Body mass index and incidence of thyroid cancer in Korea: the Korean Cancer Prevention Study-II.
OBJECTIVE
The prevalence of thyroid cancer and obesity has increased worldwide. However, their association has remained controversial and few studies have been performed in Asia. Our study evaluated the correlation between the incidence of thyroid cancer and body mass index (BMI) in Korea.


METHODS
This is a multi-centered, prospective cohort study from the Korean Cancer Prevention Study-II. A total of 141,157 individuals between 1994 and 2012, including 1546 newly developed thyroid cancer patients, were enrolled. Subjects were divided into four groups on the BMI. Person-years, incidence rate, and hazard ratios (HRs) were calculated using the Cox proportional hazard model.


RESULTS
The increasing trends of HRs of thyroid cancer in men and women younger than 50 years of age were observed as BMI increased (P trend <0.001 in both groups). However, in women older than 50 years of age, there was no association between thyroid cancer incidence and BMI.


CONCLUSIONS
Our findings suggest that positive association between thyroid cancer incidence and high BMI in men and women under 50 years old. Based on these results, we suggest that obese men and women under 50 years old are better to be considered for the higher possibility of thyroid cancer development, and more efforts are needed to control weight gain.
Department of Family Medicine, Myongji Hospital, College of Medicine, Seonam University, Goyang-si, Gyeonggi-do, 10475, Republic of Korea.
Hyun-Young
HY
Shin
Department of Public Health Science, Graduate School of Public Health, Seoul National University, Seoul, 08826, Republic of Korea.
Yong Ho
YH
Jee
Department of Epidemiology and Health Promotion and Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, 03722, Republic of Korea. RIN@YUHS.AC.
Eo Rin
ER
Cho
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000473:pathology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D056910:Republic of Korea; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000453:epidemiology* / Q000473:pathology; D055815:Young Adult
Body mass index; Cancer; Incidence; Obesity; Thyroid cancer
Int J Cancer. 2012 Sep 15;131(6):E1004-14
22511178
N Engl J Med. 2006 Aug 24;355(8):779-87
16926276
J Clin Oncol. 2005 Jul 20;23(21):4742-54
16034050
Cancer Causes Control. 2011 May;22(5):743-51
21380729
Thyroid. 2014 Jun;24(6):966-74
24555500
Ann Epidemiol. 2009 Nov;19(11):784-92
19825459
Cancer Res Treat. 2015 Apr;47(2):127-41
25761484
Int J Oncol. 2010 May;36(5):1067-80
20372779
J Int Med Res. 2012;40(6):2041-50
23321160
J Cancer Res Clin Oncol. 2015 Jan;141(1):93-8
25113832
Thyroid. 2009 May;19(5):467-72
19415996
Thyroid. 2008 Feb;18(2):141-4
18279014
Lancet. 2004 Jan 10;363(9403):157-63
14726171
Mol Cell Endocrinol. 2010 May 28;321(1):94-102
19835928
Eur J Prev Cardiol. 2014 Dec;21(12):1484-92
23864362
Surgery. 2010 Dec;148(6):1147-52; discussion 1152-3
21134545
Cancer Res Treat. 2015 Jul;47(3):362-9
25672579
Obes Rev. 2013 Dec;14(12):1006-22
24034423
Cancer Epidemiol Biomarkers Prev. 2011 Mar;20(3):464-72
21266520
Lancet. 2008 Feb 16;371(9612):569-78
18280327
J Clin Oncol. 2008 Jul 10;26(20):3395-402
18612154
Exp Diabetes Res. 2012;2012:578285
22778714
Eur J Endocrinol. 2013 May 03;168(6):879-86
23513231
Maturitas. 2016 Aug;90:17-23
27282789
Epidemiol Health. 2016 Jan 06;38:e2016002
26797220