Targeting Mutations That Cause Lung Cancer

By Hazlinda Hamzah KUALA LUMPUR, Oct 24 (Bernama) -- Lung cancer accounts for 20 per cent of medically certified deaths of cancer patients in Malaysia but developments in the medical field are improving the treatment methodologies and outcomes. Professor Dr Liam Chong Kin, a consultant chest physician with University Malaya Medical Centre, noted that lung cancer statistics have been rising steadily over the past decade, accounting for 14 per cent of all cancers in men and four percent in women. While consumption of tobacco has been blamed as the single major risk factor for the disease, non-smokers account for 15 per cent of lung cancer cases in men, while in women the figures are between 60 and 70 per cent. Lung cancer is divided into two main types, namely the small cell lung carcinoma (SCLC) and the non-small cell lung carcinoma (NSCLC), with both attributed to the uncontrolled growth of the epithelial cells due to genetic mutation. While statistics may paint a grim picture, physicians today have a better understanding of the disease pathway while patients have to undergo numerous screening methods and therapies that provide better outcomes. THE ROLE OF EFGR Dr Adel Zaatar, Consultant Radiotherapist and Oncologist with Penang Gleneagles Medical Centre, pointed out that mutations in the Epidermal Growth Factor Receptor (EGFR), a protein found in cells, have been identified as the culprits. Therefore, tests to identify these mutations and therapies targeted at them play a critical role in curtailing the progression of lung cancer. He said that the EGFR test and therapy are increasingly being incorporated in the clinical management of lung cancers for patients who test positive for EGFR mutations. While EGFR test has been available in Malaysia for some time now, a new drug Erlotinib has been introduced for EGFR therapy only recently. EGFR TESTS ARE CRUCIAL Dr Adel noted that the EGFR test and therapy are crucial, especially when looking at the fact that 30-50 per cent of Asian patients diagnosed with NSCLC show EGFR mutation. NSCLC with EGFR activating mutations are considered to be a genetically distinct form of lung cancer common in Asian women who are new smokers but have adenocarcinoma tumours. Dr Adel pointed out that once a patient is identified as suffering from EGFR Mutation Positive Advanced or metastatic NSCLC, they would be recommended to undergo EGFR therapy using inhibitors like erlotinib. Moreover, unlike the highly toxic chemotherapy, the inhibitor therapy is less toxic and improves the quality of life for patients. POSITIVE RESPONSE Meanwhile, Professor Dr R. Pathmanathan noted that many patients with mutated EGFR lung cancer adenocarcinoma have responded positively to the EGFR therapy. Dr Pathmanathan told Bernama that 1,200 tests have been conducted at the Sime Darby Medical Centre to determine EGFR mutation over the last 18 months. The tests are available in other medical centres as well. However, he pointed out that initially patients found to be EGFR mutation-positive were treated with a competitive drug before the introduction of Erlotinib. "Erlotinib was already available in other parts of the world but it was not registered in Malaysia yet. To have a drug put into the blue book, it needs to go through a list of stringent procedures and this takes time," Dr Pathmanathan added. However, the drug can only be prescribed if the patient is tested as being EGFR mutation-positive. -- BERNAMA