HPA Magazine 6
Skin cancer is the most common cancer in the world and it continues to increase in all of its forms. However, with early detection, the possibility of treating it successfully is also high.
Skin cancer is usually caused by excessive exposure to ultraviolet rays, which are more prevalent in frequently exposed areas: the face, neck, back and limbs.
Skin cancer can manifest itself in various ways and levels of severity, which in turn have different symptoms and treatments.
We spoke about this with Dr. André Laureano, Dermatologist, Master in Dermatoscopy and Preventative Cutaneous Oncology. PD from the Faculty of Medicine, University of Lisbon, where he also works as a researcher.
Although there is an increase in communication about prevention of skin cancer in the summer months, this isn’t a subject that should only be addressed at that time of year, is it?
When we speak about skin cancer, we have to consider melanoma and non-melanoma cutaneous cancer. Paradigmatic examples of the latter group are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).
Exposure to ultraviolet radiation (UV) is considered to be the main risk factor for all of these forms: Intermittent exposure without doubt for melanoma and possibly for squamous cell carcinoma, and chronic or continuous for squamous cell carcinoma. In brief, intense and seasonal solar exposure is without doubt an important risk factor for melanoma. Sunburns at this time of year, unfortunately frequent, also contribute to an increase in the risk of melanoma. These are obvious reasons for the annual campaigns for prevention at this time of year, preceding the start of another bathing season. However, we cannot forget that chronic exposure to UV radiation can increase the risk of squamous cell carcinoma and premalignant lesions, such as actinic keratosis.
In this group we must include people with continuous exposure for occupational or professional reasons. Nowadays, as we are fortunately witnessing an increasing number of people practicing outdoor sports on a daily basis, we must alert them to the risks and reiterate the importance of the use of physical preventative measures: appropriate clothing, hats, sunglasses or the frequent application of sunscreens. As the risk of skin cancer associated with sun exposure is cumulative, primary prevention efforts should be continuous (the risk is not only from the “sun or last year’s sunburn”). On the other hand, patients with much lower phototypes (light skin), red hair and freckles, with a personal or family history of melanoma, more than 50 nevi (moles/birthmarks) or who are immunosuppressed have an additionally higher risk and must be monitored in adequate programs of secondary prevention, guided by a medical specialist in Dermatology.
Are different types of cancer associated with different types of skin?
Generally speaking, all of the cancer types previously mentioned are more frequent in people with lower phototypes, in other words, people whose skin rarely or never tans and who almost always turn red or burnt on the first days of exposure to the sun. Therefore, light-skinned people, people with blond or red hair, freckles and blue eyes have an intrinsically higher risk. If we add excessive UV radiation exposure with secondary sunburns, the risk increases exponentially. Generally speaking, skin cancer is less prevalent in dark skin, although we have noted a greater frequency of a subtype of melanoma called acral lentiginous (melanoma on the soles of the feet).
What are the signs and symptoms that people should be aware of? In what circumstances should they consult a dermatologist?
That is an excellent question, because there is no doubt that patients should know their skin and know how to recognize any alteration. In this way, it has been proved that a monthly self-exam (by the patient) can contribute to an early detection of melanoma.
Some rules that everyone should know: the “ugly duckling” spot, which is a mole that is visible to the naked eye that stands out from the others. For a melanoma, the mnemonic is ABCDE. A for asymmetry, B for irregular borders, C for colours (more than two), D for diameter bigger than 6 mm and E for rapid evolution.
Despite the increase in the occurrence of melanoma with age, it persists as one of the most frequent forms of cancer in people under 40 years of age and is found mainly in areas of intermittent sun exposure, such a the trunk and limbs. Later, after age 60, melanomas are usually located in areas of continuous sun exposure, such as the face, neck, ears and men’s scalps.
For non-melanoma cutaneous cancer (base cell carcinoma, squamous cell carcinoma, actinic keratosis) we must always keep in mind that its prevalence increases with age and is most frequent in areas chronically exposed to solar radiation, such as the head (nose, ears, eyelids, lips, neck, back of the hands). As such, and particularly in these areas of our anatomy, any skin lesion that keeps growing (rapidly, or in many cases, slowly but steadily) where the surface develops scabs, erosions or ulcerations that do not heal, and often bleed, or are coarse to the touch, should be suspect for diagnosing non-melanoma cutaneous cancer.
Are there currently any techniques or exams for faster and more precise diagnoses?
Yes. That is why the programmes mentioned for secondary prevention performed by dermatologists duly trained for these techniques are so important. The complementary exams should be quick and non-invasive. Dermatoscopy is an ideal technique. Cutaneous dermatoscopy or Epiluminescence microscopy is a non-invasive diagnostic method that allows the dermatologist to observe the structures of the skin not visible macroscopically (to the naked eye). This technique allows an increase in the acuity in the diagnosis of melanocytic lesions, namely the malignant melanoma, and consequently, to lower the number of excisions or unnecessary invasive procedures, namely surgeries and the resulting scars, as well as the anxiety associated with the anticipation of a histopathology report. In this way, the complete observation of the skin in the consultation should ideally be complemented by the use of a manual dermatoscope, also of enormous use in early detection of non-melanoma cutaneous cancer, as previously referred.
On the other hand, the computerized digital dermatoscope is also a non-invasive procedure, which consists of indirect observation of cutaneous lesions with a high-resolution colour video camera adapted to the dermatoscope and connected to a computerised system. This method produces a photograph and digital registration of the melanocytic lesions (“moles”), allowing them to be mapped, or in other words, the construction of total body maps for comparison over time in different consultations. This method favours the timely diagnosis of any new lesion or modification of any already existing mole. Without doubt, it is an asset for early detection of melanoma. Because the melanoma can have a very low survival in advanced states, its earliest possible detection will be, in my opinion, the objective and greatest source of satisfaction for any dermatologist. Therefore it is fundamental to know how to use these techniques for the benefit of the patients.
Another important technique, which I also use, but is unfortunately only available in a few centres, is confocal reflectance microscopy.
The Algarve is the region with the most sun exposure in this country. Do you have any advice for residents?
Of course, and precisely because of so much sun exposure. I give advice to permanent residents as well as seasonal residents (on holiday), and I also stress it to our foreign residents from countries where the incidence of cutaneous cancer (including melanoma) is much higher than in our country.
I always stress the primary prevention efforts in early childhood and here it is of the utmost importance to educate and inform the parents. We know that, according to some studies, of around 85% of the UV radiation associated with the increase of risk potential of melanoma, the exposure occurs by the age of 18. On the other hand, during infancy or adolescence, a large number of sunburns, hours of exposure to the sun and minimal use of solar protection can contribute to a greater number of “moles” and risk of melanoma in adulthood.
General advice: always apply sun cream with a high index and broad spectrum of protection (including protectors with physical filters), not only on the beach, but also for day-to-day life, especially for outdoor sports activities or professional activities that require prolonged sun exposure, and reapply sun cream regularly; try to stay in the shade; use suitable clothes, including a hat and sunglasses; do not go to the beach between 11 AM and 5 PM. Pardon my expression, but here we can witness a “perverse” effect in the use of sun creams, which is using it in order to prolong the number of hours of exposure to UV radiation, which is wrong. We should use sun cream when exposed to the sun at the appropriate times.
The Algarve, as mentioned, is a zone where there is abundant natural exposure to UV radiation and we have already discussed its role in the risk of skin cancer. As such, I would add the enormous risks of “artificial” exposure to this radiation. In other words, the use of tanning beds, which increase the risk of melanoma by 50-100%, and should never be used by anyone.
The earlier skin cancer is detected, the earlier its treatment can begin, affording a reduction in the associated morbidity and mortality, and an increase in the quality of life for our patients.