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Skin cancer is an abnormal, uncontrolled growth of the epithelial cells that cover the outside of the body. Timely diagnosis and treatment at an early stage have a 5-year survival prognosis of more than 90%.

According to the World Health Organization (WHO), each year there are 2-3 million cases of non-melanoma skin cancers and 132,000 cases of melanoma. WHO also warned that, as ozone levels are depleted, the atmosphere is increasingly losing its filtering and protective functions, and more and more ultraviolet radiation from the sun reaches the Earth’s surface, skin cancer will increase . stronger. The researchers estimate that a 10% decrease in ozone levels would lead to an additional 300,000 cases of non-melanoma skin cancer and 4,500 more cases of melanoma skin cancer.

What is skin cancer?

Skin cancer is a condition in which skin cells grow out of control. It is common and tends to be more frequent in white people. Blacks and people of color have a lower incidence.

The incidence of melanoma is related mainly to sun exposure or a history of sunburn. These are modifiable risk factors, it is important for each individual to be aware of prevention early to avoid contracting this disease.

Types of skin cancer

There are many layers of skin but the epidermis (upper or outer layer) and dermis (lower or inner layer) are the two main layers. The epidermis is made up of 3 types of cells.

  • Squamous cells: are very thin and flat layers that form the top layer of the epidermis.
  • Basal cell: is the layer that is round in shape and lies below the squamous cells.
  • Melanocytes: These are melanocytes, located in the lower part of the epidermis. Melanin is the pigment that gives skin its different colors. The melanocytes produce more pigment when exposed to the sun. The more pigment, the darker the skin color.

BS.CKII Ngo Truong Son – Deputy Head of Oncology Department, Tam Anh General Hospital, Hanoi, said that skin cancer that starts in any skin layer will be named after that layer of skin. There are two types of skin cancer: non-melanoma skin cancer and melanoma skin cancer.

Non-melanoma skin cancer

Non-melanoma skin cancer is non-melanoma skin cancer. Non-melanoma skin cancer includes squamous cell carcinoma and basal cell carcinoma.

  • Squamous cell carcinoma: Squamous cell cancer is a type of cancer that affects the cells located on the outermost layer of the epidermis, or mucous membranes, or lungs. When cancer forms on the skin, it is called squamous cell skin cancer.
  • Basal cell carcinoma: A type of cancer that begins in the basal cells of the skin.

Squamous cell carcinoma and basal cell carcinoma are the two most common types of skin cancer, originating in the basal and squamous layers of the skin, respectively.

This type of cancer is rarely fatal, but surgical treatment often causes pain and surface disfigurement.

Non-melanoma skin cancer most commonly occurs on parts of the body that are exposed to the sun, such as the ears, face, neck, and arms. This suggests that prolonged, repeated exposure to UV radiation is a major causative factor.

In some countries, a clear relationship can be seen between the increasing incidence of non-melanoma skin cancer, i.e. higher levels of UV radiation.

Malignant melanoma skin cancer

This is a type of skin cancer that starts in the melanocytes. Of all skin cancers, melanoma causes the most deaths because it tends to spread to other parts of the body, including vital organs.

The diagnosis of this type of cancer is more likely to be accurate than for non-melanoma skin cancer.

Numerous studies have shown that melanoma risk correlates with genetic and individual characteristics as well as UV exposure behaviour.

Other less common types of skin cancer

  • Merkel cell skin cancer: This type of cancer forms due to the overgrowth of Merkel cells. This type of cancer is rare and very dangerous because it metastasizes very quickly.
  • Skin lymphoma: Cancer that forms when white blood cells in the skin grow abnormally. White blood cells work to protect the body from infection and disease and are part of the immune system.
  • Kaposi sarcoma: This is a malignant skin tumor that has almost no symptoms in its early stages. Metastasis can cause brown, red, or purple skin lumps or patches. Symptoms usually appear on the face, limbs or genitals and lymph nodes.
  • Actin keratosis is a type of skin cancer of the squamous cell epithelium. May progress to malignancy if not timely intervention and management. Small patches of skin that are pink, red, or brown are common symptoms of skin cancer.

Signs of skin cancer

When the appearance of any new spots or changes on the skin persists for two weeks or more, people should not be subjective. According to BS.CCII Ngo Truong Son, skin cancer often has no symptoms in its early stages, although symptoms can appear at any time.

Skin cancer symptoms may include:

  • New lesions on the skin or changes in size, shape, or color. These changes can vary so much that there is no way to describe what skin cancer looks like;
  • Itching or pain;
  • Non-healing sores that bleed or scab;
  • The top of the skin appears as a shiny red or skin-colored bump;
  • Rough or scaly red spots that are palpable on the skin;
  • Tumor with raised border and central crust or bleeding;
  • Skin appears nodules like warts;
  • The skin appears as a scar-like streak without a clear border.

In addition, skin cancer symptoms can vary depending on the type of skin cancer and its location on the skin. Below are general descriptions of the different symptoms associated with specific types of skin cancer.

Symptoms of basal cell carcinoma

Skin cancer usually appears on the face, neck, arms, legs, ears, and hands. These are areas that get a lot of sun exposure. However, it can also appear in other areas.

Signs of basal cell carcinoma may include:

  • A pearl or waxy bump on the skin;
  • Flat, rough, or scar-like patches on the skin;
  • Ulcers that bleed, do not heal completely, or come back.

Symptoms of squamous cell carcinoma

This type of skin cancer also tends to develop in areas that get a lot of sun exposure. In some cases, squamous cell carcinoma can affect areas that are not exposed to sunlight. This is especially true for people with darker skin tones.

Signs of squamous cell carcinoma may include:

  • A hard, red nodule;
  • Lesions are scaly or irregularly contoured;
  • Painful or itchy skin lesions.

Symptoms of malignant melanoma

Malignant melanoma can occur anywhere on the body and can develop from moles. In people with darker skin tones, melanoma tends to appear on the palms or soles.

Signs of malignant melanoma often include:

  • A change in the appearance of the mole;
  • Develops large brown spots, often with irregular edges;
  • Dark lesions on mucous membranes (nose, mouth, vagina, or anus) or fingers and toes.

Causes of skin cancer

According to BS.CCII Ngo Truong Son, the biggest cause of skin cancer is radiation from the sun’s ultraviolet rays. In addition, skin cancer can also be caused by the following risk factors:

  • People with many atypical moles: This is the highest risk factor for melanoma in people with fair skin. Melanoma is more common in people with pale skin, blue eyes, and red or blonde hair;
  • People with a history of sunburn;
  • Exposure to coal and arsenic compounds;
  • Working at altitude: UV is stronger as altitude increases (because the thinner atmosphere at higher altitudes cannot filter UV as effectively as at sea level). People who work at heights and outdoors have a higher risk of skin cancer;
  • Latitude: The sun’s rays are stronges
    t near the equator, so people who live closer to the equator have a higher risk of skin cancer;
  • Repeated exposure to X-rays;
  • Scars from diseases and burns;
  • Immunosuppression, such as in people who have had an organ transplant;
  • Male gender;
  • Age;
  • History of skin cancer;
  • Certain rare genetic diseases, such as basal cell nevus syndrome (Gorlin syndrome) or dry pigmented skin (XP);
  • Smoking (increases the risk of squamous cell cancer, especially on the lips).

How to diagnose skin cancer?

To diagnose skin cancer, the most common methods are a complete physical exam, taking a personal and family history. The physician can then evaluate the lesions with dermatoscopy, biopsy, and histopathological assessment.

A biopsy is taking a small amount of tissue for examination under a microscope. Suspected skin lesions are removed, usually after a local anesthetic is used to numb the area. The doctor also usually removes an area of ​​healthy tissue around the lesion.

The sample removed during the biopsy is then analyzed to determine if it is skin cancer. Doctors will then evaluate cells, tissues, and organs to diagnose disease.

How to treat skin cancer?

BS.CCII Ngo Truong Son said, skin cancer treatments may include:


The removal of cancerous skin and possibly subsequent chemotherapy or radiation to stop cancer cells from growing. There are many surgical methods such as cryosurgery with liquid nitrogen, dermectomy, Mohs surgery, curettage and electrodeposition.


Chemicals that stop cancer cells from growing can be taken orally, applied topically, or given intravenously. Chemotherapy can cause side effects such as hair loss, fatigue, hormonal changes, etc.

Photodynamic therapy

Laser light combines with drugs to kill cancer cells.


It is the use of high-energy beams to target the tumor to destroy cancer cells.

Biological therapy

The body’s immune system is trained to fight cancer cells.


The patient’s immune system is stimulated with a drug to destroy cancer cells.

Diet for people with skin cancer

To date, there are no official dietary recommendations for skin cancer patients. However, according to BS.CKII Ngo Truong Son, patients should limit eating foods that can cause skin allergies to reduce irritation when the skin is weakened. Depending on the location of each person, the foods that cause allergies can be different, for example, some people are allergic to seafood, nuts, cow’s milk, others are allergic to certain vegetables and fruits.

In addition, patients should limit eating processed foods, drinking alcohol, smoking, drinking soft drinks… because they are not good for health in general.

If skin cancer affects the mouth, throat, soft foods and foods such as porridge, soup, vermicelli, pho… can be beneficial.

How to prevent skin cancer

BS.CKII Ngo Truong Son recommends, to reduce the risk of skin cancer , the best way is to avoid regular exposure to the sun and other sources of UV radiation, such as: ( 7 )

  • Limit sunbathing;
  • Limit going out during the hours of high UV activity, in Vietnam it is from 10-14 hours;
  • Use a sunscreen with an SPF of 30 or higher for your entire body. Apply at least 10 minutes before going outside and reapply every 30 minutes if outdoors;
  • Should wear sunscreen (specialized type against UV rays), wide-brimmed hat;
  • Wear light-colored clothes instead of dark-colored clothes when out in the sun because black will absorb more ultraviolet rays;
  • Wear sunglasses with 100% UV protection when out in the sun;
  • Periodic health examination every year at least once and twice in people with risk factors;
  • Go to the hospital as soon as there are unexplained skin lesions that persist for more than 2 weeks and do not go away.

How long does skin cancer live?

If treated at the time of detection, non-melanoma skin cancer is rarely fatal. For early stage malignant melanoma, BS.CKII Ngo Truong Son said, the 5-year survival rate is 90% if it is treated and well controlled. The prognosis is poorer if detected and treated at the metastatic stage.