On 2016 Oct 14, Thales Batista commented:

Previously, we had explored the N-Ratio as a potential tool to select patients for adjuvant chemoradiotherapy after a D2-gastrectomy using four consecutive statistical steps. (Arq Gastroenterol. 2013 Oct-Dec;50(4):257-63.) First, we applied the c-statistic to establish the overall prognostic accuracy of the N-Ratio for predicting survival as a continuous variable. Second, we evaluated the prognostic value of N-Ratio in predicting survival when categorized according to clinically relevant cutoffs previously published. Third, we confirm the categorized N-Ratio as an independent predictor of survival using multivariate analyses to control the effect of other clinical/pathologic prognostic factors. Finally, we performed stratified survival analysis comparing survival outcomes of the treatment groups among the N-Ratio categories. Thus, we confirmed the N-Ratio as a method to improve lymph node metastasis staging in gastric cancer and suggested the cutoffs provided by Marchet et al. (Eur J Surg Oncol. 2008;34:159-65.) [i.e.: 0%, 1%~9%, 10%~25%, and >25%] as the best way for its categorization after a D2-gastrectomy. In these settings, 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%).

Recently, Fan M et a. (Br J Radiol. 2016;89(1059):20150758.) also explored the role of adjuvant chemoradiation vs chemo, and found similar results of ours that patients with N1-2 stage rather than those with N3 stage benefit most from additional radiation after D2 dissection. However, using data from the important RCT named ARTIST Trial, Kim Y et al. presents different results favoring the use of chemoradiotherapy after D2 gastrectomy in patients having N ratios >25%. These contrary finding warrants further investigation in future prospective studies, but highlight the N-Ration as a useful tool for a more taylored therapy based on radiation for gastric cancer patients. Since targeted therapy are currently focused in sophisticated molecular classifications, this approach might serve to improve patients selection for adjuvant radiotherapy based on simple and easely available clinico-phatological findings.

In these settings, we would like to congratulate the authors for their interested paper re-exploring the data from Artist Trial; and also to invite other authos to re-explore your data using a similar approach.

On 2016 Oct 14, Thales Batista commented:

Previously, we had explored the N-Ratio as a potential tool to select patients for adjuvant chemoradiotherapy after a D2-gastrectomy using four consecutive statistical steps. (Arq Gastroenterol. 2013 Oct-Dec;50(4):257-63.) First, we applied the c-statistic to establish the overall prognostic accuracy of the N-Ratio for predicting survival as a continuous variable. Second, we evaluated the prognostic value of N-Ratio in predicting survival when categorized according to clinically relevant cutoffs previously published. Third, we confirm the categorized N-Ratio as an independent predictor of survival using multivariate analyses to control the effect of other clinical/pathologic prognostic factors. Finally, we performed stratified survival analysis comparing survival outcomes of the treatment groups among the N-Ratio categories. Thus, we confirmed the N-Ratio as a method to improve lymph node metastasis staging in gastric cancer and suggested the cutoffs provided by Marchet et al. (Eur J Surg Oncol. 2008;34:159-65.) [i.e.: 0%, 1%~9%, 10%~25%, and >25%] as the best way for its categorization after a D2-gastrectomy. In these settings, 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%).

Recently, Fan M et a. (Br J Radiol. 2016;89(1059):20150758.) also explored the role of adjuvant chemoradiation vs chemo, and found similar results of ours that patients with N1-2 stage rather than those with N3 stage benefit most from additional radiation after D2 dissection. However, using data from the important RCT named ARTIST Trial, Kim Y et al. presents different results favoring the use of chemoradiotherapy after D2 gastrectomy in patients having N ratios >25%. These contrary finding warrants further investigation in future prospective studies, but highlight the N-Ration as a useful tool for a more taylored therapy based on radiation for gastric cancer patients. Since targeted therapy are currently focused in sophisticated molecular classifications, this approach might serve to improve patients selection for adjuvant radiotherapy based on simple and easely available clinico-phatological findings.

In these settings, we would like to congratulate the authors for their interested paper re-exploring the data from Artist Trial; and also to invite other authos to re-explore your data using a similar approach.