Body mass index linked to prostate tumor volume
MedWire News: A prostate cancer patient’s body mass index (BMI) is correlated with the size of his tumor, show the results of a US study.
Previous research has established a strong link between higher BMI and aggressive prostate cancer, thus Patil and team evaluated the association between BMI and percent tumor volume (defined as the size of a malignant tumor as a percentage of the space it takes up in the prostate gland).
“Based on our results, we believe having a larger percentage of tumor volume may be contributing to the aggressive nature of the disease in men with a higher BMI,” said Nilesh Patil, from Henry Ford Hospital in Detroit, Michigan.
The study was presented at the 2010 American Urology Association’s annual meeting in San Francisco today.
The researchers assessed the final specimens of 3327 patients who underwent robotic-assisted radical prostatectomy between 2001 and 2007, and calculated the average percentage of area involved in cancer.
The men were grouped according to their BMI, with less than 24.9 kg/m2 indicating normal or underweight (n=678), 25–29.9 kg/m2 indicating overweight (n=1723), 30–39.9 kg/m2 indicating obesity (n=890), and more than 40 kg/m2 indicating morbid obesity (n=36).
The mean age of the men was approximately 60 years in each BMI group, and their mean prostate weights after prostatectomy were a respective 45.8 g, 49.2 g, 50.9 g, 50.8 g, and 49.9 g.
In each BMI category, the patient’s weight was directly associated with his prostate tumor size, ie, the smaller the patient the lighter the tumor, and the larger the patient the heavier the tumor.
For BMI groups 24.9 kg/m2 and less, 25.0–29.9 kg/m2, 30.0–34.9 kg/m2, 35.0–39.9 kg/m2 and 40.0 kg/m2 and above, the respective percent tumor volumes were approximately 16, 17, 18, 20, and 23.
“As the patients’ BMI increased, the tumor volume increased synchronously,” conclude Patil and team.
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By Sarah Guy