Obesity usually shortens our lifespan and almost always increases cancer risk and worsens outcomes but a new US study found that overweight patients with advanced kidney cancer had significantly longer survival than those who were normal or underweight.
Having a high body mass index (BMI) is a well-established risk factor for clear cell renal cell carcinoma, the most common type of kidney cancer. BMI is the ratio of weight in kilograms divided by the squared height in meters.
The new study published on Monday in the Journal of Clinical Oncology involving about 7,000 patients in four databases, however, showed that when overweight individuals developed kidney cancer -- especially in its advanced, metastatic form -- their disease progressed more slowly and they lived longer than their normal-weight counterparts, Xinhua news agency reported.
In one group of nearly 2,000 patients, the median overall survival of patients with high BMI was 25.6 months compared to 17.1 months for patients with low BMI.
The report's authors, led by senior and corresponding author Toni Choueiri, director of the Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute, noted previous research showed that kidney cancer diagnosed in obese patients had less-dangerous pathological characteristics, and when treated with targeted therapies, these patients, even when their disease had spread, had better overall survival.
To explain that, they searched for molecular differences between the high and low BMI patients in two of the databases, but didn't reveal any differences in the tumors' DNA, such as gene mutations, that might account for the disparity.
(With agency input)