PHILADELPHIA – A man's height is a modest marker for risk of prostate cancer development, but is more strongly linked to progression of the cancer, say British researchers who conducted their own study on the connection and also reviewed 58 published studies.
In the September issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, 12 researchers at four universities in England studied more than 9,000 men with and without prostate cancer and estimated that the risk of developing the disease rises by about six percent for every 10 centimeters (3.9 inches) in height a man is over the shortest group of men in the study. That means a man who is one foot taller than the shortest person in the study would have a 19 percent increased risk of developing the disease.
Still, these increases in risk are a lot less than those linked with other established risk factors, such as age, family history of the disease, and race. Because of that, the researchers do not suggest that taller men be screened more often than is typical, or that their cancer treatment be altered.
"Compared to other risk factors, the magnitude of the additional risk of being taller is small, and we do not believe that it should interfere with preventive or clinical decisions in managing prostate cancer," said the study's lead author, Luisa Zuccolo, M.Sc., of the Department of Social Medicine at the University of Bristol. "But the insight arising from this research is of great scientific interest. Little is known on the causes of prostate cancer and this association with height has opened up a new line of scientific inquiry."
For example, Zuccolo says that factors associated with height - not height itself – could be risk factors for progression to fatal prostate cancer, and a plausible mechanism behind this association could be the insulin-like growth factor-1(IGF-1) system, which stimulates cell growth and has been shown to be involved in prostate cancer incidence and progression.
Because some studies have shown a much greater association between height and prostate cancer risk – some between 20 to 40 percent – the researchers then placed their results in the context of available evidence. They conducted a meta-analysis of 58 studies, and found evidence that greater stature is associated with increased prostate cancer risk. But as in their study, the overall effect varied with study design and was modest – a three to 9 percent increase risk of development per 10 centimeters, and five to 19 percent increase in risk for more advanced cancer.
"We do not believe that height itself matters in determining risk of prostate cancer or prostate cancer progression, but we speculate that factors that influence height may also influence cancer and height is therefore acting as a marker for the causal factors," Zuccolo said.