"This is the largest study of its kind to date,” said researcher Dr. Gerard Mullin. “It builds on evidence that taller height is an overlooked risk factor, and it should be considered when evaluating and recommending patients for colorectal cancer screenings.”
How height impacts cancer risk
The researchers gathered information from nearly 50 earlier studies that included data on over 280,000 cases of colorectal cancer. They also looked at data from nearly 1,500 colonoscopy patients who were enrolled in the Johns Hopkins Colon Biofilm study. The goal was to understand the link between height and colorectal cancer risk by taking information from both datasets.
Ultimately, the link between height and colorectal cancer risk was clear. The researchers learned that taller patients had a higher risk of being diagnosed with the disease than shorter patients.
“The findings suggest that, overall, the tallest individuals within the highest percentile of height had a 24% higher risk of developing colorectal cancer than the shortest within the lowest percentile,” Dr. Mullin said. “Every 10-centimeter increase (about 4 inches) in height was found to be associated with a 14% increased risk of developing colorectal cancer and 6% increased odds of having adenomas.”
The researchers speculate that this relationship between height and colorectal cancer risk may come down to organ size. They explained that taller people have larger organs, which may increase their risk of abnormalities that become cancerous.
Identifying those at the highest risk
Age and genetics are currently the two biggest risk factors associated with colorectal cancer, so health care professionals analyze them to determine which consumers have the most risk. Based on these findings, the researchers hope that height is now used to identify patients who may be most likely to develop colorectal cancer.
“For instance, tall athletes and individuals with inherited tallness, such as those with Marfan syndrome, could be screened earlier and the impact of height further explored,” said researcher Dr. Elinor Zhou. “We need more studies before we can definitively say at what height you would need earlier colorectal cancer screening.”
“Greater awareness by the public and the government will help promote more interest and funding for research, which ultimately could change guidelines for physicians to consider height as a risk for cancer,” Mullin added. “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.”