MINIMALLY INVASIVE SURGERY FOR GASTRIC CANCER: PARADIGM SHIFT

become the standard method for approaching various surgical procedures. (10) However, its use for the treatment of gastric cancer (GC) has always cast doubts on the possibility of properly performing the complex lymphadenectomy involved in these procedures. (2) As with any incorporation of a new technology in surgery, initial reports of its use involved only retrospective case series of selected patients. This large selection bias has always led to questions about the actual effectiveness of the method and its generalizability. Despite this undeniable limitation of initial studies, preliminary results from other centers, as well as our own experience, showed us that the laparoscopic approach to gastric tumors was feasible. (3) The advantages already described of the laparoscopic method, such as lower postoperative pain, earlier recovery and discharge, were maintained. The surgical time was longer, but the most important fact of these initial studies was the certainty that the postoperative complications were equivalent and the early surgical oncological parameters, such as lymph nodes count and surgical margins did not change. These results encouraged us already in 2016 to question whether it was time for a paradigm shift from laparotomic surgery to minimally invasive laparoscopic surgery. (1) Perhaps, at that time we relied on non-ideal and retrospective evidence giving the impression that it might be wishful thinking. However, the results presented in subsequent years of large prospective randomized trials eventually confirmed our initial impression. Undoubtedly a large number of studies have been published on the subject in recent years. Critical analysis of these studies is important, and details should not be confused so that wrong conclusions are not made. Some points should always be considered when analyzing these studies of the use of minimally invasive surgery in the GC: 1) What type of tumor was evaluated: early or advanced? 2) Was the surgical resection distal or total? 3) Was the study prospective randomized or were the cases selected? 4) Are the analyzed outcomes early related to long-term surgical or cancer complications? 5) Was the study of superiority or non-inferiority? 6) Does the data reproduce the reality of my practice? The major milestone in the use of laparoscopic surgery in the treatment of GC was the publication of the results of the South Korean study KLASS-01. (8) This non-inferiority study compared laparoscopic with laparotomic surgery for the treatment of early distal tumors. The laparoscopic method presented lower occurrence of surgical complications related to surgical wound without inferiority in relation to disease free survival in three years. Subsequently the Japanese study JCOG0912 confirmed the equivalence of early surgical results but late oncologic results have not yet been released. (7) Since then, laparoscopic surgery has been considered the standard for resection of early distal gastric tumors. Still evaluating early but proximal tumors, two studies KLASS-03 and JCOG1401 have already shown similar early surgical results and it is expected that long-term oncological results will be publish soon. Laparoscopic surgery in advanced tumors has always raised greater concern regarding the possibility of peritoneal dissemination by manipulation of tumors affecting the serosa as well as the possibility of incomplete lymphadenectomy in cases with high likelihood of lymph node involvement. Preliminary surgical results from three studies JLSSG0901, KLASS-02 and CLASS-01 did not show any alteration in the number of early surgical complications. (5,9,11) Analysis of early oncological criteria such as surgical margins, number of resected lymph nodes and final pathological staging did not differ between groups either. However, long-term oncological results were eagerly awaited. Fortunately, during the last International Gastric Cancer Congress held in Prague in May 2019, the authors of the South Korean study KLASS-02 and Chinese CLASS-01 presented its long-term cancer results. Both demonstrated non-inferiority of laparoscopic surgery in relation to disease free survival in three years. Shortly thereafter, the CLASS-01 study was fully published in JAMA confirming the preliminary non-inferiority data presented for laparoscopic surgery. (11) Thus, we can also state that laparoscopic surgery can be employed to treat advanced distal gastric tumors. With regard to advanced proximal tumors, South Koreans started in 2018 the KLASS-06 study, but no data are available at this time. The question whether oriental data can be extrapolated to Western patients and surgeons is always pertinent. In this context the Dutch study LOGICA serves as a bridge between the two extremes. (4) At the 2019 International Gastric Cancer Congress Prague, we also had the opportunity to evaluate the initial surgical data from this multicenter study involving 10 Dutch centers and 210 patients. Preliminary data presented did not show any difference between the techniques, but these results have not yet been published. Unfortunately, the large number of patients and funding required in these studies makes it difficult to perform in our country. Therefore, the follow-up of the results of these ABCD Arq Bras Cir Dig 2019;32(4):e1483 DOI: /10.1590/0102-672020190001e1483