Uninsured or Medicaid-insured patients are far more likely to be diagnosed with an advanced stage cancer than those with private insurance, according to a new American Cancer Society study of 3.5 million cancer patients with 12 of the most common cancer types.
What's more, many of those advanced cancers were types that could have been detected early through proper screening. That suggests people without private health insurance aren't getting the best possible care when it comes to cancer prevention and early detection, the ACS authors say.
Previous studies have shown that insurance status is an important factor in ensuring timely diagnosis and care, but they were comprised of smaller patient groups, conducted in specific regions of the country, or looked only at specific cancer types (for example, breast or oropharyngeal cancer). This is the first large-scale national study to definitively link a late-stage cancer diagnosis with insurance status across a broad range of cancer types. It appears in the March issue of The Lancet Oncology.
"The current study provides new information on insurance status and stage at diagnosis for 10 cancer sites that have not been studied previously and confirms the results for two that were previously studied (breast and colon/rectum)," said co-authors Michael T. Halpern, MD, PhD, MPH, and Elizabeth Ward, PhD, American Cancer Society, Epidemiology and Surveillance Research.
Halpern, Ward, and their colleagues analyzed data from the National Cancer Data Base (NCDB), a hospital-based registry sponsored by the American Cancer Society and the American College of Surgeons. The registry contains data from 1,400 hospitals and includes about 75% of people in the US with cancer.
Uninsured and Medicaid-insured patients showed a significantly increased risk of having an advanced-stage cancer compared with their privately-insured counterparts. They were also more likely to be diagnosed with late-stage breast and colorectal cancer, two cancers that can be detected at an early stage by screening. Furthermore, these patients had higher rates of cancers with very specific early warning signs, such as bladder cancer or melanoma.
By contrast, the likelihood of being diagnosed with a later stage of cancers with no available screening tests, such as ovarian or pancreatic cancer, didn't differ much between uninsured and privately insured patients.
"We saw a very consistent pattern. Insurance status has a tremendous impact on stage at-diagnosis, especially for those cancers that can be detected early through screening or have early warning signs," said Halpern, when the study was released.
Previous research has shown that people without insurance are less likely to get cancer screening and less likely to get other medical care that could spot early symptoms of some cancers, he and his colleagues note in the study.
The researchers collected data on cancer type, age, socioeconomic status (based on zip code of residence), insurance status at diagnosis, treatment facility, and ethnicity of 3,742,407 patients between 18 and 99 years old who were diagnosed between 1998 and 2004. Overall, 2.5% of the NCDB study population was uninsured (93,341 patients); 3.5% was covered by Medicaid (129,563 patients); 3.0% was covered under Medicare and under the age of 65 (110,442 patients); 46.3% was covered by Medicare and aged 65-99 years old (1,733,743 patients); and 44.8% were privately insured (1,675,318).
The largest patient group was women with breast cancer (814,687; 21.8% of the total), followed by men and women with lung cancer (693,697; 18.5%), men with prostate cancer (687,464 patients; 18.4%), and men and women with colorectal cancer (538,424; 14.4%). The researchers also collected data on patients with cancers of the bladder, uterus, kidney, thyroid, ovary, and pancreas, as well as patients with melanoma and non-Hodgkin lymphoma.
Independent of insurance status, researchers also found that black and Hispanic patients were more likely to be diagnosed with later stage for several of the cancer sites compared to white patients. However, minorities were also more likely to be uninsured or on Medicaid than whites.
The authors list a number of other barriers to care, from lack of access to medical facilities and cancer information to fear of screening that might also contribute to the disparities seen in the study. However, providing adequate insurance coverage is an important step toward narrowing the gap, they say.