Lung cancer

Bronchogenic carcinoma

It is the most common primary lung tumor (95%). It is 3^rd most common cause of death in UK (after heart diseases). Every year 32,000 people die of bronchogenic carcinoma. Smoking is an important risk factor (passive smoking as well).

Classification of lung tumors:

Benign tumor:

         i.            Pulmonary hamartoma

       ii.            Bronchial carcinoid

      iii.            Lipoma (rare)

     iv.            Tracheal lieomyohemangioma

       v.            Cylindroma

Malignant tumor:

         i.            Tracheal tumor

       ii.            Bronchogenic carcinoma

Classification of bronchogenic carcinoma:

a.       Small cell carcinoma

b.      Non small cell carcinoma

Classification of non small cell carcinoma:

a.       Squamous cell carcinoma (40%) – central in origin

b.      Large cell carcinoma

c.       Adenocarcinoma

d.      Alveolar carcinoma

Clinical Features of bronchogenic carcinoma:

The most common symptoms are:

·         Cough (41%)

·         Anorexia

·         Chest pain

·         Weight loss

·         Heamoptysis

·         Fever

Direct spread of tumor:

It can spread to pleura, ribs, the apical tumor can involve the lower part of bronchial plexus (C8, T1, T2) will lead to pain in shoulder and inner part of the arm. It can involve the sympathetic ganglia (result in Pancoast Tumor) ptosis, meiosis, anhydrosis, and anopthalmosis.it can involve esophagus and result in dysphagia. Heart can be involved (pericardial effusion, arrhythmias). Superior vena caval obstruction, vocal cord paralysis

Non metastatic features:

Small cell carcinoma:

Secretes ACTH, ADH, lumbar Eaton mysthenic syndrome

Non small carcinoma:

Secretes PrTH/clubbing (squamous), hypertrophic pulmonary osteodystrophy.

Other features:

o   Hyperglycemia

o   Gynecomastia

o   Weight loss

o   Disseminated intravascular coagulation

o   Hemolytic anemia

o   Myopathies

o   Neuropathies

Investigations:

CXR:

When they are more than 1cm then it can be detected on chest X-ray.

CT-chest/MRI:

They can detect even small tumor.

Fiber optic bronchoscopy:

When the tumor is near to bronchus distant tumor cannot be biopsied.

Trans-thoracic biopsy:

When the tumor is peripheral (Pneumothorax is common complication)

FBC, Serum Calcium, Glucose are supportive investigations.

Management:

Non small cell carcinoma:

Surgery is the only curative option for this tumor. Only 20-25% of t he patient will be suitable for surgery and among them only 25-30% will live for 5years.

Small cell carcinoma:

By the time small cell carcinoma is diagnosed it is widely spread so surgery is not a good option.

Contra-indications to surgery:

        I.            Malignant pleural effusion

      II.            Vocal paralysis

    III.            Forced respiratory volume in one second<1 data-blogger-escaped-.5litres=".5litres" data-blogger-escaped-font="font">

    IV.            Superior vena caval obstruction

Chemotherapy:

o   Gemcitabine

o   Mistomycin

o   Vendisine

o   Cisplastin

o   Etopside

These are various chemotherapeutic drugs. They hardly prolong life more than six months.

Radiotherapy:

If the tumor is localized it can help. But radiation pneumonitis (inflammation of alveoli) and fibrosis is the adverse effect.