Assessing the Causes of an Increase in US Thyroid Cancer Incidence
A Real Increase or Better Detection Procedures?
To what extent is the recent rise in thyroid cancer incidence in the United States due to enhanced detection procedures? Is there an actual rise in disease prevalence, or are doctors simply better able to detect and diagnose the condition?
A team led by researchers at the University of Texas MD Anderson Cancer Center set out to examine this question in a report. The study, “Impact of enhanced detection on the increase in thyroid cancer incidence in the US: review of incidence trends by socioeconomic status within the Surveillance, Epidemiology, and End Results registry, 1980-2008,” was published online ahead of print in October 2012. It appears in the journal Thyroid.
According to the researchers, the incidence of thyroid cancer in the US has been increasing over the past 30 years. They hypothesized that the increase is due to both a real increase in disease prevalence and improved detection of thyroid cancer. To test this hypothesis, the study authors compared thyroid cancer incidence in high socioeconomic status (SES) countries and low SES countries. The rationale for this decision was that SES may serve as an indicator of a country’s access to technologies that can improve thyroid cancer diagnosis.
The results showed that thyroid cancer incidence increased moderately prior to the late 1990s in the high SES countries. After that, the increase became more pronounced. However, in lower SES countries, the increase remained steady throughout the examined time period. Additionally, differences in incidence patterns were seen based on the size of patients’ tumors.
The study authors conclude that though better detection of thyroid cancer has likely played some role in the increase in thyroid cancer incidence in the United States, it cannot account for the entirety of the increase. They argue that more efforts should be made to understand and identify the causes of the true increase thyroid cancer incidence.