Benefit of a more extended pelvic lymph node dissection among patients undergoing radical prostatectomy for localized prostate cancer: A causal mediation analysis.

BACKGROUND: The therapeutic role of extended (ePLND) versus nonextended pelvic lymph node dissection (nePLND) to remove occult micrometastases in men undergoing radical prostatectomy for localized prostate cancer (PC) is conflicting. Therefore, our aim was to quantify the direct effect of ePLND versus nePLND (removal of occult micrometastases), which is not mediated through the detection of nodal disease and potential adjuvant therapy (indirect effect). METHODS: Retrospective, bi-center cohort study of consecutive patients undergoing radical prostatectomy and PLND for PC (January 2006 and December 2016). Patients were followed until April 2018 for the occurrence of either biochemical recurrence or secondary therapy (composite outcome). ePLND was compared to nePLND by unweighted and weighted survival analysis (total effect) as well as by causal mediation analysis (direct and indirect effect). RESULTS: Positive nodal disease was detected in 71 (7%) out of 1008 patients undergoing radical prostatectomy and PLND for PC (ePLND: 368 [36.5%]; nePLND: 640 [63.5%]). Survival analysis demonstrated results in favor of ePLND (unweighted hazard ratio: 0.77 [95% confidence interval: 0.59-1.01], p = .056; weighted hazard ratio: 0.75 [0.56-0.99], p = .044). The causal mediation analysis confirmed the total effect of 0.77 (0.71-0.82). After disentangling this total effect into an indirect effect (via detection of nodal disease and potential adjuvant therapy) and a direct effect (via removal of occult micrometastases), we identified an even more protective direct effect of 0.69 (0.63-0.75). CONCLUSIONS: Our results not only indicate the utility of ePLND but also that its impact is not restricted to a staging benefit and probably involves a therapeutic benefit mediated through the removal of occult micrometastases.

Photoselective vaporization of the prostate: study outcomes as a function of risk of bias, conflicts of interest, and industrial sponsorship.

PURPOSE: To investigate the outcomes of comparative studies on photoselective vaporization of the prostate (PVP) as a function of risk of bias (RoB), conflicts of interest (COI), and industrial sponsorship (IS). METHODS: We performed a systematic literature search for comparative studies on PVP [randomized controlled trials (RCTs) and non-randomized comparative studies (NRCSs)]. Study selection as well as comprehensive assessment of RoB, COIs, and IS were performed in duplicate. The identified studies were further rated by two independent board-certified urologists as either PVP-favourable or PVP-unfavourable. Descriptive statistics were performed among all identified studies and among the subgroups of studies rated as favourable and unfavourable, respectively. RESULTS: Sixty-five studies qualified for inclusion (25 RTCs and 40 NRCSs) of which 56 (86%) were rated favourable and 9 (14%) unfavourable. A majority of all studies mentioned the absence/presence of potential COIs (78%). In contrast, a sponsorship statement was only found in 29% of the investigations. Studies rated favourable demonstrated a higher percentage of COIs (39% versus 22%). IS was exclusively found among favourable studies. Furthermore, a serious or critical RoB was more often found in favourably rated NRCSs. CONCLUSIONS: COIs and IS seem to be associated with favourable study outcomes in comparative studies on PVP. The transparency of the whole research process from study conception to the dissemination of the results has to be further improved to prevent a harmful effect of COIs and IS on the internal validity of studies.

Systematic review and meta-analysis on trimodal therapy versus radical cystectomy for muscle-invasive bladder cancer: Does the current quality of evidence justify definitive conclusions?

OBJECTIVES: To systematically review and meta-analyze the current literature in a methodologically rigorous and transparent manner for quantitative evidence on survival outcomes among patients diagnosed with muscle-invasive bladder cancer that were treated by either trimodal therapy or radical cystectomy. MATERIALS AND METHODS: MEDLINE, EMBASE, CENTRAL were systematically searched for comparative observational studies reporting disease-specific survival and/or overall survival on adult patients diagnosed with localized muscle-invasive bladder cancer that were exposed to either trimodal therapy or radical cystectomy. Studies qualified for meta-analysis (random effects model) if they were not at critical risk of bias (RoB). RESULTS: The literature search identified 12 eligible studies. Three (all rated as "moderate RoB") out of 6 studies reporting on disease-specific survival qualified for quantitative analysis and yielded a pooled hazard ratio (trimodal therapy versus radical cystectomy) of 1.39 (95% confidence interval: 1.03-1.88). Four (mainly rated as "serious RoB") out of 12 studies were included in the meta-analysis of overall survival and estimated a hazard ratio of 1.39 (1.20-1.59). CONCLUSION: Pooled results were significant in favor of radical cystectomy. The conclusion is mainly driven by large population-based studies that are at high RoB. Hence, the certainty of these treatment estimates can be considered very low and further research will likely have an important impact on these estimates. At present, the ultimate decision between trimodal therapy and radical cystectomy should be left to the patient based on individual preferences and on the recommendation of a multidisciplinary provider team experienced with both approaches.