skin cancer

Skin Cancer – Its Various Types along with Causes, Signs, Symptoms and Treatments

Skin cancer is a disease in which malignant (cancer) cells form in the tissues of the skin. The Skin cancer is the abnormal growth of skin cells.

The skin is the body’s largest organ. It protects against heat, sunlight, injury, and infection. Skin also helps control body temperature and stores water, fat, and vitamin D.

There are three major types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma.

All three types of skin cancer are on the rise — but most skin cancers can be prevented by limiting or avoiding exposure to ultraviolet (UV) radiation and by paying attention to suspicious changes in the skin. If caught early enough, most skin cancers can be successfully treated.

The skin has several layers, but the two main layers are the epidermis (upper or outer layer) and the dermis (lower or inner layer). Skin cancer begins in the epidermis, which is made up of 3 kinds of cells:

  • Squamous cells: Thin, flat cells that form the top layer of the epidermis.
  • Basal cells: Round cells under the squamous cells.
  • Melanocytes: Found in the lower part of the epidermis, these cells make melanin, the pigment that gives skin its natural color. When skin is exposed to the sun, melanocytes make more pigment, causing the skin to darken.

Basal and squamous cell carcinomas are slow growing and highly treatable, especially if found early. Melanoma is the most serious form of skin cancer. It affects deeper layers of the skin and has the greatest potential to spread to other tissues in the body.

Skin cancer can occur anywhere on the body. Most often develops on skin exposed to the sun such as the face, neck, hands, and arms. But this common form of cancer also can occur on areas of the skin not ordinarily exposed to sunlight.

There are several types of cancer that start in the skin. The most common types are basal cell carcinoma and squamous cell carcinoma, which are nonmelanoma skin cancers. Actinic keratosis is a skin condition that sometimes develops into squamous cell carcinoma.

Nonmelanoma skin cancers rarely spread to other parts of the body. Melanoma, the rarest form of skin cancer, is more likely to invade nearby tissues and spread to other parts of the body.

Causes of Skin Cancer

The cause of Skin cancer can be summarized as follows:

UV light: At one time scientists believed that only UVB rays played a role in the formation of skin cancer. And UVB light does cause harmful changes in skin cell DNA, including the development of oncogenes (a type of gene that can turn a normal cell into a malignant one). UVB rays are responsible for sunburn and for many basal cell and squamous cell cancers. But UVA also contributes to skin cancer.

It penetrates the skin more deeply than UVB does, weakens the skin’s immune system and increases the risk of cancer, especially melanoma.

Other factors that may contribute to skin cancer are:

Sun exposure doesn’t explain melanomas or other skin cancers that develop on skin not ordinarily exposed to sunlight. Heredity may play a role. Skin cancer can also develop from exposure to toxic chemicals or as a result of radiation treatments.

Signs of Skin Cancer or Skin Cancer Symptoms

Skin cancer is a malignant skin disease which forms cancer cells in the tissues of the skin. This develops primarily on areas of sun-exposed skin, including the scalp, face, lips, ears, neck, chest, arms and hands, and on the legs in women. But it also can form on areas that are unexposed to the light such as the palms, spaces between the toes and the genital area.

A cancerous skin lesion can appear suddenly or develop slowly. Its appearance depends on the type of cancer. Each type of skin cancer has its own varied symptoms. Some of the signs of skin cancer or skin cancer symptoms are as follows:

Basal cell carcinoma

Basal Cell Carcinoma is considered to be the most common skin cancer, accounting for nearly 90 percent of all cases. It is the most easily treated and the least likely to spread. Basal cell carcinoma usually appears as one of the following:

  • A pearly or waxy bump on the face, ears or neck
  • A flat, flesh-colored or brown scar-like lesion on the chest or back

Squamous cell carcinoma

Squamous cell carcinoma is easily treated if detected early, but it’s slightly more apt to spread than is basal cell carcinoma. Most often, squamous cell carcinoma appears as one of the following:

  • A firm, red nodule on your face, lips, ears, neck, hands or arms
  • A flat lesion with a scaly, crusted surface on your face, ears, neck, hands or arms

Melanoma

Melanoma is considered the most serious form of skin cancer and the one responsible for most skin cancer deaths. Melanoma can develop in otherwise normal skin or in an existing mole that turns malignant. Although it can occur anywhere on the body, melanoma appears most often on the upper back or face in both men and women.

Melanoma, the most dangerous type of skin cancer shows the below mentioned warning signs:

  • A large brownish spot with darker speckles located anywhere on the body
  • A simple mole located anywhere on the body that changes in color, size or feel or that bleeds
  • A small lesion with an irregular border and red, white, blue or blue-black spots on the trunk or limbs
  • Shiny, firm, dome-shaped bumps located anywhere on the body
  • Dark lesions on the palms, soles, fingertips and toes, or on mucous membranes lining the mouth, nose, vagina and anus

Skin Cancer Treatment

There are different types of treatment for patients with nonmelanoma skin cancer and actinic keratosis. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials.

Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team. Four types of standard skin cancer treatment are used:

Surgery

One or more of the following surgical procedures may be used to treat nonmelanoma skin cancer or actinic keratosis:

  • Mohs micrographic surgery: This type of surgery is used for larger, recurring or difficult-to-treat skin cancers, which may include both basal and squamous cell carcinomas. In this procedure the doctor removes the skin growth layer by layer, examining each layer under the microscope, until no abnormal cells remain. This procedure allows cancerous cells to be removed without taking an excessive amount of surrounding healthy skin.
  • Excisional Surgery: This type of surgical treatment may be used for any type of skin cancer. The doctor cuts out (excises) the cancerous tissue and a surrounding margin of healthy skin. A wide excision, removing extra normal skin around the tumor may be recommended in some cases.
  • Electrodesiccation and curettage: In this procedure the tumor is cut from the skin with a curette (a sharp, spoon-shaped tool). A needle-shaped electrode is then used to treat the area with an electric current that stops the bleeding and destroys cancer cells that remain around the edge of the wound. The process may be repeated one to three times during the surgery to remove all of the cancer.
  • Cryosurgery or Cryotherapy: is a treatment that uses an instrument to freeze and destroy abnormal tissue, such as carcinoma in situ.
  • Laser surgery: Laser therapy. A precise, intense beam of light vaporizes growths, generally with little damage to surrounding tissue and with minimal bleeding, swelling and scarring. A doctor may use this therapy to treat superficial skin cancers or precancerous growths on lips.
  • Dermabrasion: Removal of the top layer of skin using a rotating wheel or small particles to rub away skin cells.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer.

Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy).

When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).

Chemotherapy for non-melanoma skin cancer and actinic keratosis is usually topical (applied to the skin in a cream or lotion). The way the chemotherapy is given depends on the condition being treated.

Retinoids (drugs related to vitamin A) are sometimes used to treat or prevent nonmelanoma skin cancer. The retinoids may be taken by mouth or applied to the skin. The use of retinoids is being studied in clinical trials for treatment of squamous cell carcinoma.

Photodynamic therapy

Photodynamic therapy is a treatment which destroys skin cancer cells with a combination of laser light and drugs that makes cancer cells sensitive to light. Photodynamic therapy for precancerous skin lesions is currently available by prescription. Other types of treatment are being tested in clinical trials. These include the following:

Biologic therapy

Biologic therapy or Immunotherapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy.

Below given are specific types of treatment options for different types of skin cancers. For Nonmelanoma Skin Cancer the treatments are:

Basal Cell Carcinoma

Treatment of basal cell carcinoma may include the following:

  • Mohs micrographic surgery.
  • Excisional Surgery.
  • Electrodesiccation and curettage.
  • Cryosurgery.
  • Radiation therapy.
  • Laser surgery.
  • Topical chemotherapy with fluorouracil.
  • Photodynamic therapy.
  • A clinical trial of biologic therapy.

Follow-up skin exams are important for people with basal cell carcinoma because they are likely to have a new or recurrent tumor within 5 years of the first one. After treatment, the patient should have skin exams every 6 months for 5 years and once a year after that.

Squamous Cell Carcinoma

Treatment of squamous cell carcinoma may include the following:

  • Mohs micrographic surgery.
  • Excisional Surgery.
  • Electrodesiccation and curettage.
  • Cryosurgery.
  • Radiation therapy.
  • Topical chemotherapy with fluorouracil.
  • Laser surgery.
  • A clinical trial of biologic therapy.
  • A clinical trial of biologic therapy and retinoids.

Follow-up skin exams are important for people with squamous cell carcinoma. Because squamous cell carcinoma can spread, patients should have skin exams every 3 months for several years after treatment and then every 6 months.

Actinic Keratosis

Actinic keratosis is not cancer but is treated because it may develop into cancer. Treatment of actinic keratosis may include the following:

  • Topical chemotherapy.
  • Cryosurgery.
  • Electrodesiccation and curettage.
  • Dermabrasion.
  • Excisional Surgery.
  • Laser surgery.
  • Photodynamic therapy.

Skin Cancer Prevention

It is quiet evident that doctors cannot always explain why one person gets cancer and the other does not as the exact cause of any type of cancer is unknown.

However, studies reveal what things around us and what things we do in our lives may increase our chance of developing cancer.

Anything that increases a person’s chance of developing a disease is called a risk factor; anything that decreases a person’s chance of developing a disease is called a protective factor.

Some of the risk factors for cancer can be avoided, but many cannot. For example, although one can choose to quit smoking, but cannot choose which genes have inherited from parents. Both smoking and inheriting specific genes could be considered risk factors for certain kinds of cancer, but only smoking can be avoided.

Skin cancer prevention means avoiding the risk factors and increasing the protective factors that can be controlled so that the chance of developing cancer decreases.

Although many risk factors can be avoided, it is important to keep in mind that avoiding risk factors does not guarantee that one will not get cancer. Also, most people with a particular risk factor for cancer do not actually get the disease. Some people are more sensitive than others are to factors that can cause cancer.

Either for Nonmelanoma Skin Cancer (Basal Cell Carcinoma and Squamous Cell Carcinoma) or for Melanoma studies suggested that reducing exposure to ultraviolet (UV) radiation decreases the incidence of skin cancer. Avoiding sunburns, especially in childhood and adolescence, may reduce the incidence of melanoma skin cancer.

Sun exposure can be reduced by changing patterns of outdoor activities to reduce time of exposure to high-intensity UV radiation. Whether sunscreens are effective in protecting against nonmelanoma skin cancer has not been determined. Sunscreen is not a substitute for avoidance of sun exposure.

People whose skin tans poorly or burns easily after sun exposure are particularly susceptible to nonmelanoma skin cancer as well as melanoma skin cancer. These people in particular may benefit by following prevention methods for both types of skin cancers.