Results from one study show that despite a lower overall rate of thyroid cancer, African-Americans are generally diagnosed with a higher grade of cancer than in Caucasian populations.
Other studies have been published indicating economic issues chiefly underlie the differences in cancer stage upon diagnosis.
Lower levels of access to medical care due to economic constraints, or the inability to take time off from work have been linked to a longer time between the first symptoms of cancer and the beginning of cancer treatment.
|The figure shows the thyroid cancer incidence rates by race and ethnicity for the US male and female in 2007. The thyroid cancer incidence rates are per 100, 000 US population and are age-adjusted to the 2000 US Standard Population|
Results from the study show that African Americans had double the rate of anaplastic thyroid cancer, an advanced and aggressive stage of thyroid cancer, when compared to Caucasian thyroid cancer patients. African American patients were also twice as likely as Caucasian patients to have tumors larger than four centimeters.
The study used the National Cancer Institute’s database to look at data for the years 1992-2006, tracking five year survival rates of thyroid cancer patients in 17 states. Study data examined the cases of 26,902 patients diagnosed with thyroid cancer during that time.
“We think that the mortality rate is probably due to an access to care issues,” said Christopher Hollenbeak, PhD and lead study author.
“African-Americans were more likely to present with tumors larger than four centimeters, which implies that the tumors sat there and grew a lot longer,” he said.
Papillary and follicular cancer are the most common forms, and usually diagnosed in susceptible populations such as Caucasian or Asian groups. Complete treatment success for papillary and follicular thyroid cancers is close to 90 percent.
Anaplastic thyroid cancers, on the other hand, which were shown to be more commonly diagnosed in African American patients with thyroid cancer, can be fatal much more frequently.
One surgeon interviewed agreed that the difference could be amount of time elapsed from the cancer developing, to being treated. If caught early thyroid cancer treatment usually involves a small surgery, with some patients needing to take a small amount of radioactive iodine to completely destroy the cancer.
"The prevailing theory today is that anaplastic is thyroid cancer that goes haywire from not being treated,” said David Goldberg, MD, co-author of the study and currently a professor at Penn State.
The study was published in the journal Ethnicity & Disease. Authors denied any financial conflict of interest arising from the publication of their results.