cancer

Chapter 26 Lung cancer




Questions


image Why does lung cancer occur?

image What are its clinical and pathological features?

image How can we treat lung cancer?

Lung cancer is the most common cause of cancer deaths among men in Western populations and may soon overtake breast cancer as the most common cause of cancer deaths among women.




Aetiological factors


Cigarette smoking is overwhelmingly the most common aetiological factor for primary lung cancer, which is exceedingly rare among non-smokers, in whom it is often linked to passive smoking. Primary lung cancer most commonly develops during the sixth to eighth decades but may also occur in younger individuals, especially those who are heavy cigarette smokers. Asbestos exposure is a potent risk factor for lung carcinoma, with cancer in affected patients often developing many years or even decades after asbestos exposure.



Clinical presentation


Primary lung cancer may present clinically with intractable cough, breathlessness or haemoptysis (coughing up blood). However, presentation owing to metastatic disease (e.g. neurological symptoms, jaundice) or the general symptoms of advanced malignancy (e.g. anorexia, severe weight loss) is common. Clinical examination may reveal cachexia or an enlarged liver while a chest X-ray usually reveals the primary tumour as a lung mass. The diagnosis may be confirmed using cytology (e.g. identification of malignant cells within sputum) or histopathology (e.g. needle core biopsy of the lung lesion).



Pathological features


Primary lung cancers are almost always carcinomas, although other tumours such as malignant lymphomas may exceptionally originate within the lung. Lung carcinomas are often macroscopically obvious tumours several centimetres in size, although sometimes primary lung carcinomas a few millimetres across may give rise to widely disseminated malignancy. The most common histological types of lung carcinoma are small cell and non-small cell types, with the latter subdivided into squamous cell carcinoma, adenocarcinoma and undifferentiated carcinoma. Mixtures between all histological types is not uncommonly seen. The tumours may invade local structures, metastasize via lymphatic channels to regional or distant lymph nodes and via the blood to distant sites (Fig. 3.26.1).


image

Fig. 3.26.1 The progression of lung cancer from a primary tumour.

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Jul 3, 2016 | Posted by in MUSCULOSKELETAL MEDICINE | Comments Off on cancer

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