A new American Cancer Society study of twelve types of cancer among more than 3.5 million cancer patients finds uninsured patients were significantly more likely to present with advanced stage cancer compared to patients with private insurance.
The study, which appears in the March issue of The Lancet Oncology, is the first to use national data to investigate insurance status and stage of diagnosis for a large number of cancer sites. It finds the strongest association between insurance status and advanced cancer was for cancers that can be detected early by screening or evaluation of symptoms.
For their study, American Cancer Society researchers led by Michael Halpern, M.D., Ph.D., strategic director of health services research, compared insurance status and stage at diagnosis using the National Cancer Database, a hospital-based registry capturing patient information from approximately 1,430 facilities. The database includes information for approximately 73 percent of patients diagnosed with cancer in the U.S. The new analysis included patients in the database between ages 18 and 99 diagnosed with any of 12 cancers between 1998 and 2004.
The study found consistent associations between insurance status and stage at diagnosis across multiple cancer sites. Compared to patients with private insurance, uninsured patients had significantly increased likelihoods of being diagnosed with cancer at more advanced stages. The greatest risk for diagnosis at with moderately advanced cancer (stage II) instead of the earliest stage (stage I) was in colorectal cancer, while the highest risk for diagnosis at the most advanced stage of cancer (stage III/IV) was in breast cancer. Medicaid patients also had significantly increased risks of presenting with more advanced stage disease compared to patients with private insurance for many cancer sites. The greatest increase in risk of more advanced stage diagnosis among both uninsured and Medicaid-insured occurred for cancer sites that are part of routine screening (e.g., breast, colorectal) or sites with symptoms present at early stages (melanoma, urinary bladder).
In contrast, the likelihood of diagnosis at more advanced stages for pancreas or ovary cancer, while higher, was not significant or only marginally significant for uninsured and Medicaid patients compared to privately insured patients. These two sites characteristically present with advanced stage at diagnosis and do not have screening tests or specific symptoms to allow doctors to diagnose them at an early stage.