Optimizing prognostication in patients with synchronous liver metastases from rectal cancer treated according to the liver-first approach.

Abstract

Background: Patients with rectal cancer (RC) and synchronous rectal liver metastases (sRLM) can be treated according to the liver-first approach. A proportion of patients does not complete the full treatment trajectory. This study aims to evaluate currently available prognostic factors in patients treated according to the liver-first protocol. It also aims to improve prognostication for non-completion of the treatment sequence in this highly selected patient population. Methods: Retrospective analysis of all patients treated for RC with sRLM at the Erasmus MC Cancer Institute according to the liver-first protocol. Results: In total 132 consecutive patients were included in this study, of which 90 patients (68%) completed the full treatment trajectory. Logistic regression showed that two well-known clinicopathological factors (RLM size > 5cm, bilobar RLM) were associated with not completing full treatment trajectory. Receiver operating characteristic (ROC) analysis identified the optimal cut-offs for preoperative CEA (37 ug/L), size (2.65 cm) and number (5) of RLM. The use of optimal cut-offs improved performance of the logistic regression model, as the area under the curve (AUC) increased from 0.62 to 0.73. Conclusion: The study identified optimal cut-off points for currently available clinicopathological factors, which improved prognostication in this selected patient group. The obtained Results can be used for counselling but, cannot be used to exclude patients from treatment according the liver first protocol.