Between December 1, 2003 and January 2009, 1437 patients underwent RALP procedures performed by 3 surgeons at our institution. Of these, 278 patients were excluded due to lack of follow-up at our institution and lack of postoperative PSA. Sixteen patients received adjuvant therapy and were included in our analysis. Specifically, 9 patients underwent adjuvant radiation therapy, 3 received adjuvant androgen deprivation therapy, and 4 received both. A total of 1159 patients were included in our analysis.
Patient demographics are presented in . Mean age, body mass index (BMI), and preoperative PSA values were 59.3 y, 28.1kg/m2, and 5.9ng/mL, respectively. Patients had a mean follow-up of 15.9 mo (0 to 60). Predictably, preoperative serum PSA demonstrated a statistically significant difference between the 2 groups, with higher values for those with positive surgical margins (P < .001). The distribution of clinical Gleason score (P = .003), D’Amico risk stratification (P = .001), pathological Gleason (P = .001), and pathologic stage (P = .001) also demonstrated a statistically significant difference. Patients with positive margins had higher stage, grade, and risk. Neither performance of pelvic lymphadenectomy (P = .182) nor presence of positive lymph nodes (P = .139) was statistically different between the 2 groups.
Excluded patients were compared with the analyzed patients and no statistically significant differences were found in the demographic, operative, or pathologic characteristics, with exception of frequency of pelvic lymphadenectomy. Pelvic lymphadenectomy was performed on 48.6% of excluded patients vs. 58.9% in the analyzed population (P = .002).
The frequency of positive margins in the overall cohort was 27.3%, 20.3% for pathologic stage T2, and 52.3% for pathologic stage ≥T3a disease. Specifically, in patients with Gleason score ≤6, pathologic stage T2N0M0 and T3aN0M0 had 14.9% and 65% incidence of positive surgical margin (PSM), respectively. In patients with Gleason score 7, the incidence of PSM for stage T2N0M0, T3aN0M0, T3b/T4N0M0, and TxN1Mx was 24.1%, 53.2%, 51.7%, and 12.5%, respectively. In patients with Gleason score 8 to 10, the incidence of PSM for stage T2N0M0, T3aN0M0, T3b/T4N0M0, and TxN1Mx was 17.9%, 45.2%, 50.0%, and 85.7%, respectively.
BRFS curves were generated for the overall cohort as well as individual D’Amico risk groups and are depicted in . Low-risk and intermediate-risk groups achieved a statistically significant difference in BRSF with respect to SM. In the low-risk group, mean BRFS was 56.7 vs. 51.0 mo (P = .005), and in the intermediate-risk group it was 55.2 vs. 43.5 mo (P < .001) for negative and positive SM, respectively. The high-risk group did not reach statistical significance with respect to SM. The overall cohort mean BRFS was statistically significant, 54.9 vs. 45.9 mo (P < .001) for negative and positive SM, respectively.
Biochemical recurrence-free survival for D’Amico risk groups and over all by surgical margin status.
Similar curves were generated for individual pathologic tumor stage and pathologic Gleason score for positive and negative SM and are depicted in . Patients with Gleason score of 7 and pathologic stage T2N0M0 had a statistically significant difference in mean BRFS of 55.6 and 48.7 mo (P < .001) for negative and positive margins, respectively. Others did not have a statistically significant difference in BCRF survival with respect to SM.
Cumulative biochemical recurrence-free survival by Gleason score and pathologic stage.
When surgical margins were further categorized by multiplicity and length, multiple margins and extensive margins carried a higher rate of BCR (P < .001) ( and ). The rates of positive surgical margins did not change significantly between quartile of cases (P = .243, ). Nerve-sparing surgical status did not significantly affect the incidence of positive surgical margins (P = .672, ).
Biochemical recurrence-free survival by margin length.
Biochemical recurrence-free survival buy margin multiplicity.
The multivariate prediction of time to BRFS showed pathological stage (P < .001), pathologic Gleason grade (P < .001), and SM (P = .035) as significant covariates. Data for preoperative PSA was suggestive but missed statistical significance (P = .053). While margin multiplicity and margin length were significant in univariate analysis, they were not in multivariate analysis. Hazard ratios (HR) and confidence intervals (CI) for each variable in the equation are listed in .
Multivariate analysis of biochemical recurrence-free survival