Study examines effect of early treatment
A cancer diagnosis is a frightening event, often prompting patients and physicians to act quickly. But is immediate treatment always best? DMS researchers Louise Davies, M.D., and H. Gilbert Welch, M.D., set out to answer that question as it applies to thyroid cancer.
In 2006, Davies and Welch published an article in the Journal of the American Medical Association that showed a dramatic rise in the U.S. incidence of thyroid cancer. From 1973 to 2002, thyroid cancer diagnoses more than doubled, increasing from 3.6 to 8.7 per 100,000 people per year. The sharp jump, they determined, was due almost entirely to improved diagnostic techniques. Thanks to better imaging, doctors were finding tiny tumors that would have previously gone undetected. In other words, more people were being diagnosed with cases of thyroid cancer, but some might not ever pose a threat to their health.
Tumors: To better understand how such patients should be treated, Davies and Welch turned to a database maintained by the National Cancer Institute. Focusing on patients with papillary thyroid cancer whose tumors had not spread beyond the thyroid, they compared the survival rate of patients who underwent surgery (and, in some cases, radiation therapy) to that of patients who had neither.
Close: In the journal Archives of Otolaryngology—Head and Neck Surgery, they reported that, after 20 years, 99% of patients who received treatment and 97% of untreated patients were still alive. "I was actually quite surprised that the survival curves were so close," Davies says.
She hopes people don't "make decisions based on fear or hearsay."
Given that survival for both treated and untreated patients is so high, the researchers concluded that some patients might do well to put off surgery and instead have their cancer closely monitored over time. Thyroid cancer surgery typically involves the removal of all or half of the thyroid. While effective, this can result in problems with the adjacent parathyroid glands or damage that hinders speaking and swallowing.
But Davies acknowledges that translating a population-based statistic to an individual level is easier said than done. After all, the difference between 97% and 99% survival may be small, but for 2 patients in 100, it's a matter of life or death. "I think it puts the onus on the physician to really be clear about what the risks and benefits are, and decide which risks they and the patient are going to take together," she says.
Goal: Davies won't go so far as to say the study provides evidence of overtreatment of thyroid cancer. Her goal, she says, is to help patients and physicians understand that immediate treatment isn't the only valid option. "I think it's really hard for people to not take action," she says. "There are risks associated with surgery. There are also risks associated with not doing surgery. We're just hoping people will use this information to have informed discussions and not make decisions based on fear or hearsay."
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