Association between the lymph node ratio and hepatic tumor burden: importance for resectable colorectal liver metastases?

Prognosis in patients with stage IV colorectal cancer (CRC) and liver-only metastases is first and foremost determined by resectability of the liver metastasis (as well as the primary disease), which can usually be entertained in about 20% (1). However, within the resected group of patients, there is a wide variability in outcome, related to a number of factors. Thus, identification of reliable prognostic factors that may aid in decision-making and treatment choice is welcomed. Recently, in this Journal (2), Ahmad and colleagues reported an association with primary tumor lymph node ratio (LNR) and intrahepatic tumor burden in patients with stage IV CRC and resectable liver metastasis. Notably, patients with a high LNR and greater liver tumor burden also did worse in overall survival analysis (2). The study has several limitations as addressed by the authors, including a small sample size, including patients which had neoadjuvant (radio)chemotherapy (which may influence the post-radiochemotherapy nodal status; ypN) and including patients with extrahepatic disease. Thus, the true association between the LNR and the hepatic tumor burden may be difficult to confirm per se. Still, however, the study addresses a number of interesting questions