[Does the sidedness determine the first line treatment of irresectable metastatic colorectal cancer?]

Median life expectancy of non-resectable metastatic colorectal cancer may surpass three years. However, several points of the treatment strategy are subject of ongoing debate. Optimal sequence of targeted agents is not elucidated either. Based on retrospective analyses of six clinical studies and a metaanalysis, the superiority of anti-EGFR agents such as cetuximab and panitumumab over anti-VEGF bevacizumab has been proposed in the treatment of left sided tumours.

The results of the six major clinical trials were analysed. Insufficiencies of the meta-analysis are pointed: the lack of homogeneity among control groups, the omission of later lines of therapy, the inconsistency between progression free and overall survival benefit and the high proportion of excluded patients.

The trials confirm the worse prognosis of right sided versus left sided colorectal cancers.

To date the data are not strong enough to support the preference of any of the available targeted agents at the first line setting in the treatment of left sided metastatic RAS and BRAF wild type colorectal cancers. Several trials suggest that anti-EGFR treatment has no additional benefit as compared to chemotherapy alone in the treatment of right-sided tumours. Orv. Hetil., 2017, 158(9), 340-344.