Long-term benefits of elective radiotherapy after prostatectomy for patients with positive surgical margins.

Teh BS.  Department of Radiology/Section of Radiation Oncology, Baylor College of Medicine, Houston, Texas J Urol. 2006 Jun;175(6):2097-101

The benefit of adjuvant radiotherapy after prostatectomy for patients with pathological risk factors but with an undetectable postoperative PSA remains controversial. In this retrospective study we define the benefits of elective postoperative radiotherapy in this setting.  A total of 44 patients received elective postoperative radiotherapy at a single institution in the PSA era (1989 to 1995) for positive surgical margins and undetectable postoperative PSA. Radiotherapy was delivered to a median dose of 60 Gy. Clinical target volume included the prostate bed. Pelvic nodes were not treated. The four-field box technique with customized blocking of bladder, rectum and small bowels was used and defined the planning target volume. The patients were then compared to a contemporaneous group of 189 patients with positive surgical margins who underwent radical prostatectomy without any adjuvant therapy. Failure was defined as biochemical (PSA) recurrence and was timed from first detectable PSA.

RESULTS: The 5 and 10-year biochemical no evidence of disease was 90.9% and 90.9% for the elective postoperative radiotherapy group, and 66.4% and 54.5% for the observation group, respectively (p = 0.0012). Median time to biochemical failure was also longer in the elective postoperative radiotherapy group (88.6 months) compared to the observation group (43.5 months) (p <0.001). Risk factors for biochemical recurrence on multivariate analysis were Gleason score greater than 7 (p = 0.017), established extracapsular extension (p = 0.002) and lack of elective postoperative radiation (p = 0.001).

CONCLUSIONS: This is one of the longest follow-up studies showing that elective postoperative radiation therapy is associated with improved bNED and prolonged time to recurrence. Combined radical prostatectomy and elective postoperative radiotherapy should be considered in the management of high risk prostate cancer, especially in the presence of positive surgical margins despite undetectable PSA.

Identification of factors predicting response to adjuvant radiation therapy in patients with positive margins after radical prostatectomy.

Kamat AM Department of Urology, University of Texas M.D. Anderson Cancer Center. J Urol. 2003 Nov;170(5):1860-3.

PURPOSE: Radical prostatectomy (RP) is a highly effective treatment for patients with prostate cancer. However, patients with positive surgical margins after radical prostatectomy have less than ideal outcomes with 5-year progression rates between 36% and 50%. Postoperative radiation therapy (RT) is often advocated for improving these outcomes. We identified predictors of response to adjuvant RT given for positive margins after RP. MATERIALS AND METHODS: We retrospectively reviewed the clinical records of men who underwent RP between 1987 and 1999 at our institution and who received adjuvant RT for positive surgical margins. Only patients in whom prostate specific antigen (PSA) was undetectable after RP as well as before the initiation of RT were included. Numerous clinicopathological variables, including pre-RP PSA, pathological stage, margin length and location, and extracapsular extension or seminal vesicle involvement, were assessed for their adverse effect on the biochemical recurrence rate after adjuvant RT.

RESULTS: A total of 62 men met our inclusion criteria. Median age at surgery was 60.7 +/- 6.1 years and median PSA at presentation was 9.0 ng/ml (range 1.4 to 64.9). The median RT dose was 60.0 +/- 3.6 Gy. RT was started a median of 5.0 +/- 3.6 months after RP. The 5 and 10-year biochemical disease-free survival rates for the whole group were 90.2% and 87.9%, respectively. Of all parameters tested only Gleason score 4 + 3 or greater (p = 0.037) and pre-RP PSA greater than 10.9 ng/ml (p = 0.040) were predictive of biochemical recurrence after adjuvant RT on univariate analysis. On multivariate analysis only pre-RP PSA greater than 10.9 ng/ml remained an independent predictor (p = 0.031). CONCLUSIONS: In the setting of true adjuvant RT in patients with positive margins after RP and undetectable PSA those with predominant Gleason grade 4 or greater, or PSA greater than 10.9 ng/ml at presentation are at increased risk for recurrence after adjuvant RT.