable survival. While black women are more likely to have IBC and ER+/PR+ tumors than white women, it is unclear whether the racial disparity in survival is explained by these factors. The objective of this study was to assess racial/ethnic differences in breast cancer survival by inflammatory histology and hormone receptor status. Methods This study examined breast cancer mortality among non-Hispanic white (NHW), Hispanic white (HW), black, and Asian/Pacific Islander (API) women diagnosed between 1990 and 2004. Kaplan-Meier survival curves and Cox proportional hazard ratios (HRs) assessed the relationship between race/ethnicity and survival. Results Black women had significantly poorer survival than NHW women regardless of inflammatory histology and hormone receptor status. Compared to NHWs, the HRs for black women were 1.32 (95% CI 1.21–1.44), 1.43 (95% CI 1.20–1.69) and 1.30 (95% CI 1.16–1.47) for IBC, IBC with ER+/PR+, and with ER−/PR−, respectively. Similar HRs were found for non-IBC, non-IBC with ER+/PR=, and non-IBC with ER−/PR−. API women had significantly better survival than NHW women regardless of inflammatory histology and hormone receptor status. Conclusion Compared to NHW women, black women had poorer survival regardless of inflammatory status and hormone receptor status and API women had better survival. These results suggest that factors other than histology and hormone receptor status may play a role in racial/ethnic disparities in breast cancer survival.

Racial Disparities in Breast Cancer Diagnosis and Treatment by Hormone Receptor and HER2 Status

“…For triple negative breast cancer in particular, the most aggressive subtype of the disease (17), African American women had 30–40% higher risk of being diagnosed at stage II–IV and 60% more likely to receive inappropriate treatment compared to non-Hispanic white women. These differences in stage distribution and cancer treatment may explain the poorer survival outcomes experienced by African American women with triple negative breast cancer observed in prior studies (5,20). While the higher incidence rates of triple-negative breast cancer observed among African American women are likely to be driven by differences in risk factor distributions and biology (46,47), the elevated risks of late stage disease and receipt of less optimal treatment observed for African American women regardless of tumor subtypes suggest that factors related to socioeconomic factors and access to care are likely key drivers of these long-standing disparities that have been well characterized (21,48,49).…”

“…However, results across studies that have assessed known disparities according to breast cancer subtypes have been mixed. While some studies found no difference in survival outcomes between African American and white women with triple negative breast cancer (18,19), other studies suggest that African Americans still fare a higher breast cancer mortality after accounting for ER/PR/HER2 subtypes (5,20–22). With respect to other race/ethnicities, California-based studies have found Asian/Pacific Islanders were more likely to be diagnosed with HER2+ breast cancer, but patterns of late diagnosis by breast cancer subtypes varied by subgroups within Asian/Pacific Islanders (23–25).…”

“…It has been consistently observed that minority women, especially African Americans, Hispanic whites and American Indians, are more likely to be diagnosed at more advanced stages of breast cancer (1–3), less likely to receive recommended treatment regimens (1,3,4), and more likely to have worse survival outcomes (1–3,5–7) compared to non-Hispanic white patients. Despite recent improvements in breast cancer survival overall (8,9), these racial/ethnic disparities persist and have even widened somewhat for patients with more advanced stage diseases (10–14).…”

Late-Stage Diagnosis of Breast Cancer in Brazil: Analysis of Data from Hospital-Based Cancer Registries (2000–2012)

“…That fact, which is in agreement with the evidence found in the literature, highlights the importance of social barriers and family support to promote proper women's health care. [25][26][27] This study has limitations. As the data were obtained from a secondary source, the analyses were restricted to the information provided in the HCRs.…”

Tendências temporais e fatores associados ao diagnóstico em estágio avançado de câncer do colo uterino: análise dos dados dos registros hospitalares de câncer no Brasil, 2000-2012*

“…This fact, in concordance with evidences found in the literature, indicates the importance of social barriers and family support for adequate attention to women's health. [27][28][29] It is important to consider, however, the possibility of residual confounding in the effect of age over the odds advanced diagnosis: widows tend to be older than married women and, therefore, it is possible that part of the effect found is due to more advanced age.…”