Risk of second primary papillary thyroid cancer among adult cancer survivors

Risk of second primary papillary thyroid cancer among adult cancer survivors in the United States, 2000-2015.:

Related Articles

Risk of second primary papillary thyroid cancer among adult cancer survivors in the United States, 2000-2015.

Cancer Epidemiol. 2019 Dec 26;64:101664

Authors: Schonfeld SJ, Morton LM, de González AB, Curtis RE, Kitahara CM

Abstract

BACKGROUND: While radiotherapy is a major risk factor for thyroid cancer after childhood cancer, factors contributing to increased thyroid cancer risk after adulthood cancer remain unclear.

METHODS: We evaluated second primary papillary thyroid cancer (PTC) risk among 3,175,216 ≥ 1-year adult survivors of non-thyroid malignancies from US population-based cancer registries (2000-2015), using standardized incidence ratios (SIRs). Because heightened surveillance may increase detection of indolent thyroid tumors and earlier detection of advanced tumors, we examined SIRs by PTC stage and time since first cancer (latency).

RESULTS: SIRs for second primary PTC (N = 4333) were statistically-significantly 1.2-3.5-fold elevated overall and after 23/27 first cancer types evaluated, with generally similar risks for localized and regional/distant PTC. SIRs for regional/distant PTC (N = 1501) were highest after pancreatic (SIR = 3.7; 95% confidence interval [CI] = 1.9-6.5) and soft tissue (SIR = 4.2; 95%CI = 2.8-6.2) cancers, followed by melanoma, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma, and larynx, kidney, and brain/central nervous system (SIRs = 2.0-2.9) cancers. SIRs typically decreased with increasing latency but remained statistically-significantly elevated for regional/distant-PTC ≥5 years after diagnosis of cancers of the rectum, pancreas, lung/bronchus, soft tissue, female breast, uterine corpus, prostate, and kidney, and after melanoma, Hodgkin lymphoma, CLL/SLL, and follicular lymphoma. Neither total nor regional/distant PTC were clearly associated with initial course of radiotherapy or chemotherapy.

CONCLUSIONS: PTC risk was elevated after a range of first primary adult cancers but was not clearly related to treatment. Although surveillance may contribute to elevated short-term risks of PTC, longer-term elevations in regional/distant PTC may be attributable to shared risk factors.

PMID: 31884334 [PubMed - as supplied by publisher]