Recent Advances in the Molecular Diagnosis of Colorectal Cancer Make Personalised Treatment Possible Even in Resource-Limited Settings

Abstract

Colorectal cancer is the fourth most common cancer in Nigeria with a significant proportion presenting at advanced stage partly due to non-availability of organized screening programs. The oncological challenge posed by colorectal cancer (CRC) is equally shared by rich and poor countries alike. Studies on colorectal cancer molecular heterogeneity have used genomewide gene expression-based data to group patients into four Consensus Molecular Subtypes (CMS), through which patients can now benefit from personalized immunotherapy. The recent report of complete remission in patients with locally advanced mismatch repair deficient rectal cancer treated with immunotherapy (PDL-1 inhibitor) is a game changer for the treatment of the disease. However, the exorbitant cost and sophistication of genetic analysis has precluded poor countries from benefitting from this new knowledge. Recently however, it was shown that immuno-histochemistry-based CMS classification and patient stratification is feasible and was used to sub-classify a cohort of CRC patients at the Lagos University Teaching Hospital. This cost-effective method is now available for use in other resource-limited settings as ours.