Time-to-Surgery and Survival Outcomes in Resectable Colorectal Liver Metastases: A Multi-Institutional Evaluation.

Background: Resection of colorectal liver metastases (CRLM) is associated with improved survival; however, the impact of time to resection on survival is unknown. The current multi-institutional study sought to evaluate the influence of time from diagnosis (Dx) to resection (Rx) on survival outcomes among patients with resectable, metachronous CRLM and to compare practice patterns across hospitals.

Study Design: Medical records of patients with ≤4 metachronous CRLM treated with surgery were reviewed and analyzed retrospectively. Time from Dx to Rx was analyzed as a continuous variable and also dichotomized into 2 groups (group 1: Dx to Rx <3 months and group 2: Dx to Rx ≥3 months) for additional analysis. Survival time distributions after resection were estimated using the Kaplan-Meier method. Between-group univariate comparisons were based on the log-rank test and multivariable analysis was done using Cox proportional hazards model.

Results: From 2000 to 2010, six hundred and twenty-six patients were identified. Type of initial referral (p < 0.0001) and use of neoadjuvant (p = 0.04) and/or adjuvant (p < 0.0001) chemotherapy were significantly different among hospitals. Patients treated with neoadjuvant chemotherapy (n = 108) and those with unresectable disease at laparotomy (n = 5) were excluded from final evaluation. Median overall survival and recurrence-free survival were 74 months (range 63.8 to 84.2 months) and 29 months (range 23.9 to 34.1 months), respectively. For the entire cohort, longer time from Dx to Rx was independently associated with shorter overall survival (hazard ratio = 1.12; 95% CI, 1.06-1.18; p < 0.0001), but not recurrence-free survival. Median overall survival for group 1 was 76 months (range 62.0 to 89.2 months) vs 58 months (range 34.3 to 81.7 months) in group 2 (p = 0.10). Among patients with available data pertaining to adjuvant chemotherapy (N = 457; 318 treated and 139 untreated), overall survival (87 months [range 71.2 to 102.8 months] vs 48 months [range 25.3 to 70.7 months]; p <0.0001), and recurrence-free survival (33 months [range 25.3 to 40.7 months] vs 22 months [range 14.5 to 29.5 months]; p = 0.05) were improved significantly.

Conclusions: In select patients undergoing initial resection for CRLM, longer time from Dx to Rx is independently associated with worse overall survival. In addition, despite uniform disease characteristics, practice patterns related to definitely resectable CRLM vary significantly across hospitals.