14. Pathology of Lung Cancers Flashcards
Is Lung Cancer the most common cancer and cause of death by cancer worldwide?
Yes
What percentage of all deaths in Scotland are lung cancer accountable for?
6%
What is the leading cause for lung cancer?
Tobacco
What are other causes for lung cancer?
Asbestos Environmental Radon Other occupational exposure (Chromates, Hydrocarbons, Nickel) Air pollution and Urban environment Other Radiation Pulmonary FIbrosis
What percentage of Lung Cancer can Tobacco be attributed to?
> 85%
What percentage of smokers get lung cancer?
10%
By how many times is the risk of cancer increased in both males and females?
22x Males
12x Female
Females may be more susceptible however
What is the risk related to?
Risk related to consumption
- Inhalation and Pack years (Packs per day per year)
What are the dangers of other people’s smoke?
50-100% increased risk
Causes at least 25% of so-called non smoking lung cancers
The more you smoke…
The greater your risk
Risk reduces with
abstinence but only slowly
What is caused by smoking?
Persisting genomic damage
What fraction of the world’s population smoke and what percentage of men and women?
A third of males and females
50% men
12% women
Is it true that adolescents are smoking in increasing numbers?
Yes
Where is tobacco consumption soaring?
China
S & SE Asia
South America
Where is tobacco consumption increasing?
America
How many chemical compounds are found in tobacco smoke?
4000 chemical compounds
How many of the chemical compounds found in tobacco smoke are carcinogens?
~60
What are the two main pathways of carcinogenesis in the lung?
In the lung periphery
- Bronchioloalveolar epithelial stem cells transform
- Adenocarcinoma
In the central lung airways
- Bronchial epithelial stem cells transform
- Squamous cell carcinoma
What is a key driver mutation?
Oncogene addiction
Which biomarker is smoking induced?
KRAS - approx 35%
Which biomarkers are not related to tobacco carcinogenesis?
EGFR - approx 15%
BRAF, HER2 – approx 2% each
ALK rearrangements – approx 2%
What are tumours of the lung?
Benign causes of mass lesion Carcinoid Tumour - <5% of Lung Neoplasms - Low Grade Malignancy Tumours of the bronchial gland (VERY RARE) - Adenoid Cystic carcinoma - Mucoepidermoid carcinoma - Benign adenomas Lymphoma Sarcoma
What is a very common occurrence to the lung?
Metastases
What are the four main cell types that experience carcinomas?
Squamous Cell 1970-80’s - 40-60 % NOW - 40 % Adenocarcinoma 1970-80’s - 10-25 % NOW - 41 % Small Cell Carcinoma 1970-80’s - 7-25% NOW - 15 % Large Cell Carcinoma 1970-80’s 5-15 % NOW - 4 %
Bronchioloalveolar cell carcinoma (Alveolar cell ca ) was a subtype of adenocarcinoma.
Now it is called Adenocarcinoma in situ, though the situation is complex
What are the percentages for types of Lung carcinoma?
~15% Small Cell Carcinoma
85% Adenocarcinoma
Large cell carcinomas
All = NSCLC
What term is used when a certain type of carcinoma can not be distinguished?
NSCLC
Non-small cell carcinomas
What are the traits of Primary Lung Cancer?
Probably grows ‘clinically silent’ for many years
Presents LATE in its natural history
Few, if any, signs or symptoms until disease is very advanced
May be found incidentally, during investigation for something unrelated
What is generally said about symptomatic lung cancer?
It is fatal
What are the local effects of lung cancer in terms of bronchial obstruction?
Collapse
Endogenous Lipoid Pneumonia
Infection/Abscess
Bronchiectasis
What are the local effects of lung cancer in terms of Pleural involvement ?
Pleural
- Inflammatory
- Malignant
What are the local effects of lung cancer in terms of direct invasion?
Chest wall
Nerves
- Phrenic – diaphragmatic paralysis
- L Recurrent laryngeal –Hoarse, Bovine cough
- Brachial plexus – Pancoast T1 damage
- Cervical Sympathetic - Horner’s syndrome
Mediastinum ( SVC, Pericardium )
What are the local effects of lung cancer in terms of lymph node metastases?
Mass effect
Lymphangitis carcinomatosa
What are the distant metastases?
Liver Adrenals Bone Brain Skin
What are secondary to local effects?
Neural
Vascular
What are the non-metastatic paraneoplastic effects of lung cancer (skeletal)?
Clubbing
HPOA
What are the non-metastatic paraneoplastic effects of lung cancer (endocrine)?
ACTH, SIADH, PTH
Carcinoid syndrome
Gynecomastia
What are the non-metastatic paraneoplastic effects of lung cancer (neurological)?
Polyneuropathy
Encephalopathy
Cerebellar degeneration
Myasthenia (Eaton-Lambert)
What are the non-metastatic paraneoplastic effects of lung cancer (cutaneous)?
Acanthosis nigricans
Dermatomyositis
What are the non-metastatic paraneoplastic effects of lung cancer (haematologic)?
Granulocytosis
Eosinophilia
DIC
What are the non-metastatic paraneoplastic effects of lung cancer (cardiovascular)?
Thrombophlebitis migrans
What are the non-metastatic paraneoplastic effects of lung cancer (renal)?
Nephrotic syndrome
Which of the Non-Metastatic Paraneoplastic Effects in Endocrine are small cell?
ACTH and SIADH
Which of the Non-Metastatic Paraneoplastic Effects in Endocrine are squamous?
PTH
What are the investigations for Lung Cancer?
Chest X-Ray Sputum Cytology rarely used Bronchoscopy - Bronchial biopsy - Bronchial brushings and Washings - Endobronchial US-guided aspiration (EBUS) Trans-thoracic Fine Needle Aspiration Trans-thoracic Core Biopsy Pleural effusion
Advanced Imaging Techniques
- CT scanning
- MRI, PET
- Other imaging
