Factors affecting surgical margin positivity in robotic assisted radical prostatectomy

Objectives: After radical prostatectomy, surgical margin positivity is an important indicator of biochemical recurrence and progression. In our study we want to compare the surgical margin positivity rates for retropubic radical prostatectomy (RRP) and robotic assisted radical prostatectomy (RALP) and investigate the factors affecting surgical margin positivity in RALP. Materials and methods: Data from 78 RRP and 62 RALP patients operated from 2011 May to 2016 March were retrospectively screened. Patients in both groups were compared in terms of age, postop hematocrit reduction, hospital stay, duration of follow-up, surgical margin positivity, biochemical recurrence and oncologic parameters. In RALP group it was searched the relationship between the surgical margin positivity and prostate specific antigen (PSA), positive biopsy core, biopsy Gleason scoring, pathologic stage and Gleason scoring, lymph node positivity, lymphovascular and perineural invasion, extracapsular extension, seminal vesicle invasion, prostate weight. Results: Patients in the RALP group had lower postop hematocrit reduction and shorter hospital stay (p < 0.001). There was no difference in surgical margin positivity between RALP and RRP groups (37.1% vs. 29.5%, p = 0.341). In RALP group there was a correlation between surgical margin positivity and positive biopsy core number (p = 0.011), pathologic stage (p < 0.001) and Gleason score (p < 0.001), EAU risk classification (p = 0.001), seminal vesicle invasion (p = 0.045), extraprostatic extension (p < 0.001). There was no correlation between prostate weight (p = 0.896), PSA (p = 0.220), biopsy Gleason score (p = 0.266), lymph node positivity (p = 0.140), perineural (p = 0.103) and lymphovascular invasion (p = 0.92) with surgical margin positivity. Conclusions: Positive biopsy core number, pathological stage and Gleason score, EAU risk classification, seminal vesicle invasion and extraprostatic extension are correlated with surgical margin positivity in RALP.