Analysis of the height dependence of site-specific cancer risk in relation to organ mass

Body Mass Index Trajectories Across the Adult Life Course and Pancreatic Cancer Risk

BACKGROUND

Body mass index (BMI) during adulthood has been associated with pancreatic ductal adenocarcinoma (PDAC), however, patterns of body size across the adult life course have not been studied extensively. We comprehensively evaluated the association between adiposity across adulthood and PDAC.

METHODS

We conducted a prospective analysis of 269 480 (162 735 males, 106 745 females) National Institutes of Health-AARP Diet and Health Study participants, aged 50-71 years (1995-1996) who self-reported height and weight history. Participants were followed through December 31, 2011. We examined associations between BMI (kg/m2) at ages 18, 35, 50, and 50-71 (baseline) years, their trajectories determined from latent-class trajectory modeling, and incident PDAC. Cox proportional hazard models were used to calculate multivariable adjusted hazards ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During up to 15.2 years of follow-up, 3092 (2020 males, 1072 females) patients with incident PDAC were identified. BMI at all 4 ages were statistically significantly associated with increased PDAC (per 5-unit increase, HR = 1.09-1.13) with higher magnitude associations in males than females at ages 35 years and older (Pinteraction < .05). Four BMI trajectories were created. Compared with normal-weight maintainers, normal-to-overweight, normal-to-obese class I, and overweight-to-obese class III trajectories had hazard ratios of 1.15 (95% CI = 1.06 to 1.25), 1.39 (95% CI = 1.25 to 1.54), and 1.48 (95% CI = 1.18 to 1.87), respectively (Pinteraction by sex = .07).

CONCLUSIONS

High BMI and BMI trajectories that result in overweight or obesity during adulthood were positively associated with PDAC, with stronger associations among those with early onset adiposity and those with male sex. Avoidance of excess body weight throughout the adult life course may prevent PDAC.

Adult-Attained Height and Colorectal Cancer Risk: A Cohort Study, Systematic Review, and Meta-Analysis

BACKGROUND

The influence of anthropometric characteristics on colorectal neoplasia biology is unclear. We conducted a systematic review and meta-analysis to determine if adult-attained height is independently associated with the risk of colorectal cancer or adenoma.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Library, and Web of Science from inception to August 2020 for studies on the association between adult-attained height and colorectal cancer or adenoma. The original data from the Johns Hopkins (Baltimore, MD) Colon Biofilm study was also included. The overall HR/OR of colorectal cancer/adenoma with increased height was estimated using random-effects meta-analysis.

RESULTS

We included 47 observational studies involving 280,644 colorectal cancer and 14,139 colorectal adenoma cases. Thirty-three studies reported data for colorectal cancer incidence per 10-cm increase in height; 19 yielded an HR of 1.14 [95% confidence interval (CI), 1.11-1.17; P < 0.001), and 14 engendered an OR of 1.09 (95% CI, 1.05-1.13; P < 0.001). Twenty-six studies compared colorectal cancer incidence between individuals within the highest versus the lowest height percentile; 19 indicated an HR of 1.24 (95% CI, 1.19-1.30; P < 0.001), and seven resulting in an OR of 1.07 (95% CI, 0.92-1.25; P = 0.39). Four studies reported data for assessing colorectal adenoma incidence per 10-cm increase in height, showing an overall OR of 1.06 (95% CI, 1.00-1.12; P = 0.03).

CONCLUSIONS

Greater adult attained height is associated with an increased risk of colorectal cancer and adenoma.

IMPACT

Height should be considered as a risk factor for colorectal cancer screening.

Body size and composition and risk of site-specific cancers in the UK Biobank and large international consortia: A mendelian randomisation study

BACKGROUND

Evidence for the impact of body size and composition on cancer risk is limited. This mendelian randomisation (MR) study investigates evidence supporting causal relationships of body mass index (BMI), fat mass index (FMI), fat-free mass index (FFMI), and height with cancer risk.

METHODS AND FINDINGS

Single nucleotide polymorphisms (SNPs) were used as instrumental variables for BMI (312 SNPs), FMI (577 SNPs), FFMI (577 SNPs), and height (293 SNPs). Associations of the genetic variants with 22 site-specific cancers and overall cancer were estimated in 367,561 individuals from the UK Biobank (UKBB) and with lung, breast, ovarian, uterine, and prostate cancer in large international consortia. In the UKBB, genetically predicted BMI was positively associated with overall cancer (odds ratio [OR] per 1 kg/m2 increase 1.01, 95% confidence interval [CI] 1.00-1.02; p = 0.043); several digestive system cancers: stomach (OR 1.13, 95% CI 1.06-1.21; p < 0.001), esophagus (OR 1.10, 95% CI 1.03, 1.17; p = 0.003), liver (OR 1.13, 95% CI 1.03-1.25; p = 0.012), and pancreas (OR 1.06, 95% CI 1.01-1.12; p = 0.016); and lung cancer (OR 1.08, 95% CI 1.04-1.12; p < 0.001). For sex-specific cancers, genetically predicted elevated BMI was associated with an increased risk of uterine cancer (OR 1.10, 95% CI 1.05-1.15; p < 0.001) and with a lower risk of prostate cancer (OR 0.97, 95% CI 0.94-0.99; p = 0.009). When dividing cancers into digestive system versus non-digestive system, genetically predicted BMI was positively associated with digestive system cancers (OR 1.04, 95% CI 1.02-1.06; p < 0.001) but not with non-digestive system cancers (OR 1.01, 95% CI 0.99-1.02; p = 0.369). Genetically predicted FMI was positively associated with liver, pancreatic, and lung cancer and inversely associated with melanoma and prostate cancer. Genetically predicted FFMI was positively associated with non-Hodgkin lymphoma and melanoma. Genetically predicted height was associated with increased risk of overall cancer (OR per 1 standard deviation increase 1.09; 95% CI 1.05-1.12; p < 0.001) and multiple site-specific cancers. Similar results were observed in analyses using the weighted median and MR-Egger methods. Results based on consortium data confirmed the positive associations between BMI and lung and uterine cancer risk as well as the inverse association between BMI and prostate cancer, and, additionally, showed an inverse association between genetically predicted BMI and breast cancer. The main limitations are the assumption that genetic associations with cancer outcomes are mediated via the proposed risk factors and that estimates for some lower frequency cancer types are subject to low precision.

CONCLUSIONS

Our results show that the evidence for BMI as a causal risk factor for cancer is mixed. We find that BMI has a consistent causal role in increasing risk of digestive system cancers and a role for sex-specific cancers with inconsistent directions of effect. In contrast, increased height appears to have a consistent risk-increasing effect on overall and site-specific cancers.