Tall adults could be more likely to develop bowel cancer

By Gwyn Wright via SWNS

Tall adults could be more likely than shorter ones to develop bowel cancer, according to scientists.

Researchers in the US say the tallest people are at a 24 percent higher risk from the disease than the shortest people.

The team at Johns Hopkins School of Medicine say their findings add to existing evidence that taller people are at a higher risk from colorectal cancer or polyps that can later become a serious problem.

Previous studies that probed the link have had inconsistent results, but those studies carried out inconsistent measurements of height and failed to assess the risk from adenomas, which are precancerous colon polyps.

The study, which is the largest of its kind yet, suggests height is an overlooked risk factor for bowel cancer.

The reasons for the link are unclear, but the researchers say it could be that the bigger your organs are, the higher the risk is.

Height is not as much of a risk factor for bowel cancer as age or genetics, but the researchers say it remains important and should be considered when doctors recommend patients for screening.

For the study, the team analyzed 47 major studies involving more than 280,000 bowel cancer cases and more than 14,000 cases of colorectal adenoma.

They also included data from the Johns Hopkins Colon Biofilm study, which recruited 1,459 adult patients undergoing outpatient colonoscopies to explore the relationship between cancer and bacteria stuck to the walls of the colon, known as biofilm.

The definition of tall varies around the world, so the team compared the tallest and shortest height percentile in various groups they studied.

The findings suggest the tallest people studied are at a 24 percent higher risk from the disease than the shortest people.

Every four inches of height was linked to a 14 percent higher risk from the disease and a six percent higher risk of developing adenomas.

In the US, men who are six foot one are 14 percent more likely to get the condition compared with their peers who are five foot nine.

Women who are five foot eight are 14 percent more likely to get the condition as other women who are five foot four.

The results were adjusted for demographic, socioeconomic, behavioral and other factors known to raise the risk of bowel cancer.

These factors include age and having a personal or family history of bowel cancer or adenomas, and a personal history of chronic inflammatory bowel disease.

However, in the US more than half of all colon cancers are linked to lifestyle choices such as eating, smoking and drinking too much and not taking enough exercise.

While the importance of tallness as a risk factor cannot be precisely pinpointed, its salience may be similar to factors such as cigarette smoking, moderate drinking and eating lots of processed red meat.

Currently, doctors focus on age and genetic risks when they recommend people for screening but this should be changed, the academics say.

In the US, rates of the disease have been dropping since the 1980s because of screening and healthier lifestyles.

The downward trend exists mainly in older adults and deaths from the disease have in fact been rising in Americans younger than 50 for reasons that are not yet clear.

Lead study author Dr. Gerard Mullin said: “This is the largest study of its kind to date.

“It builds on evidence that taller height is an overlooked risk factor, and should be considered when evaluating and recommending patients for colorectal cancer screenings.

“There are well-known modifiable dietary associations for colorectal cancer, such as processed red meats and smoking, but guidelines currently are fixated on family history, and height is clinically neglected when it comes to risk screening.

“Greater awareness by the public and government will help promote more interest and funding for more research, which ultimately could change guidelines for physicians to consider height as a risk for cancer.”

The study’s first co-author Dr. Elinor Zhou said: “One possible reason for this link is that adult height correlates with body organ size.

“More active proliferation in organs of taller people could increase the possibility of mutations leading to malignant transformation.

“Tall athletes and individuals with inherited tallness, such as those with Marfan syndrome, could be screened earlier and the impact of height further explored.”

The findings were published in the journal Cancer Epidemiology Biomarkers and Prevention.