Lung

Question 1

Epidemiology of lung cancer

Answer 1

Most common invasive malignancies in the United States
The male to female ratio has reached 1:1, compared to the 6:1 ratio in 1960
Lung cancer has surpassed breast cancer in the leading cause of cancer-related deaths in women.

Question 2

Risk factors for lung cancer

Answer 2

Significant tobacco exposure is defined as more than one pack of cigarettes per day. 
Occupational exposures:
- coal tar
- nickel
- chromium 
- arsenic
- radon 
Asbestos has been shown to cause mesothelioma

Question 3

Anatomy of the trachea

Answer 3

The trachea is the major airway.
The trachea begins at the lower end of the larynx and ends at T5 where it bifurcates (carina)
The wall is composed of rings of cartilage, smooth muscles and connective tissues.
Epithelial cells line the trachea.

Question 4

Anatomy of primary bronchi

Answer 4

Divides into right and left bronchi at the level of T4/T5 where the trachea bifurcates.
Form branches of decreasing size until finally reaching the microscopic level where the gases are exchanged.

Question 5

Hilum

Answer 5

Area of the lung where the blood vessels and lymphatics enter and exit the lung.

Question 6

Two categories of lung cancer

Answer 6

Small cell
Non-small cell
* mesothelioma is distinct although less frequent cetergory

Question 7

Pathology of non-small cell lung cancer

Answer 7

Non-small cell

• adenocarcinoma
• squamous cell carcinoma
• large cell adenocarcinoma

Question 8

Most common signs and symptoms of lung cancer

Answer 8

Cough: the initial symptom of lung cancer. Noted in 30-75% of lung cancer.
Dyspnea (shortness of breath): occurs in 20-60% of patients
Chest pain: not a good prognosis due to the extent of the tumour
Hemoptysis: blood in sputum
Hoarseness: usually indicates the mediastinal extension
Weight loss: can be a sign of advanced disease

Question 9

T1 stage non-small lung cancer

Answer 9

T1a: <2cm does not invade the main bronchus
T1b: >2cm but <3cm does not invade the main bronchus

Question 10

T2 stage non-small lung cancer

Answer 10

T2a: >3cm but <5cm involves the main bronchus or invades visceral pleura >2cm from carina
T2b: >5cm but <7cm involves the main bronchus or invades visceral pleura >2cm from carina

Question 11

T3 stage non-small lung cancer

Answer 11

> 3cm invades chest wall, diaphragm, mediastinal pleura or parietal pericardium or tumour in the main bronchus, <2cm from distal carina but without the involvement of carina

Question 12

N1 stage non-small lung cancer

Answer 12

Positive ipsilateral peribronchial +/- hilar lymph nodes

Question 13

N2 stage non-small lung cancer

Answer 13

Positive ipsilateral mediastinal +/- subcarinal nodes

Question 14

N3 stage non-small lung cancer

Answer 14

Positive contralateral mediastinal or hilar nodes or ipsilateral +/- contralateral scalene or superclav nodes.

Question 15

Small cell lung cancer staging

Answer 15

Limited: confined to hemithorax
Extensive: spread beyond the thorax, mets and pleural effusion

Question 16

Superior mediastinal lymph nodes

Answer 16

Upper paratracheal
Lower paratracheal nodes
Tracheobronchial angle nodes
Aortic nodes are also included: 
- aortopulmonary 
- anterior mediastinal nodes

Question 17

Inferior mediastinal nodes

Answer 17

Subcarinal nodes
Paraesophogeal nodes
Pulmonary ligament nodes

Question 18

Symptoms of local disease lung cancer

Answer 18

Weight loss is an early symptom
Cough that is more severe than normal
Hemoptysis (blood associated with the cough)

Question 19

Symptoms of regional disease lung cancer

Answer 19

Regional invasion into the surrounding lymph nodes symptoms may include:
- pain
- coughing
- dyspnea
Disease extension into the mediastinum may cause:
- dysphagia (due to esophageal compression)
- superior vena cava syndrome (dyspnea, swelling in neck, face and arm)
- hoarseness (due to compression of the larynx)

Question 20

Pancoast tumour

Answer 20

Located in the apex of the lung although other criteria must be met to be diagnosed with a Pancoast tumour.

1. pain around the shoulder and down the arm
2. atrophy of the hand muscles
3. Horner syndrome
4. bone erosion of the ribs and sometimes vertebrae

Question 21

Horner syndrome

Answer 21

Due to the Pancoast tumours involvement of the cervical sympathetic nerves.
Classically includes:
1. ipsilateral miosis (contracted pupil)
2. ptosis (drooping eyelid)
3. enophthalmos (recession of the eyeball into the orbit)
4. anhidrosis (loss of facial sweating)

Question 22

Symptoms of metastatic disease lung cancer

Answer 22

Generally associated with anorexia, weight loss and fatigue.
Paraneoplastic syndrome

Question 23

Paraneoplastic syndrome

Answer 23

Disorder arising from the metabolic effects of cancer on tissues remote from the tumour.
May appear as an endocrine, hematologic or neuromuscular disorder.

Question 24

Screening of lung cancer

Answer 24

High-risk individuals may qualify for a low-dose CT screening. Has been shown to reduce the mortality rate from lung cancer for those between the ages of 55 and 74 years with a history of at least a 30-pack year history.

Question 25

Fiberoptic bronchoscopy

Answer 25

A long flexible tube that can be used to identify up to 75% of lesions. Can also be used to obtain a specimen for biopsy.

Question 26

Endoscopic bronchial ultrasound scan

Answer 26

Less invasive allows physicians to view and biopsy regions that used to be done by invasive surgery. Involves the insertion of a bronchoscope into large airways. After the tube is placed the ultrasound probe at the end of the probe is used to examine surrounding areas.

Question 27

Squamous cell carcinoma of the lung - etiology - epidemiology - location

Answer 27

Usually associated with tobacco consumption and are more commonly centrally located in the proximal bronchi. More common in men.

Question 28

Adenocarcinoma cell carcinoma of the lung - epidemiology - location

Answer 28

More common in women and are frequently more peripheral locations.

Question 29

Small cell carcinomas of the lung - location - spread

Answer 29

Centrally located | More prone to early spread and fewer than 10% of patients are diagnosed with limited-stage.

Question 30

Large cell carcinoma of the lung | - location

Answer 30

Peripherally

Question 31

Direct spread of lung cancer

Answer 31

``` Most likely to spread to: - other parts of the lung - ribs - heart - esophagus - vertebral column A tumour that is not encapsulated may invade and attach itself to structures such as the chest wall, diaphragm, pleura, and pericardium (T3 or T4 stage tumour) ```

Question 32

Common sites for lung metastasis

Answer 32

Most commonly occur: - cervical lymph nodes - liver - brain - bones - adrenal glands - kidneys - contralateral lung

Question 33

Surgery considerations lung cancer

Answer 33

Patients that can handle the surgery and have stage I or II diseases should be considered for definitive surgery. (only 20% of patients is this recommended) Lobectomy with regional lymph nodes sampling is considered the best option. A limited wedge resection with video-assisted thoracoscopy is also utilized with good rates of regional control. Lesions that are central with the mainstem bronchus necessitate a total pneumonectomy.

Question 34

Standard ChemoRT therapy for non-small cell lung cancer

Answer 34

Concurrent, sequential or alternating chemotherapy and radiation. With radiation doses between 4500cGy and 6000cGy at 180 or 200cGy per fraction.

Question 35

Critical structures consideration for treatment of lung cancer

Answer 35

Spinal cord: 4500cGy Esophagus Heart: 3000cGy leads to a 50% chance of pericarditis Healthy lung

Question 36

Treatment volume POP lung cancer

Answer 36

Typically includes the primary tumour volume with a 2.0cm-2.5cm margin of healthy tissue. If a superior tumour or involves the mainstem of the bronchus ipsilateral supraclavicular lymph nodes should be included. Ipsilateral hilar and superior mediastinal lymph nodes should be included with a 2.0cm margin and at least 5cm below the carina. If an inferior tumour the field should extend to T10 or the diaphragm.

Question 37

TDF treatment of small cell lung cancer

Answer 37

RT alone: 60Gy/30# | ChemoRT: 54-60Gy/30#

Question 38

Prognosis of lung cancer

Answer 38

The prognosis of small cell lung cancer is poor with only 10-15% of patients surviving 3 years. Non-small cell lung cancer has a better prognosis with 15-20% of patients surviving 5 years. Survival is significantly better with the early-stage disease when surgery can be done for curative intent.