Impact of Primary Tumor Laterality on Adjuvant Hepatic Artery Infusion Pump Chemotherapy in Resected Colon Cancer Liver Metastases: Analysis of 487 Patients

Background Hepatic artery infusion (HAI) chemotherapy is associated with overall survival (OS) in patients with resected colon cancer liver metastases (CLM). The prognostic impact of primary tumor location in CLM following hepatic resection in patients receiving regional HAI is unknown. This study seeks to investigate the prognostic impact of HAI in relation to laterality in this patient population. Methods Consecutive patients with resected CLM, with known primary tumor site treated with and without HAI, were reviewed from a prospective institutional database. Correlations between HAI, laterality, other clinicopathological factors, and survival were analyzed, and Cox proportional hazard regression was used to determine whether laterality was an independent prognostic factor. Results From 1993 to 2012, 487 patients [182 with right colon cancer (RCC), 305 with left colon cancer (LCC)] were evaluated with a median follow-up of 6.5 years. Fifty-seven percent (n = 275) received adjuvant HAI. Patients with RCC had inferior 5-year OS compared with LCC (56% vs. 67%, P = 0.01). HAI was associated with improved 5-year OS in both RCC (68% vs. 45%; P < 0.01) and LCC (73% vs. 55%; P < 0.01). On multivariable analysis, HAI remained associated with improved OS (HR 0.52; 95% CI 0.39-0.70; P < 0.01) but primary tumor site did not (HR 0.83; 95% CI 0.63-1.11; P = 0.21). Additional significant prognostic factors on multivariable analysis included age, number of tumors, node-positive primary, positive margins, RAS mutation, two-stage hepatectomy, and extrahepatic disease. Cox proportional hazard regression determined no significant interaction between HAI and laterality on OS [parameter estimate (SEM), 0.12 (0.28); P = 0.67]. Conclusions Our data show an association of adjuvant HAI and increased OS in patients who underwent curative hepatectomy, irrespective of primary tumor location. Laterality should therefore not impact decision-making when offering adjuvant HAI.