Early detection key to check lung cancer

Each year, more people die of lung cancer than of colorectal, prostate and breast cancers combined. The main challenge lies in detecting it in the early stages, as even the best of treatment options cannot cure it in advanced stages.

As per a report released by the Indian Council of Medical Research (ICMR), lung cancer is turning into an epidemic in India at an alarming rate. A high-mortality cancer, it accounts for 14.5% of all cancers in men and 8.4% in women globally. It is a leading cause of cancer death in men worldwide at 22%, which means that one in five of all cancer deaths in men occurs due to lung cancer. Lung cancer accounts for 5.9% of all new cancer cases diagnosed in India (both sexes combined), while mortality is 8.82% of all cancers combined.

Lung cancer is broadly divided into small cell (SCLC) and non-small cell lung cancers (NSCLC), of which the latter is far more common. Among NSCLCs, squamous cell carcinoma (cells covering tissues and organs) has been the most common, but is now being overtaken, at least in the West, by adenocarcinoma. Rarer varieties like large cell carcinoma, carcinoid tumour and salivary gland tumours can also occur.

Early and potentially curable stages of cancer are typically without symptoms, picked up during routine health check-ups or during evaluation of unrelated illnesses. Symptoms of lung cancer could be due to the primary cancer itself (persistent cough, blood in sputum, breathlessness, chest pain, change in voice) or due to spread of the disease outside the lung (weight loss, fatigue, bone pains or fracture and persistent headache).

Initial diagnosis is often made by radiological imaging (chest X-ray, if the tumour is big enough, CT scan and MRI) and confirmed through a biopsy after which the extent of the disease is evaluated.

In early stages, potentially curative treatment is offered which usually involves surgery to remove the tumour and associated lymph nodes. More advanced cancers may require radiation or a combination of radiation and chemotherapy. In Stage IV disease, when the cancer has spread to distant areas of the body, palliative (non-curative) treatments are offered such as chemotherapy, immunologic and targeted therapies.

To quote a case in point: A 38-year-old active and fit software professional Naveen (name changed on request) had been smoking about 15 cigarettes a day since his college days. When he developed a persistent cough and fever, a chest X-ray revealed a lung abscess (collection of pus) in the lower part of his right lung. A bronchoscopy detected a tumour and the biopsy revealed cancer. Since the tumour was still in its early stages, the affected lobe of the lung and the surrounding lymph nodes were removed.

Two and a half years later, he is leading a normal life, has completely given up smoking and has become a strong advocate of anti-smoking campaigns. Unfortunately, Naveen’s happy ending is an exception rather than the norm in a cancer where survival rates are as low as 5%.

High mortality rate

More than 70,000 Indians are diagnosed with lung cancer every year. Almost 10% of all cancer-related deaths are due to lung cancer, and almost 7% of newly diagnosed cancers are lung cancers. Less than 5% of newly diagnosed patients with lung cancer survive beyond five years (as compared to 15% in the West), mainly because of the late stage at diagnosis. About 85-90% of lung cancer is caused by tobacco smoking and almost 20% of adults in India consume tobacco (GLOBOCAN data).

In Bengaluru alone, the population-based cancer registry shows an incidence rate of lung cancer of 7.3 per 1,00,000 population per year, as compared to rates of 14, 12 and 11.3 per 1,00,000 respectively in Delhi, Mumbai and Chennai (As per the National Centre for Disease informatics and Research data).

Unfortunately, the main challenge for doctors is that most patients come at an advanced stage when treatment options are non-curative and mainly directed towards prolonging life and reducing suffering. The peak period for lung cancer is the sixth decade (ages 50 to 59) but India is also witnessing patients of younger age compared to our Western counterparts.

The best precaution against this life-threatening disease is to never smoke and for smokers to quit at the earliest. Not getting exposed to second-hand smoke is also very important. A good healthy diet rich in fresh fruit and vegetables as well as being physically fit, all contribute to reducing the incidence of the dreaded cancer.

Other than individual effort, action at other levels including anti-smoking legislation, raising social awareness against smoking in public as well as educating people about the dangers of active and passive smoking is the need of the hour.

(The writer is senior consultant and Chief of Surgical Oncology, Vikram Hospital, Bengaluru)