Pathology of pulmonary neoplasia Flashcards
Aetiology of lung cancer
1-Tobacco- 85% of cases 2-Environmental radon 3-Air pollution 4-Other occupation exposure 5-Pulmonary fibrosis
Smoking and increased chances of lung cancer
1-10% of smokers develop lung cancer
2- men 22 times more likely to develop cancer. Women 12 but women more susceptible
3-Risk is related to inhalation and pack years
4-Passive smoking increases chances by 50-100%
How does it work?
-epithelial effects
-multi-hit theory
-activation of pro-carcinogens- also aided by inheritance of polymorphisms
Pathways to carcinogenesis in the lungs
Central:
-Bronchoalveolar epithelial stem cells transform
-Squamous cell carcinoma
-Almost always related to smokers
Peripheral:
-Bronchoalveolar epithelial stem cells transform
-adenocarcinoma
-not as related to smokers
-atypical adenomatous hyperplasia-adenocarcinoma in situ- invasive adenocarcinoma
Oncogene mutations
1- KRAS-35%
2-EGFR-15%
3-BRAF,HER2- 2%
4-ALK-2%- most related to smoking
Approved treatments
4- associated with peripheral
- EGFR mutation
- BRAF mutation
- ROS1 rearrangement
- ALK rearrangement
Local effects of lung cancer
1- bronchoconstriction 2-Invasion: -chest -mediastinum -nerves: phrenic-diaphragmatic paralysis brachial plexus- T1 pancost damage cervical sympathetic- horder's syndrome L-recurrent laryngeal-bovine cough 3-Pleural inflammation/ malignancy 4-lymph node metastases
Distant effects
-Metastasises to the brain, blood, liver, adrenal gland
-secondary local effects to neural and vascular
-non- metastatic paraneoplastic syndromes to:
cardiovascular,cervical, cutaneous, endocrine, neural, renal
Investigations
Chest radiograph Sputum cytology- RARE bronchoscopy trans- thoracic fine needle aspiration trans-thoracic core biopsy pleural effusion
Prognosis
when operable:
-stage 1 - 60%
-stage 2- 35%
5 year life survival
