Papillary Microcarcinoma of the Thyroid Among Atomic Bomb Survivors: Tumor Characteristics and Radiation Risk

• Published in: Cancer Vol. 116; no. 7; pp. 1646 - 1655
• Main Authors: HAYASHI, Yuzo, LAGARDE, Frederic, TSUDA, Nobuo, FUNAMOTO, Sachiyo, PRESTON, Dale L, KOYAMA, Kojiro, MABUCHI, Kiyohiko, RON, Elaine, KODAMA, Kazunori, TOKUOKA, Shoji
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Wiley-Blackwell 01-04-2010
• Subjects: Adenocarcinoma, Papillary - drug therapy; Adenocarcinoma, Papillary - epidemiology; Adenocarcinoma, Papillary - etiology; Adenocarcinoma, Papillary - pathology; Aged; Aged, 80 and over; Autopsy; Biological and medical sciences; Dose-Response Relationship, Radiation; Endocrinopathies; Female; Humans; Incidence; Japan - epidemiology; Male; Malignant tumors; Medical sciences; Middle Aged; Neoplasms, Radiation-Induced - epidemiology; Nuclear Warfare; Nuclear Weapons; Radiation, Ionizing; Risk Factors; Survivors; Thyroid Neoplasms - epidemiology; Thyroid Neoplasms - etiology; Thyroid Neoplasms - pathology; Thyroid. Thyroid axis (diseases); Tumors; Japan; Endocrinopathy; Endocrine gland; Survivor; Thyroid diseases; Thyroid gland; Malignant tumor; Thyroid carcinoma; Cancerology; thyroid; radiation; Risk factor; atomic bombs; Microcarcinoma; papillary microcarcinoma; Cancer
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/cncr.24872

: Radiation exposure is an established cause of clinical thyroid cancer, but little is known about radiation effects on papillary microcarcinoma (PMC) of the thyroid, a relatively common subclinical thyroid malignancy. Because the incidence of these small thyroid cancers has been increasing, it is important to better understand them and their relation to radiation.
: PMCs were identified in a subset of 7659 members of the Life Span Study of atomic bomb survivors who had archived autopsy or surgical materials. We conducted a pathology review of these specimens and evaluated the histological features of the tumors and the association between PMCs and thyroid radiation dose.
: From 1958 to 1995, 458 PMCs were detected among 313 study subjects. The majority of cancers exhibited pathologic features of papillary thyroid cancers. Overall, 81% of the PMCs were of the sclerosing variant and 91% were nonencapsulated, psammoma bodies that occurred in 13% and calcification was observed in 23%. Over 95% had papillary or papillary-follicular architecture and most displayed nuclear overlap, clear nuclei, and nuclear grooves. Several of these features increased with increasing tumor size, but no association was found with radiation dose. A significant radiation-dose response was found for the prevalence of PMCs (estimated excess odds ratio/Gy = 0.57; 95% confidence interval, 0.01-1.55), with the excess risk observed primarily among women.
: Exposure to low-to-moderate doses of ionizing radiation appears to increase the risk of thyroid PMCs, even when exposure occurs during adulthood. Cancer 2010. (c) 2010 American Cancer Society.