Long disease-free interval diminishes the prognostic value of primary tumor stage for patients with colorectal cancer liver metastases.

It is assumed that the impact of primary tumor stage (PTS) on prognosis gradually weakens with increasing disease-free interval (DFI) from colorectal cancer resection to liver metastases. Data from 733 patients undergoing hepatectomy in the Hepato-pancreato-biliary Surgery Department I of Peking University Cancer Hospital were retrospectively analyzed. Early and late metastases were defined as DFI ≤ and >12 months, respectively. In early metastases group, patients with T 4 stage had a significantly worse recurrence-free survival (RFS) and overall survival (OS) than those with T 1-3 stage (P = 0.002 and P < 0.001, respectively). Patients with N 1-2 stage disease also demonstrated a worse RFS and OS than those with N 0 stage (P = 0.006 and P = 0.007, respectively). In late metastases group, patients with T 4 and T 1-3 stages as well as patients with N 1-2 and N 0 stages, had comparable RFS (P = 0.395 and P = 0.996, respectively) and OS (P = 0.387 and P = 0.684, respectively). T and N stages were independent prognostic predictors only in patients with early metastases. The impact of PTS on prognosis is diminished with increasing DFI and limited only to patients with early metastases. [ABSTRACT FROM AUTHOR]