Comparative effectiveness of pathological techniques to improve lymph node yield from colorectal cancer specimens: a systematic review and network meta‐analysis

Abstract

A number of randomised controlled trials (RCT) have compared different techniques to improve lymph node yield (LNY) in colorectal cancer specimens, but data on comparative effectiveness are sparse. Our aim was to compare the relative effectiveness and rank all available techniques. A systematic search of Embase, Cochrane, PubMed and Scopus was performed for randomised trials. Pairwise was meta-analysis performed if more than two homogeneous studies were available for each comparison. Network meta-analysis was used to rank and compare all available techniques. Fifteen studies fulfilled the inclusion criteria. Techniques that were compared included methylene blue (MB), glacial acetic acid, ethanol, distilled water and formaldehyde (GEWF), Carnoy solution (CS), patent blue (PB), formalin, fat clearing (FC) and their combinations. The overall quality of studies was found to be fair. In pairwise meta-analysis MB had a higher lymph node yield weighted mean difference (WMD) = 13.67 (4.83-22.51), P < 0.01, lower number of specimens with fewer than 12 lymph nodes log odds ratio = -1.88 (-2.8, -0.91), P < 0.01 and higher LNY in patients with prior chemoradiotherapy [WMD = 9.11 (3.15, 15.08), P = 0.02] compared to formalin. Evaluation of the network plot revealed a well-connected network. In network meta-analysis MBFC had a higher LNY with [mean difference (MD) 13 and 95% credible interval (CrI) = 2.09-23.91] compared to formalin. MBFC probability of being the best technique for LNY was 91.4%. In network meta-analysis MB did not have a statistically significant difference when compared to formalin. MBFCS seems to be the most effective technique for LNY. Further studies are required to make safe conclusions for outcomes such positive lymph nodes and upstaging.

Enzymatic fat dissolution improves detection of small lymph nodes in colon cancer surgery

“…[4,5] A recent meta-analysis of randomized controlled trials reported that the use of methylene blue and FD was highly effective for harvesting lymph nodes. [11] However, evidence for the e cacy of the FD method for lymph node retrieval, as in the present study, is mixed. [12,13] In our study, the number of lymph nodes harvested was signi cantly greater in the FD group than in the conventional group, indicating that FD is effective.…”

Enzymatic Fat Dissolution Improves Detection of Small Lymph Nodes in Colon Cancer Surgery

“…Several techniques can be used for lymph node dissection, but they often involve the use of organic solvents or are complex and require more than one day to perform [ 4 , 5 ]. A recent meta-analysis of randomized controlled trials reported that the use of methylene blue and FD was highly effective for harvesting lymph nodes [ 11 ]. However, evidence for the efficacy of the FD method for lymph node retrieval, as in the present study, is mixed [ 12 , 13 ].…”