Background: Colorectal cancer (CRC) is a significant global health concern, ranking as the third most common cancer and the second leading cause of cancer-related deaths, particularly in more unfavourable populations. Reports sustain an increased frequency of cases in these populations. However, in Africa, CRC is the fifth most common invasive malignancy. Data unveil that CRC in Africa manifests at younger age and in advanced stages of the disease that, in combination with scarce clinical strategies to manage patient treatment, leads to high rates of mortality. Limited data hinder our understanding of the evolving burden of CRC in sub-Saharan Africa. Data reveals an emerging burden of CRC and anal cancer in Mozambique, challenging the perception of low incidence, mostly diagnosed at advanced stages.

Objectives: In this study, we aim to address the mutation landscape of Mozambican CRC tumours to improve the patient clinical management, focusing on KRAS, NRAS, BRAF, TP53, and microsatellite instability (MSI) phenotype.
 
Methods: A patient sample set of 30 CRC tumours from Mozambican patients was used to assess mutations in KRAS, NRAS, BRAF, and MSI phenotype through the IdyllaTM platform and the levels of p53 protein by immunohistochemistry.
Results: Our results, opposing to previous reports published on African or African descent populations, reveal a predominance of mutations in KRAS and overexpression of p53 protein, with much lower mutation frequencies in the remaining genes.

Conclusions: Identification of the mutational pattern of Mozambican CRC patients can help Mozambican clinicians better optimise treatment planning and therefore patient's outcome. Promising results obtained in our study, allied to scarcity of molecular data from Mozambican CRC patients, make imperative to enlarge our patient sample set to obtain more clinicopathological data and demographic/ancestry information.

Keywords: Colorectal cancer (CRC); KRAS; Mozambique; mutations; p53 protein.