Tuesday, May 9, 2017
Screening for thyroid cancer not recommended
The U.S. Preventive Services Task Force (USPSTF) recommends against screening for thyroid cancer in adults without any signs or symptoms. The report appears in the May 9 issue of JAMA.
This is a D recommendation, indicating that there is moderate or high certainty that screening has no net benefit or that the harms outweigh the benefits.
The incidence of thyroid cancer detection has increased by 4.5 percent per year over the last 10 years, faster than for any other cancer; however, the mortality rate from thyroid cancer has not changed substantially, despite the increase in diagnoses. In 2013, the incidence rate of thyroid cancer in the United States was 15.3 cases per 100,000 persons. Most cases of thyroid cancer have a good prognosis; the 5-year survival rate for thyroid cancer overall is 98.1 percent.
To update its 1996 recommendation, the USPSTF reviewed the evidence on the benefits and harms of screening for thyroid cancer in asymptomatic adults, the diagnostic accuracy of screening (including by neck palpation and ultrasound), and the benefits and harms of treatment of screen-detected thyroid cancer.
The USPSTF is an independent, volunteer panel of experts that makes recommendations about the effectiveness of specific preventive care services such as screenings, counseling services, and preventive medications.
The USPSTF found inadequate evidence to estimate the accuracy of neck palpation or ultrasound as a screening test for thyroid cancer in asymptomatic persons.
Benefits of Early Detection and Treatment
The USPSTF found inadequate direct evidence to determine whether screening for thyroid cancer in asymptomatic persons using neck palpation or ultrasound improves health outcomes. However, the USPSTF determined that the magnitude of benefit can be bounded as no greater than small, based on the relative rarity of thyroid cancer, the apparent lack of difference in outcomes between patients who are treated vs only monitored (i.e., for the most common tumor types), and the observational evidence demonstrating no change in mortality over time after introduction of a population-based screening program.
Harms of Early Detection and Treatment
The USPSTF found inadequate direct evidence to assess the harms of screening for thyroid cancer in asymptomatic persons. The USPSTF found adequate evidence to bound the magnitude of the overall harms of screening and treatment as at least moderate, based on adequate evidence of serious harms of treatment of thyroid cancer and evidence that overdiagnosis and overtreatment are likely consequences of screening.
The USPSTF concludes with moderate certainty that screening for thyroid cancer in asymptomatic persons results in harms that outweigh the benefits.