Effect of insurance status on all-cause and cancer-related survival in colorectal cancer

Introduction: Insurance status, SES and race are factors associated with advanced-stage colorectal cancer and decreased survival rates. Flint, Michigan has a unique population with 36.6% of citizens below the poverty line and a 62.6% non-white population. The purpose of this study is to measure the effect of insurance status and race on all-cause and cancer-related colorectal cancer survival in Flint, Michigan. Methods: Patient information was obtained from Hurley Medical Center's Tumor Registry for colorectal cancer patients aged 18-80 (n = 824) who were diagnosed or received first treatment here from 1993-2010 for 10 years post-treatment. Patients were stratified by age, gender, race, time-to-treatment and insurance status (private insurance versus nonprivate insurance-no insurance, Medicaid or Medicare). A life table survival analysis with Wilcoxon-Gehan statistic and chi-squared analysis were performed to assess impact on survival. Results: There was a statistically significant increase in cancer-related survival for private insurance holders (p = 0.035; median time 120 months), as well as a difference between age groups 0-64 vs. 65+ (p = 0.05). Private insurance holders also had higher median all-cause survival (94 months vs 35 months). When limiting time-to-treatment to 0-2 months, there was still a significant difference in all-cause survival between insurance groups. No difference in survival was detected for race or gender. Conclusions: Though many studies have shown race to be a significant factor in colorectal cancer survival, we did not find this to be the case in our population. Future studies should investigate other causes of survival discrepancies in this population.