Obese patients with an advanced form of prostate cancer survive longer than their slimmer counterparts, according to researchers at San Raffaele University in Italy. The study was presented at the 36th Annual European Association of Urology (EAU) Congress.
Obesity is generally known as a risk factor for many conditions, including several kinds of cancer. However, some studies have shown that obesity offers a survival advantage in some cancers, in what is known as the 'obesity paradox'.
For the present study, the researchers recruited 1577 patients with metastatic castration-resistant prostate cancer (mCRPC) for three phase 3 randomized controlled trials. Their average age was 69 years, and their median body mass index (BMI) was 28. The median follow-up for participants was 12 months.
In the end, the researchers found that 30% of obese patients (BMI >30) survived the 36-month follow-up. The same was true for just 20% of those who were overweight (25<BMI<30) and of normal weight (20< BMI <25).
The researchers say that this is another example of the obesity paradox. Its underlying mechanisms, however, are unknown. One suggestion, they say, is that as older obese patients tend to take medications for other conditions, their enhanced survival rate may be due to some unknown interactions.
Meanwhile, Peter Albers, Peter Albers who chairs the EAU Scientific Congress, suggested that patients with a higher BMI may tolerate treatment toxicity and side effects better than those with lower BMI's. He added that hormones found in tissue fat may have a protective effect and that healthy men with slightly higher BMI's are known to have a higher overall life expectancy compared to those who are very slim.
Until further research is conducted, however, these explanations remain hypotheses. Therefore, the researchers do not recommend weight gain for people with this disease.