Melanoma is a malignant tumour originating from melanocytes, which are the cells responsible for producing melanin, the substance that gives pigment to the skin.
For this reason, these lesions are dark brown to black in colour. However, although it rarely occurs, melanoma can also appear pink or white (amelanotic melanoma).
It is a relatively rare tumour but one of the most aggressive, accounting for approximately 5-10% of skin cancers. This type of cancer is responsible for about 80% of deaths from skin cancer.
In general, initially there are no symptoms from this disease, only morphological alterations of suspicious nodules (increased lesion, changes in colour and asymmetry), which can sometimes ulcerate and bleed. Only in advanced stages do complaints arise.
Melanoma can affect any age group and is relatively frequent in young adults of both sexes and rare during childhood. It appears more frequently in Caucasian individuals. In women, it is preferentially located in the lower limbs. In males, the location is usually in the trunk.
People with fair skin, freckles, redheads or blondes, with light eyes, atypical nevi, with a history of intense sun exposure, “sunburn” especially during childhood, have a higher risk of developing this type of cancer.
During the course of the disease, a significant percentage of patients develop locally advanced inoperable and/or metastatic melanoma (Stage IV). When diagnosed, approximately 2-5% of cases may already be in stage IV. Bearing this in mind, the probability of cure is low and the overall survival rate at five years is less than 10%.
From 2011 onwards, new, more effective drugs began to appear, with different mechanisms of action which resulted, for the first time, in an increase in the overall survival of patients with advanced melanoma.
This was the case of targeted therapies for patients with mutations in the BRAF gene and immunotherapy. Unlike antineoplastic chemotherapy, immunotherapy acts on the host and not directly on the tumour, modulating the body’s immune responses so it can fight effectively and long-lastingly against melanoma.
Immunotherapy and targeted therapies have led to an increased overall survival and long-lasting responses, often turning an aggressive disease into a chronic disease with few symptoms.
Currently, in Portugal, we treat patients with these new agents and we have international multicentre clinical trials on high-risk/advanced melanoma.
I would like to finish by leaving a message of hope and optimism, especially to our melanoma patients.
The advent of immunotherapy with checkpoint inhibitors and targeted anti-BRAF therapies radically changed the natural history of melanoma, definitively dethroning antineoplastic chemotherapy and demonstrating an incomparable efficacy in a metastatic and now also adjuvant context, in stages III.
By Dr Maria José Passos
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Dr Maria José Passos is an oncologist with extensive experience in cutaneous melanoma. She is available for consultations at the HPA Health Group
