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Soo Park, MD
Soo Park, MD
Posted: Tuesday, October 22, 2024
Patients with primary thyroid cancer who underwent radioactive iodine therapy appeared to have an increased risk of developing melanoma and other nonkeratinocyte skin cancers, particularly in the head and neck region, according to Eleni Linos, MD, DrPH, of Stanford University School of Medicine, California, and colleagues. These findings from a U.S. population–based analysis were published in JAMA Network Open.
“Although the risks of subsequent cancer do not outweigh the benefits of treatment, our findings suggest that patients treated for thyroid cancer may benefit from follow-up skin cancer screening,” the investigators commented.
Using data from 17 cancer registries in the Surveillance, Epidemiology, and End Results (SEER) database, the investigators identified 174,916 patients who were diagnosed with primary thyroid cancer between 2000 and 2019 and followed for subsequent cancers until 2020. Nearly half of the population (n = 79,576; 45.5%) received first-course thyroid cancer treatment with some type of radiation therapy.
A total of 865 nonkeratinocyte skin cancers (melanoma: n = 790) were diagnosed; of these cancers, 171 (19.8%) were located on the skin of the head or neck. After limiting the analysis to these sites in patients exposed to radioactive iodine, the investigators reported standardized incidence ratios (SIRs) that were “higher than expected” for all nonkeratinocyte skin cancers (SIR = 1.64), melanoma (SIR = 1.56), and other nonkeratinocyte skin cancers (SIR = 2.07). Those who did not receive radioactive iodine therapy were not found to have an elevated risk of developing skin cancer on the head and neck.
The standardized incidence ratio seemed to be statistically significant in patients with primary papillary thyroid cancer who were treated with any type of radiation therapy (SIR = 1.69). This did not appear to be the case in those with other subtypes of thyroid cancer, which the investigators noted was likely because of insufficient sample sizes.
Disclosure: Dr. Linos reported no conflicts of interest. For full disclosures of the other study authors, visit jamanetwork.com.
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