Upfront primary tumour resection and survival in synchronous metastatic colorectal cancer according to primary tumour location and RAS status: Pooled analysis of the Spanish Cooperative Group for the Treatment of Digestive Tumours (TTD)

Practical Implications of KRAS Mutation Status and Sidedness of Primary Tumour in Patients with Colorectal Cancer and Synchronous Liver Metastases: A Subset Analysis of the CoSMIC Study

Patients with colorectal cancer presenting with synchronous liver metastases have less favourable outcomes than those with primary-only disease. There is evidence of different genetic mutational signatures according to the sidedness of the primary tumour. KRAS mutations are key driver mutations in colorectal cancer progression. This post hoc analysis of the previously reported CoSMIC inception cohort explores the association between primary tumour sidedness and KRAS mutational status on the outcome of patients with colorectal cancer and synchronous liver metastases. Patients diagnosed with synchronous disease were recruited between April 2014 and March 2017 and, after exclusions, 83 patients undergoing colorectal primary KRAS mutation testing constituted the final study population. Data were collected prospectively on demographic profiles, treatment, and outcomes. Twenty-one patients (25%) had right-sided tumours and 62 (75%) had left-sided tumours, with 46 (55%) and 37 (45%) exhibiting wildtype and mutated KRAS, respectively. There was no difference in distribution of liver metastases by KRAS status (unilobar vs. bi-lobar; p = 0.58; Fisher’s Exact test) and no difference in 5-year survival according to KRAS mutation status (Log-rank test, p = 0.82) or tumour sidedness (p = 0.16). In summary, in this cohort of patients with colorectal cancer and synchronous liver metastases, neither KRAS mutation status nor tumour sidedness influenced survival.

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 χ² 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.