Multivariate analysis of factors affecting biochemical recurrence after radical prostatectomy

ABSTRACT

OBJECTIVE@#This study aims to evaluate the effects on biochemical recurrence (BCR) of the followingproposed prognostic factors after radical prostatectomy (RP) patients' clinical T stage, Gleason gradegroup (GG) of RP specimen, technique of operation used (open RP vs. robot-assisted laparoscopicRP), presence of positive surgical margin (PSM), length of PSM, GG at PSM, extraprostatic extension(EPE) at PSM, and presence of detectable PSA at 4-6 weeks after RP. It also aims to identify whichamong the aforementioned variables are independent predictors of risk for BCR.@*PATIENTS AND METHODS@#This is a retrospective study. Included in the study were patients who underwentRP (Open and Robot-assisted Laparoscopic technique) at two tertiary hospital branches of an academicmedical center from April 2009 to December 2015 with histopathology reports read by a singleurologic pathologist and with complete follow- up for at least one year. Excluded were those whounderwent RP but without complete follow- up. Using Pearson chi-square and z-test with level ofsignificance set at 0.05, the clinicopathologic variables including patients clinical stage, GG of RPspecimen, length of PSM, GG at positive margins, presence of EPE at positive margins, and presenceof detectable PSA after the surgery were assessed in order to know which among these factors werepredictive of BCR. Multinomial regression analysis was also used to identify which among the variableswere independent predictors of risk for BCR.@*RESULTS@#A total of 165 patients underwent RP from April 2009 to December 2015, among which 72patients were eligible for inclusion in the final analysis. Clinical T2 stage was found to be a predictorof BCR with odds ratio of 13.000 (95%CI 3.705 - 45.620; p < 0.001) as compared to stage T1. GGof final histopathology report of prostatectomy specimen was found to be a predictor of BCR, asthose with grade groups 4 and 5 had significantly increased risk of BCR with odds ratio of 70.778(95%CI 8.207 - 610.426; p < 0.001) as compared to those with grade groups 1 to 3. Patients withpositive margins had increased risk of BCR, with odds ratio of 13.458 (95%CI 13.472 - 52.171; p <0.001) compared to those with negative margins. GG at the PSM was found to be a predictor of BCR,with a grade grouping of 4 or 5 at the positive margin predicting BCR with odds ratio of 20.625(95%CI 2.241 - 189.847; p = 0.008) as compared to grade grouping of 1 or 2 at the margin. DetectablePSA after RP was found to be a predictor of BCR, with odds ratio of 115.000 (95%CI 19.457 -679.712; p < 0.001) as compared to undetectable PSA after RP. Technique of RP (p = 0.177), measuredlength of PSM (p = 0.713), and EPE at PSM (p = 0.146) were not found to predict BCR. Furthermore,clinical T stage (p = 0.007) and detectable PSA after RP (p < 0.001) were found to be independentpredictors of BCR among the risk factors examined.@*CONCLUSION@#Of the independent variables examined, clinical T stage, GG of RP specimen, presenceof PSM, GG at positive margins, and detectable PSA were found to be significant predictors of BCR. Technique of RP, measured length of PSM, and EPE at PSM were not found to predict BCR.Furthermore, multivariate analysis showed that only clinical T stage and detectable PSA after RPwere independent predictors of BCR. Attentive assessment of these predictors in the preoperativeperiod should aid the urologist in clinical decision-making and in advising patients regarding theirprognosis.