Fast recovery with fewer postoperative complications, prevention of potential tumor-related complications during chemotherapy, life quality improvement, and also can alleviate the tumor load of patients, are some advantages of PTR that may play a role in improving cancer-specific survival. However, it should be pointed out that nearly all the retrospective and prospective studies for the beneficial of PTR enrolled more multi-organ metastases mCRC patients, and with palliative treatment purpose. As for unresectable colorectal liver-limited metastases (CRLMs) with good Eastern Cooperative Oncology Group performance status (ECOG PS), the primary objective is to make metastases resectable by high-intensity conversion therapy and achieved a state of no-evidence of disease. PTR were preferred performed before enrollment in some related RCT studies, including the CELIM study, CAIRO and CAIRO2 studies. Pooled-analysis of our two RCT studies, PTR pre or post chemotherapy for these unresectable liver-limited metastases patients had less morbidities and no mortalities, but no RCTs have focused on survival benefit of pre-operation chemotherapy of PTR for unresectable CRLMs.
