Insurance Status Is Linked With Colon Cancer Survival

Being uninsured puts patients at risk of delayed or suboptimal care for serious diseases, including colon cancer. While colon cancer is potentially curable at its early stages, those who lack insurance (or who have public insurance only) are less likely to receive screening, and some studies have demonstrated that those with no insurance or public insurance are less likely to receive the chemotherapy that can reduce the risk of recurrence in phase III disease.

Recently, the Surveillance, Epidemiology, and End Results (SEER) database began to include information on insurance status, providing researchers with an opportunity to study the effect of insurance status on cancer survival at the population level for the first time.

In the May issue of Diseases of the Colon & Rectum, investigators from the German Cancer Research Center in Heidelberg published results of a study that used the SEER database to assess the survival of 58,000 patients, aged 15 to 64 years, with colon cancer who were diagnosed between 2007 and 2012.

“We found that, as expected, survival was lower for patients who had no insurance,” said Dianne Pulte, MD, lead author of the paper. However, Pulte explained, patients who had Medicaid as their only insurance had survival rates similar to that observed in those who had no insurance at all.

Pulte and her team categorized patients by insurance type—13.7% had Medicaid and 7.5% were uninsured—and assessed the frequency of cases by cancer stage, sex, race, surgical resection, and the number of lymph nodes evaluated to determine whether insurance type influenced cancer stage at diagnosis, evaluation, and treatment. Complete analysis was used to determine 1-, 2-, and 3-year survival rates by insurance status.

Those who were uninsured or who had Medicaid only were more likely to present with stage IV disease than those who had other insurance; 34.5% of those with Medicaid and 32.8% of the uninsured presented with stage IV disease, compared with 24% of those with other insurance.

Among those who had stage I to stage III disease, 74.2% of those with Medicaid—versus 77.6% of those with other insurance—had 12 or more lymph nodes examined. Furthermore, 97.6% and 97.8% of patients with Medicaid and uninsured patients, respectively, had definitive surgery (versus 99.3% of those with other insurance).

Adjusted 3-year survival among the insurance groups was as follows:

• Medicaid: 57%
• No insurance: 61.2%
• Other insurance: 75.6%.

The disparity in survival is likely multifactorial in nature, as those without insurance or with public insurance may be less likely to receive appropriate screening, which can result in later-stage disease at diagnosis. However, said Pulte, “Differences in rates of definitive surgery and adequate lymph node dissection explain some of this disparity,” a finding that is of particular interest because it is a potentially alterable risk factor.

More research into methods for decreasing these disparities and implementing public health measures to improve the quality of care for all patients is urgently needed, write the authors, to ensure the best survival outcomes on a population level.

Reference

Pulte D, Jansen L, Brenner H. Disparities in colon cancer survival by insurance type: a population-based analysis. Dis Colon Rectum. 2018;61(5):538-546. doi: 10.1097/DCR.0000000000001068.