Association of primary tumor lymph node ratio with burden of liver metastases and survival in stage IV colorectal cancer.

BACKGROUND

The primary objective of our study was to assess the association of primary tumor lymph node ratio (LNR) in stage IV colorectal adenocarcinomas (CRC) with overall survival (OS) and the extent of metastatic disease in the liver.

METHODS

We analyzed data on 53 stage IV CRC patients who underwent surgical resection of the primary tumor. The median LNR of 0.25 was used to stratify patients into high LNR (H-LNR) and low LNR (L-LNR) groups. Statistical comparison was performed using chi square test and multiple regression models. OS was calculated using the Kaplan-Meier (KM) method while cox regression was used for multivariate analysis.

RESULTS

H-LNR status was associated with the presence of >3 liver metastases (LM) [odds ratio (OR): 2.43, P=0.047] and bilobar LM (OR: 3.94, P=0.039). The OS in H-LNR patients was significantly worse in the entire cohort compared to L-LNR (9% 34% at 3 years, P=0.027). The 5-year OS in patients undergoing liver resection for LM was also significantly worse in the H-LNR group (0% 37%, P=0.013). LNR was independently associated with survival on multivariate analysis [HR: 2.63; 95% confidence intervals (CI), 1.13-6.14; P=0.025].

CONCLUSIONS

In stage IV CRC, LNR is associated with the extent of hepatic tumor burden and was an independent predictor of survival in patients undergoing liver resection.