Article

Tumors of the Bronchus and Lung

Lung cancer is the most common cause of deaths from cancer worldwide, causing 1.4 million deaths every year. Lung cancer accounts for 18% of all cancer deaths. Lung cancer strikes about 12,50,000 people a year, of them 9 lac are male and the remaining are female. The overall prognosis in bronchial carcinoma is very poor. With around 70% of the patients dying within a year of diagnosis while less than 6% surviving 5 years after diagnosis. After 1950, death rate from lung cancer increased more than three times in comparison to previous death rates. Tobacco use is the most preventable cause. However, just as tobacco use and cancer rates are falling in some developed countries; both smoking and lung cancer are rising in Eastern Europe and in many developing countries. At present, female lung cancer deaths outnumber male in some countries. It is presumed that within next 10 years, death from lung cancer will further increase. Male-female ratio of lung cancer is 4: 1. It may be mentioned that more than 90% of all tumors of the lung remain in the bronchus, 90% of it are bronchial carcinoma.

Cigarette smoking is by far the most important cause of lung cancer. It is thought to be directly responsible for at least 90% of lung carcinoma, the risk being proportionate to the amount smoked and to the tar contents of cigarettes. The death rate from the disease in heavy smokers is 40 times more than in non-smokers. Risk falls slowly after smoking cessation but remain above non-smokers for many years. It is estimated that 1 in 2 smokers dies from a smoking related disease, about half in middle age. The effect of passive smoking is more difficult to quantify but is currently thought to be a factor in 5% of all lung cancer deaths. Although smoking is by far the most important cause of cancer, there are some other factors responsible for it. These are industrial and atmospheric pollution, smoke from transport, affect of different harmful chemicals in food, industrial materials such as asbestos, silica, beryllium, cadmium etc. Excessive intake of alcohol is sometimes responsible for cancer. Genetic factors and radiation is also the cause of cancer.

Cancer may affect any organ of human body like breast, kidney, uterus, ovary, testes, thyroid, sexual organs, bone, rectum, intestine, liver, brain, etc. Even blood may be affected with cancer.

The common cell types of Bronchial Carcinoma are as follows:
a. Squamous cell 35%
b. Adenocarcinoma 30%
c. Small cell 20%
d. Large cell 15%
Primary carcinoma of other organs, in particular, the Breast, Kidney, Uterus, Ovary, Testes and Thyroid may give rise to metastatic pulmonary deposits as may an osteogenic or other sarcoma. Tumors also represent a most common cause of obstruction to a major bronchus. It may involve the lung centrally, peripherally and diffusely.

General symptoms: Fever, Anorexia, Nausea, Weight loss, Lassitude and Tiredness are the general symptoms of lung cancer.

Local symptoms: Cough is the most common early symptoms; sputum is purulent, if there is secondary infection. A change in the character of the regular cough of a smoker, particularly if associated with other new respiratory symptoms is very important.

Haemoptysis: Recurrent scanty Haemoptysis or bloodstreaking sputum in smoker is highly suggestive.

Breathlessness: Due to large pleural effusion or Tumor occludes a large bronchus

Stridor: Tumor compresses the main bronchi

Symptoms due to metastasis:

  • Pleural pain,
  • Pain in the shoulder and arm
  • Homer’s Syndrome due to involvement of superiorcervical ganglion,
    • ptosis, miosis
    • anhydrosis, enophthalmus,
  • Lymphadenopathy of sup. Cervical lymph node
  • Hoarseness of voice-due to compression over left recurrent nerve
  • Superior venacaval obstruction
  • Dysphagia-due to esophageal involvement
  • Stridar-due to involvement of trachea
  • Focal neurological signs-due to intracranial metastasis
  • Jaundice-due to liver involvement
  • Bone pain -due to bone involvement

Non-metastatic Extra-pulmonary Manifestation:
a. Endocrine:

  • Inappropriate ADH secretion causing Hyponatremia
  • Ectopic ACTH secretion (Cushing’s Syndrome)
  • Hypercalcaemia
  • Carcinoid Syndrome
  • Gynaecomastia

B. Neurological:

  • Polyneuropathy
  • Myelopathy
  • Cerebellar degeneration
  • Myasthenia gravis (Eaton-Lambert Syndrome)

C. Others:

  • Digital Clubbing
  • Hypertrophic Pulmonary Osteoarthropathy
  • Nephrotic Syndrome
  • Polymyositis
  • Dermatomyositis
  • Eosinophilia

Signs:
A. Peripheral signs:

  • Anaemia
  • Weight loss
  • Clubbing
  • Lymphadenopathy
  • Horner’s Syndrome
  • Features of SVC obstruction

B. Lung signs: It depends on the characteristics of tumor.

  • Unilateral Hilar enlargement: Central Tumor-Hilar glandular enlargement, Peripheral tumor in apical segment of a lower lobe can look like an enlargement hilar Shadow on the straight X-ray.
  • Peripheral pulmonary opacity: Usually irregular but well circumscribed may have irregular cavitation within it.
  • Lung lobe or segmental collapse: Usually caused by Tumor within the bronchus causing occlusion.
  • Pleural effusion: Usually indicates Tumor invasion of pleural spaces.
  • Broadening of mediastinal invasion.
  • Enlarged cardiac shadow: Manfestation of mediastinal invasion.
  • Elevation of hemidiaphragm
  • Rib destruction: Direct invasion of the chest wall or blood born metastatic spread can cause osteolytic lesion of the ribs.

Investigations:
A lung Tumor patient when suspected, the following investigations may be done for confirmation: 
1. Blood: Hb%-reduced, ESR (raised markedly) 
2. X-ray (Chest): Solitary nodule, collapse, consolidation, hilar lymphadenopathy, mediastinum broadening, pleural effusion, rib destruction etc. 
3. Cytological examination for malignant cells: Sputum, bronchial washing and pleural fluid. 
4. Lymph node biopsy 
5. Bronchoscopy & pleural (Tumor) biopsy 
6. Transthoracic FNAC 
7. Others: CT scan of thorax, USG of liver, radionuclide, bone scanning, Barium swallow X-ray

Treatment of lung cancer:
A. Supportive measures:

  • Nutritional supplement.
  • Blood transfusion (for correction of anaemia)
  • Analgesic (for pain)

B. Therapeutic treatment:

  • Surgery
  • Radiotherapy
  • Chemotherapy
  • LASER therapy

C. Surgical treatment:

  • Stage I & II: Fit for surgical removal
    • Lobectomy: For localized Tumors
    • Pneumonectomy: For localized Tumors.
  • Stage III & IV
    • No surgery
    • Radiotherapy given

D. Radiotherapy

  • Curative therapy: usually for stage I & II.
  • Palliative therapy: usually for stage III & below
    • SVC syndrome
    • Skeletal metastatic deposits
    • Skeletal metastatic deposits

E. Chemotherapy:
Only used in:
1. Undifferentiated carcinoma
2. Small cell carcinoma.

Drugs used in chemotherapy are:
1. Cyclophosphamide (750 mg/m square in day 1),
2. Etoposide (120 mg/m square in day 1,2,3)
3. Adriamycin (60 mg/m square in day 1)

The above regimens are given every 3 weeks for 3-6 cycles. Nausea and Vomiting peak for 3 days after each cycle of chemotherapy.

F. LASER Therapy:
Used as palliative measure via fibroptic bronchoscope to destroy Tumor tissue. Best result achieved in Tumor of main bronchi.

The author is Chest & TB Specialist and Ex-Director of National.
Institute of Diseases of the Chest and Hospital, Mohakhali, Dhaka.

  Dhaka -

Monday 22 Jan 2018

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