Lung cancer Flashcards
What is the 5 year survival rate for lung cancer?
The second worst of all cancers, first in pancreatic. This is mainly due to most patients being unfit for treatment.
Name the 2 main causes of lung cancer.
Smoking (80ish%) and asbestos exposure (4% mesothelioma - cancer of the pleura). Other causes (6%) include: environmental radon, occupational exposure (excluding asbestos), air pollution and pulmonary fibrosis.
What % of smokers get lung cancer?
10% - more males than females. Over 50% of patients with lung cancer are ex-smokers.
What is the risk of passive smoking?
Increases risk 50-100% in a non-smoker, but this is risk from a very low level.
What are the 2 main pathways of carcinogenesis in the lungs?
Adenocarcinoma and squamous cell carcinoma.
Describe adenocarcinoma.
Cancer of the lung periphery. Bronchioalveolar stem cells become transformed. Associated with newer cigarette formulations and non-smokers. AAH (atypical adenomatous hyperplasia) –> adenocarcinoma in situ –> invasive adenocarcinoma.
Describe squamous cell carcinoma.
Occurs in the central lung airways. Bronchial epithelial stem cells transform. This is the classical pathway and is VERY associated with smoking. Squamous dysplasia –> CIS (carcinoma in situ) –> invasive bronchogenic carcinoma.
Why is it important to differentiate between adenocarcinoma and squamous cell carcinoma?
They have different therapeutic implications.
Define oncogene addiction.
Oncogenes that drive growth of the cancer due to mutation. Most lung cancers are not caused by these.
Give examples of oncogenes found in lung cancer.
KRAS (smoking induced, 35% lung cancers), EGFR (15% lung cancers) –> both good targets for drug therapy. BRAF, HER2 and ALK rearrangements –> 2% prevalence each, not related to tobacco carcinogenesis.
What are the different types of tumours of the lung?
Benign causes (organising pneumonia), carcinoid tumours (low grade malignancy), bronchial gland tumours (very rare), lymphoma and sarcoma. Mets in the lung are common.
What are the 4 main types of carcinoma?
Squamous cell, adenocarcinoma (most), small cell (oat cell) and large cell.
What are the 2 histological types of carcinoma?
NSCLC’s (non-small cell 85%) and SCLC (small cell 15%).
Can lung cancers be surgically resected?
Only 10% can, but resection cures 50% on these. Generally, symptomatic lung cancer is fatal.
Describe local effects of lung cancer.
1) Bronchial obstruction (endogenous lipid pneumonia, abscess, bronchiectasis, haemoptysis), 2) Pleural (inflammatory), 3) Direct invasion (chest wall, nerves: phrenic - diaphragmatic paralysis, L recurrent laryngeal - hoarse, bovine cough as this supplies the larynx, brachial plexus - pancoast T1 damage, cervical sympathetic - Horner’s syndrome, mediastinum - SVC), 4) Lymph node mets (lymphangitis carcinomatosa - tumour spreading throughout the lymphatics of the lung)
Describe distant effects of lung cancer.
Distant mets (liver, adrenals, bone skin), neural effects, vascular effects. Paroneoplastic effects: clubbing, endocrine disorders, neurological, cutaneous (dermatomyositis), CV, renal.
Which investigations are used in lung cancer?
CXR, bronchoscopy, trans-thoracic fine needle aspiration or core biopsy, pleural effusion and advanced imaging techniques (CT, MRI, PET).
Name the prognostic factors for lung cancer.
Stage, classification, gene expression, growth rate, DNA aneuploidy, immune cell infiltration. Prognostic markers may be used to select patients for adjuvant therapy.
What is the prognosis for lung cancer?
Less than 9-9% 5YS in Scotland. If cancer is operable at stage 1, 60% 5YS. If cancer is operable at stage 2, 35% 5YS. If cancer is inoperable, treatment is always palliative.
Describe the different prognoses with different lung cancer types.
Pure bronchioalveolar carcinoma - 100% 5Ys. NSCLC - between 10 and 25%. SCLC - worst prognosis, 4% 5YS, responds to chemo but always comes back.
What are the predictive biomarkers for adenocarcinoma?
KRAS, EGFR, ALK rearrangements, BRAF and HER2 (drugs against ALK and EGFR approved in Scotland).
What are the predictive biomarkers for squamous cell carcinoma?
FRFR1 copy number, DDR1 and FGFR2 (no good drugs - use cytotoxic chemo).