Epidermal growth factor receptor (EGFR) and prostaglandin-endoperoxide synthase 2 (PTGS2) are prognostic biomarkers for patients with resected colorectal cancer liver metastases.

BACKGROUND: Resection of colorectal cancer liver metastasis (CRCLM) with curative intent has long-term benefit in ~40% of cases. Prognostic biomarkers are needed to improve clinical management and reduce futile surgeries. Expression of epidermal growth factor receptor (EGFR) and prostaglandin-endoperoxide synthase 2 (PTGS2; also known as cyclooxygenase-2) has been associated with carcinogenesis and survival. We investigated the prognostic value of EGFR and PTGS2 expression in patients with resected CRCLM. METHODS: Formalin-fixed paraffin-embedded CRCLM tissue and corresponding primary tumour specimens from a multi-institutional cohort of patients who underwent liver resection between 1990 and 2010 were incorporated into tissue microarrays (TMAs). TMAs were stained for EGFR and PTGS2 by immunohistochemistry. The hazard rate ratio (HRR) for the association between expression in CRCLM and overall survival was calculated using a 500-fold cross-validation procedure. RESULTS: EGFR and PTGS2 expression could be evaluated in 323 and 351 patients, respectively. EGFR expression in CRCLM was associated with poor prognosis (HRR 1.54; P<0.01) with a cross-validated HRR of 1.47 (P=0.03). PTGS2 expression was also associated with poor prognosis (HRR 1.60; P<0.01) with a cross-validated HRR of 1.63 (P<0.01). Expression of EGFR and PTGS2 remained prognostic after multivariate analysis with standard clinicopathological variables (cross-validated HRR 1.51; P=0.02 and cross-validated HRR 1.59; P=0.01, respectively). Stratification for the commonly applied systemic therapy regimens demonstrated prognostic value for EGFR and PTGS2 only in the subgroup of patients who were not treated with systemic therapy (HRR 1.78; P<0.01 and HRR 1.64; P=0.04, respectively), with worst prognosis when both EGFR and PTGS2 were highly expressed (HRR 3.08; P<0.01). Expression of PTGS2 in CRCLM was correlated to expression in patient-matched primary tumours (P=0.02, 69.2% concordance). CONCLUSIONS: EGFR and PTGS2 expressions are prognostic molecular biomarkers with added value to standard clinicopathological variables for patients with resectable CRCLM.

Aurora kinase A (AURKA) expression in colorectal cancer liver metastasis is associated with poor prognosis.

BACKGROUND: Five-year survival after resection of colorectal cancer liver metastasis (CRLCM) is <30%. We recently found that aurora kinase A (AURKA) drives 20q gain-associated tumour progression and is associated with disease recurrence. This study evaluates the prognostic value of AURKA expression in CRCLM of patients who underwent liver resection. METHODS: Tissue microarrays (TMAs) were generated using formalin-fixed paraffin-embedded CRCLM and matched primary tumour from a multi-institutional cohort of patients with CRCLM who underwent liver resection between 1990 and 2010. Tissue microarrays were stained for AURKA using immunohistochemistry, and a hazard rate ratio (HRR) for the association between overall survival (OS) and nuclear AURKA expression in CRCLM was calculated. Results were validated by 500-fold cross-validation. RESULTS: The expression of AURKA was evaluated in CRCLM of 343 patients. High AURKA expression was associated with poor OS (HRR 1.55, P<0.01), with a cross-validated average HRR of 1.57 (P=0.02). Average HRR was adjusted for the established prognostic clinicopathological variables in a multivariate analysis (average HRR 1.66; P=0.02). The expression of AURKA in CRCLM was correlated to its expression in corresponding primary tumour (P<0.01). CONCLUSION: The expression of AURKA protein is a molecular biomarker with prognostic value for patients with CRCLM, independent of established clinicopathological variables.