Skin Cancer Flashcards
What behavioural methods should be used in the prevention of skin cancer?
Avoid the sun at peak times, use shade, avoid sunbeds
What clothing is best to prevent skin cancer?
Tightly woven, loose fitting, dark clothing
NON MELANOMA SKIN CANCER
What types of skin cancer come under this category?
What proporation of skin cancers do these make up?
Where do they arise from?
SCC and BCC
90-95%
Arise from the keratinocytes in the epidermis; BCC = basal layer, SCC = supra-basal
With regards to the non melanoma skin cancers:
Which is the most common?
Which is more serious?
BCC
SCC
Where do melanomas arise from?
Melanocytes which are scattered along the basal layer of the epidermis
EPIDEMIOLOGY
Which type of skin cancer is most common in the elderly group?
Which type of skin cancer is most common aeged 25-45?
Which sex is more at risk of melanoma?
Which sex is more likely to die from melanoma?
BCC
Melanoma
Females (2:1)
Males
PROGNOSIS OF MELANOMA
What is the 5 year survival for a tumour that is:
< 1mm?
> 4mm?
Metastasised?
95-100%
50%
5%
TYPES OF MELANOMA
Describe a superficial spreading melanoma?
Describe a nodular melanoma?
Melanoma spreads horizontally through the epidermis first
Melanoma spreads vertically into the dermis where it can metastasise
What are some presenting features of a BCC?
Slow growing lump or non-healing ulcer
Painless
Pearly or translucent
Telangectasia
Scaly plaque
Are BCCs locally invasive?
Do BCCs metastasise?
How fast do BCCs grow?
The cells involved in a BCC are mainly found where?
The biggest problem with BCCs is when they arise where?
Yes
Rarely
Very slowly
Papillary dermis
On the central facial region
How may an SCC present?
Where do SCCs tend to present?
Are they painful?
Do they metastasise?
Warty/crusted growth or a non-helaing ulcer
Sun exposed skin
Yes, and can bleed
Yes
What is a keratoacanthoma?
A type of SCC which erupts suddenly on a sun exposed site.
May need excised or may resolve on its own.
What is the risk of metastases of an SCC?
If a patient survives an SCC, what is their chance of recurrence at 5 years?
What are some examples of precursor lesions?
SCC has associations with sites of longstanding what?
5%, but poor prognosis once this occurs
50% recurrence of a non-melanoma cancer
Actinic keratosis, Bowen’s disease (erythematous plaque)
Venous ulceration, burns or lupus vulgaris
What are some risk factors for skin cancer?
SUN EXPOSURE
Genetic predisposition (DNA repair syndromes)
Immunosuppressed
HPV infection
Enironmental carcinogens e.g. tar, smoking, radiation
What are DNA repair syndromes?
What are some examples?
Which patients are the biggest at risk group for getting and dying from SCC?
The inability to repair skin sites which have been damaged by UV light
Xeroderma pigmentosum, albinism, naevoid BCC syndrome
Transplant patients
Xeroderma pigmentosum is a DNA repair syndrome which increases the risk of skin cancers. What are some features of this?
Causes photosensitivity
Skin cancers on UV exposed sites and increased risk of other cancers
Neurological degeneration
Defect in NER genes
What is naevoid BCC syndrome?
What are some features?
An autosomal dominant familial cancer syndrome
Early onset/multiple BCCs
Palmar pits, jaw cysts, ectopic calcification
Does smoking cause cancer directly or indirectly?
How?
Indirectly
It causes genetic damage which then increases mutations and hence cancer
What is a particularly important cytokine which is very prone to causing cancer if inhibited?
TNF alpha
What is an oncogene?
Give examples?
An over-active form of a gene which positively regulates cell division
Ras, Raf
What is a proto-oncogene?
What happens once these are switched on by a mutation?
The normal, not yet mutated, form of an oncogene.
They cannot be switched off, causing cancer
What is a tumour suppressor?
Give examples?
An inactive or non-functional form of a gene which negatively regulates cell division
Rb, p53