How obesity affects patients after prostate surgery

The authors aimed to determine the impact of obesity on long-term cancer outcomes in patients after prostate surgery.

Prostate surgery is the standard treatment in patients with prostate cancer confined within the prostate gland. This involves surgically removing the prostate.

Obesity is classified as having a body mass index (BMI – measurement based on height and weight) of more than 30kg/m². Prostate cancer patients with a high BMI are more likely to experience more aggressive and advanced prostate cancer upon diagnosis than men who are of an average weight. It is unclear whether this will have an effect on outcomes following prostate cancer surgery. It is important to determine this, as obesity is a risk factor that may be modified with lifestyle and diet changes. 

The aim of this study was to determine how obesity effects patients who undergo prostate surgery.

11, 152 patients were used in this study with a follow-up time of 5 years. 56% of patients were over-weight (BMI between 25-29), 14.1% were mildly obese (BMI of between 30-35) and 2.3% were severely obese (BMI over 35). Patients who presented with a higher BMI were more likely to be younger, have a more aggressive cancer, to have undergone surgery more recently with positive surgical margins (tissue removed during surgery still shows signs of cancer) and were more likely to be African American.

Obesity was a significant predictor of biochemical recurrence-free survival (patients who did not experience a rise in prostate specific antigen [PSA- protein elevated in the blood when prostate cancer is present] after surgery) and overall survival (patients who did not die from prostate cancer following treatment) in mild and severely obese patients.

 Patients who were mildly obese had a 30% increased risk of experiencing shorter biochemical recurrence-free survival after surgery and had a 41% increased risk of experiencing a shorter overall survival compared to normal weight patients.

Patients who were severely obese had a 45% increased risk of experiencing shorter biochemical recurrence-free survival after surgery and had a 81% increased risk of experiencing a shorter overall survival compared to normal weight patients.

Mild obesity was significantly associatedwith prostate cancer-specific survival (patients who had not died from prostate cancer since treatment was received). Mildly obese patients had a 51% increased risk of experiencing shorter cancer-specific survival than normal weight patients.

The authors concluded that obesity shortens biochemical recurrence-free survival and overall survival in patients after surgery but cannot predict prostate cancer-specific survival.

This study does not include weight gained during treatment, only at the time of surgery.

If you have a high BMI and have concerns about the effect of obesity on cancer outcomes, please consult your doctor.