Things that impact racial, ethnic disparities in cancer survival

The underlying causes of racial and ethnic disparities in cancer survival must be understood to ensure that patient have the greatest chances to live, according to a recent study.

In the study, published in the Journal of Clinical Oncology, researchers found that the largest contributors to racial and ethnic disparities in cancer survival were stage at diagnosis, neighborhood socioeconomic status and marital status.

Ellis

Lead researcher Elizabeth Ellis, PhD, staff scientist at the Cancer Prevention Institute of California, and colleagues, examined cancer survival by racial/ethnic group for 877,662 patients diagnosed with breast, prostate, colorectal or lung cancer between 2000 and 2013 using California Cancer Registry data. They used mediation analysis as a novel approach to quantify the contribution of patient and tumor characteristics to racial/ethnic survival disparities.

Other findings include:

• Black patients had the lowest survival rate for all cancer types and Asian American/Pacific Islander ethnic groups had the highest survival, compared to whites. 
• Black patients with breast, prostate, and colorectal cancer were more likely to be diagnosed with late-stage tumors than whites, with stage explaining 16% to 28% of overall racial and ethnic survival disparities.
• Living in a low socioeconomic neighborhood, far more common among black and Hispanic patients than among whites or Asian Americans/Pacific Islanders, explained 5% to 18% of the overall survival disparities among racial and ethnic groups, with the largest contribution for lung cancer.
• Women with breast cancer had the most significant racial and ethnic survival disparities. Cancer deaths among black women was twice that of white women. Hormone receptor status was a significant contributor to overall breast cancer racial/ethnic survival disparities, explaining 9% of survival differences.
• Contribution of stage at diagnosis to survival disparities in colorectal cancer was larger in women (28%) than in men (16%). Among men with colorectal cancer, the influence of marital status on racial and ethnic survival disparities was as large as the influence of stage.
• Women also experienced improved lung cancer survival rates over men.
• Married patients, particularly men, also experienced improved survival over unmarried patients. Marital status explained 14% to 18% of survival disparities among men, and 6% to 14% among women.

“The strong influence of socioeconomic status and marital status suggest that social determinants, support mechanisms, and access to healthcare need to be addressed to ensure that all patients have the opportunity to experience optimal survival,” says Ellis. “Interestingly, we found that health insurance status was not a significant contributor of racial and ethnic survival disparities after controlling for stage at diagnosis and socioeconomic status, despite evidence that black-white survival disparities differ by type of health insurance.”

“Strategies to improve access to preventative care and cancer screening, especially among black and Hispanic populations, could make an important contribution to reducing cancer survival disparities,” Ellis says. “The assessment of social determinants, support mechanisms, and barriers to care may also be of particular relevance to patients in a managed care setting.”

In all clinical settings, ensuring that these social determinants are assessed, and that barriers to care for vulnerable populations are addressed, may go a long way toward the reduction of cancer survival disparities, Ellis says.