Background: Brachytherapy, active surveillance, and watchful waiting are increasingly being offered to men with low-risk prostate cancer. However, many of these men harbor undetected high-grade disease (Gleason pattern > or =4). The ability to identify those individuals with occult high-grade disease may help guide treatment decisions in this patient cohort.
Methods: The authors identified 175 cases of low-risk prostate cancer treated with radical prostatectomy. By using logistic regression analysis, 11 a priori-defined preoperative risk factors were evaluated for their ability to predict upgrading from Gleason 6 at biopsy to Gleason > or =7 at radical prostatectomy. An internally validated nomogram using all clinical variables was subsequently created to help physicians identify patients who had undetected high-grade disease.
Results: A total of 60 (34%) patients were upgraded to high-grade disease. On multivariate analyses, both prostate-specific antigen (PSA) level (P = .02) and the level of pathologist expertise (P = .007) were predictive of upgrading. The predictive nomogram contained these variables plus age, digital rectal examination, transrectal ultrasound results, biopsy scheme applied (sextant vs extended), presence of prostatic intraepithelial neoplasia, prostate gland volume, and percentage of cancer in the biopsy. The nomogram provided acceptable discrimination (C statistic 0.71).
Conclusions: The authors identified significant predictors of upgrading for patients diagnosed with low-risk prostate cancer. A nomogram based on these study findings could help physicians further risk-stratify patients with low-risk prostate cancer before embarking on treatment. Caution should be exercised in recommending nonradical therapy to individuals with a high probability of undetected high-grade disease.
Copyright 2007 American Cancer Society.