Researchers assess causes of death among those who succumb to well-differentiated thyroid cancer
While well-differentiated thyroid cancer (WDTC) tends to have a high post-surgical survival rate, individuals who have been treated for this form of thyroid disease occasionally die nonetheless, and a team of New York researchers recently attempted to determine the reasons why.
Surgeons and endocrinologists at the Memorial Sloan-Kettering Cancer Center in New York City analyzed the patient records for more than 1,800 individuals with WDTC who had been admitted to the institution between 1986 and 2005. All patients had undergone either radiation therapy or a thyroidectomy to treat their disease.
In all, 165 patients diagnosed with well-differentiated thyroid tumors had subsequently passed away, putting the hospital's rate of WDTC-related death at 9.4 percent.
However, the research team further examined the medical records in order to determine the exact causes of death in each case. They found that 142 deceased patients died from non-cancer-related causes.
Just 17 individuals were listed as having died from thyroid cancer, and another six had succumbed to unknown causes but presented with thyroid cancer at their time of death. Considering this information, the researchers concluded that the actual rate of WDTC-related death is approximately 1.3 percent.
A tumor's differentiation is the measure of its similarity to the surrounding cells. According to the National Cancer Institute (NCI), cells taken from well-differentiated tumors of the thyroid appear very similar to the surrounding glandular tissue when examined under a microscope. These carcinomas grow at a relatively slow rate and tend to stay localized.
By contrast, poorly differentiated thyroid cancer looks remarkably different than the cells that surround it. This disparity indicates severe cellular mutation, which makes such tumors more likely to grow aggressively and to spread.
The study noted that among patients whose primary cause of death was WDTC, all of them were found to have cancer recurrence elsewhere in the body. Most of these individuals - 94 percent - had malignant metastases in their lungs at the time of death.
An estimated one in 111 Americans will be diagnosed with thyroid cancer within their lifetime, according to the NCI.