Melanoma: symptoms, treatment and survival

Melanoma is a malignant tumour arising from melanocytes — the pigment-producing cells in the skin. It is the most dangerous form of skin cancer because it can spread rapidly to lymph nodes and distant organs. Around 16,000 people are diagnosed in the UK each year, and it causes approximately 2,300 deaths annually despite being less common than non-melanoma skin cancers.

Melanoma most commonly appears as a new or changing mole that is asymmetrical, has an irregular or notched border, contains multiple colours (shades of brown, black, pink, red, white or blue), is larger than 6 mm in diameter, or is evolving in size, shape, colour or sensation. Nodular melanoma can appear as a uniform dark blue-black or pink/red raised lump that may bleed. Any suspicious or changing skin lesion should be assessed by a GP.

The ABCDE rule is an NHS-recommended checklist for assessing moles: A — Asymmetry (one half differs from the other); B — Border (irregular, ragged or blurred edges); C — Colour (multiple shades or colours within the lesion); D — Diameter (greater than 6 mm, though smaller melanomas exist); E — Evolution (any change in the mole, or new symptoms such as bleeding, itching or crusting). Any lesion meeting one or more criteria should be assessed by a GP without delay.

Around 16,000 people are diagnosed with melanoma in the UK each year, making it the fifth most common cancer in adults under 50. It is most frequently diagnosed in adults aged 55–64 and is slightly more common in women than men in younger age groups. Incidence has risen by more than 130% in the UK over the past 30 years, driven largely by increased UV exposure and sunbed use.

UV radiation — from sunlight and sunbeds — is the primary cause of cutaneous melanoma. UV radiation damages the DNA in melanocytes, triggering mutations in genes such as BRAF, NRAS and CDKN2A that drive malignant transformation. Intermittent intense sun exposure and sunburn are particularly associated with melanoma risk, in contrast to basal cell carcinoma which is more strongly linked to cumulative total exposure.

Yes. The World Health Organization classifies sunbeds as Group 1 carcinogens — meaning there is conclusive evidence they cause cancer in humans. Using a sunbed before the age of 35 increases the lifetime risk of melanoma by approximately 75%. The UK banned the commercial use of sunbeds by under-18s in 2011. The NHS advises avoiding sunbeds entirely.

Risk is greatest in people with: fair skin, red or blonde hair, blue or green eyes; a large number of moles (more than 50) or atypical (dysplastic) moles; a personal or family history of melanoma; previous severe sunburn, especially in childhood; sunbed use; immunosuppression; or a large congenital melanocytic naevus. People from all ethnic backgrounds can develop melanoma, though it is significantly less common in people with darker skin.

Any suspicious pigmented lesion identified by a GP or self-examination is referred urgently to a dermatologist under the NHS Two Week Wait pathway. The dermatologist assesses the lesion clinically and with a dermatoscope (dermoscopy). If melanoma is suspected, the entire lesion is excised under local anaesthetic with a 2 mm margin (diagnostic excision), and the tissue is sent for histopathological analysis. Diagnosis is confirmed on pathology, not on clinical appearance alone.

A sentinel lymph node biopsy (SLNB) is a surgical procedure performed at the time of wide local excision for melanomas thicker than 1 mm. A radiotracer and blue dye are injected near the melanoma site; the first lymph node(s) to receive drainage from the tumour site (sentinel nodes) are identified, removed and examined for melanoma cells. SLNB provides important staging information and identifies patients who may benefit from completion lymph node dissection or adjuvant systemic therapy.

Melanoma is staged from Stage I to Stage IV. Stage I: thin tumour (≤2 mm) confined to the skin with no ulceration or lymph node involvement. Stage II: thicker tumour or ulceration, still confined to the skin. Stage III: cancer has spread to regional lymph nodes or nearby skin. Stage IV (metastatic): cancer has spread to distant organs (lung, brain, liver, bone or distant skin). Stage I five-year survival exceeds 95%; Stage IV five-year survival is approximately 25% with modern treatment.

For localised melanoma: wide local excision with margins according to tumour thickness (0.5–2 cm), plus sentinel lymph node biopsy for tumours >1 mm. For Stage III: surgery, and adjuvant systemic therapy (pembrolizumab, nivolumab or BRAF/MEK inhibitors for BRAF-mutated tumours). For Stage IV (metastatic): immunotherapy (anti-PD-1 ± anti-CTLA-4) or BRAF/MEK inhibitor combination (for BRAF V600-mutated tumours). Radiotherapy is used for brain metastases and palliative symptom control.

Immunotherapy for melanoma uses checkpoint inhibitor drugs to unleash the immune system against cancer cells. The most effective agents are anti-PD-1 antibodies — pembrolizumab (Keytruda) and nivolumab (Opdivo) — often combined with the anti-CTLA-4 antibody ipilimumab (Yervoy) for higher-risk Stage III–IV disease. This combination produces durable responses in a significant proportion of patients with Stage IV melanoma, with five-year survival rates of approximately 40–52% in clinical trials, compared with below 10% before immunotherapy was available.

Approximately 50% of melanomas carry a BRAF V600E or V600K mutation — an error in the BRAF gene that drives rapid cancer cell growth. BRAF inhibitors (vemurafenib or dabrafenib) combined with MEK inhibitors (cobimetinib or trametinib) block this signalling pathway, producing rapid tumour shrinkage in most BRAF-mutated melanomas. They are an alternative to immunotherapy in BRAF-positive disease and may be preferred when a rapid response is needed. Resistance eventually develops in most patients, limiting long-term durability.

Five-year survival for melanoma in the UK is approximately 90% overall, reflecting the high proportion diagnosed at early stages. By stage: Stage I — over 95%; Stage II — approximately 80%; Stage III — approximately 60%; Stage IV — approximately 25%, rising to 40–52% in clinical trial populations treated with combination immunotherapy. Survival rates have improved dramatically over the past decade due to targeted therapy and immunotherapy.

Early-stage melanoma (Stage I–II) confined to the skin is cured in the majority of patients through wide local excision. Stage III melanoma (lymph node involvement) is treated with curative intent using surgery plus adjuvant systemic therapy. Stage IV (metastatic) melanoma is not generally considered curable, but a significant minority of patients achieve very long-lasting responses with combination immunotherapy. 'Complete responders' who achieve no detectable disease on imaging have been reported surviving for ten or more years.

Yes. While most melanomas arise on the skin, melanocytes are also present in the eye, mucous membranes (mouth, nose, throat, genitals) and very rarely in internal organs. Uveal melanoma (melanoma of the eye) is a distinct disease treated differently from cutaneous melanoma and associated with a higher rate of liver metastasis. Mucosal melanomas are rarer still, tend to present late and have a worse prognosis. Nail-bed melanoma (subungual melanoma) can be mistaken for a bruise or fungal infection.

The NHS recommends regular self-examination — ideally once a month — to look for any new moles or changes in existing ones. Use the ABCDE rule and compare to previous appearances (photographs can help). Ask a partner or friend to check difficult-to-see areas such as the back and scalp. See your GP promptly if you notice any change rather than waiting for a scheduled GP appointment. People with many moles or a family history of melanoma may be offered routine dermatologist review.

A normal mole (benign melanocytic naevus) is a symmetrical, evenly coloured, well-defined spot that remains stable over time. Melanoma is asymmetrical, has an irregular or blurred border, may contain multiple colours, is often larger than 6 mm and — most importantly — evolves or changes. However, not all melanomas arise from pre-existing moles: approximately 50% develop in previously normal-appearing skin. Any new or changing skin lesion should be assessed by a GP, not assumed to be benign.

Yes, though it is significantly less common. Melanoma in people with darker skin (Fitzpatrick types V and VI) tends to present as acral lentiginous melanoma — on the palms, soles or under the nails — sites less associated with UV exposure. This type is often diagnosed at a more advanced stage, partly because awareness is lower among patients and clinicians. Melanoma in dark-skinned individuals carries a worse prognosis overall, primarily due to later diagnosis.

In low-income countries, melanoma is commonly diagnosed late because dermatology services are concentrated in urban hospitals. Immunotherapy (pembrolizumab, nivolumab) and BRAF-targeted therapy — the standard of care in the UK — cost tens of thousands of pounds per patient per year and are unaffordable for most poor patients globally. World Aid Network funds cancer treatment through locally-licensed oncologists, helping to bridge this treatment inequality.