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
describe features of SCC
keratinising / crusted tumour that can ulcerate with surrounding erythema and can bleed easily when traumatised
sore and painful
variable appearance
grows quicker than BCC
how do we investigate a SCC?
Excisional biopsy - remove all with wide margins
incisional biopsy - part excised (good for large lesions or those in cosmetically important areas)
careful examination of lymph nodes and any large nodes can be examined histologically by FNA
usually requires CT/MRI to stage
describe the TNM staging for SCC?
T1 = 2cm
T2 2-5cm
T3 >5 cm
T4 invading deeper extradermal structures
N1 = regional lymph nodes N2-3 = any lymph node
M1 = distant metastasis
describe the clinical staging for SCC
stage 1 = T1
Stage 2 = T2,3
stage 3 = T4, No/N1
stage 4 = M1
what is the main method of managing SCC?
surgical excision is preferred method - may use mohs micrographic surgery
what methods other than surgical excision are available for managing SCC?
curettage and electrodesiccation - suitable for multiple lesions
cryotherapy - for small in situ SCC or premalignant changes
topical treatment - superficial lesions or precancerous changes
photodynamic therapy
radiotherapy
is a 2ww referral to specialist skin cancer clinic indicated in SCC?
.all patients referred to specialised skin cancer clinic - 2WW
what is prognosis for SCC like?
variable depends on depth of tumour
poor prognosis if metastatic
what factors determine metastatic potential of SCC?
site = SCC from sun exposed areas pose the greatest risk , then lip/ear and then non exposed areas
diameter = larger the more likely with 2cm being the cut off
depth = >4cm
histology = poor differentiation
immunocompromised host.
how is SCC prevented?
avoid sun exposure
educate on checking for lesions
educate to use suncream
out of the skin cancers which is most aggressive?
melanoma but least common
list the different types of melanoma.
which is the most common and most aggressive?
superficial spreading
nodular
lentigo maligna
acral lentiginous
superficial spreading is most common but least aggressive (other than lentigo maligna which is benign)
nodular is the most aggressive.
how do the superficial spreading melanomas appear, and who do they mainly affect?
appear on all body surfaces but particularly the legs
appear large, flat, irregular and grows laterally before vertical invasion.
brown, black, grey or pink, central or halo depigmentation
mainly effect white females and median age of 56yrs
least aggressive and most common
how do the nodular melanomas appear and who do they mainly affect?
appear on all body surfaces
palpable , uniform bluish black, bleeds and ulcerates
most aggressive
mainly white males and median age is 49yrs
what are the features of the lentigo malignas?
melanoma in situ
appear flat, irregular, shades or brown/ black and hypopigmentation
slow growing but have the potential to become invasive
occur on sun exposed areas esp head and neck
mainly occur in white females and median age 70
what are the features of acral lentiginous
melanoma occurring on palms, soles and mucus membranes
mainly in black males and median age =61
palpable irregular nodule
black and irregularly coloured
usually present late
what is meant by amelanotic melanoma?
lack melanin
what is the pathophysiology behind melanoma?
arises from melanocytes (found in basal cell layer) and produce melanin
once melanoma cells have reached the dermis they can spread to other tissues via lymphatics / blood and to lung, skin, bone, brain and liver
BRAF gene = protein kinase implicated in melanoma
what is the clinical staging used for melanoma?
1a = T1a 1b = T1b or T2a 2a = T2b or T3 a 2b = T3b or T4 2c = T4b 3 = any T , N1-3 4 = M1
what is the TNM staging used for melanoma?
T1 1mm or less T2 = 1-2mm T3 = 2- 4mm T4 = more than 4 mm for all of the above can be split into a = without ulceration, b = with ulceration N1 = 1 node N2 = 2-3 nodes N4 = 4 or more nodes
M1a = distant skin, subcut M1b = lung mets M1c = any other mets
what is the 2ww referral criteria for melanoma?
if suspicious lesion, dermascopy suggests so and 2 or more points on following 7 point weighted check list
major (2 points)
- change in size
- irregular shape
- irregular colour
minor (1 point)
- largest diameter >/ = 7mm
- inflammation
- oozing
- change in sensation
where do melanomas appear?
can occur anywhere but in women more likely on legs and men more likely on head neck and trunk
what is the ABCDE rule for melanoma?
A = asymmetry B = borders - irregular , notched or scalloped C = colour - many colours or uneven distribution or changed colour D = diameter - >6mm E = evolution
what are the risk factors for melanoma?
more common in women
previous invasive carcinoma
moles - the more moles, the greater the risk
sun exposure - short burst of sunburn in childhood
skin type 1 and 2
FHx
what investigations should be done for melanoma?
dermoscopy
excisional biopsy and histopathology
- gold standard
- can confirm if malignant melanoma or lentigo maligna
- can determine the Breslow thickness and thus prognosis
CT imaging
sentinel lymph node biopsy
other investigation - LFTs, liver USS, CXR, FBC, LDH, bone scan, brain scan
what is dermascopy?
reveals structures within the lesion that cant be seen by the naked eye
gives you indication about histology
- see different colours
- melanocytic lesion
- deep melanin within the tissue appears bluer in colour, whereas superficial colours are brown/ black
what is the prognosis of melanoma like?
poor
Breslow thickness is most important prognostic factor
when there are distant metastasis = incurable
how is stage 1-2 melanoma managed?
wide local excision with varying excision margins according to Breslow thickness
aleast 1cm margin for stage 1 and 2cm for stage 2
how is stage 3 melanoma managed?
lymphadenopathy if sentinel biopsy positive
adjuvant radiotherapy after surgical resection in patients with locally / regionally advanced disease
how is stage 4 melanoma managed?
symptomatic palliative care
chemotherapy and monoclonal Abs
radiotherapy can be used on mets
what is the Breslow thickness excisional margin rule ?
Breslow thickness of:
in situ - 5mm excision margin <1mm - 1cm excision margin 1,01 mm - 2mm - 1 -2cm excision margin 2.01mm -4 mm = 2-3cm excision margin >4mm = 3cm excision margin
what is Vemurafenib?
targeted therapy
inhibitor of BRAF which is expressed in 60% of melanomas
how is melanoma prevented?
avoid excess sun , sunbeds and sunburn
check moles
name and describe two premalignant lesions..
actinic keratosis - chronic sun exposed sites, rought and pigmented skin. very low potential of developing into skin cancer. can use topical treatments
bowens disease - SCC in situ - treat topically to reduce risk of developing into SCC
how are premalignant lesions treated?
topical treatment e.g. 5 flurouracil cream
what sun screen advice could you give someone?
apply 15 - 30 mins before sun
re-apply every 2 hours
are BCC more common in men or women?
men
what should be done on examination with anyone with a suspicious lesion?
full skin check
how is the Breslow thickness categorised into risk
thickness of :
<0.76 mm = low risk
0.76 to 1.5mm = medium risk
>1.5mm = high risk
