Last Updated:November 19, 2024, 16:16 IST

DNA serves as a blueprint that guides the future of lung cancer treatment

While most lung cancers are sporadic, a small percentage may have hereditary components

Lung cancer continues to be one of the most prevalent and deadly cancers globally, with a concerning rise in cases in India, from 98,278 in 2020 to 103,371 in 2022. The disease is primarily linked to environmental and lifestyle factors like smoking and air pollution, but genetic mutations also play a role in its development. Early-stage lung cancer may go unnoticed, but as it progresses, symptoms like chest pain, coughing, weight loss, and difficulty in breathing appear.

Household and outdoor air pollution are major contributors to lung cancer and disproportionately affect vulnerable populations such as children, women, the elderly, and individuals with pre-existing conditions. On the other hand, a family history of lung cancer, particularly in non-smokers or those with multiple affected relatives, can suggest a potential inherited genetic predisposition to the disease.

Inherent gene mutations are less common but can significantly increase the overall risk, however, acquired mutations play an important role in the development of lung cancer. These mutations also serve as important genomic biomarkers for deciding the best treatment options. Dr Suruchi Aggarwal, Head – Scientific Affairs, MedGenome shares how DNA influences lung cancer treatment.

Lung cancer treatment has witnessed a revolution in recent years, largely driven by the increasing understanding of genetics and personalized medicine. The era of “one-size-fits-all” treatments is going away and targeted therapies tailored to an individual’s genetic profile, offering better outcomes and fewer side effects.

Genomic testing performed on tumor samples or through liquid biopsy, identifies genetic mutations or alterations such as EGFR, ALK, ROS1, BRAF, KRAS, and others through the Next Generation sequencing technique. These mutations are the drivers of cancer progression and therapies have been designed to target the mutated cancer cells. For example, if L858R or Exon 19 del mutation in the EGFR gene is identified in a Non-small cell lung cancer patient, the EGFR inhibitors are used, which block the growth pathways resulting in a highly effective personalized treatment. Nevetheless, cancer cells can evolve, rendering these treatments ineffective over time. Genetic analysis further helps identify secondary mutations that cause resistance, such as the T790M mutation in EGFR-mutated lung cancer. This information allows doctors to switch to second-line or next-generation treatments, maintaining disease control.

There are other molecular biomarkers like PD-L1 expression or tumor mutational burden (TMB) which guide immunotherapy decisions. Immunotherapies, such as checkpoint inhibitors, harness the body’s immune system to attack cancer cells. Knowing the genetic and molecular landscape of the tumor ensures precision medicine and the right patients can avail of these innovative therapies, improving success rates.

The liquid biopsy technology is particularly transformative for lung cancer which enable non-invasive analysis of circulating free DNA (cfDNA) from a blood sample, especially when tissue is not available or is inadequate. Liquid Biopsy can be very useful in newly diagnosed patients to identify targetable mutations as well as in treated patients, it allows real-time monitoring of genetic changes, treatment response, and early detection of relapse.

Genetic insights pave the way for participation in cutting-edge clinical trials. Patients with rare genetic alterations like MET amplifications can access experimental therapies, offering hope even in advanced stages of lung cancer.

While most lung cancers are sporadic, a small percentage may have hereditary components. For example, inherited mutations in genes like TP53 or RB1 can predispose individuals to lung cancer. Genetic testing not only helps in risk assessment for families but also informs surveillance strategies and early interventions.

DNA serves as a blueprint that guides the future of lung cancer treatment. With genetic testing and personalized approaches becoming more accessible, patients have a greater chance of effective, precise care.

Lung cancer has long been associated with smoking, and for good reason. Tobacco use is the leading cause of lung cancer, responsible for approximately 85% of cases globally. However, dismissing lung cancer as “just a smoker’s disease” can be misleading and dangerous. Many non-smokers are diagnosed with lung cancer each year, and the reasons behind these cases are diverse and complex.

This article explores the hidden risk factors for lung cancer, emphasizing that it can affect both smokers and non-smokers alike.

Understanding Non-Smoker Lung Cancer Cases

While smoking remains the primary risk factor, nearly 10-20% of people who develop lung cancer have never smoked in their lives. These cases often surprise patients and even healthcare providers. Non-smoker lung cancer can stem from environmental, genetic, and lifestyle factors.

Hidden Risk Factors for Lung Cancer

1. Secondhand Smoke

Secondhand smoke, or passive smoking, is a significant risk factor. Prolonged exposure to smoke from others increases the likelihood of lung cancer in non-smokers by 20-30%.

2. Radon Exposure

Radon, a naturally occurring radioactive gas, is the second leading cause of lung cancer in the U.S. Radon seeps from soil into buildings through cracks in the foundation, often accumulating to dangerous levels in poorly ventilated homes.

3. Air Pollution

Outdoor air pollution from vehicles, factories, and burning fossil fuels is linked to lung cancer. Fine particulate matter (PM2.5) can penetrate deep into the lungs, causing long-term damage. Indoor air pollution, such as smoke from cooking or heating with unventilated wood or coal, also poses risks.

4. Occupational Hazards

Certain jobs expose individuals to carcinogens like asbestos, arsenic, diesel exhaust, and industrial chemicals. Prolonged exposure in industries like construction, mining, and manufacturing increases the risk of lung cancer.

5. Genetic Factors

Some people inherit genetic mutations that predispose them to lung cancer. Even without external risk factors, these individuals may develop the disease due to hereditary vulnerabilities.

6. Lung Scarring and Infections

Conditions like tuberculosis (TB) or chronic obstructive pulmonary disease (COPD) can lead to lung scarring, which increases susceptibility to lung cancer.

7. Lifestyle and Diet

A poor diet lacking fruits and vegetables may contribute to lung cancer risk. Antioxidants found in healthy foods help combat cellular damage that could lead to cancer.

Preventive Measures

Avoid Smoking and Secondhand Smoke: If you smoke, seek help to quit. Non-smokers should limit exposure to secondhand smoke.

Test for Radon: Check your home’s radon levels and install mitigation systems if necessary.

Minimize Air Pollution Exposure: Use air purifiers indoors and limit outdoor activities during high pollution days.

Protective Equipment at Work: Follow safety guidelines and use protective gear in hazardous occupations.

Adopt a Healthy Lifestyle: A balanced diet and regular exercise strengthen immunity and reduce cancer risks.

While smoking remains the leading cause of lung cancer, it’s crucial to recognize and address the other hidden risk factors that contribute to this disease. By spreading awareness, implementing preventive measures, and promoting early detection, we can better protect both smokers and non-smokers from lung cancer.

(This article is meant for informational purposes only and must not be considered a substitute for advice provided by  qualified medical professionals.)