The purpose of the study: to analyze the efficacy of combined modality treatment including preoperative chemotherapy with gemcitabine/cisplatin in patients with stage II-III esophageal cancer (EC). Materials and methods: The study included 70 patients with stage II-III EC, who were treated at the Cancer Research Institute (Tomsk, Russia) from 2012 to 2019. The patients were divided into 2 groups. Group I comprised 35 patients, who received 2 cycles of preoperative chemotherapy with gem-citabine (1250 mg/m2 on days 1 and 8) and cisplatin (80 mg/ m2 on day 1) followed by radical surgery. Group II included 35 patients who underwent surgery alone. All patients underwent subtotal resection of the esophagus with simultaneous esophageal reconstruction using gastric tube (68.6%) or colon tissue (31.4%). Results: The overall tumor response to preoperative chemotherapy according to RECIST 1.1 criteria was 57.1%, including complete response (5.7%) and partial response (51.4%). No severe complications were observed. R0 resection was achieved in all patients (100%). No difference in the rate of postoperative complications between Group I and Group II was found (34.3% and 40%, respectively). There was no statistically significant difference in the mortality rate between treatment groups (8.6% versus 57%) (p>0.05). Pathological complete tumor response was 5.7%. In Group I patients, the 2-year disease-free and overall survival rates were 71.8% and 81.3%, respectively. The corresponding values in Group II patients were 39.4% and 51.5%, respectively (p=0.01). Conclusion: Preoperative chemotherapy for patients with stage II-III EC demonstrated high response rates, having no adverse effect on the perioperative period and mortality. The 2-year survival rates were significantly higher in patients, who received combined modality treatment with preoperative chemotherapy than in patients, who underwent surgery alone.
1039 ENDOSONOGRAPHIC MEASUREMENTS OF TUMOR THICKNESS AND SURFACE AREA TO EVALUATE TUMOR RESPONSE AFTER NEOADJUVANT CHEMORADIOTHERAPY IN PATIENTS WITH ESOPHAGEAL CANCER; A MULTICENTER PROSPECTIVE COHORT STUDY