Lung cancer has emerged as one of the leading causes of cancer-related mortality among women globally. In the United States, it surpassed breast cancer in 1987 as the primary cause of cancer deaths among females. Similarly, in India, lung cancer is increasingly being recognized as a major public health concern among women.
According to data from the National Cancer Registry Programme (NCRP) for the period 2012–2016, lung cancer ranks among the top five cancers affecting women in India, accounting for 6.2% of all female cancer cases. The highest age-adjusted incidence rates were reported in Aizawl District, Mizoram (27.9 per 100,000), followed by the state of Mizoram (18.0 per 100,000). Major metropolitan cities such as Bengaluru, Chennai, Delhi, and Mumbai have also witnessed a significant rise in lung cancer cases from 1982 to 2016.
Alarming Trends and Epidemiological Shifts
Dr. Vishnu Hari, Senior Consultant and Head of Medical Oncology, Haematology & Bone Marrow Transplant at Sarvodaya Hospital, Sector-8, Faridabad, highlights several critical trends. One of the most concerning is the rising incidence of lung cancer among Indian women, which is gradually nearing the rates observed in men. Approximately 32% of female lung cancer cases occur in the 55–64 age group. Adenocarcinoma is the predominant histological subtype in women, representing 53% of cases, compared to 34% in men.
Interestingly, a substantial proportion of female lung cancer patients in India are non-smokers. A study conducted in Kolkata found that over two-thirds of female patients with lung cancer had no history of smoking. This finding underscores that lung cancer is not exclusively a smoker’s disease and points to the need for greater clinical vigilance.
Challenges in Diagnosis and Delayed Detection
Lung cancer symptoms in women are often subtle and misdiagnosed, contributing to delayed treatment and poor prognosis. The underlying causes of missed diagnoses include a combination of biological differences, sociocultural factors, and systemic biases in healthcare. In India, nearly 50% of female lung cancer cases are diagnosed at an advanced stage, significantly reducing the chances of survival.
Common symptoms such as persistent cough, fatigue, shortness of breath, back pain, or hoarseness are frequently attributed to less serious conditions like asthma, allergies, menopause, or anxiety. Moreover, women often experience nonspecific symptoms, such as shoulder pain, which can be overlooked. These atypical presentations, combined with caregiving responsibilities and a tendency to prioritize family over personal health, further delay medical evaluation.
Non-Smoker Lung Cancer: Environmental and Genetic Factors
The increasing incidence of lung cancer among non-smoking women in India points to significant environmental and genetic risk factors. Exposure to air pollution, secondhand smoke, and indoor biomass fuel (commonly used for cooking in rural households) is re major contributor.
Biologically, lung cancer in non-smoking females often manifests as adenocarcinoma and is frequently associated with mutations in the EGFR (Epidermal Growth Factor Receptor) gene. These mutations render tumors more responsive to targeted therapies such as EGFR tyrosine kinase inhibitors (e.g., gefitinib or erlotinib), leading to improved survival outcomes compared to traditional chemotherapy. Conversely, lung cancers in smokers, typically squamous cell carcinoma or small cell lung cancer, are less likely to harbor such mutations and are generally treated with chemotherapy or immunotherapy, especially given the higher tumor mutational burden from tobacco exposure.
These biological distinctions highlight the importance of advanced molecular testing at the time of diagnosis to identify actionable mutations and guide personalized treatment strategies.
The Need for Increased Awareness and Early Detection
Given that nearly 75% of lung cancer cases in India are diagnosed at Stage 3 or 4, early detection remains a critical determinant of survival. Raising awareness among women and primary care providers about the potential for lung cancer in non-smokers is essential. Persistent or unexplained respiratory symptoms should prompt timely diagnostic imaging, including chest X-rays or CT scans.
Public health campaigns must stress that lung cancer can affect women irrespective of smoking status. Promoting annual health check-ups, detailed medical histories, and minimizing gender bias in clinical evaluations can contribute to earlier diagnoses and better outcomes.
Conclusion
Lung cancer in women is increasingly prevalent in India, with a projected 30,109 new cases anticipated by 2025. However, it continues to be underrecognized due to societal, diagnostic, and biological complexities. A gender-sensitive approach to awareness, diagnosis, and treatment is vital. Recognizing unique risk profiles, improving access to early screening, and incorporating molecular testing into routine diagnostics can significantly enhance survival outcomes for women affected by this disease.
