Aims: Surgeons involved in the treatment of gastric cancer are interested in the extent of lymphadenectomy as the latter may not only influence the reliability of the tumour, node and metastasis classification but also be relevant for the long-term oncological outcome. The purpose of the study was to evaluate the prognostic role of the number of resected lymph nodes (as an indicator of the scope of lymphadenectomy) and of the number of metastatic lymph nodes on the long-term mortality for all causes and to provide clinicians with estimates of predictive survival probabilities.
Methods: The study involved 615 cancer patients subjected to a curative (R0) subtotal or total gastrectomy in a randomized Italian trial. According to the trial protocol, a D2 lymphadenectomy had been advised. The number of resected and metastatic lymph nodes was analysed as a continuous variable in multiple Cox models.
Results: There was no difference in operative mortality (about 1.8%) according to the number of lymph nodes in the specimen (< or =15, 16-25, >25). The risk of long-term death for all causes tended to decrease with increasing number of resected lymph nodes up to about 25, and then could be considered stable for wider lymphadenectomies. An increasing risk of death for all causes was associated with an increasing number of metastatic lymph nodes; the risk could be considered stable for more than 20 metastatic lymph nodes.
Conclusions: A lymphadenectomy including more than 25 lymph nodes is suggested, provided that there is a low risk of operative mortality.