Cancer of the lung.

 

Introduction

Cancer of the trachea, bronchus, lung and pleura account for 25% of all cancers.

Second most common tumour in men and women.

Bronchogenic malignancy usually arises in the epithelium that lines the bronchus.

First statistical correlation to indicate aetiology

 

Aetiology

Smoking is the principle aetiological factor - 80% of cases smoking related

20 + a day increases risk by 40 times - In ex-smokers the risk reduces over 20 years to near normal.

Passive smokers also have an increased incidence.

No identified familiar syndromes, due to overwhelming environmental aetiological factors

Consistent acquired genetic changes - oncosupressor gene deletion on 13q14 also two possible loci in 3p and 11p

Asbestos - potentiating with tobacco smoke, (a synergistic effect).

Good correlation between asbestos and mesothelioma, (a tumour of the pleura)

Radiation

Town people have a higher incidence than country dwellers.

Definite carcinogens identified in petrol and diesel fumes

Radon, 222Rn, from soil and rocks - ground floor houses with restricted flow of air

The radon correlation is good after accounting for smoking, the effect is cumulative.

Pulmonary scaring

 

Pathological features

A tumour mass usually surrounds a main bronchus

Bronchial mucosa ulcerated or roughened and nodular

Evidence of lymphatic spread

Carcinoma narrows lumen of effected bronchus - obstruction - stasis - infection - bronchopneumonia - abscess formation.

Direct invasion of the pericardial sac and heart.

Compression of vena cava causing cyanosis

Metasteses - lymph nodes in neck, groin, axilla, adrenals, brain, liver, bones, thoracic, vertebrae.

Paraneoplasic syndromes include, neuropathy, myopathy, Cushings, hypercalcaemia and gnnaecomastia.

Metastatic routs from lung cancers;

 

Histology and cytology

Small cell, (oat cell), smoking related, neurosecretory cells paraneoplastic effects

Non small cell, squamous, adenocarcinoma, large cell

Metaplasia columnar squamous

 

Complications

Pain, locally and from spread

Necrosis and cavitation

Pleural effusion, (may be haemorrhagic).

Vascular involvement, haemorrhage or obstruction, (eg. involving the superior vena cava).

Dyspnoea Cough

Collapse of a segment due to blockage Immunosuppression

Infection Lung abscess

PNS involvement Metastases

Malnutrition due to hypermetabolic state or side effects of treatments

Anxiety, depression Grieving and death

 

 

Clinical features.

Clinical feature % of presenting feature

Cough 42%

Cough and pain 15%

Blood in sputum (haemoptysis) 7%

Pain from pleural involvement 22%

Subsequent chest infection 5%

Malaise, (brain, bone) 5%

Weight loss 5%

Shortness of breath 5%

Hoarseness 5%

Distant spread 5%

No symptoms 5%

Blockage of a large bronchi

Suspect in pneumonia which does not respond to antibacterials

Enlarged subclavian lymph nodes

Change in volume or odour of sputum

Finger clubbing

Paraneoplastic effects, increased ADH and ACTH

 

Investigations

clinical picture, X ray, cytology, biopsy, radioisotope scan, CT, or MRI,

biochemistry and haemotology. fibreoptic bronchoscopy transthoracic fine-needle aspiration

 

Treatments,

Surgery Radiation therapy for cure Symptomatic radiation therapy, eg. for bone pain, Chemotherapy Laser therapy Terminal care Possible immunotherapy

 

Lung secondaries

From primary neoplasms in the breast, abdominal organs, renal cells, testicles and lymphomas

More common than lung primaries

 

Management considerations

Curative measures

Pre and post op Support through therapies

 

Relief of respiratory symptoms

Prepare pt for therapies Elevate head of the bed to drain upper body

Teach breathing exercises Treat cough eg. expectorants and antibacterials

Support during pleural tap.

 

Improvement of nutritional status

Adequate balanced diet Small regular meals

Protein, vitamin and energy supplements Food from home

Enteral support Observe for wasting and oedema

 

Prevent complications

Observations for upper body venous congestion Pleural effusions

Infections ADLs to promote comfort

 

Pain

 

Affect

Encourage expression of concerns Communication skills listening

Promote independence and normal activity Get help, councillor, chaplain etc.

Family and social care Use voluntary help

Hospice and McMillan advice