Transcript SKIN CANCER - Continuing Medical Education

SKIN CANCER
Dr. D. Czarnecki MD MBBS
Skin Cancer
• Skin cancer is a major health problem in Australia
• The most common skin cancer is the Basal Cell
Carcinoma (BCC)
• The next most common is the Squamous Cell
Carcinoma (SCC)
• The least common is the Melanoma (MM)
• BCC and SCC are often grouped together as nonmelanoma skin cancer (NMSC)
• Skin cancer dose not kill many Australians but
treating cancers causes considerable morbidity.
Skin Cancer
• Not all races have an equal risk of developing skin
cancer
• Skin cancers overwhelmingly develop in white
people
• The following slide has the incidences of NMSC in
different races in different parts of the world
• The highest incidence found was in white Australian
men living in tropical Queensland
• The incidence in coloured people was lower, even
when they lived in the tropics.
NMSC - incidence
Tropical Australia (men
only)
3090 per 100,000
Hawaii (white- both
sexes)
Hawaii (Japanese)
927
Hawaii (Filipino)
Arabian Peninsula
South Africa (Blacks)
Californian Chinese
Japan
14
2
<1
1
1
55
Skin Cancer
• A BCC – nodular type. Most
of these occur on the head.
• BCCs slowly grow
• BCCs rarely metastasize –
about 1 in 100,000
• It is often difficult to tell
BCCs from SCCs on clinical
grounds
Skin Cancer
• A BCC – superficial type
• This is now the most
common type of BCC and
most occur on the back
• It is pink, well demarcated,
and slightly scaly
• There is a small area of
ulceration
A morphoeic BCC – it looks like marble
The red area is the biopsy site
The BCC grows between collagen bundles
hence the indistinct margin
BCC
• Treatment of BCCs:
• Surgery has the lowest recurrence rate (5-8%)
• Radiotherapy has a 12% recurrent rate
• Imiquimod fails in 20-40% (higher failure rate in
thicker tumours)
• Photodynamic therapy fails in 40% after 4 years of
follow up
• Cryotherapy has a high failure rate and should not
be used unless a thermocouple is used (to measure
skin temperature at a set depth)
Skin Cancer
• An SCC on the forehead
• SCCs are most often found
on the head or hands
• SCCs metastasize in about
5% of cases
• The regional lymph node is
the most common site of
metastasis
SCC
• The average age for an SCC to develop in Melbourne is 71. This
means that many patients die of other causes before
metastases are obvious.
• The Metastatic rate could be higher.
• The risk factors for metastasis are
Thickness > 4 mm
male sex
located on the ear
a recurrent SCC
perineural spread is present
the patient is immunosuppressed
SCC
• An SCC on the nose
• There are metastases in
the submental lymph
nodes
• The patient had chronic
lymphocytic leukaemia
and died shortly after of
the leukaemia
metastases
SCC
• A recurrent SCC in front
of the ear.
• The initial pathology
report stated that it was
incompletely excised
• A wider, deeper
excision is mandatory
Skin Cancer
• A safety margin is needed
• A 4 mm margin of normal looking tissue is
recommended for BCCs (not morphoeic) and SCCs
• A 4 mm margin will give a 95% chance of removing
the tumour
• For morphoeic BCCs a 10 mm margin is
recommended
Skin Cancer
• You must review the patient
• Overall – 2/3rds will develop a new skin cancer
within 5 years
• The risk is higher the greater the number of skin
cancers a patient has had removed
• Patients with skin cancer have an increased risk of
developing non-Hodgkins lymphoma
• Regular review enables the doctor examine for
cancers and to re- inforce the message about
protection from sunburn.
You must review your patients
A recurrent skin cancer
Melanoma
• Melanomas are the least common skin
cancers. There were fewer than 10,000
invasive melanomas registered in Australia
in 2003. There were about 40% more
melanomas-in-situ. In 2003 there were about
14,000 melanomas removed from Australians
• About 1000 Australians die each year of
melanoma. This is fewer than commit suicide
or die in car accidents.
The number of invasive melanomas excised
from Australians – AIHW (www.aihw.gov.au)
Melanoma
• Not all races are at risk of melanoma. The disease is
overwhelmingly one of white people.
• The main risk factors for a melanoma are (in
decreasing order of importance:
A previous melanoma
A previous BCC or SCC
More than 150 moles
A skin that sun burns easily and tans poorly
A first degree relative with a melanoma
Immunosuppression
The incidence of melanoma in different
countries (cases per 100,000)
Victoria
37.00
India
0.1
Hong Kong
0.1
China
0.1
Arabian Peninsula
0.1
Japan
0.4
Melanoma
• Had a melanoma? – 10% get another
• A family history (FH) increases the risk
• 1 first degree relative – doubles the risk
• 2 first degree relatives – 5 times the risk
• 3 first degree relatives – 35 to 70 times the risk
• Had a BCC or SCC? – greater risk than a +ve FH
•
•
x 8 for men
x 4 for women
Melanoma
• A typical melanoma
• It is asymmetrical
• The A B of melanoma:
• A – asymmetry
• B – biopsy
asymmetrical
pigmented lesions
Melanoma
• When you see a
pigmented lesion
• Draw a line down the
middle
• If one half does not look
like the other half • TAKE A BIOPSY
It is asymmetrical
Melanoma
• Taking a punch biopsy or a shave biopsy
• Will not increase the risk of metastases
• Studies have found no risk if such a biopsy is taken
and the definitive surgery is carried out within two
weeks
• Punch or shave biopsies are not encouraged
because thickness is the main prognostic factor and
a biopsy may miss the thickest area
• However, if unsure, and you do not wish to excise
the lesion, take a biopsy
Melanoma
• This melanoma is thick
– at the inferior end
• It is ulcerated
• Thickness and
ulceration are the two
most important
prognostic factors
Melanoma
• If you think the lesion is a melanoma – excise it
• Guides lines
• Excise with a 2 mm margin, await the pathology
report, and if it is a melanoma, carry out a wider
excision
• Margins
• Melanoma-in-situ – 5 mm margin
• Melanoma < 1 mm thick – 1 cm margin
• Melanoma > 1 mm thick – 2 cms margin
Melanoma
• Prognostic factors (a worse prognosis)
• Thickness
• Ulceration
• Male sex
• Site – ear, palms, soles
• Old age
• Level IV in thin melanomas
Melanoma
• This melanoma
developed on the toe.
The patient had many
naevi and had had a
BCC.
• Melanomas on the feet
are uncommon.
• You need to examine
the entire body.
Melanoma
Symmetrical
A blue naevus
Asymmetrical
A thin melanoma
Carefully look the shape and
colouring of each half are different
Melanoma
Symmetrical
Pear shaped
Asymmetrical – melanoma next
to a seborrhoeic keratosis
Growing into the seborrhoeic keratosis
Melanoma
Asymmetrical
Asymmetrical