cancer- lung Flashcards
aetiology of lung cancer
-Lung cancer is the most common cause of death from cancer globally. It is the leading cause of cancer death in Australia
-Lung cancer almost exclusively involves carcinomas
I.e. tumours arising from the epithelial cells that line the trachea, bronchi or lungs
-There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC)
-Often other types, particularly breast and renal, can metastasise to the lung as a secondary spread
risk factors for lung cancer
- Age
- Genetics
- Tobacco smoking
- Diet and alcohol
- Chronic inflammation from infections and other medical conditions (COPD, TB)
- Ionising radiation
- Occupational exposures (asbestos, metals, silica)
- Air pollution (geographical location)
signs and symptoms of lung cancer
- Haemoptysis (coughing up blood)
- New or changed cough
- Shortness of breath or difficulty breathing
- Weight loss/loss of appetite
- Chest/shoulder pain
- Fatigue
- Hoarseness
- Fever
what are 2 types of lung cancer
non-small cell lung carcinoma (NSCLC)
small cell carcinoma
what is adenocarcinoma (NSCLC)
- Comprises around 40% of all lung cancer
- Arises from small airway epithelial, type II alveolar cells, which secrete mucus and other substances
- Adenocarcinoma is the most common type of lung cancer in smokers and non-smokers in men and women
- Tends to occur in the periphery of the lung
- tends to grow slower and has a greater chance of being found before it has spread outside of the lungs
what is squamous cell carcinoma (NSCLC)
- Comprises 25–30% of all lung cancer cases
- Arises from early versions of squamous cells in the airway epithelial cells in the bronchial tubes in the centre of the lungs
- Strongly correlated with cigarette smoking
what is large cell carcinoma (NSCLC)
- Accounts for 5–10% of lung cancers
- Often begins in the central part of the lungs, sometimes into nearby lymph nodes and into the chest wall as well as distant organs
- Strongly associated with smoking
what is the staging of lung cancer
Clinicians use a staging system for lung cancer called TNM:
- T – size of tumour
- N – spread of cancer to the lymph nodes
- M – spread to another area (metastases)
what is stage T1 of TMN
There are 4 main stages for T: T1 lung cancer means that the cancer is still inside the lung. T1 is broken down into 3 sub-stages:
- T1a – the tumour is no wider than 1cm
- T1b – the tumour is between 1cm and 2cm wide T1c – the tumour between 2cm and 3cm wide
what is stage T2 of TMN
T2 is used to describe 3 possibilities:
- the tumour is between 3cm and 5cm wide, or the tumour has spread into the main airway or the inner lining of the chest wall, or
- the lung has collapsed or is blocked due to inflammation
what is stage T3 of TMN
T3 is used to describe 3 possibilities:
- the tumour is between 5cm and 7cm wide, or there is more than 1 tumour in the lung, or
- the tumour has spread into the chest wall, the phrenic nerve (a nerve close to the lungs), or the outer layer of the heart (pericardium)
what is stage T4 of TMN
T4 is used to describe a range of possibilities including:
- the tumour is wider than 7cm, or
- the tumour has spread into both sections of the lung (each lung is made up of 2 sections, known as lobes), or
- the tumour has spread into an area of the body near to the lung, such as the heart, the windpipe, the food pipe (oesophagus) or a major blood vessel
what is stage N of TMN
There are 3 main stages for N:
- N1 is used to describe cancerous cells in the lymph nodes located inside the lung or in the area where the lungs connect to the airway (the hilum)
- N2 is used to describe 2 possibilities: there are cancerous cells in the lymph nodes located in the centre of the chest on the same side as the affected lung, or there are cancerous cells in the lymph nodes underneath the windpipe
- N3 is used to describe 3 possibilities: there are cancerous cells in the lymph nodes located on the chest wall on the other side of the affected lung, or there are cancerous cells in the lymph nodes above the collar bone, or there are cancerous cells in the lymph nodes at the top of the lung
what is stage M of TMN
There are 2 main stages for M:
- M0 – the cancer has not spread outside the lung to another part of the body
- M1 – the cancer has spread outside the lung to another part of the body
what is one sclc
pulmonary metastasis
medical investigations utilised for lung cancer
- Chest x-ray
- Contrast enhanced CT chest
- PET/CT
- Sputum cytology
- Complete blood count/lft’s/rft’s
- Bronchoscopy
- Endobronchial ultrasound *(ebus)
- Biopsy
- Thoracentesis
- Lung function test (spirometry)
- VATS
what medical imaging modalities are used for lung cancer
chest x-ray CT PET/CT biopsy MRI
use of chest x-ray in lung cancer imaging
- Widespread availability, often the first modality used
- Low sensitivity compared to CT
- Often appears as a speculated lesion
- May also be inferred from other pathology, unresolved pneumonia, lobe collapse
use of CT in lung cancer imaging
- Easily accessible
- Fast, painless, non-invasive
- 3D chest view
- Allows for accurate measurement
- Uses ionising radiation
- Modality of choice for staging
- Sometimes, due to surrounding atelectasis, it is hard to delineate the tumour margins
- Size and involvement of lymph nodes
use of PET/CT in lung cancer imaging
- Standard procedure in the initial staging and diagnostic work-up
- PET demonstrates data on the metabolic behaviour of a lesion
- Accurate in assessing mediastinal or chest wall infiltration
- Allows for differentiation of tumour from surrounding atelectasis
- Fdg-pet complements other imaging modalities, but has greater sensitivity for staging given that changes in tissue metabolism usually occur ahead of anatomical changes.
- Good for detection of nodal metastasis
disadvantages of PET/CT in lung cancer imaging
- Small tumours (<8mm)
- Tumours of low metabolic activity
- Breathing artefact
use of biopsy in lung cancer imaging
- Tumours can be centrally located, invading mediastinal structures or peripherally located invading the chest wall
- Tumour margins can be smooth, lobulated or speculated
- They can be uniformly solid or can have central necrosis or cavitation
- Whatever the appearance, a biopsy is needed
- CT guidance allows for ease of biopsy
use of MRI in lung cancer imaging
- For lung cancer, radiologists still only consider superior sulcus tumour (Pancoast’s tumour) and assessment of possible invasion of the spinal cord canal as indications for chest MRI
- MRI can be of use specifically for assessing invasion of the superior vena cava or myocardium, or extension of the tumour into the left atrium via pulmonary veins
- MRI can be used to characterise solitary nodules, differentiate lung cancer from secondary changes, & evaluate mediastinal involvement
treatment options for lung cancer
surgery
thermal ablation
RT
chemotherapy
alternative treatment options for lung cancer
immunotherapy laser therapy photodynamic therapy cryosurgery electrocautery clinical drug trials
follow up care for lung cancer
-Follow up with the clinician 4-6 weeks post RT
-Then every 3-6 months for the first two years
-CT & PET scanning usually 4-8 weeks after completion of treatment
-Bronchoscopy could be used as a follow up study also
-Where cure is not a possibility, palliative treatment is recommended
Counselling/Occupational Therapy
what surgery is used for lung cancer
lobectomy
pneumonectomy
wedge resection
why is thermal ablation used for lung cancer
The destruction of tissue by extreme hyperthermia (elevated tissue temperatures) or hypothermia (depressed tissue temperatures)
- The overall objective of thermal tumour ablation is quite similar to that of surgery: remove the tumour and a 5–10-mm thick margin of seemingly normal tissue
- Often undertake percutaneously or via a minimally invasive method
why is RT used for lung cancer
- Radiotherapy might be used either as the main treatment for lung cancer, after surgery to kill cancer cells that remain, before surgery to shrink the tumour, or to relieve symptoms of advanced lung cancer.
- Some patients can not tolerate surgery due to co-morbidities and therefore are offered conventional radiotherapy.
- Conventional radiotherapy fails to control the primary neoplasm in 60-70% of cases.
- Stereotactic body radiation therapy (SBRT) is a non-invasive cancer treatment in which numerous small, highly focussed and accurate beams target tumours. This technique minimises the exposure to surrounding healthy tissues.
- SIDE EFFECTS: HAIR LOSS, LOSS OF APPETITE, SKIN IRRITATION, FATIGUE, RADIATION PNEUMONITIS
why is chemotherapy used for lung cancer
- Approximately 40% of newly diagnosed lung cancer patients are stage IV.
- Therapy should also be stopped if the cancer grows or if, after four treatment cycles, the disease is stable but the treatment is not shrinking the tumours
- Usually used for SCLC
- Side effects include; anaemia, risk of infection, mouth ulcers, hair loss, nausea & vomiting.
- trials of combination chemotherapy have shown superior response rates and survival compared with single-agent chemotherapy
