Melanoma: signs, diagnosis and treatment

Cancer Research UK describes melanoma as abnormal skin cells growing and dividing out of control. The cells involved, melanocytes, sit in the deep layer of the epidermis and make melanin. People with brown or black skin do not have more melanocytes, but theirs make more melanin.

It can start in an existing mole or on apparently normal skin. Rarely, it begins in the eye or in the lining of body surfaces, called mucosal melanoma, and these are described separately.

It can occur at any age but is more common in older people. Unlike most cancers it is also quite common in younger adults.

The NHS tells people to check their skin, using a mirror or a friend for areas they cannot see. A new mole or a change in an existing one may be a sign. It sets out features that tend to separate melanoma from ordinary moles.

The NHS says melanoma is more common on sun-exposed areas, and rarer types can affect the eyes, soles of the feet, palms or genitals. For people with black or brown skin, it most often appears on the soles, palms or under a nail.

Cancer Research UK explains that melanomas on the palms, soles and under the nails are usually acral melanomas, which are not related to sun exposure and are diagnosed more often in people with brown or black skin. NHS inform advises checking these areas for dark spots or changes.

A dark streak under a nail that has not been caused by injury is one of the NHS reasons to see a GP.

The NHS says to see a GP for a mole that has changed size, shape or colour, is painful or itchy, is inflamed, bleeding or crusty, a new or unusual mark that has not gone away after a few weeks, or a dark area under a nail not caused by injury.

At the appointment, the GP asks about your health and family history and looks at the mole. They may photograph it for review by a dermatologist, called teledermatology. If cancer is possible you may get an urgent referral, which NHS inform says should lead to a hospital appointment within 2 weeks. The NHS stresses an urgent referral does not definitely mean cancer.

The specialist examines your skin, often with a magnifying dermatoscope. The NHS says they may cut out the mole and a small rim of surrounding skin for the laboratory, called an excision biopsy. NHS inform adds that a mole that looks unusual but not clearly cancerous may be monitored with regular photographs instead.

If melanoma is confirmed, the NHS says more tests may include a CT or MRI scan, tests on the lymph nodes and blood tests. These show how deep the cancer is and how far it has spread, which is its stage. NHS inform describes sentinel lymph node biopsy, ultrasound and fine needle aspiration for nodes, and gene testing of the melanoma cells to guide targeted or immunotherapy drugs.

A clinical nurse specialist usually becomes your main point of contact. The NHS also lists a free Melanoma Focus helpline run by skin cancer nurses.

The NHS says treatment depends on where the cancer is, whether it has spread and your general health, and that surgery is the main treatment, especially if found early. A multidisciplinary team plans care. NHS inform says most people have a wide local excision, removing more tissue around the original site, and for early melanoma this is often the only treatment needed.

Surgery may also remove swollen lymph glands or deposits elsewhere. A plastic surgeon may operate on visible areas, and a skin graft may be used for large defects. Radiotherapy is sometimes used to shrink large melanomas and relieve symptoms.

Targeted medicines and immunotherapy are used for melanomas that cannot be removed surgically or have spread. The NHS says chemotherapy works less well for melanoma than those options and is mainly considered when other treatments are not possible.

Cancer Research UK stresses that survival statistics describe large groups and cannot predict one person's outcome. For England in 2013 to 2017, it reports almost everyone with stage 1 surviving 5 years or more, around 85% for stage 2 and almost 75% for stage 3.

For stage 4 it says newer immunotherapy treatments have had very good results and some people live with stage 4 melanoma for a long time, though not everyone, and published figures do not yet reflect these newer treatments.

If melanoma is advanced and cannot be cured, the NHS says treatment aims to limit the cancer and its symptoms and help you live longer, with palliative care or symptom control teams involved.

Suspected melanoma is handled through the urgent suspected cancer pathway on the NHS, so private assessment is mainly about speed of the first look. A private dermatologist or mole-mapping clinic can examine moles and arrange removal and histology.

If melanoma is confirmed, treatment decisions and follow-up are usually made by a skin cancer multidisciplinary team, whether care began privately or on the NHS.