TROP2 overexpression in colorectal liver oligometastases is associated with poor prognosis after liver resection

The aim of this study was to assess trophoblast antigen protein 2 (TROP2) expression in liver oligometastases and its prognostic value for colorectal liver oligometastasis (CLO) patients undergoing liver resection.

We retrospectively selected 129 consecutive CLO patients who underwent curative liver resection between June 1999 and December 2016. Immunohistochemistry (IHC) was performed to detect TROP2 expression in paraffin-embedded specimens. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan–Meier method and log-rank test, and independent prognostic factors were identified with Cox regression modeling.

TROP2 was expressed in 72.9% (94/129) of liver oligometastatic tissues. TROP2 expression in primary tumors and liver oligometastases was significantly positively correlated (r = 0.758, p < 0.001). Survival analysis indicated that CLO patients with high TROP2 expression had worse 3-year RFS (44.2% versus 66.4%, p = 0.007) and 3-year OS rates (70.3% versus 85.4%, p = 0.035) than did those with low TROP2 expression. Multivariate analysis indicated that high TROP2 expression was independently associated with poor RFS [hazard ratio (HR) = 2.017; 95% confidence interval (CI) 1.198–3.396; p = 0.023] and OS (HR = 2.090; 95% CI 1.037–4.214; p = 0.039). Gene expression profile analysis indicated that high TROP2 expression was associated with TNFα signaling via NF-κB, the inflammatory response and epithelial–mesenchymal transition (EMT).

TROP2 overexpression was associated with an unfavorable oncologic prognosis in patients with CLO undergoing liver resection. Detecting TROP2 expression may be valuable for guiding postoperative treatment among CLO patients.