Tumor Site and Perigastric Nodal Status are the Most Important Predictors of Para-Aortic Nodal Involvement in Advanced Gastric Cancer

Background This study was designed to identify pathological predictors of para-aortic nodal invasion in advanced gastric cancer.Methods Between 1990 and 2007, 294 patients with advanced gastric cancer underwent gastrectomy with D2 lymphadenectomy + para-aortic nodal dissection in Siena and Verona, Italy.Results Forty-seven (16%) patients had para-aortic node metastases. Of these, 91%, 88%, and 74%, respectively, also had metastases at stations No. 3, No. 1, and No. 7. Para-aortic node metastases were never observed when stations No. 1 and No. 3 were both negative. Patients were divided into three groups, according to the risk of para-aortic node invasion: (1) high-risk group (n = 24, 8.2%), presenting a 42% risk and comprising T3/T4 cancers with mixed/nonintestinal histology, arising from the upper third; (2) low-risk group (n = 138, 46.9%), presenting a 0–10% risk and including middle-lower third tumors—either T2 irrespective of histology, or T3/T4 with intestinal histology; (3) intermediate-risk group, comprising all other patients (n = 132, 44.9%). Their risk ranged between 16% and 30%, but increased up to 21–37.5% after excluding 33 patients with negative No. 1 and No. 3 stations.Conclusions The combination of tumor site, histology, and T stage with perigastric nodal status allowed identification of patients at higher risk of para-aortic nodal invasion who could benefit from para-aortic nodal dissection.