Tony Chu - Skin Cancer2
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Transcript of Tony Chu - Skin Cancer2
Tony Chu
Dermatology at Imperial College, Hammersmith Campus
Prevention and Management of Skin Problems
Dermatology IC at Hammersmith
Skin and Renal Transplantation
Renal transplantation demands systemic immunosuppression to prevent graft rejection
Immunosuppression has a major impact on the skin increasing the incidence of infections, pre-cancerous and cancerous changes in the skin
Many of the skin problems related to immunosuppression can be reduced with appropriate advice and management
Dermatology IC at Hammersmith
Immunosuppression and Infection
Infections are more common in the immunosuppressed patient:Acute bacterial - folliculitis, furunculosis, abscesses,
cellulitis, erysipelasChronic infection - tuberculosisViral infections - herpes simplex, wartsFungal - ringworm, tinea versicolor
Most can be treated conventionally
Dermatology IC at Hammersmith
Warts and the Immunosuppressed
Warts are caused by the human papilloma virus They are commonest in childhood but a common
nuisance at all times of life Human papilloma virus is now implicated in the
development of cervical cancer - HPV types 16, 18, 45 and 31parts of the viral DNA - E6 and E7 - link to specific
genes in human cells, transforming them into cancer cells
Dermatology IC at Hammersmith
Immunosuppression, Warts and Skin Cancer
Genetic model - Epidermodysplasia verruciformis
Genetic immunosuppression predisposes to infection with specific wart viruses - HPV 5 and 8
Following sun exposure, the virus leads to transformation of skin cells into cancer cells and the development of squamous cell carcinomas
Dermatology IC at Hammersmith
Warts in Renal Transplant Recipients
Warts tend to develop after 4 to 5 years following transplantation
Increased in sun exposed areas Many will contain EV warts virus or other
oncogenic viruses Real risk of these warts developing into squamous
cell carcinomas following sun exposure
Dermatology IC at Hammersmith
Warts in Renal Transplant Recipients
Management:Regular checks with a DermatologistTreatment of all warts - usually use cryotherapyAvoid sun exposure
One major problem is the number of warts that some recipients develop - can number in the thousands
Dermatology IC at Hammersmith
Too Many Warts A number of our patients attend every 6 weeks and
have >100 warts frozenPainful and time consuming
Important to target all warts as you cannot predict which are potentially going to develop into skin cancers
Imiquimod - cream that enhances immune systems ability to deal with viral infectionsused successfully in RTR without effects on the graft
Dermatology IC at Hammersmith
Skin Cancer and Renal Transplant Recipients
In the normal population, the commonest type of skin cancer is the basal cell carcinoma ( basal cell carcinoma : squamous cell carcinoma is 10:1)
In the renal transplant recipient, squamous cell carcinomas are 10X as common as basal cell carcinomas
Squamous cell carcinomas are metastatic - can spread to other parts of the body - and this is increased with immunosuppression
Dermatology IC at Hammersmith
Skin Cancer and Renal Transplant Recipient
Incidence of melanoma is greatly increased in the renal transplant recipient
Melanoma is the most aggressive skin cancer seen in man
These may arise from pre-existing moles or come up in normal skin
Melanomas are often more aggressive in the immunosuppressed
Dermatology IC at Hammersmith
Skin Cancer
The major factor in skin cancer formation is sun exposure
Skin type is also important in dictating how the skin reacts to the sunPale Celtic skin is most at riskDark afrocaribean skin is least at risk
Dermatology IC at Hammersmith
The Sun and Man
Effects on the skin are acute and chronic Acute - protective
- Skin tanning
- Epidermal thickening
- Sun burn Chronic
- Photocarcinogenesis
- Photoaging
Dermatology IC at Hammersmith
Ultraviolet Spectrum
100-280 280-210 310-400
UVC UVB UVA
X rays Visible
Stratosphere - Ozone Layer
UVC100-280
UVB280-315
UVA315-400
X-ray Visible Light400-700
Dead Sea Level Sea Level
Dermatology IC at Hammersmith
Basal Cell Carcinomas
Commonest skin cancer in Caucasian populations
Major cause is sun exposure Common sites on face and trunk Not metastatic
Dermatology IC at Hammersmith
Squamous cell carcinoma
Second most common skin cancer in Caucasian populations
Caused by sun exposure - chronic sun exposure Most at risk are those with pale skin who burn in the sun Commonest on sun exposed areas Pre-cancerous lesion is the solar keratosis Metastatic potential - to regional lymph nodes, then
liver, lungs etc
Dermatology IC at Hammersmith
Melanoma
Third most common skin cancer Caused by severe intermittent bouts of sun
exposure Found on sun exposed and non-exposed sites Second most common cancer to affect young
women High metastatic potential - local, lymph nodes,
lung, liver and brain
Dermatology IC at Hammersmith
Melanoma
30% arise in a pre-existing moleFeatures to look out for are asymmetry of the mole,
irregular shape and irregular colour Most commonly arise in normal skin in renal
transplant patients
Dermatology IC at Hammersmith
Methods of Preventing Long Term Skin Damage
Avoid sun Avoid midday sun Use photo-protective
clothing, hats etc Use sunblocks
Dermatology IC at Hammersmith
Avoid Sun
Almost impossible Society worships the bronzed body beautiful Even on a cloudy day, UV will get through to the
earth’s surface Sunlight is tricky - it will reflect off water, sand
and other structures and can get to you even in the shade
SandSEA
Dermatology IC at Hammersmith
Avoid the Mid-day Sun
Simple physics At mid-day the sun is directly above you and the
amount of stratosphere it need to penetrate to get to you is less so more gets through
Avoid sun exposure for an hour or two either side of mid-day
UV Radiation path lengths for differing Solar Elevations
Atmosphere
Surface
EARTH
Midday
Sun Directly Overhead
3pm
YY
X
Dermatology IC at Hammersmith
UV Protective Clothing
The finer the weave, the greater the protection Silk is best Nylon stockings have an SPF of about 2 Panama hats give poor protection - holes let light
through Cotton cricket hat is better
Dermatology IC at Hammersmith
Sunscreens
Reflectant - reflect UVB and to a lesser extent UVA
Absorbent - absorb principally UVB into specific chemicals and re-
emit as insignificant quantities of
heat
Dermatology IC at Hammersmith
Sun Protection Factor
Indication of the amount of time it is safe to spend in the sun without burning
ie an SPF of 10 would allow an exposure ten times greater than normal
Dermatology IC at Hammersmith
How can the Renal Transplant Recipient Avoid Skin Cancer
Proper counselling before and after transplantation
Regular use of high factor sun blocks - SPF 60, regardless weather
Sun protective clothing Avoid intense sun exposure Avoid the mid-day sun
Dermatology IC at Hammersmith
How can the Renal Transplant Recipient Avoid Skin Cancer
Seek advice and treatment for any warts that come up
Regular screening by Dermatology Department after 5 years post transplant
Urgent advice about lumps that come up on the skin or moles that are changing
Dermatology IC at Hammersmith
How can the Renal Transplant Recipient Avoid Skin Cancer
Effect of immunosuppressantAzathioprine and cyclosporin seem to have the same
effect on the skin Likely that tacrolimus will be the sameAnecdotally, one patient who was developing a
squamous cell carcinoma every 6 weeks was changed to mycophenolate mofetil with no detriment to his renal function and has been free of tumours for 6 months