Individuals with papillary thyroid cancer of any size that has not spread beyond the thyroid gland (no extraglandular extension or lymph node metastases at presentation) will most likely experience favorable outcomes regardless of whether they receive treatment within the first year after diagnosis or whether they are treated by hemithyroidectomy or total thyroidectomy, according to a report in the May issue of Archives of Otolaryngology–Head & Neck Surgery.
Louise Davies, MD, and colleagues from the Dartmouth Institute for Health Policy and Clinical Practice at Dartmouth Medical School in Hanover, N.H., and the Department of Veterans Affairs Medical Center in White River Junction, Vt., explained that while papillary thyroid cancer is commonly found during autopsy among patients who died of other causes, “The advent of ultrasonography and fine-needle aspiration biopsy has allowed many previously undetected cancers to be identified, changing the epidemiology of the disease.”
Utilizing cancer cases and individual treatment data from National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program, the researchers analyzed cause of death through the National Vital Statistics System for this patient-population.
Davies and colleagues identified 35,663 patients with papillary thyroid cancer that had not spread to the lymph nodes or other areas at diagnosis for inclusion in their study. Of these patients, 1.2 percent did not undergo immediate, definitive treatment, they said.
The authors determined that over the course of an average follow-up period of six years, six of these patients died of their cancer. The researchers found that this number was not significantly different from the rate of cancer death among the 35,223 individuals who did undergo immediate treatment, 161 cases over an average of approximately seven years of follow-up.
Davies and colleagues estimated the 20-year survival rate from cancer to be 97 percent for those who did not receive immediate treatment and 99 percent for those who did.
“Over the past 30 years, the detected incidence of thyroid cancer has increased three-fold, the entire increase attributable to papillary thyroid cancer and 87 percent of the increase attributable to tumors measuring less than 2 centimeters,” wrote the authors.
“These data help put management decisions about localized papillary thyroid cancer in perspective: papillary thyroid cancers of any size that are confined to the thyroid gland, have no lymph node metastases at presentation and do not show extraglandular extension are unlikely to result in death due to the cancer,” the authors concluded.