MELANOMA and OTHER SKIN CANCERS: a GUIDE for MEDICAL PRACTITIONERS Australia Has Among the Highest Rates of Skin Cancer in the World
Total Page:16
File Type:pdf, Size:1020Kb
MELANOMA AND OTHER SKIN CANCERS: A GUIDE FOR MEDICAL PRACTITIONERS Australia has among the highest rates of skin cancer in the world. Two in three Australians will develop some form of skin cancer before the age of 70 years. Skin cancer is divided into two main types Causes of melanoma and other Gender skin cancers Men are more likely to develop and die from • Unprotected exposure to UV radiation remains melanoma than women. Mortality from the single most important lifestyle risk factor melanoma rises for males from 40 years and for melanoma and other skin cancers. increases with age. Men over the age of 40, compared to women of similar age, are more Melanoma Non-melanocytic skin cancer • UVA and UVB radiation contribute to skin than one and a half times more likely to be Melanoma develops in the melanocyte (NMSC) damage, premature ageing and skin cancer. diagnosed with melanoma and more than twice (pigment-producing) cells located in the • Squamous cell carcinoma (SCC) • An intermittent exposure pattern carries the as likely to die from it. epidermis. Untreated, melanoma has a develops from keratinocytes in the highest risk for developing melanoma and The mortality rate for males aged 50–80 years is high risk for metastasis. epidermis and is associated with risk BCC. UV exposure in adulthood or childhood two to three times that of females. The most common clinical subtype is of metastasis. Overall, SCC is most contributes to BCC and melanoma risk. commonly found on the face, particularly superficial spreading melanoma (SSM), • Actinic keratoses and SCC are associated the lip region, ears, nose, cheek and Melanoma in Indigenous making up 55–60% of all melanoma. SSM with the total amount of sun exposure eyelid, and then on the neck, dorsum Australians and non- Caucasian is most commonly found on the head accumulated over a lifetime. and neck (per unit area). Other common of hands and forearms. In males, SCC is patients sites are the trunk in males and lower commonly found on the head and neck, • Other risk factors for NMSC can include exposure to some chemicals (e.g. arsenic); The incidence of melanoma in Indigenous extremities in females. and in females it is commonly found on Australians is low. For the period 2008–2012, the lower limbs, followed by the head and radiation therapy and psoralen (PUVA) However, SSM can develop on any part treatment for psoriasis; immunosuppressive twenty-two Indigenous Australians died from of the body, including parts not heavily neck. SCCs may arise from premalignant melanoma, representing 0.4% of all melanoma actinic keratoses. therapy; and some rare genetic conditions exposed to ultraviolet (UV) radiation. predisposing people to skin cancer (e.g. deaths. For the same period, there were 7,300 deaths from melanoma overall. The incidence • Basal cell carcinoma (BCC) also Xeroderma pigmentosum, albinism). In WA in 2017: of melanoma in non-Caucasians is also low. develops from keratinocytes in the • There were more than 1,400 new cases of However, non-Caucasians are more likely to epidermis and is the most frequently Risk factors for melanoma melanoma (11% of all cancer diagnoses) experience delayed diagnosis and have poorer diagnosed cancer in Australians. It can • Multiple naevi (moles) and over 130 deaths. clinical prognosis compared to Caucasians. be found most commonly on the head • Multiple dysplastic naevi • Men over the age of 40 were more and neck but also on the trunk and limbs. • Personal or family history of melanoma Non-Caucasians tend to develop than one and a half times more likely It can also be found in areas not exposed • Increasing age clinical melanoma subtypes that are rare in to be diagnosed with melanoma and to sunlight. • High levels of intermittent sun exposure Caucasian populations: more than twice as likely to die from it, (e.g. during outdoor recreation) • Acral lentiginous melanoma on the palms compared to women of similar age. In WA in 2014, there were 83,151 paid • Occupational sun exposure and soles. Medicare services for NMSC, and • The lifetime risk of developing melanoma • Personal history of NMSC • Subungual melanoma within the nail matrix. by age 85 years was one in 21 for men 82 deaths. • Fair skin that burns easily, freckles and does and one in 30 for women. not tan • Fair or red hair and blue or green eyes • Immune suppression and/or being a transplant recipient. Melanoma diagnosis The ABCD(E) acronym can help distinguish Superficial spreading an SSM from a normal mole: Any lesion that displays the EFG features over melanoma (SSM) Asymmetry: the lesion is irregular in a period of more than one month should be Melanoma can develop in pre-existing moles or A shape or pattern. more commonly, de novo. investigated. • SSM is the most common form of Border: the border or outline of a If melanoma is suspected, diagnosis should not be B melanoma is usually irregular. melanoma. delayed and urgent referral or immediate excision • SSM can appear as a new spot or as a Colour: there is variation in colour change in the size, colour or shape of an with a 2mm margin is recommended. C within the lesion. existing mole. • A patient diagnosed with SSM is at Diameter: the lesion is usually greater increased risk of developing a new primary than 6 mm across. melanoma. D However, suspect lesions of smaller Lentigo Maligna (LM) Diagnosis tools diameter should also be investigated. A slow growing form of melanoma in situ that Dermoscopy uses a hand-held magnifying Nodular melanoma (NM) can be difficult to recognise. LM can resemble device to allow the visualisation of diagnostic Evolving: the lesion changes over This is a dangerous form of melanoma that a freckle. It develops in sun-damaged older features of skin lesions that are not seen with E time (size, shape, surface, colour, skin, especially on the head and neck. Margin the naked eye. It increases diagnostic accuracy can metastasise early. It differs from SSM in symptoms e.g. itch). appearance. determination can be challenging and local and reduces unnecessary excision of benign recurrence is more common than in other types • NM has no radial growth within the epidermis lesions. Training in dermoscopy is recommended of melanoma. Incidence is increasing. but penetrates vertically into the dermis for clinicians routinely involved in skin cancer early. The ABCDE acronym cannot be used to aid treatment. diagnosis of NM but the following features Biopsy and excision • Sequential digital dermoscopy imaging • NM can develop de novo in normal- for melanoma or suspicious appearing skin or within another type of EFG – can assist with the diagnosis (SDDI) involves the assessment of successive naevi dermoscopic images to allow the detection of melanoma. Elevated: the lesion can appear as • Excision of the entire lesion with a suspicious dermoscopic change in melanomas • NM is more likely to be symmetrical and a small, round and raised lump on 2mm margin is recommended. that lack dermoscopic evidence of melanoma uniform in colour (red, pink, brown or black), E the skin. Colour may be uniform at a particular time. is more frequently lighter coloured than SSM, throughout the lesion and may be • Partial biopsies (punch biopsy or shave and feels firm to the touch. black, brown, pink or red. excision) are less accurate than excisional • Total body photography allows the detection of suspicious changes and is useful in high- • Over time, NM may develop a crusty surface biopsy and should be avoided. If complete Firm: the lesion feels firm to the risk patients or patients with dysplastic that bleeds easily. excision is impractical, a large incisional F touch biopsy incorporating as much of the atypical naevus syndrome. • NM develops most commonly on sun- part of the lesion as possible is the best • In vivo confocal microscopy allows damaged skin and in older people, Grows: a nodule that has been alternative. non-invasive “optical biopsy” with the particularly men. growing progressively for more than a G • The excision or biopsy should not interfere visualisation of the morphology and • Approximately 10–15% of total melanomas month should be assessed as a matter organisation of the cells in deeper layers of of urgency. with subsequent treatment. For this diagnosed are NM. reason, wide excisions, flap reconstructions the skin. It is useful for difficult diagnoses and curettage of suspicious lesions are and margins (i.e. amelanotic melanoma, LM) contraindicated. and is used in specialised centres. Smartphone applications for pigmented lesions Melanoma apps are smartphone applications that assess risk of pigmented lesions using a smartphone camera and underlying algorithm. None of the melanoma apps tested have shown high enough agreement with a specialist clinical opinion to be considered adequate for assessing high-risk pigmented lesions. Treatment for melanoma Other treatment options Appropriate primary treatment will depend on the Breslow thickness of the tumour. Surgery • Sentinel lymph node biopsy (SLNB) should T cells, (namely the cytotoxic T lymphocyte Tis - Melanoma Melanoma cells are found only in the non-vascular epidermis be discussed with all patients with lesions associated protein 4 (CTLA-4) receptor and and have not penetrated into the dermis. over T1b (>0.8mm). These patients should be the programmed death 1 (PD-1) receptor). in situ. discussed at a multidisciplinary melanoma The combination of immunological therapies meeting such as the Western Australian seems more efficient but more toxic (possible The melanoma is less than 1 mm thick. T1 Kirkbride Melanoma Advisory Service side-effects include fatigue, arthralgia, joint (WAKMAS) before definitive treatment is pain and major autoimmune disease). The melanoma is between 1 mm and 2 mm thick. T2 undertaken. – Current immunotherapy drugs in use include • Resection of isolated metastases can be Nivolumab, Ipilimumab and Pembrolizumab.