AskID: skin cancer

We asked Prof Caitriona Ryan:
‘In recent years people have become much more aware of skin cancer and are more careful in the sun, but so many of my patients report being “sun-worshippers” in their youth, sunbathing without adequate sun protection with frequent sunburns, and using tanning beds to maintain a year round glow. Now, decades later, they are terrified that their past will come back to haunt them in the form of skin cancer.

The frequencies of both melanoma and non-melanoma skin cancer have increased rapidly in recent years and are projected to increase exponentially over the next 20 years. Currently there are over 11,000 cases of skin cancer per year in Ireland, almost 1,000 of which are melanoma. If melanoma is recognised and treated early, it is almost always curable, but if it is not, the cancer can advance and spread to other parts of the body, where it becomes difficult to treat and can be fatal. Early detection is crucial. The most common forms of skin cancer are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). If left untreated, some types of NMSC can spread to other parts of the body but thankfully NMSC can almost always be completely cured and treated early.
In those who are worried about significant sun damage in their past, a baseline skin check with your GP or Dermatologist can be very helpful. Your GP or Dermatologist will then advise an appropriate time interval or a follow-up visit. In those without a history of atypical moles, skin cancer or pre-cancers (actinic keratoses), annual reviews are generally not necessary.
The most important warning signs of a melanoma are changes in the size, shape or colour of a mole. Here’s a handy 5-point check, which we call the ABCDE of melanoma:

A is for Asymmetry; Is one half of the spot unlike the other half?
B is for Border: Does the spot have an irregular, scalloped, or poorly defined border?
C is for Colour: Does the spot have varying colours from one area to the next, such as shades of tan, brown or black, or areas of white, red, or blue.
D is for Diameter: While melanomas are usually greater than 6 millimetres (about the size of a pencil eraser), they can be smaller.
E is for Evolution: Is your spot changing shape or appearance
Consult with your GP or dermatologist immediately if you have a changing or new mole, or any skin abnormality, such as a lump, ulcer, lesion or skin discolouration that has not healed after 4 weeks. While it may not be skin cancer, it's always best to get checked. Skin cancer is not always preventable but you can reduce your chance of developing it by avoiding overexposure to UV light. To prevent more cumulative damage, wear SPF on sun-exposed areas on a daily basis whether it is sunny or not.