Predictive Biomarker Testing in Colorectal Cancer: KRAS and BRAF Mutation Frequency and Testing Algorithm in Developing Countries

Publish : July 24, 2017
Total Download : 6

Niraj Kumari *,  Narendra Krishnani **, Ashok Kumar***, Balraj Mittal ****
* Additional Professor, Department of Pathology Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow
Email: nirajpath@yahoo.co.in, Fax: 91 522 2668017, Phone: 91 522 2495236
** Professor, Department of Pathology Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow  
Email: narendrakrishnani@yahoo.co.in, Fax: 91 522 2668017, Phone: 91 522 2494246
*** Professor, Department of Surgical Gastroenterology Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow
Email: doc.ashokgupta@gmail.com, Fax: 91 522 2668017, Phone: 91 522 2494324
**** Professor, Department of Biotechnology Baba Saheb Ambedkar University Lucknow, India
Email: balrajmittal@gmail.com., Fax: 91 522 2668017, Phone: 91 522 2494324
Correspondence: Niraj Kumari*
Received  12 november 2016;   accepted   5 May 2017.

   

Abstract


Background: Predictive biomarker testing is mandatory before initiating targeted therapy in metastatic colorectal cancer (mCRC). Mutation frequencies and their association with clinicopathological features vary widely across populations. In low socio-economic countries, appropriate selection of cases is important for biomarker testing.  
Methods: 110 CRC cases were evaluated for KRAS-BRAF mutation and association with clinicopathological features by PCR-Sanger sequencing method.  
Results: Patients <40 years constituted 20%. Right and left-sided CRC constituted 34.5% and 63.5% respectively. KRAS mutation was seen in 18.2% and BRAF (V600E) in 0%. No association was found between KRAS mutation and clinicopathological features. All mCRC cases were wild except one. Patients aged <40 years showed lower mutation rate (13.6%) than patients of >40 years (21.6%). Young age was significantly associated with perineural invasion and necrosis. Right-sided tumors were significantly larger (>4 cm) than left-sided, had lower stage and lymphnode metastasis.
Conclusion: Lower KRAS mutation was found in CRC in north Indian patients. Young age and location but not mutation status showed significant association with tumor size, perineural invasion, necrosis, stage and lymphnode metastasis. In countries with low socio-economic conditions, predictive biomarker testing should be undertaken judiciously, starting with common biomarker testing followed by extended panel.  
Running Title: Predictive Biomarker Testing And Colorectal Cancer

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Address of editorial Corresponce
✎  Vorachai Sirikulchayanonta, MD, Editor-in-Chief: Asian Archives of Pathology, Faculty of Science, Rangsit University, Pathumthani 12000, Thailand.
✉  Email address: asianarchpath@gmail.com, vorachai7@gmail.com