RESUMEN
AIM: The correct analysis of lymph node status is one of the most important parameters for the accurate pathological diagnosis of colorectal cancer. Our aim was to evaluate the number of lymph nodes among the specimens obtained from colorectal resections due to colorectal cancer, before and after the routine use of a lymph node revealing solution (LNRS). METHOD: Data from 780 surgical specimens from patients of both genders with colorectal cancer were studied. The cases were divided chronologically into two groups: the conventional group included 497 specimens treated with conventional methods, i.e. without the use of the LNRS (January 2000 to July 2007), and the LNRS group included 283 specimens examined through the routine use of this solution (August 2007 to July 2012). RESULTS: Most patients were female (57.4%) with a median age of 62 years. The median lymph node number was 18, and 75.9% of the cases (592) had 12 or more nodes dissected. Lymph node metastases were noted in 334 cases (42.8%). A median of 24 lymph nodes was dissected in the LNRS group compared to 15 in the conventional group (P < 0.001). The LNRS group had 9.2% of cases with fewer than 12 lymph nodes dissected compared with 32.6% in the conventional group (P < 0.001). CONCLUSIONS: The use of the LNRS increases the number of lymph nodes obtained from colorectal cancer surgical specimens and can help to reduce the number of cases with < 12 lymph nodes.