Excess body weight, weight gain and obesity-related cancer risk in women in Norway: the Norwegian Women and Cancer study

Marisa Da Silva,Idlir Licaj,Elisabete Weiderpass,Charlotta Rylander,Lauren Lissner

doi:10.1038/s41416-018-0240-5

Abstract

BackgroundExcess body weight and weight gain have been reported to independently increase the risk of several cancers. There are few published studies in nationally representative populations of women on specific, ‘obesity-related’ cancers in relation to prior weight change and relevant confounders.MethodsBased on self-reported anthropometry, we prospectively assessed body mass index (BMI), weight change over 6 years and subsequent obesity-related cancer risk in the Norwegian Women and Cancer study. We used Cox proportional hazard models to calculate hazard ratios and restricted cubic splines to model potential non-linear dose–response relationships.ResultsExcess body weight increased the risk of overall obesity-related cancer, postmenopausal breast, colorectal, colon, endometrial and kidney cancer, with endometrial cancer showing a threefold elevated risk. High weight gain ( ≥ 10 kg) increased the risk of overall obesity-related cancer, postmenopausal breast, endometrial and pancreatic cancer. The association between high weight gain and pancreatic cancer was strong, with 91% increased risk.ConclusionsMaintaining stable weight in middle adulthood, irrespective of BMI category at baseline, and avoiding excess body weight are both important in the prevention of several obesity-related cancers in women. Our finding of increased risk of pancreatic cancer in women with moderate and high weight gain is novel.

Highlights

Excess body weight and weight gain have been reported to independently increase the risk of several cancers
In total, 135,708 women were included in the body mass index (BMI) analysis and 80,930 women who responded to Q2 were included in the weight change analysis (Fig. 1)
In this study, we assessed the relationship between BMI, weight change and obesity-related cancer risk in a large and nationally representative cohort of women in Norway

Summary

Introduction

Excess body weight and weight gain have been reported to independently increase the risk of several cancers. High weight gain ( ≥ 10 kg) increased the risk of overall obesity-related cancer, postmenopausal breast, endometrial and pancreatic cancer. The global burden of cancer has increased alongside the obesity prevalence, with 13 cancer types defined as obesity-related.[2,3] The cancers with sufficient evidence of a positive association with overweight or obesity ( referred to as excess body weight) are cancer of the breast (postmenopausal), colon–rectum, endometrium, ovary, pancreas, kidney, gallbladder, gastric cardia, liver, oesophagus (adenocarcinoma), meningioma, thyroid and multiple myeloma. Weight gain is associated with several obesity-related cancers independent of body composition.[4] nationally representative studies on weight gain and the risk of less-commonly diagnosed obesityrelated cancers such as pancreatic and kidney cancer in women are rare. There is an evident research gap on weight gain and specific obesity-related cancers

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