Obese Men May Have Higher Risk for Biochemical Recurrence Following Radical Prostatectomy
Among men with prostate cancer who underwent radical prostatectomy, those who were obese had a higher risk of biochemical recurrence, according to data presented at the American Association for Cancer Research (AACR) Special Conference on Obesity and Cancer: Mechanisms Underlying Etiology and Outcomes, held January 27–30 in Austin, Texas.
Biochemical recurrence was defined as two consecutive prostate-specific antigen (PSA) measurements ≥ 0.2 ng/mL after prostatectomy, which is indicative of recurrent prostate cancer.
“Obesity and metabolic syndrome have become increasingly widespread in our society,” said Arash Samiei, MD, a basic scientist and clinical researcher in the Department of Urology at the Allegheny Health Network in Pittsburgh. “Prostate cancer is the most common cancer in men, and up to 30% of patients will develop recurrence after radical prostatectomy. We wanted to investigate the association between obesity and metabolic syndrome with the oncologic outcome following prostate removal.”
Dr. Samiei explained that previous studies linking high body mass index (BMI) and metabolic syndrome to increased risk of recurrence following radical prostatectomy have been controversial. To build upon previous research, Dr. Samiei and colleagues performed a large study with long-term follow-up to conduct a more comprehensive analysis.
Study Design
Researchers conducted a retrospective study of all radical prostatectomies (1,100 surgeries) performed by two surgeons at Allegheny General Hospital in Pittsburgh between 2003 and 2013. They analyzed Gleason score; pathologic stage; preoperative PSA; biochemical recurrence time; surgical margin status; and metabolic factors, such as fasting glucose, triglycerides, cholesterol levels (including high-density lipoprotein [HDL]), preoperative BMI, and blood pressure.
Patients were categorized as having low-, intermediate-, or high-risk prostate cancer based on pathologic staging and grading of the disease. Metabolic syndrome positivity was determined using the World Health Organization (WHO) classification, where at least three of the following five factors are simultaneously present in an individual—insulin resistance or type 2 diabetes, obesity, high total cholesterol or low HDL levels, high triglycerides, and hypertension.
The average age of the patient at diagnosis was 60 years, and the average follow-up time was 48 months. Among the patients studied, 34% were obese as defined by BMI, and 19% had metabolic syndrome.
Major Findings
Dr. Samiei and colleagues found a higher percentage of obese patients in the high-risk group (41.2%) compared to obese patients in the low- and intermediate-risk groups (32%). Additionally, biochemical recurrence was higher in patients with BMI ≥ 30 (32.4%) compared to patients with BMI < 30 (16.9%). Patients with metabolic syndrome had more than a fourfold increased risk of biochemical recurrence compared to those without metabolic syndrome.
“Our study indicates that prostate cancer patients who are obese or have metabolic syndrome undergoing radical prostatectomy may have a higher chance for recurrence of the disease, and these individuals should have more focused follow-up care,” said Dr. Samiei. “By preventing metabolic syndrome, men with prostate cancer may have a higher chance of a favorable oncologic outcome following surgery.”
Dr. Samiei noted that because this was an observational, retrospective study, future work should include the design of large, multicenter prospective studies.
This study was sponsored by the Western Pennsylvania Prostate Cancer Foundation.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
