Skin cancer has made the news in recent weeks with two items that may affect you:
- Imiquimod (Aldara™, by 3M) cream has been given approval for the treatment of superficial basal cell cancer.
- The ABCD guide for the diagnosis of melanoma has been re-evaluated. New recommendations suggest ABCD and now E for describing pigmented skin lesions that suggest cancer.
Imiquimod: How It Works
Imiquimod (Aldara™) 5% cream is the first new treatment for superficial basal cell skin cancer in 30 years. The first line treatment for most skin cancers has been their surgical removal. This novel treatment uses another strategy. This drug, which is applied 5 times per week to the superficial basal cell cancer, produces an inflammation. This inflammation is the body's immune response. The drug then directs cells in the skin to produce substances such as interferon and tumour necrosis factor, which is nature's way of attacking viruses and cancers.
What Kind Of Skin Cancers Can It Treat?
This cream was initially developed to treat genital warts. (Click on Wart Treatment by Type of Drug and Procedure for more information). It was then approved for the treatment of actinic keratosis. These are red scaly precancerous spots usually in fair skinned people who have had a great deal of sun exposure over many years.
Basal cell cancer:
There are many subtypes of basal cell cancers. This cream has gained approval for the superficial type only as the atypical cells are close to the surface where the cream can readily penetrate. It is an exciting time when new ways of treatments are developed to challenge the conventional methods. With time and experience, such treatments might become commonplace, not just to treat skin cancers but perhaps to be applied to sun damaged skin in order to attempt to prevent new cancers.
Possible future indications:
Melanomas are the most serious types of skin cancers. The vast majority of these lesions are pigmented, only a small percentage are without a dark pigmentation. About ½ of these develop from preexisting moles and the others arise from normal, but usually sun damaged skin. Since the skin is visible, great efforts have been made to teach patients, the public, and all types of health professionals the features of melanomas. Melanomas that are treated early can be cured, so rapid diagnosis is best.
The New Evaluation Guide:
The features of a lesion (mole) described as atypical and that should raise your suspicions are categorized as one of ABCD:
- A – Asymmetrical – the shape is uneven
- B – Border – the border is irregular
- C – Colour – the colour is dark brown or black
- D – Diameter – it should have a diameter of 0.6cm (the size of a pencil eraser)
There is a now an additional letter has been added:
- E – Evolving – the lesion is evolving or changing
The more complete the description the better, but we have to guard against making it too complicated. Another way of looking at these lesions could be:
- A – Atypical, out of step with other moles
- B – Black
- C – Colour variation within the lesion/changing mole
- D – Dark brown
For information on self evaluation, click on Skin Cancer Self-Examination.
In my practice, I see many melanomas that are smaller than 0.6cm, so don't let size be the deciding factor. In other words, if you are suspicious of a mole, do not wait for a lesion to become 0.6cm before having it checked.
Richard Thomas, MD, FRCPC is Assistant Clinical Professor of Dermatology, Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada.