Tallness associated with increased cancer risk

July 28, 2011

Tall women are more likely than short women to develop cancer, British researchers report in a study published online July 21 in The Lancet Oncology.

Tall women are more likely than short women to develop cancer, British researchers report in a study published online July 21 in The Lancet Oncology.

The prospective cohort study by investigators at the University of Oxford collected information on height and other variables related to cancer in 1.3 million middle-aged women without previous cancer between 1996 and 2001. The researchers then followed the women for cancer incidence for a total of 11.7 million person-years (median, 9.4 years per woman), during which 97,376 cancers occurred. The tallest women (above 5 feet, 9 inches) were 37% more likely to develop a tumor than the shortest women (under 5 feet). The increase in risk was statistically significant for 10 types of cancer: colon, rectal, malignant melanoma, breast, endometrial, ovarian, kidney, lymphoma, non-Hodgkin lymphoma, and leukemia. A meta-analysis of the study and 10 other prospective studies found a similar association between height and cancer risk in men.

“Obviously, height itself cannot affect cancer, but it may be a marker for something else,” says lead author Jane Green, DPhil, adding that there “may be a basic common mechanism.” The researchers speculate that growth hormones might be that mechanism. Higher levels of growth hormone could produce more cells capable of mutating and becoming tumors or they could speed the rate of cell division, raising the risk of cancer.

The researchers hypothesize that increasing height may have played a role in the rise in cancer incidence in Europe in the past century. An increase of 1 cm per decade in average height, as is believed to have occurred during that time, could have led to 10% to 15% more cancers than if heights hadn’t increased, they say.

The meta-analysis found little variation in height-associated relative risks (RRs) for total cancer across Europe, North America, Australasia, and Asia. The researchers conclude that “the relation between height and total cancer RRs is similar in different populations.”