Unexplained iron-deficiency anaemia (IDA) are associated with BRAF V600E mutation in colorectal cancer patients

Background: BRAF gene encodes a serine-threonine kinase that inhibits the RAS/MAPK intracellular pathway. BRAF mutations occur at an early stage of colorectal carcinoma (CRC), and their presence, 10-20% of CRC, is usually associated with inferior prognosis.
Methods: From 41 consecutive CRC confirmed referrals (age 43-93, mean age=70.2, SD=12.97, Male=21, Female=20) from the 2 week wait cancer pathway (2009-2013), we retrospectively collected data from the symptoms at presentation, haemoglobin, ferritin and investigations' outcome including TNM stage. Gene profile analysis data (KRAS, Microsatellite Instability -MSI, BRAF) were retrospectively collected and associated with the presentation profile above. Statistical analysis of the data was performed using SPSS software based on X2Fischer's Exact Test.
Results: BRAF V600E is significantly associated with right-sided CRC (p=0.015). Also there is an association between unexplained IDA at the stage of presentation and BRAF V600E mutation (p=0.007). There was no statistical significant difference between KRAS and BRAF status (p=0.529), BRAF and TNM stage (p=0.515 for T stage, p=1.000 for N stage and p=1.000 for M stage). MSI-High tumours tend to be associated with BRAF V600E mutation (p=0.05 spearman's rho with correlation coefficient -0.531 N=1)
Conclusion: BRAF V600E mutation could be associated with right-sided tumours and subsequently related unexplained IDA at the stage of presentation. Further research should be conducted in order to dichotomize the impact of tumour location and IDA on BRAF gene status separately. mutations and microsatellite instability phenotype predict specific anatomical subsite in colorectal cancer patients.