[Lymph node dissection: what for? From esophagus to rectum: surgical and lymph node related prognostic factors]

Surgery has still a key role in curative treatment of digestive carcinomas, and for almost all localisations, lymph node status is a major prognostic factor. As far as oesophageal and gastric cancer are concerned, there is not yet any internationally standardized approach. Occidental guidelines recommend more limited lymph node dissections than Asiatic ones. Lymph node numbers requested during surgery of such cancers remain high, at least 23 lymph nodes for oesophageal cancer, and 25 for a D2 or D1.5 lymphadenectomy for gastric cancer. Generalisation of neo-adjuvant and adjuvant treatments has not yet modified these standards. On the other hand, rectal cancer surgery is well standardized since the global adoption of Total Mesorectal Excision (TME) for the late eighties. Development of mini-invasive techniques (laparoscopy and robot-assisted surgery) enabled an important decrease of surgery related morbidity as well as an enhanced post-operative recovery. However, rectal cancer surgery still has an important morbidity. Development of neo-adjuvant chemo-radiotherapy as well as in-depth knowledge of risk factor of lymph node invasion opened up the path for transanal full thickness resection without lymphadenectomy. The goal of such an approach is to avoid TME's morbidity without risking local recurrence rate increase. As a consequence, this technique might need to be completed with a TME case histological factors are not favorable.