CLINICAL FEATURES & MANAGEMENT OF LUNG CANCER - 18-08-03 (pp 357-363, 18th Davidsons)

Aetiology: smoking. Associations: berrylium, cadmium, chromium, asbestos. 
Epidemiology: Most common malignancy in western nations. Incidence expected to double in future. 

Pathology: Bronchus is affected most. Types: Small Cell, NSLC (i.e.: squamous, adenocarcinoma, large cell), Carcinoids. For more information, refer to Path notes.

Clinical features: 
Local: 1) cough / sputum (2nd pneumonia), 2) haemoptysis, 3) SOB (lobar collapse 2nd to obstruction)

Chest wall: 1) Stridor (compression of trachea from 2nd mets in paratracheal nodes), 2) chest pain (involvement of intercostal nerves)

Metastatic: LOW & LOA - cardinal signs of metastasis. 1) Horner's syndrome (sympathetic chain), 2) Pancoast's syndrome (shoulder + inner arm pain), 3) Dysphagia (oesophageal obs), 4) Haemtogenous spread to brain (seizures), liver (jaundice), bone (bone pain), skin (nodules). 

Non-metastatic (Paraneoplastic syndromes): 1) hypercalcaemia (polyuria, nocturia, constipation, fatigue, coma), 2) ADH (hyponatraemia) / ACTH syndromes (cortisol problems).

Clinical signs (Talley & O Connor - Resp Chapter): 
There may be physical signs of lobar collapse, wheezes (partial obstructing tumour), signs of pleural effusion, pneumonia, bilateral engorgement of jugular veins (superior vena cava syndrome). 

HPOA (tender wrists + clubbing --> periositis of long bone followed by subperiosteal new bone). 

Investigations:
The aims of the investigations are: 1) confirm clinical Dx, 2) Stage, 3) Grade

Radiology (CXR): There are a wide range of radiological findings in Lung cancer. Read Information box on pp: 361 (18th Ed Davidsons). CT scans can provide information about the extent of spread. 

Bronchoscopy: This is very useful because it can provide with tissue samples for histological investigation. 

Sputum cytology: This is very diagnostic and useful in patients who are not fit for bronchoscopy. You will see malignant cells on cytology.

Needle aspiration: This is useful if patient has metastatic lymphadenopathy, skin nodules, liver or bone marrow mets. 

Generally, localised tumours have good prognosis compared to metastatic tumours. Staging of the tumour is most important. 

MANAGEMENT OF LUNG CANCER
Surgical resection is the appropriate cure, one which is not possible in 85% of cases (palliative therapy best option). 

Surgical treatment: Cure established for localised tumours. Surgery is not advised for metastatic disease. 5 year survival rates are about 55% --> 75% (Stage I & II cancer). 

Radiotherapy: Best for reducing the distressing effect of symptoms. CHART (continous hyperfractionated accelerated radiotherapy) is similar to conventional radiotherapy in terms of total dose, but it is given more frequently and is preferred. 

Chemotherapy: This can be combined with radiotherapy (good effect in small-cell carcinoma) --> IV cyclophosphamine, doxorubicin, vincristine. Given every 3 weeks for 3-6 cycles. S/E: nausea + vomitting --> which can be treated with 5Ht3 receptor antagonists. 

Laser thearpy: This is useful if the carcinoma is obstruting the bronchi producing lung collapse. The laser is used to kill off the cancer, therefore re-aerating the collapsed lung. 

General aspects: pain relief, counselling, hypercalcaemia (re-hydration, biphosphonates, maintain urine output). 

Malignant pleural effusions: These are managed by draining the pleural effusion and then to prevent recurrence, and give substance that causes intense inflammatory reaction --> adhesion of the pleura occur --> pleurodesis.