Oncological outcomes in minimally invasive gastric cancer surgery

In the first part of this dissertation an assessment was made on current available evidence regarding outcomes in minimally invasive gastrectomy in comparison to open gastrectomy. Improvement of short-term surgical outcomes were seen in the treatment of gastric cancer patients in Asian countries. In Europe most patients are diagnosed at an advanced disease stage. A separation was made between Asian studies and Western studies. This showed improved outcomes in minimally invasive gastrectomy in comparison to open gastrectomy in both Asian and Western studies. The only significant difference was more blood loss and longer operation duration in the Western studies. There was a trend in favor of the Asian studies regarding less postoperative complications and postoperative mortality. No randomized clinical trials evaluating the outcomes of minimally invasive gastrectomy in Europe was found. Based on the available evidence a randomized clinical trial was set up in several European hospitals comparing short-term and long-term outcomes between minimally invasive and open total gastrectomyn (STOMACH trial). Primary outcome was complete oncological resection reported as number of lymph nodes resected and radicality. The second part of this dissertation described the results of the STOMACH trial. Complete oncological resection defined by the number of resected lymph nodes and radicality was similar between both groups. Additionally three-year survival was similar in both groups. The number of resected lymph nodes and a radical resection are important prognostic factors and a marker for the quality of the surgical treatment. In this randomized clinical trial, the mean number of resected lymph nodes was 40.7 in the minimally invasive group and 44.3 in the open group. Further diving into the extent of lymph node resection; in Asian countries several trials have reported better outcomes with a D2 resection in comparison to D1 resection. Adequate D2 resection was rather low in our cohort. It was noted that this was mainly due to a low lymph node yield of nodes in station 10. Dissection of the lymph nodes in the splenic hilum has been associated with a higher rate of intraoperative and post operative complications. In our cohort a big discrepancy was seen between the surgically reported resected lymph node station and the lymph nodes found by the pathologist in these lymph node stations. More lymph nodes can be found if a dedicated surgicopathological team assesses the specimen. In Asian countries it is more common that the surgeon removes the separate lymph nodes from the specimen in the operating theater, whereas in this trial the specimen was send en-bloc to the pathologist. A pooled analysis of the data from the STOMACH and LOGICA trial was made regarding short term surgical and oncological outcomes. There were no differences in postoperative recovery and complete oncological resection in minimally invasive gastrectomy compared to open gastrectomy in patients with advanced gastric cancer. Further strengthening the results of these trials. The third part of this dissertation showed the results of quality of life in patients treated for advanced gastric cancer. A systematic review was conducted to evaluate which questionnaires were suitable to assess quality of life in patients with gastric cancer. No difference in quality of life after minimally invasive versus open total gastrectomy was found. Global health and physical functioning decreased directly after surgery in order to return to baseline at six months postoperatively. More patients in the minimally invasive group continued with postoperative chemotherapy. Which might suggest a better overall recovery in the minimally invasive group. Regardless of more patients in the minimally invasive group receiving postoperative chemotherapy, this did not result in a difference in quality of life between both groups.