Prognostic value of pre- and post-operative circulating tumor cells detection in colorectal cancer patients treated with curative resection: a prospective cohort study based on ISET device.

Abstract

BackgroundCirculating tumor cells (CTCs) have been regarded as a promising biomarker for colorectal cancer (CRC); however, the prognostic value of post-operative (op) CTCs is still unclear. This study aimed to compare the recurrence prediction value of pre- and post-op CTCs in CRC patients treated with curative resection.Patients and methodsConsecutive CRC patients treated with curative resection from January 2014 to March 2015 were identified. CTCs from 2.5 mL peripheral blood were enumerated with an ISETdevice-CTCBIOPSY® before and after surgery. Based on the status of pre- and post-op CTCs, the included patients were grouped into four cohorts: pre- and post-op CTCs−, pre-op CTCs− but post-op CTCs+, pre-op CTCs+ but post-op CTCs−, and pre- and post-op CTCs+. The 3-year recurrence-free survival (RFS) rate of patients was analyzed.ResultsA total of 138 patients (79 [57.2%] male; median age=62 [43–75] years) were enrolled. Patients with pre-op CTCs− had a 19.2% higher 3-year RFS rate (86.2%) than the combined cohorts with pre-op CTCs+ (67.0%) (P=0.038). Patients with post-op CTCs+ had aa 25.6% lower 3-year RFS rate (57.1%) than the combined cohorts with post-op CTCs− (82.7%) (P=0.001). Moreover, patients with pre- and post-op CTCs+ had a 25.1% lower 3-year RFS rate (53.8%) than patients with pre-op CTCs+ but post-op CTCs− (78.9%) (P=0.004). Multivariate analyses confirmed that post-op CTCs+ (HR=2.82, 95% CI=1.39–5.75, P=0.004), but not but pre-op CTCs+ (HR=2.17, 95% CI=0.75–6.31, P=0.153), was independently associated with shorter 3-year RFS rate.ConclusionPost-op CTCs+, but not pre-op CTCs+, is an independent indicator of poor prognosis for CRC patients treated with curative resection. Patients with post-op CTCs+ have a higher risk of recurrence those with pre-op CTCs+. Evaluation of post-op, rather than pre-op, CTCs is warranted.