In a culture where the word "cancer" sends chills down your spine, gives you goose bumps, and has been equated with death, early diagnosis and treatment is strongly advised. However, not all cancers will become deadly and require aggressive treatments, as some tumors are viewed “harmless” because they grow so slowly and are less likely to be a threat. According to a recent study published in JAMA Otolaryngology-Head & Neck Surgery, thyroid cancer rates have tripled due to overdiagnosis, not better treatment, as harmless tumors are painfully mistaken for thyroid cancer.
Typically, in 85 percent of thyroid cancer cases, thyroid removal is done despite guidelines suggesting less aggressive surgery is an option for lower-risk thyroid tumors. During the procedure, surgeons make a 3- to 4-inch cut in the middle of the patient’s neck, right on top of the thyroid gland, or they make a smaller cut less than 2 inches long, says Medline Plus. Thyroid removal is recommended by a doctor if there is cancer of the thyroid, or when noncancerous or benign tumors of the thyroid are causing symptoms.
A team of researchers at Dartmouth College in New Hampshire sought to investigate the proportion of people dying from thyroid cancer, since the disease has been viewed as clinically significant over the past few decades. In the study, U.S. government data from the Surveillance, Epidemiology, and End Results (SEER) program and thyroid cancer mortality from the National Vital Statistics System were used to analyze trends in the disease. The study also observed male and female participants 18 and older who were diagnosed with thyroid cancer between 1975 and 2009 and lived in Atlanta, Ga.; Connecticut; Detroit, Mich.; Hawaii; Iowa; New Mexico; San Francisco and Oakland, Calif.; Seattle and Puget Sound, Wash.; and Utah.
The findings revealed the incidence of thyroid cancer tripled from 4.9 per 100,000 in 1975 to 14.3 per 100,000 in 2009. However, the mortality rate was viewed as “stable” with approximately 0.5 deaths per 100,000 during the study period. This dramatic rise was mostly seen in papillary thyroid cancers — the most common and least deadly — going from three cases per 100,000 to more than 12 per 100,000. While the results suggest there is an ongoing epidemic, researchers believe this is largely due in part to overdiagnosis and overtreatment of the disease.
Dr. Gilbert Welch and Dr. Louise Welch, authors of the study from the Geisel School of Medicine at Dartmouth College in Hanover, N.H., report that the size distribution of detected thyroid cancers has gone toward smaller lesions (≤1 cm), and larger lesions (>2 cm), which they believe is evidence of overdiagnosis, according to Medscape. Patients whose tumors are labeled as cancerous are often told treatment is necessary, but these findings are challenging this common notion. “Our old strategy of looking as hard as possible to find cancer has some real side effects,” Welch said.
The results of this study has prompted researchers, like Dr. Brian Burkey, a Cleveland Clinic head and neck cancer specialist, to observe is simply active surveillance could be a better alternative than surgery or radiation. Burkey is planning to have patients diagnosed with thyroid cancers to be randomly assigned treatment or just observation during his pending study. “Thyroid cancer even if treated has a fairly high recurrence rate even if it doesn’t kill,” he told HealthDay.
The surge in thyroid cancer cases, and the stable mortality rates call on physicians to share with patients the uncertainty that exists with small thyroid cancers. CT scans and ultrasound has led to more thyroid cancers being diagnosed, but they cannot reveal which ones are more aggressive. Not all tumors will grow and cause harm to the patient, although it is not possible to know which ones are harmless. Until there is more awareness that thyroid cancer is a slow-growing disease, like prostate cancer, and aggressive treatments are not always necessary, this upward trend will continue in the U.S.
Source: Welch G, Davies L. Current Thyroid Cancer Trends in the United States. JAMA Otolaryngol Head Neck Surg. 2014.