skin cancer Flashcards
what is the most common cause of primary cancer?
skin cancer
what cancer is most common in women aged 25-29?
malignant melanoma
what are the risk factors common to all skin cancers?
UV light
- short periods resulting in sunburn for melanoma
- chronic exposure - BCC and SCC
family history
skin type - 1 and 2
immunosuppression - ciclosporin/tacrolimus
Xeroderma pigmentosum
what are the effects on sunlight?
good for well being and vitamin D production
UVB can sunburn and has direct effects on DNA damage and carcinogenesis
UVA is less damaging
what is the most common type of skin cancer?
Basal cell carcinoma
where do basal skin cancers arise from and occur?
basal cell layer of the skin
majority from sun exposed areas
what is the appearances/ features of a basal cell carcinoma?
perly rolled edges with central ulceration and telangiectasia on the surface
don’t metastatise but can ulcerate and invade locally to cause extensive damage especially if on the face
other features - persistent sore erythematous plaque with scales (bit like psoriasis)
slow progression
what are the different subtypes of basal cell carcinoma?
nodular superficial infiltrative pigmented BCC basosquamous
what do nodular BCC look like?
well defined, shiny, telangiectasia , usually on face
easy to treat
what do pigmented BCC look like?
brown blueish grey tinge
what do superficial BCC look like?
usually on upper trunk and shoulder
erythematous
well defined scaly plaque
what are the features of an infiltrative BCC?
extend and keep coming back because difficult to remove
usually on the face
more aggressive
poorly defined
characterised by thickened yellowish plaques
what is a basosquamous BCC?
mixed BCC and SCC
how do we diagnose BCC?
usually made by appearance
biopsy can confirm histological subtype
clinical examination for lymphadenopathy
what are the criteria for BCC to be managed at the GP?
when a BCC is classed as low risk it is managed by GP:
- >24 yrs and NOT immunocompromised and no Gorlins syndrome
- lesion below clavicle, <1cm, well defined, nodular subtype and in an area where surgical excision is difficult
Do BCC have a 2ww for secondary referral?
no 2ww unless lesion is on the face or at risk of significant impact
how are the majority of BCC treated?
mainly by surgical excision and radiotherapy
can use mohs micrographic surgery when it is hard to obtain clear margins or it is the infiltrative subtype.
indication for radiotherapy is when BCC is incompletely surgically excised or recurrent.
in which condition should radiotherapy not be used and why?
Gorlins syndrome due to carcinogenic potential
what other methods are there for removing BCC (other than surgery and radiotherapy) - explain each
electrocautery - destroy tumour and then scrape away with cureattage
cryotherapy (with liquid nitrogen)- used for small low risk lesions. however histology wont be available unless incisional biopsy taken first. can cause a sore blister
topical imiquimod/ flurouracil - for superficial ones
photodynamic therapy - apply photosensitising agent and then light therapy which will destroy cancer cells. good for superficial ones, actinic keratosis and bowens disease
what is mohs micrographic surgery?
tumour is removed in stages, at each stage margins are checked to see if they are tumour clear. repeated until clear margins.
time consuming, specialist equipment needed
but high success rate
what is prognosis for BCC like?
good - however at risk of developing more BCC/ SCC or melanoma
rarely metastasis
the bigger they are the more at risk of metastasis
what is Gorlins syndrome?
autosomal dominant condition multiple BCC pitting of palms and soles jaw cysts abnormalities in the spine cataracts
where do SCC arise from?
arise from keratinising cells of the epidermis and occur in sun exposed areas
can arise from pre-malignant conditions - actinic keratosis, bowens disease and leukoplakia
arise from area of chronic inflammation - e.g. marjolin ulcer
do SCC metastasise?
has the potential but not as dangerous as melanoma
what are the risk factors for SCC?
standard risk factors for skin cancer (UV, skin type)
AND
tobacco smoke and industrial chemicals (arsenic)
chronic inflammation around skin e.g. osteomyelitis
HPV infection