Men's Weight Linked to Prostate Cancer Growth
Obesity, Weight Gain May Raise Prostate Cancer Risks
A man's weight gain may affect his prostate cancer prognosis and raise the
risk of the disease progressing, according to a new study.
Researchers found men who were obese at the time their prostate cancer was
diagnosed as well as those who gained weight quickly before their diagnosis
were more likely to have an aggressive form of the disease. These men were more
likely to have prostate cancer that progressed after surgical treatment.
Although previous studies have suggested a link between obesity and the risk
of developing prostate cancer, researchers say this is the first study to show
a relationship between a man's weight at different ages and the risk of
prostate cancer progression after diagnosis and surgical treatment.
Researchers say if further studies confirm these results, doctors should
consider a man's weight and his history of weight gain when designing a
prostate cancer treatment plan, such as incorporating diet and exercise
strategies to reduce the risk of prostate cancer progression.
Obesity Tied to Prostate Cancer Progression
In the study, published in Clinical Cancer Research, researchers
followed 526 men with prostate cancer who were treated with surgery
(prostatectomy). The study lasted about 4.5 years.
Researchers checked whether the men had rising prostate-specific antigen
(PSA) levels following their initial prostate cancer treatment, which the
researchers call biochemical failure.
"After surgery, a patient's PSA should go back to being undetectable,
but if it begins to rise, that is an indicator of progression," researcher
Sara Strom, PhD, associate professor at the University of Texas M.D. Anderson
Cancer Center, says in a news release.
"Thirty percent of men who have biochemical failure will develop a
life-threatening cancer metastasis, and so PSA is the only marker we have as
yet to predict whose cancer will spread."
Overall, 18% of the men experienced biochemical failure, and the results
showed that the men's weight was associated with the risk of prostate cancer
progression in at least three ways:
- Men who were obese at the time of prostate cancer diagnosis were more
likely to experience rising PSA levels than those who were not obese. Obesity
is defined as having a body mass index (BMI, a measure of weight in
relationship to height) of 30 or more.
- Men who were obese at age 40 had a greater rate of biochemical
- Men who gained weight at the greatest rate between age 25 and the time of
their prostate cancer diagnosis experienced disease progression significantly
sooner (after an average of 1.5 years) compared with those who gained weight
more slowly during adulthood (an average of 3 years).
"These findings support the view that the development of aggressive
forms of prostate cancer may be influenced by environmental effects that occur
early in life," says Strom.
Researchers say it's unclear exactly how obesity contributes to prostate
cancer risk but possible explanations include hormonal changes, poor diet, and
low physical activity.