Obesity doubles prostate cancer patients' death risk

Overweight or obese men diagnosed with prostate cancer are at a substantially higher risk of death within five years of screening, researchers in the United States found. Men with excess body fat are twice as likely to die from the disease, compared to those who are thinner, warns the novel study.

The findings, which published online Monday and scheduled to appear in the Dec. 15 issue of the journal Cancer, confirm the earlier studies that touted the obesity as a risk factor for several common caners and other health problems.

Last month, Australian researchers linked the obesity to esophageal cancer, the increasingly rising cancer in some countries. Researchers at Queensland Institute of Medical Research and University of Queensland, who reported their findings in the journal Gut, suggested at the time that obesity is an independent risk factor for developing esophageal cancer.

A recent landmark study by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF) unveiled that excess body fat can cause six different types of common cancers. The WCRF/ AICR report, titled “Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective”, suggests that super-size meals, lack of exercise and obesity can significantly increase the risk of a variety of common cancers, including those affecting the colon, kidneys, pancreas, esophagus, uterus and breasts in post menopausal women.

Now, the new US study, conducted by Dr. Jason Efstathiou and colleagues from Massachusetts General Hospital in Boston, linked the obesity to the most common malignancy in men, Prostate cancer.

To confirm their findings of a link between excess body fat and the fatal incidence of prostate cancer, the researchers studied 788 patients diagnosed with advanced prostate cancer. 241 patients of the total were considered at normal body weight, while 402 were overweight and 145 were considered at clinically obese.

After following the patients for a period of eight years, during which they examined the relationship between BMI (body mass index) and mortality, the researchers specifically found that a greater BMI at the time of cancer diagnosis was an independent risk factor for prostate cancer-related death.

The death rate after five years of treatment was 13.1 percent for overweight men, 12.2 percent for obese men, and 6.5 percent for men with a normal BMI, says the study. Compared to men with normal BMI, the overweight men were more than 1.5 times more likely to die from the disease. In Addition, obese men were 1.6 times more likely to die from their disease compared to men with normal weight.

Obesity is normally measured by body mass index (BMI) that divides the weight by the square of the height. It is a simple and frequently used method for estimating body fat:

A BMI less than 18.5 is ‘underweight’
A BMI of 18.5 - 24.9 is ‘normal weight’
A BMI of 25.0 - 29.9 is ‘overweight’
A BMI of 30.0 - 39.9 is ‘obese’
A BMI of 40.0 or higher is ‘severely (or morbidly) obese’.

American Obesity Association (AOA) has described the obesity on its Website as a complex, multi-factorial chronic disease involving environmental (social and cultural), genetic, physiologic, metabolic, behavioral and psychological components. It is the second leading cause of preventable death in the U.S.

Today, obesity has become a burning issue in many of the countries, mostly the developed ones. It has reached almost epidemic levels in the United States where nearly 127 million adults are overweight, 60 million obese and 9 million severely obese.

As per the estimates of Canadian Cancer Society, nearly one-third of Canadian men are obese. In the United Kingdom, where Obesity is the second biggest cause of death among people, about a fifth of the U.K. population suffers from obesity. A whopping 300 million people around the world are obese.

According to the American Cancer Society (ACS), more than 218,000 men in the US alone will be diagnosed with prostate cancer this year, and as predicted 27,000 will die from the disease, while in Canada an estimated 22,300 men are expected to get prostate cancer this year.