Cancer Risk Increases With Height

A woman’s cancer risk appears to increase with her height, a new study shows.

An analysis of 20,928 postmenopausal women showed that the taller a woman is, the greater her risk for a number of cancers, including breast, colon and skin cancer, among others. The finding, published in Cancer Epidemiology, Biomarkers & Prevention, is not expected to change screening recommendations and shouldn’t alarm those with a tall stature. Instead, say scientists, the association between height and cancer may help guide researchers to study hormones and growth factors that influence height and may also play a role in cancer.

“We know that cancer is a disease in which hormones and growth factors modify things,” said Geoffrey C. Kabat, a senior epidemiologist in the department of epidemiology and population health at the Albert Einstein College of Medicine of Yeshiva University in New York. “Height itself is not a risk factor, but it really appears to be a marker for one or more exposures that influence cancer risk.”

Nobody really knows why cancer risk is associated with a taller stature. It may have to do with hormones and growth factors that spur both height and cancer cells. It may be that height simply increases the surface area of the body’s organs, resulting in a greater number of overall cells and higher subsequent risk of malignancy.

While the current study focused only on women, other research has also found an association between height and cancer among men. One study found that taller men were at slightly higher risk for aggressive prostate cancer. In May, the Journal of the National Cancer Institute reported that height differences between men and women may help explain why men have an overall greater risk of developing cancer in non-sex specific organs like kidneys and lungs. That study, of 65,000 men and women, showed that sex differences in height may explain a third to a half of a man’s excess cancer risk compared to women.

Height can be influenced by a number of factors beyond genetics. The amount and type of foods consumed in childhood can influence height, and childhood nutrition may also play some role in cancer risk. A higher circulating level of a protein called insulin-like growth factor, which can be influenced by factors like exercise, stress, body mass index and nutrition, is also associated with both increased height and an increased cancer risk.

The data for the latest analysis were collected from the Women’s Health Initiative, the largest-ever study of postmenopausal women. The researchers identified 20,928 women who had received a cancer diagnosis during the 12-year study period. The data set included not only the woman’s height but also her age, weight, education, smoking habits, alcohol consumption and whether she used hormone therapy. This allowed the scientists to control for other factors that could influence cancer risk and more closely determine the strength of the association with height.

They found that for every 4-inch change in height, there was a 13 percent increase in risk for developing any type of cancer. The cancers most strongly associated with height were cancers of the kidney, rectum, thyroid and blood. Risk for those cancers increased by 23 to 29 percent for every 4-inch increase in height.