The taller a postmenopausal woman is, the greater risk she faces of developing cancer, according to a new study.
In a paper published Thursday in the journal Cancer Epidemiology, Biomarkers & Prevention, researchers concluded that a woman's cancer risk increased 13% with every 4 inches of height.
The study is the latest of several to report an association between women's height and cancer, according to lead study author Geoffrey Kabat, a cancer epidemiologist at Albert Einstein College of Medicine in New York.
While it is unlikely that height in and of itself promotes cancer, the multitude of factors that influence growth -- such as nutrition, genetics and environment -- are likely responsible.
"Height was significantly positively associated with risk of all cancers, [including] cancers of the thyroid, rectum, kidney, endometrium, colorectum, colon, ovary, and breast, and with multiple myeloma and melanoma," the authors concluded.
The study was based on data from 144,701 women, aged 50 to 79, who particiapted in the Womens's Health Initiative study in the 1990s. Researchers adjusted for other potential cancer risks, such as weight, smoking, alcohol consumption and hormone therapy, as well as for frequency of cancer screening.
When researchers examined the study cohort, they found that the women's average age and body mass index decreased as their height increased, whereas their average weight, rate of smoking and alcohol intake increased with height.
"As anticipated, younger women and women with higher income had greater mean height compared to older women and women with lower income, respectively," authors wrote.
Researchers offered a number of possible explanations for the connection between height and cancer risk.
Height is associated with increased milk intake in childhood, and higher levels of insulin-like growth factor, which promotes cell growth and inhibits programmed cell death, the authors noted.
Increased height might also be the result of exposure to steroid hormones. Authors noted too that taller women might have larger organs and skin surface area, which may put more cells at risk of malignant growth.
"Height should thus be thought of as a marker for one or more exposures that influence cancer risk rather than a risk factor itself," the authors wrote.
But because the study did not include men or premenopausal women, the conclusions about height are limited.
Also, the study data did not include information on leg length and sitting height -- known biomarkers of growth hormone exposure.
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