Women's height linked to cancer risk: study

The taller a post-menopausal woman is, the greater her risk for developing cancer, according to a study by researchers at Albert Einstein College of Medicine of Yeshiva University that has been published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Geoffrey Kabat, Ph.D

Geoffrey Kabat, PhD, and a team of researchers at Albert Einstein College of Medicine have found that the taller a postmenopausal woman is, the greater her risk for developing cancer.

Height was linked to cancers of the breast, colon, endometrium, kidney, ovary, rectum, and thyroid, as well as to multiple myeloma and melanoma.

These associations did not change even after adjusting for factors known to influence these cancers. The study included 20,928 women recruited to the Women's Health Initiative (WHI), the largest, multi-site longitudinal study looking at risks among postmenopausal women.

"We were surprised at the number of cancer sites that were positively associated with height. In this data set, more cancers are associated with height than were associated with body mass index (BMI)," saysGeoffrey Kabat, PhD., senior epidemiologist in the department of epidemiology and population health at Einstein. "Ultimately, cancer is a result of processes having to do with growth, so it makes sense that hormones or other growth factors that influence height may also influence cancer risk."

Some genetic variations associated with height are also linked to cancer risk, and more studies are needed to better understand how these height-related genetic variations predispose some men and women to cancer, according to the authors.

Dr Kabat and colleagues used data from the WHI, a large, multi-centre study that recruited post-menopausal women between the ages 50 and 79, between 1993 and 1998. At study entry, the women answered questions about physical activity, and their height and weight were measured.

The researchers identified 20,928 women who had been diagnosed with one or more invasive cancers during the follow-up of 12 years. To study the effect of height, they accounted for many factors influencing cancers, including age, weight, education, smoking habits, alcohol consumption, and hormone therapy.

They found that for every 10-cm (3.94 inches) increase in height, there was a 13 per cent increase in risk of developing any cancer. Among specific cancers, there was a 13 per cent to 17 per cent increase in the risk of getting melanoma and cancers of the breast, ovary, endometrium, and colon. There was a 23 per cent to 29 per cent increase in the risk of developing cancers of the kidney, rectum, thyroid, and blood.

Of the 19 cancers studied, none showed a negative association with height.

Because the ability to screen for certain cancers could have influenced the results, the researchers added the participants' mammography, Pap, and colorectal cancer screening histories to the analyses and found the results remained unchanged.

"Although it is not a modifiable risk factor (modifiable risk factors can be changed, controlled, or treated, e.g., diet, lifestyle. Height is a non-modifiable risk factor because it cannot be changed), the association of height with a number of cancer sites suggests that exposures in early life, including nutrition, play a role in influencing a person's risk of cancer," said Dr. Kabat.

"There is currently a great deal of interest in early-life events that influence health in adulthood. Our study fits with this area."