FROM THE JOURNAL OF CLINICAL ONCOLOGY
Racial disparities in survival rates among young patients exist for those diagnosed with both early-stage and late-state colorectal cancer (CRC), investigators have found.
A review of Surveillance, Epidemiology, and End Results (SEER) data on young-onset CRC incidence and mortality rates showed that overall and cancer-specific survival rates were significantly lower for non-Hispanic black (NHB) patients when compared with non-Hispanic white (NHW) and Hispanic patients, reported Dr. Andreana Holowatyi of Wayne State University, Detroit, and her associates.
“Study of patients with young-onset CRC offers an opportunity to examine differences in cancer-specific survival by race, minimizing the potential impact that routine CRC screening among individuals 50 years of age and older might have on CRC-related outcomes,” the authors wrote (J Clin Oncol. 2016 May 2. doi: 10.1200/JCO.2015.65.0994).
The authors reviewed SEER data on 28,145 men and women aged 20-49 years at the time of CRC diagnosis. The sample included 19,497 NHWs, 4,384 NHBs, and 4,264 Hispanic patients and excluded patients who were diagnosed with cancer upon autopsy, patients who survived less than 2 months post diagnosis, and patients who were diagnosed with histopathologic subtypes other than adenocarcinoma. Patients diagnosed with any other type of cancer prior to their CRC diagnoses were excluded from survival analysis.
Stratification of patients by tumor stage and site showed that NHB patients were at an increased risk of cancer-specific death from colon cancers diagnosed at every stage, with the greatest differences observed among those with stage II cancers (hazard ratio, 1.69; 95% confidence interval, 1.33-2.14; P less than .001).
NHB patients were more likely to have CRCs of the proximal colon, compared with NHW and Hispanic patients (39.9% vs. 30.3% vs. 30.7% respectively; P less than .001) and more likely to have more advanced stage cancer. In addition, the NHB subpopulation included a significantly higher percentage of women, compared with NHW and Hispanic patients (50.3% vs. 45.8% vs. 46.3%, P less than .001).
In Cox proportional hazard models controlling for age, sex, race, county-level poverty, tumor stage, surgical intervention, and radiation therapy, Dr. Holowatyi and her associates found that NHB patients had significantly higher risk of cancer-specific death in colon cancers (HR, 1.35; 95% CI 1.26 to 1.45; P less than .001) and rectum/rectosigmoid junction cancers (HR, 1.51; 95% CI 1.37 to 1.68; P less than .001), compared with NHWs. Similar findings were reported for risk of overall death.
“Further studies of the clinical and molecular characteristics of young-onset CRCs are needed to explore potential tumor/treatment interactions associated with racial differences in survival and to refine clinical algorithms for CRC treatment and early detection,” the authors wrote.
This study was supported by funding from the Cancer Biology Graduate Program at Wayne State University, the National Cancer Institute, and an Epidemiology Core and National Institutes of Health Center grant. The authors did not have any disclosures to report.
