The effect of primary tumour resection on patients with synchronous metastatic colorectal cancer treated with cetuximab-containing regimens.

BACKGROUND

This study aims to assess the effect of primary tumour resection (PTR) on patients with metastatic colorectal cancer (mCRC) treated with cetuximab.

METHODS

This retrospective cohort study was conducted in a tertiary cancer center in Turkey. Patients with mCRC between January 2009 and December 2020 were extracted from the electronic hospital management system. Patients with RAS wild-type synchronous metastatic left-sided colon or rectum cancer who had cetuximab-containing treatment protocol were included in the study. The primary outcomes were overall survival (OS) and progression-free survival (PFS). The secondary outcome was response rates.

RESULTS

A total of 111 patients with mCRC were included in this study. PTR was performed in 57.7% of all patients. Fifty-nine (53.2%) and 52 (46.8%) patients had rectal and left colon tumours, respectively. The combination treatment with cetuximab was FOLFIRI in 62.2% and FOLFOX in 29.7% of all patients. In subgroup analysis, the median PFS was 7.9 and 9 months in PTR (+) and PTR (-) patients, respectively. The difference between the groups was not statistically significant (P = 0.3). The median OS was 33 months in all patients. In subgroup analysis, the median OS was 39 and 27.9 months in PTR (+) and PTR (-) patients, respectively. The difference between the groups was statistically significant (P = 0.002). After adjusting for confounding factors, PTR and ECOG performance score were the independent prognostic factors for OS.

CONCLUSION

PTR improved the OS in patients with RAS wild-type synchronous left-sided colon or rectum cancer treated with cetuximab-containing chemotherapy regimens.