Cancer Flashcards
Melanoma risk factors
FH
Light skin
Red hair
Sun exposure
Sunbed
Immunosuppressant
Melanoma molecular pathogenesis
MAPK pathway
KIT mutation - acral and muscosal melanoma
BRAF gene - Intermittent sun exposure, but low for high cumulative exposure
P16 - tumour suppressor
CD8+ T cell recognise melanoma specific antigens and may kill tumour cells
CD4+ helper cells also play a role
Melanoma types
Superficial spreading Nodular Lentigo maligna Acral lentiginous Unclassifiable
Superficial spreading
Most common in fair skin
Grey
Horizontal growth then vertical growth - asymmetrical and irregular border
Nodular
Second most common
Blue to black or pink to red
Rapid
No asymmetry or border irregularity as no horizontal growth
Lentigo maligna
Elderly
Chronically Sun damaged skin
Asymmetrical brown to black and irregular border
Invasive Lentigo maligna melanoma
Acral lentiginous
Uncommon
70s
Palms and soles and around nails
More commonly POC
Amelonotic melanoma - lack pigment
Self detection
Asymmetry Border irregularity Colour varitaion Diameter greater than 5mm Evolving
Prognostic factors
Increased Breslow thickness >1mm - from granular layer to bottom of tumour Ulcer Age Male Trunk, head, neck Lymph involvement
Melanoma investigation
Dermoscopy - not considered in isolation
Melanoma management
Primary excision down to subcutaneous fat - 2mm peripheral margin
If melanoma confirmed on primary excision - wider excision performed - margin determined by Breslow depth
5mm for in situ
10mm for more than 1mm thick
Sentinel lymphoma node biopsy - sentinel node closest and thus most likely to contain disease - offered for pT1b+
Imaging for stage 3 and 4 and 2 without SLNB
Immunotherapy or mutated oncogene target therapy for unresectable or metastatic
Keratinocyte carcinoma
Pale skin
UV damage
Actinic keratoses - Bowen’s disease - Squamous cell carcinoma (may metastasise) - basal cell carcinoma (never metastasise)
Basal cell carcinoma
Most common skin cancer
UV significant risk factor
Dependent on stroma produced by dermal fibroblast
Sonic hedgehog patched signalling pathway
Squamous cell carcinoma
UV radiation significant risk factor
Addition of genetic alterations - p53 most common
Ill defined
Rapidly growing
Immunosuppressed
Actinic keratoses
Confined to epidermis
Usually head, neck, upper trunk and extremities
Difficult to distinguish from SCC - need biopsy
Red and scaly
Treat with 5-flurouracil cream or cryotherapy