Height as a Cancer risk

By EDUARDO GONZALES, MD - Q: Is it really true that tall people have a higher risk for cancer than short people? A friend told me she read a newspaper article that said so. I’m concerned because I’m 6’3”. --Andy P., Las Pinas City

MANILA, Philipines -- A: Taller people might indeed have an increased risk of developing a wide range of cancers. A recent research study whose findings were published online by The Lancet Oncology, a reputable medical journal, last July 21, 2011 suggested as much. The research was conducted by a group of Oxford University scientists led by Jane Green and included 1.3 million middle-aged UK women as subjects. The subjects were recruited between 1996 and 2001 and during an average follow-up time of about 10 years, 97,000 of the women were diagnosed with cancer. The study assessed the association among height, other factors relevant for cancer, and cancer incidence.

After analyzing the data they have gathered, the researchers concluded that for every four inches (10cm) above five feet, a person had a 16 percent increased in total cancer risk from many different types of cancer, including cancers of the breast, ovary, womb, kidney, bowel, rectum, leukemia, malignant melanoma, lymphoma, and non-Hodgkin’s lymphoma. Furthermore, although the study had only women subjects, the researchers said the height link was also present in men because they likewise conducted a meta-analysis after they combined their results with those from 10 previous studies that showed a similar link in men.

Actually, the Oxford research study is not the first to explore the relationship between height and cancer. A number of earlier epidemiological studies have already indicated that taller people are at a greater risk of developing cancers. One of the more noteworthy among these studies was conducted by Dr. Jaime Guevara-Aguirre of Quito, Ecuador who found out that people of severely short stature are less likely to develop cancer or diabetes during a 22-year study of 99 Ecuadorian dwarfs. Another significant work was done by a group of US researchers who, after analysis of 13 previous studies found out that the risk of testicular cancer among men increases by 13 percent for every extra two inches in height.

But tall people like you need not worry too much, the existing evidence on this matter is not yet conclusive. Besides, being tall has its own advantages, including lower risk of other conditions such as heart disease.

The studies that have been conducted so far have not identified the reasons for the correlation between height and cancer. A couple of possible explanations were postulated by the Oxford researchers: taller people have more cells and therefore they have more cells that can mutate and become malignant; and, taller people have higher levels of growth hormones while growing up. These higher levels of the hormone that promotes cell growth and division could account for increased risk of mutation among the cells.

Obviously, more confirmatory studies on the relationship between height and cancer need to be undertaken. In the meantime, since there is nothing much we can do about our height, we should be much more concerned with the lifestyle factors that have already been confirmed to contribute to cancer. We can all reduce our risk for cancer significantly if we: