Association of Insurance Status and Ethnicity With Cancer Stage at Diagnosis for 12 Cancer Sites: A Retrospective Analysis

Abstract

ABSTRACT Persons living in the United States who lack private medical insurance are less likely to have access to medical care and to take part in cancer screening programs. Regional studies suggest that uninsured and Medicaid-insured individuals are likelier than those who are privately insured to present with advanced-stage cancer, but this has not been confirmed using contemporary national-level information. Complicating the problem is the observation that cancer patients from ethnic minorities are likelier than non-Hispanic whites to be uninsured or Medicaid insured. This study sought relationships between insurance status and disease stage at the time of diagnosis for twelve cancer sites (breast, colorectal, kidney, lung, melanoma, non-Hodgkin lymphoma, ovary, pancreas, prostate, urinary bladder, uterus, thyroid). The study population included 3,742,407 patients whose characteristics resembled those of the U.S. population not included in the analysis. The patients, diagnosed in the years 1998–2004, were enrolled in the U.S. National Cancer Database, a hospital-based registry with patient information from approximately 1430 facilities. Uninsured and Medicaid-insured patients were significantly more likely than privately insured patients to present with advanced-stage (stage III or stage IV) cancer. The relationship was most evident for patients whose cancers can potentially be detected at an early stage by symptom assessment or screening. They include breast and colorectal cancers, lung cancer, and melanoma. Compared with privately insured patients, the odds ratios (ORs) for advanced-stage disease at diagnosis for uninsured and Medicaid-insured patients with colorectal cancer were 2.0 (95% confidence interval, 1.9–2.1) and 1.6 (1.5–1.7), respectively. For advanced-stage melanoma, the OR was 2.3 (2.1–2.5) for uninsured patients and 3.3 (3.0–3.6) for Medicaid-insured patients compared to privately insured patients. Compared with white patients, blacks and Hispanics had an increased risk of advanced-stage disease at diagnosis independently of insurance status. The investigators conclude that cancer patients residing in the United States who are uninsured or have Medicaid insurance are at a considerably increased risk of having more advanced disease when diagnosed than are privately insured patients.