A large review of the data showed that cancer specific survival and prognosis were improved in renal cell carcinoma (RCC) patients who were overweight or obese compared with patients with a normal body mass index (BMI).
Why this is remains unknown; however, some theoretical explanations are:
- Patients with a higher BMI are more likely to receive medical testing for other reasons and may be more likely to have an incidental diagnosis of RCC at an earlier stage when treatment is more successful
- Some research has demonstrated a more favourable tumour biology in obese patients, specifically the expression of metabolic and fatty acid genes, key components of tumour growth, are down-regulated
- The role of fat tissue at the molecular level is considered a factor in improving survival.
The researchers recommend additional research into the fundamental biological mechanisms of this finding in order to determine the true significance of BMI on outcomes in patients with RCC.