Health Day reporter
MONDAY July 12, 2021 (HealthDay News) – When men have advanced prostate cancer, obesity could offer a survival benefit, a preliminary study suggests.
Italian researchers found that among men with prostate cancer that had spread throughout the body, those who were obese were less likely to die in the next few years.
About 30% were still alive after three years, compared to 20% of normal-weight and overweight men, according to the study.
Researchers pointed out that no one advises men to gain weight as a defense against prostate cancer: obesity is associated with a higher risk of developing and dying from various chronic diseases, including a number of cancers.
But over the years, some studies have shown that cancer patients with a higher body mass index (BMI) tend to survive longer – a phenomenon sometimes referred to as the ‘obesity paradox’.
The new findings suggest that the paradox could also apply to advanced prostate cancer.
However, an expert not involved in the study urged caution in the findings.
Critically, it is unclear why the study patients were obese or thin, said Dr Vinayak Wagaskar, urologist at Icahn School of Medicine at Mount Sinai in New York City.
He noted that BMI was only measured after the men developed advanced cancer that no longer responded to hormone therapy – and not right after they were diagnosed with prostate cancer.
This is important, in part, because some treatments for prostate cancer, including hormone therapy and steroids, can cause weight gain.
Additionally, Wagaskar said, the patients’ weight could have been affected by additional medical conditions they had.
He said the study raises an “interesting concept,” but stressed the need for more research – with men’s BMIs measured at the time of diagnosis.
For the study, Dr Nicola Fossati and colleagues at San Raffaele University in Milan looked at data from nearly 1,600 men who had participated in previous clinical trials. All of the patients had metastatic prostate cancer that did not respond to hormone therapy. Metastatic means it has spread to distant sites in the body.
While early-stage prostate cancer is highly treatable, metastatic cancer is different: About 30% of men with such advanced disease survive for five years, according to the American Cancer Society.
In this study, Fossati’s team found that men with a BMI of 30 or more – the cutoff for obesity – were 29% less likely to die over three years than those with a lower BMI.
The results were presented on Sunday at the annual meeting of the European Urological Association (EAU), which is being held online. Research presented at meetings is generally considered preliminary until it is published in a peer-reviewed journal.
In a press release from the meeting, Fossati said: “This obesity paradox has been observed in other cancers, possibly due to the relationship between tissue fat and cancer genomes, and more research is needed in this area. “
On the other hand, he said, the results may reflect some interaction between cancer chemotherapy and other drugs.
“Obese patients in this older age group tend to take drugs for other conditions,” Fossati noted, “and we don’t fully understand how these drugs interconnect.”
Dr Peter Albers, chairman of the UAE Scientific Congress Bureau, also warned that the reasons for the obesity paradox, in general, are uncertain.
“It may be that patients with a higher BMI are able to better tolerate the toxicity of the treatments and their side effects,” Albers said in the statement. “In prostate cancer, it could be due to the protective impact of hormones present in fat tissue; and it is known that healthy men with a slightly higher BMI have a higher overall life expectancy than very thin men.
But, he stressed, these are just conjectures.
“More research is needed to identify the biological mechanism behind these different findings,” Albers said. “Until this mechanism is proven, we cannot recommend any change in treatment for patients with advanced prostate cancer.”
In fact, Wagaskar said, some other studies have linked obesity not only to a higher risk of developing prostate cancer, but also to “worse cancer-related outcomes.”
Fossati agreed that a healthy weight range should be the goal. “Obesity is a risk factor for many cancers and other diseases,” he said, “and patients should always aim for a healthy BMI of 18-24”.
The American Cancer Society has more information on the causes and prevention of prostate cancer.
SOURCES: Vinayak G. Wagaskar, MBBS, MCh, instructor, department of urology, Icahn School of Medicine in Mount Sinai, New York City; European Urological Association annual meeting, press release and online presentation, July 11, 2021
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