Cancer is a phenomenon where cells become abnormal, multiply and grow at an extraordinary rate with the normal controls becoming ineffective. These fast-growing cells form lumps called tumors. If these tumors are benign (harmless in the long run) there is little cause for worry. If the tumor turns malignant (harmful and worsens over time), it needs treatment.
Skin cancer is the most common type of cancer in the country, with more than one million people being diagnosed with one type or another. There are two main types of skin cancers, non-melanoma and melanoma. The most common non-melanoma cancers are basal cell carcinoma and squamous cell carcinoma.
Melanoma: This is a dangerous form of skin cancer, that develops most often due to exposure to ultraviolet light. The UV light is present in sunlight. Man-made instruments like tanning beds and sun lamps are sources of UV light too. Moles are pigmented benign tumors. Moles, most often are harmless, but an unusual number of moles on a person increases the risk of developing melanoma. Other risk factors include having green, blue or hazel eyes, or having light-colored hair. Again, fair-skinned people who are prone to sunburn and freckling have more chances of developing melanoma. A family history of cancer will increase the risk.
Basal cell carcinoma: This is the most common type of skin cancer prevalent in the country and also one with the least risks. It affects the basal cells that are found in the bottom layer of the epidermis (the top layer of the skin). People over the age of 40 are more likely to get affected. It grows slowly and is unlikely to spread to other parts of the body, though it can occasionally spread to nearby tissues under the skin and bone. As in melanoma, the risk factors are similar to the risks factors for basal cell carcinoma.
Squamous cell carcinoma: This is the second most common form of skin cancer. It appears mostly where there has been a prolonged exposure to UV rays from sunlamps and tanning beds. It affects the head, neck, lips, ears, arms, hands and legs. This form of skin cancer can spread to nearby lymph nodes, bones, and tissues, where it becomes difficult to treat. When detected early, it can be easily treated.
Squamous cell carcinoma is caused by the genetic defects in the squamous cells – a thin layer of cells between the outer layer of skin cells and the basal cells that form the epidermis. Due to an anomaly in the immune system, new cells are produced faster than the rate at which old skin cells are shed. This forces the new abnormal cells to the surface of the skin, forming lesions. The risks factors are similar to basal cell carcinoma. A weakened immune system and a rare genetic disorder named xeroderma pigmentosum are also risk factors.
Merkel cell carcinoma: Merkel cell carcinoma is a relatively rare but an aggressive and high-risk form of skin cancer that has a tendency to recur and spread all over the body. It occurs when cells in the skin called Merkel cells lose control and multiply rapidly. Merkel cells are found at the bottom of the epidermis – the outer layer of skin. The mortality rate is about 33%. It occurs more often in persons over 50 years of age who have fair skin.
The other forms of skin cancer include cutaneous sarcoma, Kaposi sarcoma, and actinic keratosis.
