EVALUATION OF N-RATIO IN SELECTING PATIENTS FOR ADJUVANT CHEMORADIOTHERAPY AFTER D2-GASTRECTOMY

• Main Authors: Wilson Luiz da COSTA JUNIOR, Felipe Jose Fernandez COIMBRA, Thales Paulo BATISTA, Heber Salvador de Castro RIBEIRO, Alessandro Landskron DINIZ
• Format: Article
• Language: English
• Published: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia (IBEPEGE) 2013-12-01
• Series: Arquivos de Gastroenterologia
• Subjects: Neoplasias gastricas; Escisao de linfonodo; Quimioterapia adjuvante; Radioterapia adjuvante
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-28032013000400257&lng=en&tlng=en

Context Whether adjuvant chemoradiotherapy may contribute to improve survival outcomes after D2-gastrectomy remains controvertial. Objective To explore the clinical utility of N-Ratio in selecting gastric cancer patients for adjuvant chemoradiotherapy after D2-gastrectomy. Methods A retrospective cohort study was carried out on gastric cancer patients who underwent D2-gastrectomy alone or D2-gastrectomy plus adjuvant chemoradiotherapy (INT-0116 protocol) at the Hospital A. C. Camargo from September 1998 to December 2008. Statistical analysis were performed using multiple conventional methods, such as c-statistic, adjusted Cox's regression and stratified survival analysis. Results Our analysis involved 128 patients. According to c-statistic, the N-Ratio (i.e., as a continuous variable) presented “area under ROC curve” (AUC) of 0.713, while the number of metastatic nodes presented AUC of 0.705. After categorization, the cut-offs provide by Marchet et al. displayed the highest discriminating power – AUC value of 0.702. This N-Ratio categorization was confirmed as an independent predictor of survival using multivariate analyses. There also was a trend of better survival by adding of adjuvant chemoradiotherapy only for patients with milder degrees of lymphatic spread – 5-year survival of 23.1% vs 66.9%, respectively (HR = 0.426, 95% CI 0.150–1.202; P = 0.092). Conclusions This study confirms the N-Ratio as a tool to improve the lymph node metastasis staging in gastric cancer and suggests the cut-offs provided by Marchet et al. as the best way for its categorization after a D2-gastrectomy. In these settings, the N-Ratio appears a useful tool to select patients for adjuvant chemoradiotherapy, and the benefit of adding this type of adjuvancy to D2-gastrectomy is suggested to be limited to patients with milder degrees of lymphatic spread (i.e., NR2, 10%–25%).