Impact of Upfront Chemotherapy on the Effect of Primary Tumour Resection for Asymptomatic Synchronous Colorectal Cancer With Unresectable Metastases: A Propensity-Score-Matched Cohort Analysis

BACKGROUND: It is controversial whether primary tumour resection (PTR) and the sequencing of chemotherapy and PTR are associated with the survival of patients with incurable stage IV colorectal cancer. This study aimed to explore the effects of PTR and the sequencing of chemotherapy and PTR on asymptomatic colorectal cancer with synchronous unresectable metastases (asmCRC). PATIENTS AND METHODS: Patients with asmCRC were retrospectively identified from a single centre and categorised into 3 groups: PTR followed by chemotherapy (POC), upfront chemotherapy followed by PTR (UFC), and palliative chemotherapy (PC). The primary end points included median overall survival (OS) and progression-free survival (PFS). Clinical features were analysed using χ(2) test, while survival curves were generated using the Kaplan-Meier test. Propensity-score matching (PSM) was performed when comparing survival between POC and UFC groups. RESULTS: From 2008 to 2014, 255 patients were identified and included into the POC (n = 101), UFC (n = 40), and PC (n = 114) groups. The UFC and POC groups had significantly better median OS compared with the PC group (40.7 vs 16.3 months, P < .0001; 39.7 vs 16.3 months, P < .0001). Before PSM, the UFC group had better median PFS than the POC and PC groups (18.5 vs 9.7 months, P = .038; 18.5 vs 6.1 months, P < .0001). After PSM, UFC has better PFS than POC (P = .038). And the UFC group did not have higher postoperative or preoperative morbidity compared with the POC group (P = .235). CONCLUSIONS: Primary tumour resection could improve the survival of patients with asmCRC. Compared with POC or PC, UFC was associated with a better median PFS without significantly increasing preoperative or postoperative morbidity.