The ratio of positive lymph nodes (LNs) to the total LN harvest is called the LN ratio (LNR). It is an independent prognostic factor in gastric cancer (GC). The aim of the current study was to evaluate the impact of neoadjuvant chemotherapy (NAC) on the LNR (ypLNR) in patients with advanced GC. We retrospectively analysed the data of patients with advanced GC, who underwent gastrectomy with N1 and N2 (D2) lymphadenectomy between August 2011 and January 2019 in the Department of Surgical Oncology at the Medical University of Lublin. The exclusion criteria were a lack of preoperative NAC administration, suboptimal lymphadenectomy (<D2 and/or removal of less than 15 lymph nodes), and a lack of data on tumor regression grading (TRG) in the final pathological report. A total of 95 patients were eligible for the analysis. A positive correlation was found between the ypLNR and tumor diameter (p < 0.001), post treatment pathological Tumour (ypT) stage (p < 0.001), Laurén histological subtype (p = 0.0001), and the response to NAC (p < 0.0001). A multivariate analysis demonstrated that the ypLNR was an independent prognostic factor in patients with intestinal type GC (p = 0.0465) and in patients with no response to NAC (p = 0.0483). In the resection specimen, tumor diameter and depth of infiltration, Laurén histological subtype, and TRG may reflect the impact of NAC on LN status, as quantified by ypLNR in advanced GC.
Keywords: gastric cancer; lymph node ratio; neoadjuvant chemotherapy.