Shall metastatic lymph node ratio be accepted as a prognostic factor in the patients underwent lymphadenectomy with inadequate lymph nodes for gastric cancer?

A relation between the number of resected lymph node and the number of metastatic lymph nodes in gastric cancer is the ratio of lymph nodes demonstrating that pN category was influenced by the extension of the lymphadenectomy. The necessity of accurate lymph node staging has been stated vital while evaluating different treatment consequences. This study evaluates use of ratio of lymph nodes as a prognostic factor in the patients with gastric cancer who underwent the surgery with inadequate lymph nodes removal. Eighty-eight gastric cancer patients with average age 64.3 and male/female ratio 1.3/1 were reviewed. The relation between the number of resected lymph nodes and the number of metastatic lymph nodes was analysed according to 2 different staging systems and evaluated against the other prognostic factors too. Pearson correlation of the variables and multivariate analysis then ROC curve analysis were used to collate the ratio and the pN stage. The number of lymph node metastases increased with the number of resected lymph nodes but the number of metastatic lymph node was not adequate to make the staging true (<15). Though the lymph node ratio is supposed to be a better prognostic factor than the number of metastatic lymph nodes no difference had been exposed favoring the ratio of lymph nodes in the study. ROC curve of both variables did not show difference (0.692 and 0.709, respectively) but both variables were used as a significant prognostic factor (p<0.0001). According to the multivariate analysis the hazard ratio for the pN stages showed a significant increase (p=0.006, HR=1.8, 95% CI=1.184-2,671) with significant difference, which favored pN stages as a better prognostic factor against the ratio. The ratio of the lymph nodes seems not to be a good prognostic factor in the patients underwent lymphadenectomy with 15 lymph nodes or lower. However it needs further evaluation. [Turk J Cancer 2009;39(4):146-154]