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The highly visible but easily neglected form of cancer

Summer is here and the outdoor types are ready to put on their new swimwear to head to the beach for water fun and to acquire a healthy tanned look. When it comes to sun protection, ladies tend to be more conscious of the need and will apply sunscreen products to avoid getting burnt. Men on the other hand might take a more cavalier approach. Even if people do the right thing and apply sunscreen before heading out into the sun, do they remember to replenish it during their outdoor activities?


Sun exposure is indeed helpful for the body to manufacture vitamin D but that can be achieved by sun tanning for just over 10 minutes. Long exposure to the sun, without proper sun screening, could easily cause sun burn. In a worst-case scenario, it could cause skin cancer, which is becoming more common. The Hong Kong Cancer Registry’s 2015 statistics show that non-melanoma skin cancer was the seventh most common form of cancer, with more than 1,000 cases every year. Excessive absorption of UV rays due to prolonged exposure to the sun is the leading cause of skin cancer. This means one cannot be too careful when spending time in the sun.


The most common form of skin cancer is basal cell carcinoma. It accounts for more than half of the clinically diagnosed cases. It occurs more commonly on the head, the neck and the hands, i.e. the parts of the body that are more often uncovered. An early symptom is the presence of a slightly protruding bump that may not be visually detectable. Affected people might dismiss such growths as pimples or boils. Even if they are suspicious of the cause of the growths, they may find reasons to rationalise it and won’t seek medical advice until the growths fester or the symptoms deteriorate.


Recently, I saw an expatriate chef who had a 2-3cm dark red bruise mark on his forehead. He thought it was bruising from a bump. As he is taking long-term blood thinning medication, he didn’t pay the bump much attention even when the bruising didn’t fade after a few days, as he thought the medication had slowed the healing of the blood vessels. It was only when the red patch grew much bigger and the pain did not go away, that he went to seek medical help. As the doctor suspected skin carcinoma, he was referred to me for a further check-up.


A biopsy is needed to diagnose skin cancer. If it’s a small growth, all affected tissues can be removed at the same time as the biopsy, in effect to kill two birds with one stone. However, if the growth is large, cutting it off together with the skin tissues 2-3 mm around the growth in order to remove all the malignant tissue will create too big a wound. It will affect a person’s appearance,  so cosmetic surgery is also required. In the initial consultation, surgical specialists face a challenge to determine how much skin tissue to cut away for biopsy before it is confirmed to be a carcinoma.


Other skin cancer types, other than basal cell carcinoma, are squamous-cell carcinoma and malignant melanoma. All three can spread, and malignant melanoma is particularly tricky to deal with, because it can spread to the lymph nodes or the brain, the liver or the lungs at an early stage, making treatment more difficult, and thus increasing the mortality rate. This means early discovery is paramount.


Skin cancer can be hereditary. It is advisable for people who have family members succumbing to skin cancer to visit a dermatologist and get a full-body skin spots record for future comparison and reference. We may not remember clearly when certain colour spots appear on our body, or whether their shape or size has changed. Doing a full-body colour spot record will help lower the risk of wrong diagnoses and enable early action when skin tissue anomalies are detected.


Tips for preventing skin cancer:

  1. Choose sunscreen which effectively blocks UVA and UVB rays. UVA rays can penetrate glass or clothing. They are rated by a factor of 5* and it is recommended to use products with at least a 3* factor. For UVB, factor higher than SPF30 is preferred.
  2. Your sunscreen lotion should be water-proof.
  3. There are physical or chemical sunscreen products. For physical sunscreen products, choose those containing titanium dioxide or zinc oxide, which have less allogenic side effects or irritants; for chemical sunscreen, it is advisable to choose those that contain Avobenzone.
  4. Apply sunscreen half an hour before heading out into the sun, and re-apply every two hours, or immediately after sweating, washing or bathing.
  5. Use umbrellas, wide-brimmed hats and sun-glasses (that sit as close to the face as possible to filter the amount of light entering the eyes, and the lenses should fully cover the eye region). Wear long-sleeved tops and long pants (impenetrable by light) which is more effective than using sunscreen.
  6. The sun is strongest between 11 am and 3pm. Avoid outdoor activities during this period.
Consult your dermatologist for sunscreen product recommendations.

The above information is provided by Dr. Alec Fung Ho Chuen and Dr. Henry Kwan Tim Lok.