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.

Plastic and Reconstructive Surgeons' Knowledge and Comfort of Contralateral Prophylactic Mastectomy: A Survey of the American Society of Plastic Surgeons.

Background: Despite limited oncologic benefit, contralateral prophylactic mastectomy (CPM) rates have increased in the United States over the past 15 years. CPM is often accompanied by breast reconstruction, thereby requiring an interdisciplinary approach between breast and plastic surgeons. Despite this, little is known about plastic surgeons' (PS) perspectives of CPM. The purpose of this study was to assess PS practice patterns, knowledge of CPM oncologic benefits, and perceptions of the CPM decision-making process. Methods: An electronic survey was sent to 2,642 members of the American Society of Plastic Surgeons (ASPS). Questions assessed demographics, practice patterns, knowledge of CPM oncologic benefits, and perceptions of the CPM decision-making process. Results: ASPS response rate was 12.5% (n = 329). Most responders worked in private practice (69%), were male (81%) and had been in practice for ≥15 years (60%). The median number of CPM reconstructions performed per month was 2-4. Fifty-five percent of PS reported routine attendance at a breast multidisciplinary conference. Responders reported CPM discussion was most likely to be initiated by the patient (51%) followed by the breast surgeon (38%), and plastic surgeon (7.3%). According to PS, the most common reason patients choose CPM is a perceived increased contralateral cancer risk (86%). Most plastic surgeons (63%) assessed the benefits of CPM as worth the risk of additional surgery and the majority (53%) estimated the complication rate at 2X the risk of unilateral surgery. The majority (61%) of PS estimated risk of contralateral cancer in an average risk patient between <2 and 5% over 10 years, which is consistent with data reported from the current literature. Most plastic surgeons (87%) reported that there was no evidence or limited evidence for breast cancer specific survival benefit with CPM. A minority of PS (18.5%) reported discomfort with a patient's choice for CPM. Of those surgeons reporting discomfort, the most common reasons for their reservations were a concern with the risk/benefit ratio of CPM and with lack of patient understanding of expected outcomes. Common reasons for PS comfort with CPM were a respect for autonomy and non-oncologic benefits of CPM. Discussion: To our knowledge, this is the first survey reporting PS perspectives on CPM. According to PS, CPM dialogue appears to be patient driven and dominated by a perceived increased risk of contralateral cancer. Few PS reported discomfort with CPM. While many PS acknowledge both the limited oncologic benefit of CPM and the increased risk of complications, the majority have the opinion that the benefits of CPM are worth the additional risk. This apparent contradiction may be due to an appreciation of the non-oncologic benefits CPM and a desire to respect patients' choices for treatment.