Evaluation of the extent of lymphadenectomy in a randomized trial of Western- versus Japanese-type surgery in gastric cancer.

Abstract

PURPOSE In the context of a prospective, randomized trial of gastric cancer treatment, comparing Western surgical resection with limited lymphadenectomy (R1) versus Japanese surgical resection with extended lymphadenectomy (R2), we analyzed adherence to the specified surgical-pathologic guidelines. PATIENTS AND METHODS Following evaluation of 389 patients, we quantified noncompliance (ie, performance of less dissection than specified) and contamination (ie, performance of more extensive dissection than specified). Of 389 patients, pathologic data permitted identification of 237 eligible patients treated with curative intent. RESULTS Noncompliance occurred in 84% of R1 and R2 cases, with magnitude significantly (P < .001) higher in R2 cases versus R1 cases. Contamination occurred in 48% of R1 cases and 52% of R2 cases, with the magnitude of contamination moderate and equally distributed between the two groups. The contamination in R1 resections and the noncompliance in R2 resections lead to a partial homogenization of the groups, undermining the likelihood of detecting any potential therapeutic advantage to R2 dissection. CONCLUSION The observed tendency to perform R1 resections combined with insufficient retrieval of lymph nodes underlines the need for increased surgical-pathologic standardization in this trial. Potential remedies are discussed. Proper conduct of clinical trials requires reliable means of standardizing performance of the surgical-pathologic team, an elusive but important goal.