BRAF V600E mutation in colorectal cancer is associated with right-sided tumours and iron deficiency anaemia

Abstract

Background: BRAF gene encodes a serinethreonine kinase that inhibits the RAS/MAPK intracellular pathway. BRAF mutations occur at an early stage of colorectal cancer and their presence, 10-20% of colorectal cancer (CRC), is usually associated with inferior prognosis.

Materials and methods: From 41 consecutive CRC confirmed referrals from 1,446 suspected cancer cases (mean age=67.99+13.451, male=21, female=20), we retrospectively analyzed collected data from haemoglobin (Hb) and symptoms at presentation, location of tumor and stage of the disease, including lymphovascular invasion (LVI). Gene profile analysis data (KRAS, BRAF) were retrospectively collected and associated with the presentation profile above.

Results: There was no significant correlation in presentation Hb levels and eventual disease staging (p>0.05 for all associations). Patients with right-sided tumours were found to have a lower Hb level than patients with either left-sided colonic or rectal tumours. Hb levels were also significantly lower in patients with the BRAF V600E mutation. KRAS status or LVI status did not have a specific correlation with Hb levels.

Conclusion: BRAF V600E mutation might be associated with right-sided tumors and subsequently related unexplained iron-deficiency anaemia (IDA) at presentation. This finding may affect the choice of clinical strategy for investigation of unexplained IDA. Further research should be conducted in order to identify and support the potential biological explanation of the findings above.

Keywords: BRAF V600E; KRAS; colorectal cancer; iron-deficiency anaemia; molecular biomarkers.