ADJUVANT CHEMOIMMUNORADIO/CHEMOIMMUNOTHERAPY SIGNIFICANTLY IMPROVED 5-YEAR SURVIVAL OF ESOPHAGEAL/CARDIOESOPHAGEAL CANCER PATIENTS AFTER RADICAL SURGERYOleg Kshivets Surgery Department, Siauliai Public Hospital, Lithuania

OBJECTIVE: This study aimed to determine expediency of adjuvant chemoimmunoradiotherapy and chemoimmunotherapy for esophageal and cardioesophageal cancer (ECEC) patients (ECECP) after complete en block (R0) esophagogastrectomies (EG) through left or right thoracoabdominal incision.

METHODS: We analyzed data of 407 consecutive ECEC patients (age=55.6±8.6 years; tumor size=6.7±3.3 cm) radically operated and monitored in 1975-2010 (m=305, f=102;EG Garlock=271, EG Lewis=136, combined EG with resection of pancreas, liver, diaphragm, colon transversum, lung, trachea, pericardium, splenectomy=125; adenocarcinoma=212, squamous=185, mix=10; T1=62, T2=96, T3=140, T4=109; N0=167, N1=56, M1A=184, G1=116, G2=96, G3=195; esophageal cancer=135, cardioesophageal cancer=272): only surgery=324, adjuvant treatment-AT=83 (chemoimmunoradiotherapy=35: 5-FU+thymalin/taktivin +radiotherapy 45-50Gy, adjuvant chemoimmunotherapy=48).

Survival curves were estimated by the Kaplan-Meier method. Differences in curves between groups of ECECP were evaluated using a log-rank test. Multivariate Cox modeling, multi-factor clustering, structural equation modeling, Monte Carlo, bootstrap simulation and neural networks computing were used to determine any significant dependence.

RESULTS: For total of 407 ECECP overall life span (LS) was 1612.6±2070.5 days, (median=783 days) and cumulative 5-year survival (5YS) reached 40%, 10 years – 32.7%, 20 years – 23.5%. 101 ECECP lived more than 5 years without ECEC. 215 ECECP died because of ECEC. 5YS of CECP was superior significantly after AT (60.8%; LS=1589.4±1916 days) compared with surgery alone (36.4%; LS=1618.5±2111 days) (P=0.00018 by log-rank test). Cox modeling displayed that 5YS of ECECP after complete EG significantly depended on: AT, N, age, weight, cell ratio factors (P=0.000-0.042). Neural networks computing, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and AT (rank=1), N (rank=2), weight (3), healthy cells/cancer cells (CC) (4), lymphocytes/CC (5), monocytes/CC (6), age (7), leucocytes/CC (8), erythrocytes/CC (9). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; urea under ROC curve=1.0).

CONCLUSIONS: adjuvant chemoimmunoradiotherapy and chemoimmunotherapy significantly improved 5-year survival of esophageal and cardioesophageal cancer patients after surgery.