Lung Cancer: Screening, Staging, and Treatment Options
05 April 2019
Lung cancer is the leading cause of cancer-related deaths worldwide, with approximately 1.5 million deaths each year. In Malaysia, lung cancer is the most common cancer to affect men across all ethnic racial groups and accounts for over 20% of all cancer-related deaths.
Types of Lung Cancer
Non-Small Cell Lung Cancer (NSCLC)
NSCLC accounts for about 80% of cases of lung cancer. If diagnosed early, it has a very good prognosis. Early-stage NSCLC is often best treated with a surgical operation to remove the portion of the lung affected by the tumor, and the patient may additionally require chemoradiotherapy either before or after the operation to eliminate microscopic disease, reduce recurrence, and improve survival.
Small Cell Lung Cancer (SCLC)
SCLC accounts for about 20% of cases of lung cancer. In contrast to NSCLC, it usually carries a poorer prognosis and is best treated with chemotherapy.
Stages of NSCLC
NSCLC has four stages, namely stages I, II, III, and IV, based on the international TNM classification. The stage refers to the extent of spread and will determine both treatment offered and prognosis.
Stage I and II
Early stage NSCLC is often best treated with a surgical operation (lung resection) to remove that portion of the lung affected by the tumour (eg. wedge resection, lobectomy or pneumonectomy). The patient may additionally require chemoradiotherapy either before or after the operation to eliminate microscopic disease, reduce recurrence and thus improve survival. The goal of therapy in early stage NSCLC is curative treatment.
Stage III and IV
More advanced NSCLC (stages III and IV) may be amenable to surgical resection in selected cases (if the tumour is still localised to the lung) but often treatment is palliative chemoradiotherapy to improve quality of life only, without any survival benefit, particularly where the cancer has spread elsewhere outside the lungs (metastasis) via the bloodstream or lymph glands.
How Lung Cancer is Diagnosed?
Common symptoms of lung cancer include a persistent cough, coughing up blood, chest wall pain, unexplained weight loss or breathlessness, or recurrent chest infections. Unfortunately, many patients may not have any symptoms whatsoever until the tumor is at an advanced stage.
To accurately diagnose and stage the disease, several routine investigations are required, including chest x-rays, CT scans, PET scans, bronchoscopy, and pulmonary function tests.
A sample of tissue from the affected lung or associated lymph nodes or accompanying fluid is essential to confirm the histological diagnosis.
Lung Cancer Treatment Options
The diagnosis, staging, and subsequent treatment of any lung cancer patient may involve several medical specialists, including a chest physician, radiologist, pathologist, thoracic surgeon, and oncologist, in addition to allied healthcare professionals such as physiotherapists, dieticians, and palliative care nurses.
Early-stage NSCLC is often best treated with a surgical operation to remove the portion of the lung affected by the tumor, and the patient may additionally require chemoradiotherapy either before or after the operation to eliminate microscopic disease, reduce recurrence, and improve survival.
More advanced NSCLC may be amenable to surgical resection in selected cases but often treatment is palliative chemoradiotherapy to improve quality of life only, without any survival benefit, particularly where the cancer has spread elsewhere outside the lungs.
Screening for Lung Cancer
Screening for NSCLC with low-dose CT scans is recommended for high-risk individuals, including adult males with a long history of smoking, those with a family history of cancer, previous lung infection with tuberculosis, or exposure to environmental chemicals/vapors.
However, screening is not without limitations, and a false positive result may cause unnecessary anxiety or lead to unnecessary invasive investigations.
