Lung Cancer Flashcards
Describe the incidence of lung cancer.
Second most common cancer in both men and women
Incidence is falling in men and rising in women
Most people are old when they get it (low survival rate)
In which UK country is lung cancer the most prevalent cancer?
Scotland - reflects high smoking prevalence
Greater Glasgow and Clyde have higher levels of lung cancer than the Scottish average
What are the death rates for lung cancer?
Most common cause of death from malignant disease
5% of annual deaths
25% of male cancer deaths
18% of female cancer deaths
What is the survival rates for lung cancer?
- 4% 1 year survival
7. 8% 5 year survival
Describe aetiology of lung cancer.
Smoking - the single greatest cause of preventable illness and early death
90% of lung cancer is attributable to smoking
Stopping smoking reduces risk but depends on number of years smoking and takes time
Which types of lung cancer is smoking most closely related to?
Squamous carcinoma
Small cell carcinoma
What are the risk factors for lung cancer?
Environmental pollution Ionising radiation (radon, uranium) Asbestos Other - fibrosing conditions of lung - HPV - hereditary Smoking
Describe the pathogenesis of lung cancer.
Chronic irritation/stimulation of cells by carcinogens
Increased cell turnover - increased accumulation of genetic abnormalities
Progressive accumulation of genetic abnormalities in molecules involved in the cell cycle, signalling and angiogenesis pathways
- e.g ras or p53
Little known about rate of progression/regression
Phenotype changes potentially reversible (but genotypic alterations persist)
Describe the histological changes from normal lung tissue to lung cancer?
Normal Hyperplasia Metaplasia Dysplasia Carcinoma in situ Clinical cancer
What are the 4 major histological types of lung cancer?
Small cell carcinoma Non-small cell carcinoma - squamous - adenocarcinoma - large cell
What other histological types of lung cancer are there apart from the 4 main types?
Tumours of the neuroendocrine cells - carcinoid Tumours of the pleura - mesothelioma Tumours of the lymphatic system - lymphoma Miscellanoeous - chondroid hamartoma
Why have rates of adenocarcinomas risen, while squamous carcinomas have fallen?
This is because filter tips, lower tar and nicotine mean that smoking associated lung cancers (squamous) are decreasing.
For this same reason people are inhaling the smoke deeper into the lungs, exposing the peripheral areas -> adenocarcinoma rise
Where do adenocarcinomas, squamous and small cell carcinomas arise?
Adenocarcinoma - peripheral
Squamous and small cell carcinomas - central tumours arise in the hilus of the lung
Why is the separation of small cell carcinoma from non-small cell carcinomas important?
Treatment purposes
- small cell requires chemotherapy as the first line of treatment
- non-small cell can be operated on first (if the patient is amenable to surgery), and may require no chemotheapy
What do small cell carcinomas looks like in the lung?
Black, discoloured lymph nodes embedded in a large tumour
Describe small cell carcinoma.
Most aggressive form of lung cancer
Metastasises early and widely (very advanced when found)
Good response to chemotherapy, but often relapses