Twenty‐four‐month postradiation prostate biopsies are strongly predictive of 7‐year disease‐free survival |
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| Authors: | Juanita M. Crook MD Shawn Malone MD Gad Perry MD Libni Eapen MD Julie Owen MD Susan Robertson MD Charles Ludgate MD Sharon Fung MSC Gina Lockwood M Math |
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| Affiliation: | 1. Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario, Canada;2. Fax: (416) 946‐4586;3. Department of Radiation Oncology, Ottawa Regional Cancer Center, Ottawa, Ontario, Canada;4. Department of Radiation Oncology, Northeastern Ontario Regional Cancer Center, Sudbury, Ontario, Canada;5. Department of Pathology, Ottawa Hospital, Ottawa, Ontario, Canada;6. Department of Vancouver Island Cancer Center, British Columbia, Canada;7. Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario, Canada |
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| Abstract: | BACKGROUND: The objective of this study was to evaluate the predictive value of prostate biopsies that were obtained 24 months after the completion of radiotherapy (RT) with respect to disease‐free survival (DFS) in a randomized trial that compared 3 months versus 8 months of neoadjuvant hormone therapy before conventional dose external RT. METHODS: From February 1995 to June 2001, 378 men were randomized to receive either 3 months or 8 months of combined flutamide and goserelin before they received 66 Gray of RT at 4 participating centers. By risk group, 26% of patients were categorized as low risk, 43% were categorized as intermediate risk, and 31% were categorized as high risk. The 2 treatment arms were balanced in terms of age, Gleason score, clinical tumor classification, risk group, and presenting prostate‐specific antigen level. The median follow‐up for the patients who remained alive was 6.6 years (range, 1.6‐10.1 years). Of 361 evaluable patients, 290 patients remained alive. Post‐RT prostate biopsies were performed between 24 and 30 months after the completion of RT in 3 of the 4 centers. Biopsies that had residual tumor with severe treatment effect were considered indeterminate, and biopsies that had minimal or no treatment effect were considered positive. RESULTS: The 5‐year rate of actuarial freedom from any failure for the 3‐month arm versus the 8‐month arm was 72% versus 75% (P = .18). The DFS for patients who had negative and indeterminate biopsies was similar. Two‐year post‐treatment biopsy status was a strong predictor of 5‐year DFS rate (82% and 83% for negative and indeterminate biopsies, respectively, vs 27% for positive biopsies; P < .0001). Multivariate analysis indicated that biopsy status (P < .0001) and Gleason score (P < .0001) were the strongest determinates of biochemical DFS. CONCLUSIONS: Two‐year post‐RT prostate biopsies were strongly predictive of subsequent DFS. Biopsies with severe treatment effect were considered negative. Cancer 2009. © 2008 American Cancer Society. |
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| Keywords: | prostate cancer radiotherapy neoadjuvant hormone therapy postradiation prostate biopsies |
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