Greater adult-attained height correlated with increased risk for colorectal cancer and adenoma, according to a meta-analysis published in Cancer, Epidemiology, Biomarkers & Prevention.Researchers from Johns Hopkins School of Medicine arrived at the finding after adjusting for demographic, socioeconomic, behavioral and other known risk factors.“Tallness is an overlooked risk factor for several adverse health conditions and is not on the radar for doctors to bear in mind when evaluating health maintenance and prevention. Those who are considered tall for their culture should be considered for earlier screening for colorectal adenomas than the general population,”Gerard E. Mullin, MD, associate professor of medicine and director of Johns Hopkins Hospital Integrative GI Nutrition Services at The Johns Hopkins School of Medicine, told Healio.Background Mullin and colleagues pursued the research because the influence of anthropometric characteristics on colorectal neoplasia biology was unclear.“We knew that there were modifiable factors such as smoking, alcohol use and processed meat consumption that raised the risk for digestive tract cancers that are not considered by doctors in screening for colon cancer, but what about nonmodifiable factors?” Mullin said. “We knew that certain conditions with excessive body size and tallness, such as acromegaly and Klinefelter syndrome, raised risk for colon cancer — but what about basketball players and athletes?”Mullin said the thought first occurred to him years ago when he was at a New York Yankees baseball game and their 36-year-old outfielder, Darryl Strawberry, was taken out of a playoff game due to advanced colon cancer. “That was the first time I had heard of a young person with advanced colon cancer,” Mullin said. “I saw him at a vegan restaurant in Miami in 2019 and he looked healthy and fit. It wasn’t his diet. I wondered if it was his height and began to look for a link in the literature and was struck that there were positive studies on many digestive tract cancers. So, we focused on a possible line of colon cancer and attained tallness.”MethodologyMullin and colleagues searched MEDLINE, EMBASE, the Cochrane Library and Web of Science for studies on the association between adult-attained height and colorectal cancer or adenoma. They identified 47 observational studies involving 280,644 colorectal cancer and 14,139 colorectal adenoma cases. The researchers also gathered original data from the Johns Hopkins Colon Biofilm study, which enrolled 1,459 adults who received outpatient colonoscopies.Researchers estimated HRs and ORs of colorectal cancer/adenoma with increased height using random-effects meta-analysis.Key findings Thirty-three studies had data for colorectal cancer incidence per 10 cm increase in height — 19 yielded an HR of 1.14 (95% CI, 1.11-1.17) and 14 an OR of 1.09 (95% CI, 1.05-1.13).In addition, 26 studies had data comparing colorectal cancer incidence between individuals within the highest vs. the lowest height percentile — 19 showed an HR of 1.24 (95% CI, 1.19-1.3) and seven an OR of 1.07 (95% CI, 0.92-1.25). Four studies had data assessing colorectal adenoma incidence per 10 cm increase in height, showing an overall OR of 1.06 (95% CI, 1-1.12).Mullin told Healio that the positive adenoma data surprised researchers.“Most of all that the apparent magnitude of risk was comparable to the risk of frequent processed red meat consumption, cigarette smoking or moderate alcohol consumption,” Mullin said. “We controlled for many of the risk factors for adenoma and colon cancer, such as family history, inflammatory bowel disease and even diet, and found attained height as an independent risk factor.”ImplicationsAs a result of their findings, Mullin and colleagues recommended that height be considered a risk factor for colorectal cancer screening. They added that more research is necessary to define the tallness risk parameters that can translate the finding into the clinical care setting.Mullin suggested research into the use of DNA stool testing for neoplasia in tall individuals, testing their positivity with age-matched controls.“It also would be interesting to see if there is a factorial interaction of attained height with the aforementioned modifiable factors, such as diet, and/or nonmodifiable ones, such as genetic," Mullin said.For more information:Gerard E. Mullin, MD, can be reached at Johns Hopkins University School of Medicine, Department of Gastroenterology and Hepatology, 600 N. Wolfe St., Baltimore, MD 21205; email: gmullin1@jhmi.edu.