Non-Melanoma Skin Cancer Flashcards Preview

Pathobiology of Human Disease > Non-Melanoma Skin Cancer > Flashcards

Flashcards in Non-Melanoma Skin Cancer Deck (16)
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1
Q

What are the most common type of cells in the epidermis?

A

Keratinocytes

2
Q

What specific groups of cancers does non-melanoma skin cancers refer to?

A

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)

3
Q

What are the four subtypes of BCCs?

A

Nodular (~half are this type), morphoeic, pigmented, superficial

4
Q

What is the first sign of non-melonama skin cancer?

A

A lump or patch on the skin that doesn’t heal after a few weeks

5
Q

What cells do BCCs and SCCs develop from?

A

BCC - basal cells; SCCs - keratinocytes

6
Q

What are the risk factors of BCC and SCC?

A

Mainly UV exposure.
BCC from sunburn/recreational exposure to sunlight
SCC mainly linked to overall sun exposures (eg outdoor workers)

7
Q

How is UV light thought to induce DNA mutations?

A

Induces direct DNA mutation via covalent bonding between adjacent pyrimidines (UVB) and formation of ROS (UVA)

8
Q

What is Patched1?

A

[the protein product of PTCH] Is a cell surface receptor, inhibits SMO

9
Q

Where is the PTCH gene found?

A

Chromosome 9q22

10
Q

What is SMO?

A

Smoothened; a G-protein coupled receptor

11
Q

What happens if Patched1 is mutated?

A

Cessation of SMO inhibition –> activation of Gli1 –> uncontrolled cell proliferation

12
Q

What is Gli1?

A

A transcription factor

13
Q

What other genes are associated with the pathogenesis of BCC?

A

CYP, GST (detoxify mutagens) and p53 (tumour suppressor gene)

14
Q

How does SCC arise?

A

From precursor lesions of actinic keratosis (AK) and Bowen’s disease

15
Q

What gene mutations are associated with SCC?

A

p53, Ras, c-Myc

16
Q

What treatments are used for NMSC?

A

Surgery is the main treatment, radiotherapy, chemotherapy occasionally, immunotherapy