Discussion
N0, gastric cancer
GASTRIC CANCER, PATHOLOGY, METASTASES, GASTRIC CANCER
This retrospective analysis investigated three-year survival, lymphadenectomy, and potential differences in metastatic lymph node distribution between OTG and MITG for advanced gastric cancer after neoadjuvant chemotherapy. Results showed no difference in three-year survival between both groups. Additionally, no differences were observed between OTG and MITG for the number of resected lymph nodes and adequacy of lymphadenectomy performed, indicating that MITG is non-inferior to OTG regarding adequacy of oncological resection.Interestingly, in 72.9% of cases, surgeons reported that a modified D2 lymphadenectomy was performed, whereas pathology results revealed that an adequate D2 lymphadenectomy, defined as lymph nodes present in all resected D2 stations, was only achieved in 32.3% of cases. Suggesting that even if stations are deemed resected according to anatomical landmarks, no lymph nodes may be present in the resected tissue. Alongside, the effect of neoadjuvant therapy on lymph node yield remains to be determined [Several randomized trials reported non-compliance in D2 lymphadenectomy. In a large Dutch trial, conducted by the Dutch Gastric Cancer Group, randomization was set between D1 and D2 lymphadenectomy [A significant difference was seen in positive lymph nodes in station 7 (left gastric artery), 9.3% in the open group versus 34.9% in the minimally invasive group (No differences in survival were seen between D2 lymphadenectomy and patients with D1 + lymphadenectomy or less, although it should be noted that the sample size was relatively small and type 2 errors cannot be excluded. However, overall survival at 3 years was worse for patients with tier two nodal metastases compared to patients with N0 or tier one nodal metastases, further underwriting the importance of an adequate D2 lymphadenectomy.The results are in line with the trial by the Dutch Gastric Cancer Group, which reported no differences in 5-year survival between D1 and D2 lymphadenectomy. At 15-year follow-up disease-specific survival was significantly better for the D2 lymphadenectomy group, while overall survival remained similar [Taking into account that patients in the MITG group more often had a N3 nodal status and more often had involvement of tier two nodes, no differences were observed in overall survival between OTG and MITG, even after correction for these factors.A previous study, assessing prognostic factors based on clinicopathological outcomes, revealed a poorer prognosis in patients with N3 nodal involvement and patients with involvement of tier two lymph nodes. None of the patients in this study received peri-operative chemotherapy [One limitation of this study was that differences in type of lymphadenectomy was not a primary outcome in this trial and the patient groups might be too small to give an accurate conclusion. All resected lymph node stations were marked by the surgeon and further examined by the pathologist, giving important insights into difficulties and compliance with D2 lymphadenectomy in patients with gastric cancer treated with multimodality treatment. Several studies suggested that the overall survival is associated with the number of retrieved lymph nodes [Techniques for retrieval and marking of lymph nodes influence overall lymph node yield, for example, one study found that more lymph nodes were reported if a dedicated surgicopathological team assessed the specimen [