AOSP28 SURVIVAL IMPACT OF THE EXTENT OF PELVIC LYMPH NODE DISSECTION IN PATIENTS UNDERGOING RADICAL CYSTECTOMY FOR BLADDER CANCER

Extended versus standard lymph node dissection for urothelial carcinoma of the bladder in patients undergoing radical cystectomy

BACKGROUND

In the treatment of urothelial carcinoma of the bladder, we are currently uncertain of the benefits and harms of standard pelvic lymph node dissection (PLND) compared to extended PLND.

OBJECTIVES

To assess the effects of extended versus standard PLND in patients undergoing cystectomy to treat muscle-invasive (cT2 and cT3) and treatment-refractory, non-muscle-invasive (cT1 with or without carcinoma in situ) urothelial carcinoma of the bladder.

SEARCH METHODS

We performed a comprehensive literature search using multiple databases (PubMed, Embase, Cochrane Controlled Trials, Web of Science, and LILACS), trial registries, and conference proceedings published up to April 29, 2019, with no restrictions on the language or status of publication.

SELECTION CRITERIA

We included randomized controlled trials in which participants underwent radical cystectomy (RC) for muscle-invasive or therapy-refractory non-muscle-invasive urothelial carcinoma of the bladder with either an extended PLND with a superior extent reaching as far cranially as the inferior mesenteric vein, or a standard PLND with a superior extent of the bifurcation of the internal and external iliac artery, with otherwise the same anatomical boundaries.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the included studies and extracted data from them for the primary outcomes: time to death from any cause, time to death from bladder cancer and Clavien-Dindo classification of surgical complications grade III-V, and the secondary outcomes: time to recurrence, Clavien-Dindo I-II complications and disease-specific quality of life.We performed statistical analyses using a random-effects model and rated the certainty of evidence according to the GRADE approach.

MAIN RESULTS

The search identified one multicenter trial based in Germany that enrolled 401 participants with histologically confirmed T1 grade 3 or muscle-invasive urothelial carcinoma. The median age was 67 years (range: 59 to 74) and the majority of participants were male (78.3%). No participant received neoadjuvant chemotherapy; a small subset received adjuvant chemotherapy (14.5%).Primary outcomesOur results indicate that extended PLND may reduce the risk of death from any cause over time as compared to standard PLND, but the confidence interval includes the possibility of no effect (hazard ratio [HR]: 0.78, 95% confidence interval [CI]: 0.57 to 1.07, 401 participants, low-certainty evidence). After five years of follow-up, this may result in 83 fewer deaths (95% CI: 174 fewer to 24 more overall deaths) per 1000 participants: 420 deaths for extended PLND compared to 503 deaths per 1000 for standard PLND. We downgraded the certainty of evidence by two levels due to study limitations and imprecision.Our results indicate that extended PLND may reduce the risk of death from bladder cancer over time as compared to standard PLND but, again, the confidence interval includes the possibility of no effect (HR: 0.70, 95% CI: 0.45 to 1.07, participants = 401, low-certainty evidence). After five years of follow-up, this corresponds to 91 fewer deaths per 1000 participants (95% CI: 176 fewer to 19 more bladder cancer deaths): 264 deaths for extended PLND compared to 355 deaths per 1000 for standard PLND. We downgraded the certainty of evidence by two levels due to study limitations and imprecision.Based on follow-up of up to 30 days, we are uncertain whether extended PLND leads to more grade III-V complications as compared to standard PLND, because of study limitations and imprecision (risk ratio [RR]: 1.13, 95% CI: 0.84 to 1.52, participants = 401, very low-certainty evidence).Secondary outcomesWe are uncertain whether extended PLND reduces the risk of recurrence over time as compared to standard PLND, because of study limitations and imprecision (HR: 0.84, 95% CI: 0.58 to 1.22, participants = 401, very low-certainty evidence).Based on follow-up of up to 30 days, we are uncertain whether extended PLND leads to similar grade I-II complications as compared to standard PLND because of study limitations and imprecision (RR: 0.94, 95% CI: 0.74 to 1.19, participants = 401, very low-certainty evidence).We found no trials that reported on disease-specific quality of life.

AUTHORS' CONCLUSIONS

Results from a single trial indicate that extended PLND in patients undergoing radical cystectomy for invasive urothelial carcinoma of the bladder may reduce death from any cause and death from bladder cancer over time; however, the results include the possibility of no effect. We are uncertain whether the risk of serious complications up to 30 days may be increased. We are also uncertain as to whether the risk of recurrence over time or the risk of minor complications up to 30 days changes. We were unable to conduct any of the preplanned subgroup analyses, in particular, analyses based on extended lymph node dissection templates, clinical tumor stage, and use of neoadjuvant chemotherapy that may be important effect modifiers. Important additional data is expected from a larger, ongoing trial that will also consider the role of neoadjuvant chemotherapy. Inclusion of this trial in the meta-analysis may help address the issue of imprecision which was a common reason for downgrading the certainty of the evidence.

The anatomical limits and oncological benefit of lymphadenectomy in muscle invasive bladder cancer

BACKGROUND

Lymphadenectomy is part of standard treatment for muscle invasive bladder cancer. The objective of this review is to provide an up-to-date review on the available scientific evidence in this field.

ACQUISITION OF EVIDENCE

We conducted a literature review in PubMed of relevant articles up to the present (2016). We found a systematic review published in 2014 that included the comparative studies published up to that year, and we updated the review with new relevant publications since that date.

SYNTHESIS OF THE EVIDENCE

The number of lymph nodes is not the best indicator for determining the quality of the lymphadenectomy given that the number can vary depending on numerous factors that depend not only on the surgeon but also on the patient and on the pathologist. The definition of standard anatomical territories and a meticulous extraction of the lymph nodes in these territories are more reproducible than the numbers of nodes removed. The optimal extension of lymphadenectomy is a topic of debate. The evidence published to date indicates that any extension of lymphadenectomy is better than not performing it, although it appears that limited lymphadenectomy is insufficient for the oncological control of the disease and that superextended lymphadenectomy provides no oncological benefit versus extended lymphadenectomy.

CONCLUSIONS

Despite a certain amount of controversy in terms of the optimal extension of lymphadenectomy, performing lymphadenectomy in all cases appears to be recommendable according to the available evidence. Extended lymphadenectomy provides greater oncological benefit than more limited dissections, while more extensive lymphadenectomies are not recommended.