If you don’t take a temperature.
The Study: The Fukushima nuclear reactor disaster in the wake of the great Japanese earthquake of 2011 sent ripples of fear of radiation-induced malignancies, most notoriously thyroid cancer, throughout the surrounding communities. A massive thyroid ultrasound screening program of over 300K residents 18 years and younger at time of the accident indeed demonstrated an increased incidence of thyroid cancers, almost exclusively papillary thyroid carcinoma, roughly 50x that expected among those 15-18 years. But the number was still far less than that following Chernobyl—an accident resulting in far higher absorbed doses. Plus the genetic signatures were markedly different than those associated with Chernobyl that carried RET mutations and instead were in-line with idiopathic thyroid cancers that carry BRAF mutations. Finally these screenings occurred at a time interval much shorter than the anticipated latency period among an iodine-sufficient cohort, such as the Japanese.
Bottom Line: The natural incidence of subclinical thyroid cancer is probably an order of magnitude greater than we think among pediatric patients, making the strategy of observation more attractive than ever. l Ohtsuru, JAMA Otolaryngol Head Neck Surg 2018