Thyroid cancer detected by ultrasonography may be non-progressive, negating the need for treatment, according to a study published in JAMA Otolaryngology–Head & Neck Surgery.1
While methods for detecting cancer are improving, the growth patterns of many cancers are hard to predict, which can make treatment decisions difficult. While thyroid cancer incidence was 15 times higher in 2001 than in 1993 among South Koreans, as few as 10% of these cancers are progressive.
For this observational study, researchers enrolled 116 patients who were diagnosed with or were suspected of having thyroid cancer after the Fukushima Daiichi Nuclear Power Plant accident, which occurred in March of 2011. The authors measured the growths’ change in diameter over a median observation period of .461 years to determine a growth pattern.
Of the 116 patients, 39 were male and 77 were female; the median age was 17.5 years. At initial screening the median tumor diameter was 13.5 mm; at follow-up the median diameter was 14.2 mm. No correlation with age and tumor diameter was noted.
The patients were categorized into 3 groups: more than a 10% decrease in tumor size (Group 1; 7 patients), a change of -10% to 10% in size (Group 2; 81 patients), and more than a 10% increase in size (Group 3; 28 patients).
Groups 1, 2, and 3 had mean size percentage changes of -16.5%, 1.7%, and 24.1%, respectively. The authors noted, however, that “the coefficient of growth was significantly and negatively correlated with the tumor diameter…suggesting a reduction of the growth rate with time.”
The results suggest that ultrasonography can determine which cases of thyroid or suspected thyroid cancer are likely to undergo growth arrest after initial proliferation, which may spare patients unnecessary treatment.
- Midorikawa S, Ohtsuru A, Murakami M. Comparative analysis of the growth pattern of thyroid cancer in young patients screened by ultrasonography in Japan after a nuclear accident: the Fukushima Health Management Survey. JAMA Otolaryngol Head Neck Surg. 2017 Nov 16. doi: 10.1001/jamaoto.2017.2133 [Epub ahead of print]