Pathology of lung cancer Flashcards
what is the most common cause of cancer-related death?
lung cancer
what is the eading cause of lung cancer?
tobacco
what is the second most common cause of lung cancer?
asbestos
what are some other causes of cancer apart from tobacco and asbestos?
- Environmental radon
- Other occupational eg. exposure, chromates, hydrocarbons, nickel
- Air pollution and Urban environment
- Other radiation
- Pulmonary fibrosis
- (passive smoking)
what are the two important groups of compounds in cigarettes that are thought to cause lung cancer?
- ploycyclic aromatic hydrocarbons
- N-nitrosamine
what type of lung cancer are the N-nitrosamines thought to cause?
adenocarcinomas in the periphery of the lungs
what type of lung cancer are the poly cyclic hydrocarbons thought to cause?
squamous cell carcinoma
what is the multi-hit theory of carcinogenesis in lung cancer?
about 3-6 “hits” are required before a cancer forms. these mutations to important genes must be in the correct order too
how may genetics affect the likelyhood of cancer forming?
- people may have polymorphisms that allow them to metabolise pro-carcinogens
- or may be more easily addicted to nicotine
what sort of cells are the target for carcinogens?
stem cells
which type of lung cancer is usually found in non-smokers?
peripheral lung adenocarcinoma
what is the most common driver mutation in lung cancer?
KRAS
give an example of a driver mutation which is smoking induced?
KRAS
which driver mutations are not smoking induced?
EGFR
BRAF
HER2
ALK rearrangements
what is an addictive oncogene?
an oncogene that when inactivated will stop the growth of the cancer
what is important about addictive oncogenes in terms of treatment?
may allow molecular target therapy to inactivate this gene and stop the cancer from spreading
give an example of a cause of a benign mass lesion in the lung?
pneumonia
give some examples of some tumours in the lung which arent lung cancer
- carcinoid tumour
- tumour of bronchial glands
- lymphoma
- sarcoma
- metastases
why are metastases so common in the lung?
all the blood in the body passes through them so a cancer can easily metastasise through the blood
what are the 4 main types of lung cancer?
squamous cell
adenocarcinoma
small cell carcinoma
large cell carcinoma
historically what types of lung cancer were grouped together as non-small cell carcinomas
any cancers that are not small cell carcinoma.
- adenocarcinoma
- squamous cell carcinoma
- large cell carcinoma
- others
by the time that lung cancer becomes symptomatic is it possible to be treated completely?
no, symptomatic lung cancer is usually fatal
what are the local effects of lung cancer in terms of bronchial obstruction?
- collapse
- endogenous lipoid pneumonia
- infection/abscess
- bronchiectasis
what is endogenous lipoid pneumonia?
cancer stops muco-ciliary escalator and mucous and macrophages build up below the cancer
what are the local effects of lung cancer in terms of pleura?
- inflammation of the pleura (pleurisy)
- malignant spread to the pleura
what are the local effects of lung cancer in terms of direct invasion?
- invasion of the chest wall
- invasion of the mediastinum (superior vena cava, pericardium
- invasion of nerves eg. phrenic, left recurrent plexus, brachial plexus, cervical sympathetic
if lung cancer spreads to the phrenic nerve what happens?
diaphragmatic paralysis
if lung cancer spreads to the left recurrent laryngeal nerve what happens?
hoarse, bovine cough (not sudden exhalation)
if lung cancer spreads to the brachial plexus what happens?
Pancoast T1 damage,
pain and weakness in the muscles of the arm and hand
if lung cancer spreads to the cervical sympathetic nerve what happens?
Horner’s syndrome.
constriction of one eye, loss of sweating on one side of the face, dropping of one eyelid
what are the effects of a lung cancer on lymph nodes?
- mass effect, many lymph nodes cancerous
- lymphangitis carcinomatosa- interstitial cancer of lymph drainage of lungs, it blocks this drainage blocks it.
what are the distant effects of lung cancer?
distant metastases in liver, adrenals, bone, brain, skin.
secomdary to local effects: neural or vascular.
non-metastatic effects- eg. hormone production, fnger clubbing and hypertrophic pulmonary osteoarthropathy- inflammation of periosteum
what are some investigations carried out to diagnose lung cancer?
- chest x-ray
- sputum cytology (examining sputum for cells) (rarely used)
- bronchoscopy (bronchial biopsy, brushings and washings and endobronchial US-guided aspiration)
- trans-thoracic fine needle aspiration
- trans-thoracic core biopsy
- pleural effusion
- advanced imaging techniques (CT, MRI, PET)
what determines the prognosis of Lung cancer?
- stage of disease
- classification: type of disease
- markers, oncogenes, gene expression profiles.
what is the five year survival rate of lung cancer patients?
<9.8% in scotland
what is the 5 year survival rate in patients with operable stage I lung cancer?
> 60%
what is the 5 year survival rate in patients with operable stage II lung cancer?
35%
what is the 5 year survival rate of patients with non-small cell carcinomas?
10-15%
what is the 5 year survival rate of patients with small cell carcinomas?
4%
median survival 9 months
what will help select a patient’s therapy after a diagnosis has been made?
predictive biomarkers
which predictive biomarkers will help decide the treatment of patients with adenocarcinoma?
EGFR, HER2, KRAS, BRAF
ALK translocation, ROS1 translocations
which predictive biomarkers will help decide the treatment of patients with squamous cell carcinoma?
very few as very little effective molecular targeted therapy
which type of lug cancer can immunotherapy be used to treat?
non-small cell lung cancer
