News & Events

Height May Be a Risk Factor for Prostate Cancer

Posted to the Web: Wednesday, September 03 , 2008
September 3, 2008 — Tall men, especially those who are long-legged, may be at slightly increased risk for prostate cancer. In addition, that cancer, when it occurs, is more likely to be high grade than tumors occurring in men of more modest stature.

Those findings come from a study published in the September issue of Cancer Epidemiology, Biomarkers & Prevention.

Compared with other risk factors for prostate cancer, such as age or African-American race, being tall adds only slightly to a man's chances of developing the disease. Men who are a foot taller than the shortest man in the study would have about a 19% increased risk for prostate cancer, the researchers found.

In addition, taller men had about a 12% increased risk for high-grade adenocarcinoma of the prostate. Height was not, however, associated with incidence of low-grade disease, the authors found.

Some of the factors that influence height may also increase cancer, said lead author Luisa Zuccolo, MSc, a PhD candidate in the department of social medicine at Bristol University in the United Kingdom.

"We do not believe that height itself matters in determining risk of prostate cancer or prostate cancer progression," she said. "But we speculate that factors that influence height may also influence cancer, and height is therefore acting as a marker for causal factors."

The investigators note that serum levels of nsulin-like growth factor-I (IGF-1) in childhood may play a role in cancer risk in adulthood. Taller men tend to have had higher serum levels of IGF-1 in childhood, and higher levels of the growth factor in adulthood have been linked to higher prostate cancer risk.

Ms. Zuccolo and colleagues conducted a nested case-control study involving 1357 men, ages 50 to 69 years, with prostate-specific antigen (PSA)–detected prostate cancer who were enrolled in a clinical trial of localized prostate cancer therapies. The cases were linked to 7990 controls matched by age, general practice, and date of assessment.

The authors also conducted a meta-analysis of 58 studies in which a possible link between height and prostate cancer risk was explored.

They found in their case-control study that for every 10 cm of additional height, the odds ratio (OR) for PSA-detected cancer was 1.06 (95% confidence interval [CI], 0.97 - 1.16; P = .20 for trend). When they looked at the association of height by prostate cancer grade, they found that for men in the tallest vs the shortest quartile, the OR for high-grade cancer was 1.24 (95% CI, 1.06 - 1.43; P < .01 for trend), with most of the excess risk occurring in men with longer legs in comparison to their trunk height (OR, 1.14; 95% CI, 1.02 - 1.28; P = .02 for trend). The results were similar in the meta-analysis, the authors noted.

Clinical Implications

"We do not envisage any changes in protocols for screening and/or treatment," Ms. Zuccolo told Medscape Medical News. "At this stage the research is interesting from a scientific point of view because it opens new paths of invesigation, but we do not recommend any changes in guidelines or any particular intervention with respect to people's height."

That sentiment was echoed by Anthony D'Amico, MD, PhD, chief of genitourinary radiation oncology at the Brigham & Women's Hospital and Dana-Farber Cancer Institute in Boston, Massachusetts. He was not involved in the study but was asked to provide independent commentary on it for Medscape Medical News.

"I don't think we should screen people who are taller at a younger age, because I don't think the level of evidence is strong enough to support that taller people are more likely to get high-grade cancers," he said.

Dr. D'Amico commented that while the study was extremely well done in terms of statistical methods, the data need to be viewed with caution.

"The number of comparisons they make is quite large: low-grade, high-grade, localized and locally advanced prostate cancer, and under each of those categories there are 3 subcategories [height, leg length, and trunk length], and with such a large number there's a distinct possibility that something may be as significant just by chance," he said.

Dr. D'Amico also noted that an association between height and risk for high-grade disease does not suggest that height itself is a risk factor, but instead may be a cofactor with other, biologically relevant risk factors.

"People with high IGF levels are not necessarily taller," he said. "It depends really on what those levels were at birth and during the time when you're growing, not necessarily what they are when you're an adult.

It's a biologically plausible argument, but the only way to know for sure that IGF, height, and high-risk prostate cancer are all associated is to take a group of people who have high IGF levels when they're young, show that they're taller when they grow up, and then show that those taller people have a disproportionately high risk for high-risk prostate cancer," Dr. D'Amico said.

Cancer Epidemiol Biomarkers Prev. 2008;17(9):2325-2336.