Evaluation of carcinoembryonic antigen (CEA) density as a prognostic factor for percutaneous ablation of pulmonary colorectal metastases.

Abstract

To evaluate the prognostic value of carcinoembryonic antigen (CEA) density and other clinicopathological factors for percutaneous ablation of pulmonary metastases from colorectal cancer. CEA density was calculated as: "absolute serum CEA pre-ablation/volume of all lung metastases [mm³]". Median CEA density was the cut-off for high and low groups. Cox-regression was used to determine prognostic factors for survival. A total of 85 patients (102 ablation sessions) were followed for a median of 27 months. High CEA density was significantly associated with worse overall survival compared to low CEA density (adjusted HR: 2.12; 95 % CI: 1.22-3.70, p=0.002; median survival: 25.7 vs. 44.3 months). The interval between primary resection of the colorectal carcinoma and first ablation was also a prognostic factor, a duration >24 months being associated with better survival compared to a shorter interval (0-24 months) (adjusted HR: 0.55; 95 % CI: 0.31-0.98, p=0.04). Moreover, a disease-free interval >24 months was significantly associated with low CEA density compared to a shorter interval (0-24 months) (adjusted OR: 0.29; 95 % CI: 0.11-0.77, p=0.01). Serum CEA density and interval between primary resection of a colorectal carcinoma and pulmonary ablation are independent prognostic factors for overall survival. In two patients with identical CEA serum levels, the patient with the lower/smaller pulmonary tumour load would have a worse prognosis than the one with the higher/larger pulmonary metastases. • CEA density is an independent prognostic factor for colorectal pulmonary metastases. • A lower CEA density is associated with better overall survival. • CEA may play a functional role in tumour progression. • High CEA density is associated with smaller tumours. • Interval between pulmonary ablation and primary colorectal carcinoma is a prognostic factor.