Correlation of tumor location and biochemical recurrence in localized and locally-advanced prostate cancer in post-robotic radical prostatectomy patients

ABSTRACT

OBJECTIVE@#This study aims to determine the tumor location of prostate adenocarcinoma in patientswho underwent Robotic Radical Prostatectomy (RRP) for localized and locally-advanced prostatecancer and the correlation of the tumor location with the incidence of biochemical recurrence.@*PATIENTS AND METHODS@#The authors reviewed the patient database of a single Urological Oncologistfrom January 2015 to April 2017 for patients who underwent RRP for localized or locally-advancedprostate cancer. They also reviewed the histopathologic report of the prostatectomy specimens todetermine pathologic T-stage, prostate volume, and post-operative Gleason score. The histopathologicexamination of specimens was interpreted by a single Urological Pathologist based on the 2014International Society of Urological Pathology Gleason Scoring System. Eligible patients were thendivided into three groups those with pure anterior tumor location, pure posterior tumor location,and mixed tumor location. Presence of positive surgical margins, mean follow-up period, andbiochemical recurrence were determined for these groups. Patient demographic data were analyzedusing test of proportions. Correlation of tumor location with biochemical recurrence was derivedusing Pearson chi-square test.@*RESULTS@#Of the 113 patients included in the study, 63 (55.8%) were clinically-staged T2 patients while27 (23.9%) and 23 (20.3%) were clinical stage T1 and T3, respectively. On pre-operative prostatebiopsy, 27 (23.9%) patients had a Gleason score of 8-10. Thirty-eight (33.6%) and 30 (26.6%) had aGleason score of 6 (3+3) or 7 (3+4), respectively Average prostate volume was 42.8 grams. Ninety-five (84.1%) of the patients had mixed tumor location, 11 (11.6%) had pure posterior tumor location,and only 7 (6.2%) had pure anterior tumor location. In those with pure anterior or posterior tumorlocations, majority were low-grade prostate cancers (Gleason 6(3+3) and Gleason 7(3+4)) whilethose with mixed tumor location had low to high-grade prostate cancers (Gleason 7 (3+4) and Gleason7 (4+3.)) Majority of the patients had pathologic T2c and T3a tumors across all groups. Positivesurgical margins were present in 31% of those with mixed tumor location and only 0.9% in those withpure anterior or posterior tumor location, respectively. Only 10 patients from the population hadbiochemical recurrence, 9 of which had mixed tumor location while 1 had pure posterior tumorlocation. Pearson chi-square test shows no significant relationship between tumor location andbiochemical recurrence at 95% CI (p= regional involvement 0.695.) Furthermore, there is a very weak positive correlation (R=0.069) between tumor location and biochemical recurrence.@*CONCLUSION@#Majority of patients who underwent RRP have mixed tumor location. There is poorcorrelation between prostate cancer tumor location and biochemical recurrence.