Correlation between the number of positive nodes, number of dissected nodes and survival of patiens with colorectal cancer

Abstract

13585 Background: According to the TNM classification, the prognosis of patients suffering from colon and rectal cancer has been defined taking into account the number of nodes reported positively. Objective: This work is intending to establish a relation between the number of positive nodes and the number of dissected nodes, relating it with the overall survival. Methods: 5500 medical records of patients were reviewed. 771 out of these corresponded to gastrointestinal cancer (14%) from which 351(6.38%) corresponded to colorectal cancer. From this group, 291 patients (82.9%) underwent a surgery. A relation between the number of positive nodes and the number of dissected nodes was established and called proportion of positivity (positive nodes/ dissected nodes × 100) and this was in turn related to a five year overall survival. Two groups were analyzed: proportion of positivity > than 50% and proportion of positivity < than 50%. Results: A report of 209 patients showing nodes was obtained (59.5%), with a means of 10.4 (rank 0–31) of dissected nodes per patient and a means of positive nodes of 2.4 (rank 0–22). Comparing the two groups the statistic significance starts to be obvious from the 18 months and the difference between the two groups continues increasing until the five years. The survival to five years for the group with the proportion > than 50% was 39% (IC 95%:13.4–64.5) compared to the survival for the group with a proportion < than 50% that was 75.7% (IC 95%:67.6–83.7) p<0.05. Conclusions: The proposal shows that not only is the absolute number of positive dissected nodes as only prognostic indicator (TNM) but also that before nodes dissections with low number of them, it is possible to establish a reliable prognostic relationship by calculating the proportion of positivity. The above said does not consider that the nodal dissection can be less than recommended, on the contrary obtaining the biggest number of nodes will mean bigger equivalence of the proposal and a bigger possibility to detect positive nodes. No significant financial relationships to disclose.