Cancer- Lung and Breast

Question 1

What are the survival patterns for lung and breast cancer?

Answer 1

5 year survival for lung cancer in the UK is 10%
5 year survival for breast cancer in the UK is 87%

Question 2

How common is breast cancer in women and how is it first diagnosed?

Answer 2

25% of the total number of new cancer cases
screening is performed by the use of a mammogram (x-ray of the breast)

Question 3

What are the risk-factors of breast cancer?

Answer 3

Genetics: About 5-10% of breast cancer cases are thought to be hereditary by involving mutations in genes
Age
Gender- Male breast cancer is rare
Family and personal history- occurrences of breast cancer in patient or in close relatives increase risk

Question 4

What is the classification of breast cancers?

Answer 4

• Hormone receptor positive (ER+ and PR+)
• HER2 positive
• Triple negative ER- PR- HER2-

Question 5

What are the most common mutations in breast cancer?

Answer 5

Point mutations in PIK3CA and loss of function in TP53

Question 6

In the 20th Century what was most classification of tumours based on?

Answer 6

Based on histology
A slice of tumour tissue is stained with a general protein stain and inspected by a trained pathologist with a microscope

Question 7

What is Immunohistochemistry (IHC)?

Answer 7

Visualising the abundance of specific proteins in tissue sections using antibodies
Crucial in breast cancer diagnosis and classification

Question 8

To look at the expression of genes and proteins in a tumour what does this usually require?

Answer 8

Requires a physical sample of the tumour tissue which usually requires an invasive operation

Question 9

How can we avoid using invasive physical samples?

Answer 9

By using blood samples?
Everyone has a little free DNA in their circulating blood
In a cancer patient, some of this DNA comes from the tumour

Question 10

How common is lung cancer in the UK?

Answer 10

Third most common in the UK
But caused the highest number of deaths
Biggest cause is smoking

Question 11

What are the several classes of lung cancer?

Answer 11

• Small-cell lung cancer (15%)- Usually seen in cells near the bronchi
• Adenocarcinoma (40%)- Most prevalent form of lung cancer and usually arises in cells lining the alveoli
• Large cell carcinoma (15%)- Can begin in any part of the lung
• Squamous cell carcinoma (30%)- These tumours appear in the flat cells that line the inside of the airways

Question 12

How are non-small localised lung cancers (NSCLCs) treated?

Answer 12

Sometimes cured by surgery. Small cell lung cancers are usually treated with chemotherapy and radiotherapy

Question 13

How do mutation rates appear in smokers?

Answer 13

Appear around 10 fold higher than in the lung cancer in non-smokers

Question 14

What process classifies lung cancers?

Answer 14

Through molecular analysis (DNA mutations), showing a parallel classification to that provided by histology

Question 15

What types of mutation are common in lung cancers?

Answer 15

Some lung adenocarcinomas have mutations which activate the Epidermal Growth Factor Receptor (EGFR)
AND
Others have mutations fusing the EML4 gene to the gene encoding the ALK growth factor receptor

Question 16

How are the mutations in Adenocarcinoma g lung cancers treated?

Answer 16

Treated with drugs that inhibit EGFR and ALK receptors

Question 17

What did large scale sequencing of DNA from lung cancer tissue samples identify?

Answer 17

Many mutations including fusions of the ALK growth factor receptor gene to the EML4 gene in about 5-10% Adenocarcinoma patients
These mutations causes over activation of the ALK receptor driven growth signalling (PI3K)

Question 18

What is ALK?

Answer 18

Is a receptor tyrosine kinase. Existing drug programmes identified drugs which can inhibit the ALK kinase in ALK mutant lung cancer

Question 19

What is Sotorasib?

Answer 19

An inhibitor of mutant KRAS
Drug approved for lung cancer patients in 2022