Lung cancer is the most frequent cause of mortality worldwide, with an estimated 40% of cancer-related deaths. In India, lung cancer constitutes 6.9 per cent of all new cancer cases and 9.3 per cent of all cancer related deaths in both sexes. Overall survival of patients with Non-Small Cell Lung cancer has been historically poor, with a 5-year survival of 24% for all patients and 5.5% for those with distant metastases. The 5-year relative survival rate for metastatic disease is approximately 6% when patients receive historic cytotoxic chemotherapy regimens.
However, the silver lining is the presence of oncogenic driver mutations in 75% lung cancer patients, most common being EFGR (Epidermal Growth Factor Receptor) in 25% making them eligible for newer targeted therapies or immunotherapies lifting the 5-year survival rates to a miraculous 15% to 50%, depending on the biomarker. This excellent impact of molecular signature on patient survival makes it essential to test as many patients as possible by NGS in the quest to detect the actionable mutation, the biomarker for companion diagnostics. Onlymyhealth editorial team spoke to Dr. Kirti Chadha, Chief Scientific Officer, Metropolis Healthcare Limited, to know about the importance of genetic testing for lung cancer.
Importance Of Genetic Testing To Detect Lung Cancer
Awareness and increasing early detection of lung cancer through low-dose CT screening has been proven to be one of the easiest ways to combat lung cancer. Smoking is the leading cause of lung cancer, but many people who get this cancer never smoked. Apart from smoking, environment and one’s genes also raise risk.
Genetic testing plays an integral part in diagnosing and treating lung cancer. Genetic testing looks for mutations which help develop tailored treatment plans. Using genetic testing, one can identify changes in lung cells that may trigger and contribute to cancer growth - “biomarkers”. Identifying the biomarkers helps oncologist arrive at the best approach to treatment. These targeted therapies are less invasive than traditional cancer treatments because they do not destroy healthy cells — they stop only the cancer cells from growing and reproducing.
How to do genetic testing?
Testing can be done in two ways. Biopsy where we remove tissue from the lungs to be tested. Another approach is called a liquid biopsy. Through a blood draw, able to detect the cancer’s abnormalities. Genomic testing by Next Generation Sequencing is becoming the standard of care. While genomic testing was previously done only in people with stage IV cancer, there has been a concerted shift in recent years to check in the earlier stages to provide targeted treatments that can extend quantity and quality of life which is a major paradigm shift.
Patients who have surgical options for their lung cancer, biomarker testing plays an important role in optimising treatment and maximizing the chances of it being successful. Innovative improvements in our understanding of disease biology, application of predictive biomarkers, and refinements in treatment have led to remarkable progress in the past two decades and transformed outcomes for many patients.