[Bronchial carcinoma--an overview]

The incidence of lung cancer has exploded in this century. The disease is most commonly diagnosed in the 65-75 year age group but can occur as young as 30 years. Cigarette smoking is usually related to lung cancer in men and the risk of developing lung cancer increases with duration of smoking and the number of cigarettes smoked per day. The risk of developing lung cancer decreased to almost that of non smokers after 10-15 years of non smoking. People exposed to asbestos have an 80 fold increase in lung cancer if they smoke. Some increased risk is associated with exposure to radioactive materials--(uranium when mined underground), arsenic and chromium. Lung cancer is more common in city than in rural dwellers. Cell Types: Squamous 34%, Large Cell 28%, Adenocarcinoma and Bronchoalveolar 20%, Small Cell 17%, Mixed 1%.

Patients with lung cancer present with several symptoms, signs, and laboratory findings, depending upon the location, growth characteristics, and metabolic activity of the tumour. Asymptomatic: usually patients with solitary pulmonary nodules. Non-specific systemic symptoms: fatigue, weight loss and loss of appetite. Respiratory Symptoms: Haemoptysis, symptoms (and signs) of intrathoracic spread of tumour (hoarseness, pleuritis or pleural effusion, paralysed diaphragm, dysphagia, superior vena cava obstruction, Pancoast s syndrome. Symptoms from extrathoracic metastases: (mediastinal supraclavicular and neck), liver, brain, adrenals, bone and contralateral lung, in approximately that order. Systemic syndromes unassociated with metastatic spread of the primary tumour, often seen with the undifferentiated cell-types: Endocrinopathies (1. hypercalcemia, 2. Cushing s syndrome, 3. inappropriate secretion of antidiuretic hormone (SIADH), 4. gynecomastia, 5. carcinoid syndrome (rare); Neuromuscular disorders (1. myasthenic (Eaton-Lambert) syndrome, 2. peripheral neuropathy, 3. cerebellar degeneration); Connective-tissue syndromes (1. clubbing of fingers/toes (common), 2. hypertrophic pulmonary osteoarthropathy (rare), 3. dermatomyositis, 4. acanthosis nigricans, 5. non specific arthralgia). Diagnosis-The three requirements for diagnosis of lung cancer are: locating the tumour precisely, determining its specific histological cell type, assessing its extent (staging). The next diagnostic procedures are useful: sputum cytology, Pleural aspiration and biopsy, fibre optic bronchoscopy, needle aspiration biopsy. Surgery is the treatment of choice in NSCLC. Chemotherapy: it is the treatment of choice in those patients with small cell carcinoma with limited disease. The combination of chemotherapy with concurrent radiotherapy is now used. Prognosis for patients with lung cancer depends upon cell type, tumour size, location, spread, coexisting disease, and the patient s age. Numerous regimes of palliative radiotherapy and chemotherapy have been investigated as alternatives or adjuncts to surgery; results are often encouraging in the short term, poor in the long term. A great deal of clinical research continues in this area.