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


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


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


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


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


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


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


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


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


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


The Sun and Man

Effects on the skin are acute and chronic Acute - protective

- Skin tanning

- Epidermal thickening

- Sun burn Chronic

- Photocarcinogenesis

- Photoaging


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


Basal Cell Carcinomas

Commonest skin cancer in Caucasian populations

Major cause is sun exposure Common sites on face and trunk Not metastatic


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


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


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


Methods of Preventing Long Term Skin Damage

Avoid sun Avoid midday sun Use photo-protective

clothing, hats etc Use sunblocks


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


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


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


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


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


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



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



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

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Tony Chu - Skin Cancer2