Pulmonary Neoplasia Flashcards
What are types of lung neoplasms?
- Primary
* Metastatic - secondary tumours (very common)
What are the 2 types of primary lung neoplasm?
- Benign (rare)
* Malignant (very common)
How have lung cancer rates changed in males and females?
- Male incidence down 15%
* Female incidence up 13%
What is the mortality of lung cancer?
90% mortality after 1 year diagnosis
What carcinogens are present in tobacco smoke?
- polycyclic hydrocarbons
- aromatic amines
- phenols
- nickel
- cyanates
Why is there a significant link between smoking and lung cancer?
- 20% of smokers die of lung cancer
* Also suffer laryngeal, cervical, bladder, mouth, oesophageal and colon cancer
What are other risk factor for lung cancer?
- Asbestos
- nickel
- chromates
- radiation
- atmospheric pollution
- genetics
What are local effects of lung cancer?
- obstruction of airway (pneumonia)
- invasion of chest wall (pain)
- ulceration (haemoptysis)
Where can lung cancer metastasise?
- lymph nodes (mass in the neck or axilla)
- bones (pathological fracture)
- liver (jaundice, liver failure)
- brain
What are systemic effects of lung cancer?
- Weight loss
* ‘ectopic’ hormone production - PTH (squamous cancer), ACTH (small cell cancer)
Are lung tumours homogenous?
No, very heterogenous
What are 4 types of lung cancer associated with smoking?
- adenocarcinoma (35%)
- squamous carcinoma (30%)
- small cell carcinoma (25%)
- large cell carcinoma (10%)
How common is lung cancer?
Most common after skin cancer
What is the single commonest brain malignancy?
Metastases from lung cancer
What are ectopic hormones?
Hormones that are not native to the hormone in which they arise
What are examples of ectopic hormones produced by lung cancer?
- Parathyroid hormone (PTH) - squamous cancer
* Adrenocorticotropic hormone (ACTH) - small cell cancer
What are 2 categories of lung cancer tumours?
- Neuroendocrine tumours
* Bronchial gland tumours
What is the most common type of lung cancer?
Adenocarcima
What percentage of those diagnosed with adenocarcinoma are non-smokers?
Approximately 25%
In what ways can lung cancer be diagnosed histologically?
- Bronchoscopy and biopsy of the tumour if seen
- Biopsy or needle aspiration of metastases (especially mediastinal or supraclavicular lymph nodes)
- Endobronchial ultrasound guided specimens (EBUS)
What does the classification of lung cancer influence?
- Prognosis
- Treatment
Pathogenesis/biology
Epidemiology
What is the main feature of squamous cell carcinoma?
Keratin formation
What are features of adenocarcinoma?
- Gland formation
* Mucous production
What is the prognosis of small cell carcinoma and large cell carcinoma?
- Small cell worst - all dead in one year
* Large cell – worse than squamous or adenocarcinoma
List adenocarcinoma, squamous carcinoma, undifferentiated carcinoma and small cell carcinoma in order of severity
- Small cell carcinoma - lowest survival time
- Undifferentiated carcinoma
- Squamous carcinoma
- Adenocarcinoma - highest survival time
What is the most simple classification of lung cancer?
- Small cell lung cancer (SCLC)
or - Non-small cell lung cancer (NSCLC)
What is the treatment for lung cancer?
- Small cell known to be chemosensitive but with rapidly emerging resistance
- Surgery
- New “targeted” treatments based on pathologically identified abnormal DNA or other markers in tumour
What are new developments in chemotherapy for lung cancer?
Differing NSCLC regimens for squamous cell and adenocarcinoma (e.g. pemetrexed contraindicated in squamous carcinoma)
But there is often real difficulty in subtyping tumours on small biopsies
Immunohistochemistry can help
What are new developments in chemotherapy for lung cancer?
- Differing NSCLC regimens for squamous cell and adenocarcinoma (e.g. pemetrexed contraindicated in squamous carcinoma)
What can be used to overcome difficulties in sub typing tumours via biopsies?
Immunohistochemistry
What are examples of targets for immunohistorchemistry in lung cancer?
- Adenocarcinoma expresses TTF (thyroid transcription factor) 1
- SCC expresses nuclear antigen p63 and high molecular wt. cytokeratins
What are potential therapeutic targets for SCLC?
- Oncogenes - myc
* Tumour suppressor genes - p53, Rb, 3p
What are potential therapeutic targets for NSCLC?
- Oncogenes - myc, K-ras, her2
* Tumour suppressor genes - p53, 1q, 3p, 9p, 11p, Rb
What is the normal pathway of epithelium growth factor signalling in lung epithelium?
MAPK/ERK pathway
How can lung cancer affect the normal pathway of epithelium growth factor signalling in lung epithelium?
- EGFR over-expression
- RAS mutation
- BRAF mutation
What type of cancer does EGFR gene mutation/over-expression result in?
Adenocarcinoma (especially in non-smokers and Asian populations)
What are targeted treatments for the molecular pathology of lung cancer?
- Tumours caused by point mutations in EGFR gene respond to tyrosine kinase inhibitors (erlotinib)
- EML4-ALK fusion oncogene is also a target for specific drug treatment (crizotinib)
What is the significance of tumour cells expressing PD-L1?
- PD-L1 binds to the PD (programmed death) receptor on T lymphocytes inactivating the cytotoxic immune response
- Targeted therapy can inhibit this effect and enhance immune killing of tumour
What are the stages of progression to cancer in bronchial (large airway) tumours?
- Squamous metaplasia
- Dysplasia
- Carcinoma in situ
- Invasive malignancy
What are the stages of progression to cancer in peripheral adenocarcinomas of the lung tissue?
- Atypical adenomatous hyperplasia
- Spread of neoplastic cells along alveolar walls (bronchioloalveolar carcinoma)
- True invasive adenocarcinoma
What are the prognostic indicators in lung cancer?
- Tumour stage
* Tumour histological subtype
How are tumours staged?
TNM
- T - size of primary tumour
- N - lymph nodes affected
- M - metastasis (spread of secondary tumours)
What is a carcinoid?
Neuroendocrine neoplasms of low grade malignancy in the lungs
What are examples of bronchial gland neoplasms found in the lungs?
- Adenoid cystic carcinoma
- Mucoepidermoid carcinoma
(Very rare, tumours more often seen in salivary glands)
Are pleural neoplasms often benign?
No, benign tumours are very rare
What is the primary malignant pleural neoplasm?
Mesothelioma
