【 Skin cancer 】 Can long-term exposure to UV cause cancer? Identify the causes and precursors of skin cancer

【 Skin cancer 】 Can long-term exposure to UV cause cancer? Identify the causes and precursors of skin cancer

Skin cancer is one of the most common cancers in Hong Kong. The three most common cancers are basal cell carcinoma, handheld dermatoscope squamous cell carcinoma (collectively referred to as non-melanoma skin cancer), and melanoma skin cancer, with non-melanoma skin cancer accounting for about 90% of all skin cancers. In 2002, there were 980 new cases of non-melanoma skin cancer in Hong Kong, accounting for 2.9% of all new cancer cases in Hong Kong, or about 13 new cases per 100,000 population. In the past 10 years, the number of new cases in Hong Kong has also increased significantly by 20%!

Many people think that long-term exposure to sunlight and ultraviolet rays is the culprit of skin cancer. electronic dermatoscope Some people believe that adults need to take adequate sun protection measures to avoid skin cancer, so children should not pay attention to sun protection. But is it really the case? Before we discuss the dangers of UV rays on the skin, let's look at the causes and precursors of skin cancer.

Skin cancer precursor

Different types of skin cancer will have different symptoms, 365nm UV Lamp and the more common precursor information includes the following 1:

The new patches on the skin look different from the surrounding spots.

Itching, pain, or inflammation in the affected area

The wound will not heal for a long time

The mole or spot becomes larger, deformed, or discolored.

Moles on body are as follows:

1. Asymmetrical appearance

2. Irregular or blurred edges

3. Uneven color and chroma

4. Size over 6 mm or tends to get larger.

5. Irregular surface protrusions

Skin cancer most often develops on the nose, cheeks and other areas that are often exposed to the sun. The morphology of basal cell carcinoma, some of which look like moles or skin color, with a layer of wax around the edges, an ulcer in the middle, and bloodshot streaks next to it; Squamous cell carcinoma causes the skin to grow and thicken, one of which protrudes like a mushroom, and may have ulcers and desquamation in the middle. It is worth mentioning that Asian melanomas often appear in places where sunlight does not easily reach, such as the soles of the feet, palms, nail beds or mucous membranes. At first, new spots will appear on the skin, or the original spots or moles on the body will suddenly change.

However, even if the above changes in the skin, it is not necessarily a problem of skin cancer, because most skin tumors are actually benign. If either of these conditions is found on the skin, or if the skin symptoms persist for more than two weeks and do not improve, it is important to see a doctor as soon as possible for further confirmation or for an early biopsy.

Learn more about skin cancer symptoms:

[Skin cancer] A sudden mole? Not symmetrical? Itchy?

The main cause of skin cancer: ultraviolet rays

The skin is the largest organ in the body and plays a role in protecting the body from invasion or injury by foreign bacteria in daily life, as well as lowering body temperature and preventing dehydration through perspiration. When DNA is damaged during cell metabolism, it can lead to abnormal cell proliferation and eventually skin cancer. Among them, the biggest culprits that can damage the deep tissues of the skin are the ultraviolet rays in the sun, as well as ultraviolet A (UVA) and ultraviolet B (UVB) whose wavelengths can penetrate deep into the dermis.

Sunlight has been classified as a Class 1 carcinogen by the World Health Organization. Ultraviolet light in the sun, to be precise. We must not ignore the existence and harm of ultraviolet rays! Uv rays are present no matter what the weather, season and temperature, and no one can stop them, especially for outdoor activities such as hiking, swimming and surfing, which expose them to more sunlight and UV rays.

Ultraviolet (Ultraviolet) harmful to human body are UVA and UVB, both of which have a certain wavelength in China, and can enter the dermis, resulting in skin tanning and sunburn. Compared with UVB, UVA can penetrate deeper into the skin, and the irradiation will destroy the elastic fibers and collagen of the skin, resulting in skin relaxation and wrinkles. When it is serious, it will destroy the DNA in the skin cells and induce the appearance of skin cancer! Among them, UVB has been regarded as the main cause of non-melanoma skin cancer, and UVA is prone to melanoma skin cancer, so once long-term exposure to the sun without adequate protective measures, it will increase the risk of skin cancer in the long run.

Causes of skin cancer

Skin cancer prevention

Because skin cancer is often associated with long-term exposure to UV rays, the most important thing to prevent skin cancer against this biggest risk factor is to reduce the damage caused by UV rays! The best way, of course, is to reduce direct sunlight to your skin, especially when the sun is at its fiercest, and use sunscreen! If you must walk in the sun, take appropriate sun protection measures such as using an umbrella, wearing a wide-brimmed hat, wearing sunglasses that block UV rays, and applying a broad-spectrum sunscreen that blocks UVA and UVB rays.

Skin cancer prevention

It is important to note that outdoor UV rays can cause cumulative effects on the skin. Even if the surface is not sunburned or burned, skin tissue may already be damaged, and most skin damage has formed before adulthood. If the damaged skin cells are still not properly protected, it will increase the risk of skin cancer in the future. Therefore, early prevention is very important, and parents should help children develop the concept and habit of sun protection from an early age. Long-term use of artificial UV rays should also be avoided to avoid increasing the risk of melanoma and skin cancer.

Dr Tse Yiu-cheong, a clinical oncologist in Hong Kong, said: "To reduce your risk of skin cancer, you should first learn how to protect yourself from the sun. There are many sunscreen products on the market, including sunoils, UV-resistant clothing and umbrellas, which can effectively reduce the exposure of UV rays to the skin, but it is important to consider that each product has its drawbacks, such as sunoils can easily be washed away by sweat, sunumbrellas can reflect UV rays on the ground, and the extent of UV protection clothing is not enough."

Sum up

Although the incidence of skin cancer in Hong Kong has increased in recent years, fortunately, the mortality rate is not very high. As long as adequate sunscreen measures are taken on weekdays, the damage of ultraviolet rays can be greatly reduced, and the skin can be protected to a great extent! In addition, the skin is the easiest organ to observe, and the precursors of cancer will be more easily noticed. When you find any abnormal signs of abnormal changes in the skin, you should seek medical attention as soon as possible, even if you are unlucky enough to be diagnosed, it can increase the cure rate.

UV cause cancer collectively referred

1