Minority patients and those of lower socioeconomic status are far more likely to have advanced thyroid cancer at diagnosis than white patients and those in higher economic brackets.
In one of the most comprehensive studies of its kind, the team from the University of California, Los Angeles, looked at nearly 26,000 patients with well-differentiated thyroid cancer and analyzed the impact of race and socioeconomic factors on the stage of presentation, as well as patient survival rates.
“Race, social status, wealth, and health insurance coverage make a difference in how far a thyroid cancer has advanced by the time a patient first sees a doctor,” said lead study author Avital Harari, MD, of the University of California in Los Angeles (UCLA). The study was published in the Journal of Endocrinology and Metabolism (2014; doi:10.1210/jc.2013-2781).
Researchers hope the study results will lead to strategies aimed at increasing access to health care and help make doctors who treat thyroid cancer patients more aware of how aggressive this cancer can be in certain socioeconomic and racial groups.
“We hope our work highlights the importance of developing interventions that will lead to equalization of care, better preventative practices, and earlier treatments,” Harari said.
Although the overall incidence of thyroid cancer is low compared with other cancers, it has been rising in recent decades. The increase cannot fully be explained by improved diagnostics or earlier identification of the disease in patients, Harari said. Advanced thyroid cancers are generally very treatable, but some may have a heightened morbidity and mortality risk, especially if the cancer has spread beyond the thyroid.
Although previous studies have shown that exposure to radiation, family history, and an underactive thyroid are known risk factors for thyroid cancer, the UCLA team was interested in finding other factors that may be contributing to both the increase in this cancer and the presentation of the disease in its advanced stages.
For the study, researchers analyzed data on 25,945 patients with advanced thyroid cancer disease from the California Cancer Registry between the years of 1999 and 2008. The majority of patients were white (14,802 [57%]); 6,303 (24%) were Hispanic; 3,901 (15%) were of Asian/Pacific Islander descent; and 939 (4%) were black.
Patients with low socioeconomic status in all racial groups had more advanced disease than those with higher incomes. Black patients consistently presented with later stages of disease and had worse survival rates than any other racial group.
Even after adjusting for age, sex, socioeconomics, and type of health insurance, minority groups continued to have higher odds of presenting with more advanced disease than whites.
Patients who were poor and uninsured or who had Medicaid had higher odds of presenting with metastatic disease than patients with private health insurance, the researchers found.