THURSDAY, July 13, 2017 -- The larger a man, the greater his risk of getting and dying from aggressive prostate cancer, a new study suggests.
Every additional 4 inches of height increased a man's chances of being diagnosed with high-risk prostate cancer by 21 percent, and their odds of dying from prostate cancer by 17 percent, researchers found.
The same held true regarding the size of a man's waist. Every 4-inch increase in waist circumference increased the odds of developing aggressive prostate cancer by 13 percent and the risk of dying from prostate cancer by 18 percent.
"I definitely think these results encourage men to have a healthy weight, and to have more public health policies that prevent obesity," said lead researcher Aurora Perez-Cornago, a nutritional epidemiologist with the University of Oxford in England.
Perez-Cornago and her colleagues came to their conclusions based on data from nearly 142,000 men in eight European countries who participated in a large-scale study of cancer and nutrition.
Among these men, just over 7,000 developed prostate cancer during an average 14 years of follow-up, including 728 diagnosed with aggressive cancer and 1,388 with advanced-stage cancer. Of those diagnosed, 934 died from their cancer.
Previous studies have suggested a potential link between prostate cancer and a man's height or weight, but this is the first to assess whether those factors influence the risk of being diagnosed with either a slow-growing or aggressive cancer, Perez-Cornago said.
Height by itself was not linked to a man's overall risk of developing prostate cancer, nor was it associated with risk of being diagnosed with low- or intermediate-grade prostate cancer, researchers said.
However, height did influence a man's risk of being diagnosed with aggressive prostate cancer and of dying from prostate cancer, the study showed.
Similarly, body-mass index and waist circumference both were shown to directly predict risk of developing high-grade prostate cancer.
The study only found an association between height, weight and aggressive prostate cancer risk; it couldn't prove a cause-and-effect link.
But the association between height and prostate cancer risk isn't new, said Victoria Stevens, strategic director of laboratory services for the American Cancer Society.
Researchers suspect the increased risk from height is probably related to early childhood nutrition that promoted fast growth, Stevens and Perez-Cornago said.
There are two main theories regarding the possible link between obesity and prostate cancer.
One is that obesity influences hormones in the body in a way that promotes prostate cancer, Stevens and Perez-Cornago said.
On the other hand, it may simply be more difficult to catch prostate cancer early in men who are obese, Stevens said.
"In obese men, they're less likely to have their cancer detected at an early stage, in part because the digital rectal exam is tougher to do," Stevens said. "If they have a large prostate, it's easier to miss something in it."
PSA blood tests for prostate cancer also are less reliable in obese men, because they tend to have a higher volume of blood that dilutes and masks elevated levels of prostate-specific antigen, Stevens said.
Stevens and Perez-Cornago did not agree whether tall men and obese men should be tested more frequently for prostate cancer.
Perez-Cornago said it might be a good idea in particular for tall men to be more closely screened, since they can't do anything about that risk factor. On the other hand, obese men can reduce their risk by losing weight.
But Stevens noted that in general cancer experts have been reconsidering the value of prostate cancer screening for all men, since most of these tumors are never life-threatening.
The 15-year survival rate of men diagnosed with prostate cancer is 96 percent, according to the American Cancer Society.
Prostate cancer expert Dr. Sumanta Pal agreed with Stevens.
"Screening for prostate cancer, as per many existing guidelines, remains a highly individualized practice that needs to be tailored to patients based on factors such as family history, but at present, not factors such as height or weight," said Pal, an assistant clinical professor with City of Hope in Duarte, Calif.
The study was published July 12 in the journal BMC Medicine.
For more information on prostate cancer survival rates, visit the American Cancer Society.
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