Advances in para-aortic nodal dissection in gastric cancer surgery: A review of research progress over the last decade.

Approximately 17%-40% of para-aortic lymph node (PAN) metastasis occurs in patients with advanced gastric cancer. As the third tier of lymphatic drainage of the stomach and the final station in front of the systemic circulation, PAN infiltration is defined as distant metastasis and plays a key role in the evaluation of the prognosis of advanced gastric cancer. Many clinical factors including tumor size ≥ 5 cm, pT3 or pT4 depth of tumor invasion, pN2 and pN3 stages, the macroscopic type of Borrmann III/IV, and the diffuse/mixed Lauren classification are indicators of PAN metastasis. Whether PAN dissection (PAND) should be performed on patients with or without the macroscopic PAN invasion remains unascertained, regardless of the numerous retrospective comparative studies reported on the improved prognosis over D2 alone. Another paradoxical result from many other studies showed no significant difference in the overall survival between these two lymphadenectomies. A phase II trial launched by the Japan Clinical Oncology Group indicated that two or three courses of S-1 and cisplatin preoperatively followed by radical surgery with D2 + PAND and postoperative S-1 is the current standard strategy for the treatment of patients with extensive lymph node metastasis, and this regimen could be substituted by a promising strategy with effective combination chemotherapy or suitable chemotherapy duration. This review focuses on the advances in radical gastrectomy plus PAND with or without chemotherapy for patients with advanced gastric cancer.