There are several types of skin cancers. The commonest are basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma. These are often related to sun exposure and some may have a genetic basis.
BCC is often on the head and neck, and may look like a pinkish mole, pigmented growth or ulcer. They grow very slowly on the skin, and rarely spread to other organs. They are often treated successfully with skin surgery.
SCC often looks like a scaly growth or ulcer which is increasing in size. It may spread to the nearby lymph nodes. Surgery is curative and may be combined with radiotherapy depending on the stage.
Malignant melanoma is the most dangerous form of skin cancer as they can spread very quickly to other organs in the body and become fatal. Melanoma may arise from any mole and not necessarily over sun exposed areas.
Diagnosis can be difficult for the layman. However, if any skin growth is growing, or causing itch, pain or bleeding, or if any ulcer is not healing, one should see a dermatologist for a skin check. Moles should be regularly monitored for the "ABCD" changes of melanoma: A for asymmetry, B for border irregularity, C for colour changes and D for diameter increase.
People with a past history or family history of skin cancer and those who have sun damaged skin should get a regular skin check at least once a year. If you have a past history or family history of abnormal (dysplastic) moles or melanoma, you should get a skin check once in 6 months.