Obesity and the prevention of thyroid cancer: Impact of body mass index and weight change on developing thyroid cancer - Pooled results of 24 million cohorts

Mohanad R Youssef; Adin S C Reisner; Abdallah S Attia; Mohamed Hosny Hussein; Mahmoud Omar; Anna LaRussa; Carlos A Galvani; Mohamed Aboueisha; Mohamed Abdelgawad; Eman Ali Toraih; Gregory W Randolph; Emad Kandil

doi:10.1016/j.oraloncology.2020.105085

Obesity and the prevention of thyroid cancer: Impact of body mass index and weight change on developing thyroid cancer - Pooled results of 24 million cohorts

Oral Oncol. 2021 Jan:112:105085. doi: 10.1016/j.oraloncology.2020.105085. Epub 2020 Nov 7.

Affiliations

¹ Department of Surgery, Tulane University, School of Medicine, New Orleans, LA, USA.
² Tulane University, School of Medicine, New Orleans, LA, USA.
³ Division of Minimally Invasive Surgery and Bariatric, Department of Surgery, Tulane University, New Orleans, LA 70112, USA.
⁴ Department of Surgery, Tulane University, School of Medicine, New Orleans, LA, USA; Department of Otolaryngology Head and Neck Surgery, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
⁵ Department of Surgery, Tulane University, School of Medicine, New Orleans, LA, USA; Genetics Unit, Department of Histology and Cell Biology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
⁶ Division of Thyroid and Parathyroid Surgery, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, MA, USA.
⁷ Department of Surgery, Tulane University, School of Medicine, New Orleans, LA, USA. Electronic address: ekandil@tulane.edu.

PMID: 33171329
DOI: 10.1016/j.oraloncology.2020.105085

Abstract

Background: Body weight may be a modifiable risk factor predisposing to different cancers. To establish a potential impact of weight change on thyroid cancer risk, we conducted a meta-analysis to evaluate the effect of body mass index (BMI) and weight change over time as a risk of developing thyroid cancer (TC).

Methods: A systematic search was performed up to February 25, 2020. Pooled relative risk (RR) were estimated using fixed and random models. Heterogeneity between articles was examined using Q-test and I² index. Evaluation of publication bias was conducted with Egger's regression test.

Results: A total of 31 studies including 24,489,477 cohorts were eligible. Pooled analysis revealed that normal and underweight cohorts were associated with a decreased risk of TC (RR = 0.68, 95%CI = 0.65-0.71, p < 0.001) and (RR = 0.92, 95%CI = 0.91-0.93, p < 0.001), respectively. In contrast, overweight and obese cohorts were more likely to develop TC (RR = 1.26, 95%CI = 1.24-1.28, p < 0.001 and RR = 1.50, 95%CI = 1.45-1.55, p < 0.001, respectively). Obesity was associated with higher risk of developing TC among women (RR = 1.29, 95%CI = 1.14-1.46, p < 0.001), but not men (RR = 1.25, 95%CI = 0.97-1.62, p = 0.08). Furthermore, weight gain increased the risk of developing TC (RR = 1.18, 95%CI = 1.14-1.22, p < 0.001), while weight loss decreased the risk (RR = 0.89, 95%CI = 0.85-0.93, p < 0.001). Results showed similar trends of weight change effect in both males and females.

Conclusions: Obesity is associated with higher risk of developing TC in women. However, maintaining a healthy weight is associated with reduced risk of TC in both women and men. Shifting our practice to include weight control strategies will help lead to cancer prevention.

Keywords: Obesity; Thyroid cancer.

Publication types

Meta-Analysis
Systematic Review

MeSH terms

Body Mass Index*
Body Weight*
Cohort Studies
Confidence Intervals
Female
Humans
Male
Obesity / complications*
Overweight / complications
Publication Bias
Risk Assessment
Risk Factors
Sex Factors
Thinness
Thyroid Neoplasms / etiology*
Thyroid Neoplasms / prevention & control*
Weight Gain