Skin Cancer Flashcards
What is the epidemiology of non-melanoma skin cancer?
Basal and squamous cell carcinoma
131000 cases every year in UK - underestimate
BBCs account for 70%
What are the risk factors for non-melanoma skin cancer?
UV radiation, photochemotherapy, chemical carcinogens, ionising radiation, human papilloma virus, familial cancer syndromes and immunosuppression
What are the characteristics of basal cell carcinoma?
Slow growing
Locally invasive
Rarely metastasise
Nodular
Can look pigmented or morphoeic (difficult to diagnosis as poorly defined)
Describe the nodular characteristic of BCC
Pearly rolled edge
Telangiectasia
Central ulceration
Arborizing vessels on dermoscopy
What is the surgery for BCCs?
Excision is gold standard - ellipse with rim of unaffected skin
Curettage is some circumstances
Imiquimod if superficial
What are the indications for Mohs surgery?
Site, size, subtype, poor clinical margin definition, recurrent, perineural or perivascular involvement
What is Mohs surgery?
Aim is to remove all cancer cells and preserve healthy tissue + prevent scarring
Thin layers are removed
What is the indications for Vismodegib?
Locally advanced BCC not suitable for surgery or RT
Metastatic BCC
How does Vismodegib work?
Selectively inhibits abnormal signalling in Hedgehog pathway
Shrinks tumour and heals visible lesions in some
Median progression free survival 9.5 months
What are the side effects of Visodegib?
Hair loss, weight loss, altered taste, muscle spasm, nausea and fatigue
Describe squamous cell carcinoma
Derived from keratinising squamous cells
Usually skin exposed areas
Can metastasise - 16%
Can ulcerate
What are the characteristics of squamous cell carcinomas?
Faster growing, tender, scaly/ crusted or fleshy growths
Well differentiated
What is the treatment for SCC?
Excision and maybe RT
Follow up if high risk
What is high risk for SCC and need follow up?
Immunosuppressed, >20mm diameter, >4mm depth, ear, nose, lip, eyelid, perineural invasion and poorly differentiated
What is keratoacanthoma?
Variant of SCC
Erupts from hair follicles in sun damaged skin
Grows rapidly and may shrink and resolve after a few months
What is the treatment for keratoacanthoma?
Surgical excision
What are the risk factors for melanoma skin cancer?
UV radiation
Genetic susceptibility - fair skin, red hair, blue eyes and tendency to burn easily
Familial melanoma and melanoma susceptibility genes
What is the ABCDE rule for melanoma skin cancer?
Asymmetry
Border - irregular
Colour - multiple colours
Diameter - >7mm
Evolution - is it changing