Gastric cancer is one of the most common and deadly cancers worldwide. Data from the GLOBOCAN database showed that gastric cancer was responsible for over 1,033,000 new cases and 78,200 deaths in 2018, ranking fifth for cancer incidence and third for cancer mortality. Overweight and obesity have been considered a risk factor for many types of cancer. A prospective study of more than 900,000 U.S. adults indicated that obesity caused approximately 20% of cancer deaths in women and 14% in men, making obesity the second biggest preventable cause of cancer.1
For most previous studies evaluating obesity and gastric cancer risk, traditional anthropometric measures, including body mass index (BMI) and waist circumference (WC), were used as the exposure measurements. Although these indices provide simple, cheap, and crude measures of body size, they could neither directly discriminate between lean and fat mass, nor precisely evaluate the distribution of fat mass.2 Epidemiological evidence concerning the association between body composition and gastric cancer risk has emerged, but is still inadequate.3 Further investigations could identify the effects of key composition, fat, or lean mass, on gastric cancer development. These results may provide evidence for individualized weight management for the prevention of gastric cancer.
In this study by Liu et al., the authors utilized data from the UK Biobank to establish a correlation between adiposity and gastric cancer. The UK Biobank is a large biorepository which has collected data about body composition and cancer incidence from 0.5 million UK adults. Based on the UK Biobank dataset, we carried out this prospective analysis to confirm the relationship between body composition (including total/trunk/arm/leg body fat mass and body fat‐free mass) and risk of gastric cancer. At recruitment in 2006–2010, the participants underwent a range of physical measurements and detailed assessments of health‐related factors. Blood, urine, and saliva samples were also collected for biochemical analysis.
UK Biobank evaluated baseline fat free mass (kg) and fat mass (kg) with electrical bio‐impedance analysis (Tanita BC418MA body composition analyser) of over 93% participants. The whole body as well as site‐specific (trunk, leg, arm) fat‐free mass/fat mass were evaluated. UK Biobank also evaluated body composition in 5,170 participants using dual‐energy X‐ray absorptiometry (DXA). Trained staff measured standing height using the Seca 202 device (Seca, Hamburg, Germany) and assessed waist/hip circumference with the Wessex non‐stretchable sprung tape measure (Wessex, United Kingdom). BMI was calculated by dividing body weight (in kilograms) by height squared (in meters squared). UK Biobank obtained data on cancer diagnoses from the Health & Social Care Information Centre for participants in England and Wales, and the NHS Central Register for participants in Scotland. To compare the ability of predicting gastric cancer across various body composition and anthropometry measures, the Hazard ratios (HRs) per standard deviation (SD) increase were evaluated with Cox regression.
This study included a total of 465,292 participants, of which 213,843 were males and 251,449 were females. 326 cases of gastric cancer were documented over a median follow‐up of 6.6 years. For males, those in the highest quartile of whole‐body fat‐free mass had a 70% increased risk of gastric cancer as compared with those in the lowest quartile (Adjusted HR 1.70, 95% CI 1.01 to 2.89). For female participants, compared with females in the lowest quartile of whole‐body fat‐free mass, those in the highest quartile was associated with a 2.47 times greater risk of gastric cancer (Adjusted HR 2.47, 95% CI 1.15 to 5.32).
For both genders, fat‐free mass was likely to associate with an increased risk of gastric cancer, particularly for those distributed in the trunk and arm in males. In male participants, each 5‐unit increase in BMI and WC was associated with a 17% (Adjusted HR 1.17, 95% CI 1.01 to 1.37) and 9% (Adjusted HR 1.09, 95% CI 1.02 to 1.15) increase in the risk of gastric cancer, respectively. No evidence of associations between these anthropometric measures with gastric cancer were observed in females.
In this prospective cohort of over 0.46 million participants, the authors observed that fat‐free mass, particularly those distributed in arm and trunk in females, was associated with an increased risk of gastric cancer. While whole body fat mass and arm fat mass were associated with a decreased risk of gastric cancer in females. For both genders, arm fat‐free mass was likely to be the strongest predictor of gastric cancer risk. Traditional anthropometric measures, including BMI and WC, were associated with increased risk of gastric cancer in males, but not in females. Collectively, these findings indicated that fat‐free mass and fat mass may play a different role in gastric cancer development in males and females.
According to the authors “Overall, this large‐scale prospective study suggested that fat‐free mass tended to associate with increased risk of gastric cancer in both genders, while fat mass was associated with reduced gastric cancer risk in females. For both genders, arm fat‐free mass was likely to be the strongest predictor of gastric cancer risk. In clinical practice, our findings provided evidence for individualized weight management for the prevention of gastric cancer.”
References
- Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018;68(6):394‐424.
- Jensen MD. Role of body fat distribution and the metabolic complications of obesity. J Clin Endocrinol Metab. 2008;93(11 Suppl 1):S57‐S63.
- MacInnis RJ, English DR, Hopper JL, Giles GG. Body size and composition and the risk of gastric and oesophageal adenocarcinoma. Int J Cancer. 2006;118(10):2628‐2631.
