The taller a postmenopausal woman is, the greater her risk for developing cancer, according to a study.
Height was linked to cancers of the breast, colon, endometrium, kidney, ovary, rectum and thyroid, and to multiple myeloma and melanoma, and these associations did not change even after adjusting for factors known to influence these cancers.
The study, published July 25 on the website of Cancer Epidiemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, included 20,928 postmenopausal women who were identified from a large cohort of 144,701 women recruited to the Womens Health Initiative.
We were surprised at the number of cancer sites that were positively associated with height, Geoffrey Kabat, PhD, the studys lead author and a senior epidemiologist in the Department of Epidemiology and Population Health at Albert Einstein College of Medicine of Yeshiva University in New York City, said in a news release. In this data set, more cancers are associated with height than were associated with body mass index.
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.
Kabat and colleagues used data from the WHI, a large, multicenter study that recruited postmenopausal women, ages 50 to 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 isolate 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-centimeter (3.94-inch) increase in height, there was a 13% increase in risk of developing any cancer. Among specific cancers, there was a 23% to 29% increase in the risk of developing cancers of the kidney, rectum, thyroid and blood; and a 13% to 17% increase in the risk of getting melanoma and cancers of the breast, ovary, endometrium and colon. 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, the association of height with a number of cancer sites suggests that exposures in early life, including nutrition, play a role in influencing a persons risk of cancer, Kabat said. There is currently a great deal of interest in early-life events that influence health in adulthood. Our study fits with this area.
Some genetic variations associated with height are also linked to cancer risk, and more studies are needed to better understand how these predispose some men and women to cancer, according to the authors.
Study abstract: http://cebp.aacrjournals.org/content/early/2013/07/25/1055-9965.EPI-13-0305.abstract.