Sign In
Advertisement

Melanoma

Read in Hindi

Melanoma, a tumour formed because of malignant transformation, is one of the most dangerous forms of skin cancer. Melanoma is difficult to manage after metastasis as the survival rate of the patient significantly drops. Hence, prompt diagnosis and early treatment are the best management for melanoma. Melanoma affects only 22.1 out of 10,000 individuals residing in the USA. Melanoma accounts for 75% of skin cancer mortality and only ~4% of skin cancer cases. Because of the high death rates associated with metastatic melanoma, an improved understanding of melanoma pathogenesis is the requirement of the hour. 

Also Read

Types

There are four types of melanoma; they are classified as per the tumour's growth pattern:


  1. Nodular melanoma or tumours that are blue-black, and these tumours may lack pigment in certain situations. This melanoma type accounts for ~15%–30% of melanoma cases.

  2. Acral lentiginous melanoma appears as flat, brown stains with irregular borders. These lesions can be brown or black with ulcerations in later stages. Acral lentiginous lesions account for 4%–10% of melanoma cases.

  3. Lentigo maligna melanoma is a type of tumour larger than 3 cm, with marked borders, tan and flat. Therefore, in the initial stages of lentigo maligna melanoma, they appear similar to freckle-like lesions.

  4. Usually, superficial spreading melanoma is flat elevated in later stages and irregular in structure. These lesions are of 2 cm diameter with peripheral notches and variegated colours, indentations or both.

Stages

Stages of melanoma as per the growth of the tumour are listed below:

Stage I: Less than or equal to 0.75 mm

Stage II: 0.76–1.5 mm

Stage III: 1.51–2.25 mm

Stage IV: 2.26–3.0 mm

Stage V: >3.0 mm

Stages as per the pathogenesis of tumour are listed below:

Level one: Melanoma cells are confined to the epidermis (melanoma in situ)

Level two: Invasion of single cells or small nests of melanoma in the papillary dermis

Level three: Melanoma cells expand and occupy the papillary dermis

Level four: Invasion in the reticular dermis

Level five: Invasion in the subcutaneous fat.

Symptoms

Signs of melanoma are listed below:


  • Knowing how to spot a melanoma is important because early melanomas are highly treatable.

  • Melanoma can appear as scaly patches, moles, raised bumps or open sores.

Causes And Risk Factors

Causes

The causes of melanoma are listed below-


  • Personal characteristics - Unique features such as red hair, pale complexion, blue eyes, skin sensitivity to sunlight, and immunosuppression because organ transplantation for haematology malignancies such as blood cancer can be a probable cause of melanoma.

  • Family history - A family history of melanoma increases the risk of occurrence of this disease in an individual.

  • Atypical mole syndrome - Dysplastic nevus syndrome over ten years increases the risk of developing melanoma by 10.7%. This risk increases, even more, when family members are affected with the same condition.

  • Sun exposure - Lifetime exposure to high UVA and UVB radiation has shown that individuals who use sunscreen are associated with a higher risk of developing melanoma.

  • Socioeconomic status - A lower socioeconomic status is linked to the detection of typically advanced melanoma during the time of diagnosis.


Risk Factors


Risk factors for melanoma are listed below:

  • Exposure to UVA or UVB radiation for an extended time period.

  • Skin sensitive to light, which usually leads to sunburns.

  • Family history of melanoma.

  • Immunosuppression.

  • Special personal characteristics.

Prevention

Melanoma can be prevented by minimizing exposure to sunlight. The following measures can help you avert melanoma:


  • Prevent going out in the sun, especially between 10 AM and 4 PM

  • Cover your head with hats, wear sunglasses and a long-sleeved shirt and pants to prevent skin exposure to the sunlight.

  • Do not use tanning beds.

  • Protect your lips with lip balm and skin by applying sunscreen.

  • Young children and infants older than six months should be protected by applying sunscreen.

  • Sunscreen with a broad-spectrum of skin protection factor (SPF) of 30 or more should be used often.

Diagnosis

The diagnosis of melanoma includes physical examination and laboratory workup. In physical examination, melanoma characteristics such as asymmetry, irregular border, colour variation, predominantly white, and red and blue tones in a black or brown lesion; diameters >6 mm or elevated surface of the tumour are evaluated with biopsy. Moreover, the biopsy helps us differentiate stages 1 and 2 in thickness, and it can obtain a specimen for pathological testing.

Laboratory investigations such as complete blood count, lactate dehydrogenase, and complete blood chemistry panel such as alkaline phosphatase, total protein, hepatic transaminase and albumin are evaluated.

Radiographic imaging is considered a diagnostic workup.


  • CT scan of chest abdomen or pelvis.

  • Chest radiography

  • Ultrasonography is one of the best imaging for studying lymph node involvement in melanoma.

  • MRI of the brain.

  • A positron emission tomography (PET) scan is used to identify the site of metastasis.

Treatment

Treatment of melanoma is listed below:

Surgical resection

Surgical resection is the method of surgically removing the tumour and surrounding healthy tissue for localized and non-malignant melanoma. Sentinel lymph node biopsy is performed in patients with tumour sizes of >0.8 mm. On identifying the melanoma cells in the sentinel lymph nodes, the remaining lymph node may be surgically removed. In certain conditions, the metastatic tumour may be attempted for surgical resection.

Chemotherapy

The patients with metastatic melanoma relying only on surgical treatment is insufficient, and drug therapies play an essential role in managing melanoma. Dacarbazine has remained the standard of care for metastatic melanoma. The survival rate is 27%, and the survival period is from 5 to 11 months.

Targeted therapies

Targeted therapies such as BRAF inhibitors, dabrafenib and vemurafenib are approved to treat metastatic and unresectable BRAF-mutated melanoma. However, 50% of the patient receiving these drugs develop secondary resistance in a short time period.

Immune response in melanoma or immunotherapies

Immune checkpoint inhibitors a type of immunotherapy that is used in melanoma treatment. There are three immune checkpoint inhibitors drugs, such as ipilimumab, nivolumab and pembrolizumab, used to treat melanoma.

Lifestyle/management

Diet modifications of the melanoma patient play an important role in the management:

Modifying the diet by increasing the intake of fruits and vegetables is beneficial in the prevention of cancer. Tea and coffee are rich in antioxidants such as quinic acid, ferulic acid, caffeic acid, coumaric acid and chlorogenic acid, which are beneficial for preventing cancer.

Prognosis And Complications

Prognosis


There is a poor prognosis reported in melanoma if prognostic factors are listed below: Evidence of tumour in regional lymph nodes, greater tumour thickness, a high number of positive lymph nodes, anatomic sites such as the trunk or face lesions that are associated with the poor prognosis than extremity regions, male sex, presence of distant metastasis, presence of ulceration, and presence of regression on histologic examination.

  1. Prognostic factors are dependent on the stage of melanoma and its diagnosis.

  2. Patients with stage one disease have a five-year survival rate of >90%.

  3. Patients suffering from stage 2 of melanoma have a five-year survival rate of 45%–77%.

  4. Patients with stage 3 of melanoma have a five-year survival rate from 27% to 70%.

  5. Metastatic melanoma disease patients have a grave prognosis with a five-year survival rate of <20%.


Complications


The complications of melanoma are listed below:

  • Secondary infection is caused by normal skin barrier destruction.

  • Scarring of the skin, which can result in lesions or treatment.

  • Local recurrence in more advanced cases before diagnosis.

  • Lymphedema, which is most commonly seen in the patients with the removal of lymph nodes.

  • Depression and anxiety.

  • Metastasis is common in the advanced stages of melanoma and squamous cell carcinoma.

Alternate Treatments

There are no alternative treatments for melanoma.

References.


  1. Stat Pearls. alignant melanoma [Updated on December 5, 2020] Available at https://www.ncbi.nlm.nih.gov/books/NBK470409/.  (https://www.ncbi.nlm.nih.gov/books/NBK470409/)

  2. Cancer Biology and therapy. Current state of melanoma diagnosis and treatment. [Internet] [Updated on 23 May, 2019] Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6804807/.  (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6804807)

  3. HHS Public access. Melanoma: Molecular Pathogenesis and Therapeutic Management [Internet] Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4346328/.  (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4346328)

  4. Cleveland Clinic. Melanoma [Internet] Available at https://my.clevelandclinic.org/health/diseases/14391-melanoma.  (https://my.clevelandclinic.org/health/diseases/14391-melanoma)

  5. Nutrition & Metabolism. Dietary compounds and cutaneous malignant melanoma: recent advances from a biological perspective. [Internet] Available https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6528337/. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6528337/)

Videos

Health Calculator

Photo Gallery