FACTORS PREDICTING RESPONSE TO NEOADJUVANT CHEMOTHERAPY IN LOCALLY ADVANCED GASTRIC CANCER

Objective: In the treatment of local advanced gastric cancer (LAGC), it is recommended to start with neoadjuvant chemotherapy (NAC). Although the benefits of NAC have been shown, it is still not fully understood which patients respond better. The aim of this study was to investigate the effect of hematological and histopathological parameters on the response to chemotherapy. Material and Method: A retrospective examination was made of 38 patients who underwent surgery for LAGC after receiving NAC. Evaluations were made by comparing the demographic characteristics, histopathological characteristics in an endoscopic biopsy of the tumor, preoperative hemoglobin levels, and neutrophil-lymphocyte ratios with the postoperative pathological response to determine which tumor characteristics gave a better response. Results: In the postoperative histopathological evaluation, there was a pathological complete response to chemotherapy in two patients (6%), grade 1 in 9 patients (24%), grade 2 in 13 patients (34%), and grade 3 in 14 patients (36%). A statistically significant relationship was determined between the histopathological absence of perineural invasion and pathological complete response (p=0.023). Conclusion: A relationship between perineural invasion and poor response to chemotherapy was determined. Although not at a statistically significant level, there was also observed to be a poor response to chemotherapy in the presence of low grade and lymphovascular invasion.