How common is skin cancer in Indian subcontinent?
Skin cancer is relatively uncommon in Indian subcontinent. Our dark-coloured skin has high melanin pigment which protects us from UV rays and skin cancer. However, there are a few skin cancers such as squamous cell cancer, basal cell cancer, cutaneous lymphomas and melanomas frequently seen in our patients.
What are the risk factors?
Ultra violet rays are the most important factor for skin cancer. People living in equatorial region with light coloured skin have high exposure to sun and are at the highest risk for skin cancer. People working with toxic chemicals and arsenic containing agents are prone to skin cancer, and also people living in ‘arsenic regions’ (containing high arsenic in water). Chronic infection (irritation) may lead to skin cancer. There are few genetic conditions (e.g. xeroderma pigmentosa) associated with skin cancer.
How can we prevent skin cancer?
Protection from excessive exposure to sunlight and UV rays, avoiding toxic chemical agents and arsenic will help to prevent skin cancer. Treatment of chronic irritation of skin, healthy lifestyle and food habits help to prevent cancer.
What are the common skin cancers?
In India squamous cell cancer (SCC) is the most common skin cancer. Chronic irritations from infection and chemical agents are the causes of SCC. SCC tends to metastasise (spread) to regional lymph nodes and other organs. Once there is metastasis, prognosis is not optimal. Another common tumour is basal cell cancer, usually seen on the face. ‘Mycosis fungoides’ is lymphoma of skin, and the patient has multiple lesions throughout the body. Patients have excessive itching and occasional bleeding from the lesions. Melanoma is one of the aggressive skin cancers, and produces dark coloured nodules.
How do we treat them?
Skin cancers are treated with local form of treatment (surgery or radiation therapy). Surgery is the preferred option in localised lesions. Radiation therapy is considered in extensive lesions, if there is microscopic residual disease after surgery and in patients with high risk of recurrence. ‘Total skin radiation’ is the treatment option in ‘cutaneous T-cell lymphoma’. Chemotherapy is considered in some lymphomas and metastatic disease. Brachytherapy is also a curative option in localized basal cell cancer.
What is ‘total skin radiation’?
This is a special radiation therapy technique where we treat the entire skin with low dose radiation.
Does ‘melanoma’ occur only in the skin?
Melanoma is the tumour of melanin containing cells. It is mostly seen in the skin, but also in eye, gut and other organs. Melanoma has a high tendency to spread in lymph nodes, liver and other organs.
What is the prognosis?
Prognosis depends upon the size, depth of invasion, extent of the lesion and also on complete removal of the tumour. Localized cancer of skin has excellent prognosis after complete removal. Skin cancers are considered ‘cured’ after adequate surgery or radiation therapy.
Can common moles transform to cancer?
There is a small risk that a common mole also can transform to cancer. Sudden change in colour, size, texture, and bleeding are the signs of malignant transformation.
Do persons with vitiligo have more risk of cancer?
There is no scientific rationale behind this argument. However, few persons with genetic instability disorders (e.g. Ataxia telangiectasia, Bloom’s syndrome) have skin lesions as well as high risk of cancer.