SKIN CANCER: CAUSES, SYMPTOMS, TREATMENT


'Cancer' a common word heard in day to day life. Cancer is a major condition affecting people over the globe.

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other body parts.

There are several types of cancer which affect individuals. Some of the common types of cancer include breast cancer, blood cancer, skin cancer, stomach cancer.

One of the major type of cancer found in western countries is Skin Cancer.

To understand skin cancer , its important to understand the structure and layers of skin.




  1. STRUCTURE OF SKIN:

Skin is the largest organ of the body. It provides a barrier between your body’s essential organs, muscles, tissues, and skeletal system and the outside world. This barrier protects you from bacteria, changing temperatures, and chemical exposure.


Skin has two main layers, both of which serve a purpose. Beneath the two layers is a layer of subcutaneous fat, which also protects your body and helps you adjust to outside temperatures. Some health conditions start or exist only in certain layers of your skin.

The layers of skin are as follows;

  • Epidermis: The epidermis is the top layer of your skin. It’s the only layer that is visible to the eyes. The epidermis is thicker than you might expect and has five sublayers.

  • Dermis: The dermis is thicker than the epidermis and contains all sweat and oil glands, hair follicles, connective tissues, nerve endings, and lymph vessels. While the epidermis covers your body in a visible layer, the dermis is the layer of skin that really enables the function of pathogen protection that your body needs

  • Subcutaneous Fat: The layer of skin beneath the dermis is sometimes called the subcutaneous fat, subcutis, or hypodermis layer. This layer provides insulation for your body, keeping you warm. It also provides a cushion that works like a shock absorber surrounding your vital organs.

1. WHAT IS SKIN CANCER?

Skin cancers are cancers arising from the skin. They have an ability to grow and invade normal cells and other parts of body. Skin cancer is the out-of-control growth of abnormal cells in the epidermis, the outermost skin layer, caused by unrepaired DNA damage that triggers mutations. These mutations lead the skin cells to multiply rapidly and form malignant tumors.

Skin cancer is the most common form of cancer, globally accounting for at least 40% of cancer cases. The most common type is nonmelanoma skin cancer, which occurs in at least 2–3 million people per year.

Globally in 2012, melanoma occurred in 232,000 people and resulted in 55,000 deaths.

White people in Australia, New Zealand, South Africa have higher rates of skin cancer.


2. TYPES OF SKIN CANCER:

There are 3 main types of cancer, they are as follows;

  1. Basal Cell skin Cancer( BCC)

  2. Squamous cell Skin Cancer (SCC)

  3. Melanoma

The first 2 types of cancer are called as non melanoma type skin cancer.

Let us now understand the details of each type of skin cancer;


2.1 Basal Cell Skin Cancer : Basal cell carcinomas (BCCs) are abnormal, uncontrolled growths that arise from the skin’s basal cells in the outermost layer of skin (epidermis) Basal-cell cancer grows slowly and can damage the tissue around it but is unlikely to spread to distant areas or result in death. It often appears as a painless raised area of skin that may be shiny with small blood vessels running over or may present as a raised area with an ulcer.

a. Basal Cell :One of three main types of cells in the top layer of the skin, basal cells shed as new ones form. BCC most often occurs when DNA damage from exposure to Ultraviolet radiation from the sun or indoor tanning triggers changes in basal cells in the outermost layer of skin (epidermis), resulting in uncontrolled growth.

b. Appearance of Basal Cell Carcinoma :

BCCs can look like open sores, red patches, pink growths, shiny bumps, scars or growths with slightly elevated, rolled edges and/or a central indentation. At times, BCCs may ooze, crust, itch or bleed.

The lesions commonly arise in sun-exposed areas of the body. In patients with darker skin, about half of BCCs are pigmented (meaning brown in color).

It’s important to note that BCCs can look quite different from one person to another.

c. Associated Danger: While BCCs rarely spread beyond the original tumor site, if allowed to grow, these lesions can be disfiguring and dangerous. Untreated BCCs can become locally invasive, grow wide and deep into the skin and destroy skin, tissue and bone.

The longer you wait to have a BCC treated, the more likely it is to recur, sometimes repeatedly.

There are some highly unusual, aggressive cases when BCC spreads to other parts of the body. In even rarer instances, this type of BCC can become life-threatening.

Because BCCs grow slowly, most are curable and cause minimal damage when caught and treated early.

Understanding BCC causes, risk factors and warning signs can help you detect them early, when they are easiest to treat and cure.

d. Area affected :These cancers most often develop on skin areas typically exposed to the sun, especially the face, ears, neck, scalp, shoulders and back.

e. Risk Factors: There are several risk factors for Basal cell carcinoma, they are as follows;

  • UV exposure from sun or indoor tanning.

  • History of skin cancers

  • Age over 50 years

  • People with fair skin

  • Men are more prone to develop BCC than females.

  • People having having chronic inflammation or skin conditions.

f. Warning Signs: There are few warning signs of BCC that are noted, The warning signs are as follows;

  • An open sore that does not heal, and may bleed, ooze or crust. The sore might persist for weeks, or appear to heal and then come back.

  • A reddish patch or irritated area, on the face, chest, shoulder, arm or leg that may crust, itch, hurt or cause no discomfort.

  • A shiny bump or nodule that is pearly or clear, pink, red or white. The bump can also be tan, black or brown, especially in dark-skinned people, and can be mistaken for a normal mole.

  • A small pink growth with a slightly raised, rolled edge and a crusted indentation in the center that may develop tiny surface blood vessels over time.

  • A scar-like area that is flat white, yellow or waxy in color. The skin appears shiny and taut, often with poorly defined borders. This warning sign may indicate an invasive BCC.




2.2 Squamous cell skin Cancer : Squamous cell carcinoma (SCC) is an uncontrolled growth of abnormal cells arising from the squamous cells in the outmost layer of skin (epidermis).Squamous cell carcinoma (SCC) of the skin is the second most common form of skin cancer, characterized by abnormal, accelerated growth of squamous cells. When caught early, most SCCs are curable.

SCC of the skin is also known as cutaneous squamous cell carcinoma (SCC). Adding the word “cutaneous” identifies it as a skin cancer and differentiates it from squamous cell cancers that can arise inside the body, in places like the mouth, throat or lungs.

a. Squamous Cell : One of three main types of cells in the top layer of the skin (the epidermis), squamous cells are flat cells located near the surface of the skin that shed continuously as new ones form.

SCC occurs when DNA damage from exposure to ultraviolet radiation or other damaging agents trigger abnormal changes in the squamous cells.

b. Appearance :

SCCs can appear as scaly red patches, open sores, rough, thickened or wart-like skin, or raised growths with a central depression.

At times, SCCs may crust over, itch or bleed. The lesions most commonly arise in sun-exposed areas of the body.

SCCs can also occur in other areas of the body, including the genitals.

SCCs look different on everyone.

Commonly presents as a red, crusted, or scaly patch or bump. Often a very rapidly growing tumor.

c. Areas Affected : SCCs are common on sun-exposed areas such as the ears, face, scalp, neck and hands, where the skin often reveals signs of sun damage, including wrinkles and age spots.

d. Risk factors : The risk factors for squamous cell carcinoma are as follows;

  • Unprotected exposure to UV radiation from the sun or tanning beds.

  • Weakened immune system due some illness or immunosupressent medicines.

  • Skin pre cancer conditions like acitinic keratosis.

  • Age of person over 50 years.

  • Fair skin people are more prone to develop this type of cancer.

  • Sun sensitive conditions like xeroderma pigmentosum.

  • Chronic inflammation and skin conditions.

  • History of any type of skin cancers.

e. Warning Signs: SCC of the skin can develop anywhere on the body but is most often found on exposed areas exposed to ultraviolet radiation like the face, lips, ears, scalp, shoulders, neck, back of the hands and forearms. SCCs can develop in scars, skin sores and other areas of skin injury. The skin around them typically shows signs of sun damage such as wrinkling, pigment changes and loss of elasticity.

SCCs can appear as thick, rough, scaly patches that may crust or bleed. They can also resemble warts, or open sores that don’t completely heal. Sometimes SCCs show up as growths that are raised at the edges with a lower area in the center that may bleed or itch.

f. Associated Dangers: SCCs can sometimes grow rapidly and metastasize if not detected and treated early. As many as 15,000 deaths occur from invasive SCC of the skin each year in the U.S.

2.3 Melanoma : Melanoma is a cancer that develops from melanocytes, the skin cells that produce melanin pigment, which gives skin its color.Melanoma is a serious form of skin cancer that begins in cells known as melanocytes.

melanoma is more dangerous because of its ability to spread to other organs more rapidly if it is not treated at an early stage.

a. Melanocyte: Melanocytes are skin cells found in the upper layer of skin. They produce a pigment known as melanin, which gives skin its color. There are two types of melanin: eumelanin and pheomelanin.

When skin is exposed to ultraviolet radiation from the sun or tanning beds, it causes skin damage that triggers the melanocytes to produce more melanin, but only the eumelanin pigment attempts to protect the skin by causing the skin to darken or tan.

Melanoma occurs when DNA damage from burning or tanning due to UV radiation triggers changes (mutations) in the melanocytes, resulting in uncontrolled cellular growth.

Naturally darker-skinned people have more eumelanin and naturally fair-skinned people have more pheomelanin.

While eumelanin has the ability to protect the skin from sun damage, pheomelanin does not. That’s why people with darker skin are at lower risk for developing melanoma than fair-skinned people who, due to lack of eumelanin, are more susceptible to sun damage, burning and skin cancer

b. Appearance: Melanomas present in many different shapes, sizes and colors. That’s why it’s tricky to provide a comprehensive set of warning signs.


c.Types: There are four main types of melanoma. They are as follows;

  • Superficial spreading Melanoma

  • Lentigo Melanoma

  • Acral Lentiginous Melanoma

  • Nodular Melanoma




Superficial Spreading Melanoma

This is the most common form of melanoma.

How and where it grows: It can arise in an existing mole or appear as a new lesion. When it begins in a mole that is already on the skin, it tends to grow on the surface of the skin for some time before penetrating more deeply. While it can be found nearly anywhere on the body, it is most likely to appear on the torso in men, the legs in women and the upper back in both.

What it looks like: It may appear as a flat or slightly raised and discolored, asymmetrical patch with uneven borders. Colors include shades of tan, brown, black, red/pink, blue or white. It can also lack pigment and appear as a pink or skin-tone lesion.

Lentigo Melanoma

This form of melanoma often develops in older people. When this cancer becomes invasive or spreads beyond the original site, the disease is known as lentigo melanoma.

How and where it grows: This form of melanoma is similar to the superficial spreading type, growing close to the skin surface at first. The tumor typically arises on sun-damaged skin on the face, ears, arms or upper torso.

What it looks like: It may look like a flat or slightly raised, blotchy patch with uneven borders. Color is usually blue-black, but can vary from tan to brown or dark brown.

Acral Lentiginous Melanoma

This is the most common form of melanoma found in people of color, including individuals of African ancestry.

How and where it grows: It often appears in hard-to-spot places including under the nails and on the soles of the feet or palms of the hands.

What it looks like: It may appear as a black or brown area.

Nodular Melanoma

This is the most aggressive type of melanoma. It accounts for 10 to 15 percent of all cases.

How and where it grows: The tumor grows deeper into the skin more rapidly than other types and is most frequently found on the torso, legs and arms, as well as the scalp in older men. It is usually invasive at the time it is first diagnosed.

What it looks like: Nodular melanoma is often recognized as a bump on the skin, usually blue-black in color, but not uncommonly can also appear as a pink to red bump.

d.Risk Factors: There are certain risk factors associated with Melanoma. Following are the risk factors of Melanoma;

  • Unprotected or excessive UV exposure

  • Weakened Immune system

  • Many moles on the body, increase the risk of Melanoma

  • Fair skin people are more prone to develop melanoma

  • Genetics

  • Family history of having Melanoma.

e. Stages of Melanoma:

Stage 0 and I are localized, meaning they have not spread.

  • Stage 0: Melanoma is localized in the outermost layer of skin and has not advanced deeper. This noninvasive stage is also called melanoma in situ.

  • Stage I: The cancer is smaller than 1 mm in Breslow depth, and may or may not be ulcerated. It is localized but invasive, meaning that it has penetrated beneath the top layer into the next layer of skin. Invasive tumors considered stage IA are classified as early and thin if they are not ulcerated and measure less than 0.8 mm.

  • Stage II: Intermediate, high-risk melanomas are tumors deeper than 1 mm that may or may not be ulcerated. Although they are not yet known to have advanced beyond the primary tumor, the risk of spreading is high, and physicians may recommend a sentinel lymph node biopsy to verify whether melanoma cells have spread to the local lymph node biopsy Thicker melanomas, greater than 4.0 mm, have a very high risk of spreading, and any ulceration can move the disease into a higher subcategory of stage II. Because of that risk, the doctor may recommend more aggressive treatment.

  • Stage III: These tumors have spread to either the local lymph nodes or more than 2 cm away from the primary tumor through a lymph vessel but not yet to the local lymph nodes. Thickness no longer plays a staging role. If local lymph nodes are palpable, meaning they feel enlarged when examined by a doctor, the tumor has reached them, and they are removed

  • . Sometimes melanoma is present even in lymph nodes that are not palpable. Sentinel lymph node biopsy (SLNB) is a technique used to determine whether the disease has spread to one or more nearby lymph nodes. Melanomas that have spread to very small areas of nearby skin or underlying tissue but have not reached the lymph nodes are known as “satellite tumors” — and are also included in stage III.

  • The staging system includes metastases so tiny they can be seen only by microscope (micrometastases). The degree of disease advancement depends on whether the tumor has reached the nodes, the number of nodes involved, the number of cancer cells found in them and whether they are microscopic or are palpable and can be seen with the naked eye.

  • Stage IV: The cancer has advanced to distant body areas, lymph nodes or organs, most often the lungs, liver, brain, bone and gastrointestinal tract.

  • The two main ways to determine the degree of advancement in stage IV melanoma are the site of the distant tumors and the presence of elevated serum lactate dehydrogenase (LDH) levels. LDH is an enzyme that turns sugar into energy; the more found in blood or body fluids, the more damage has been done.

f. Warning Signs:The first five letters of the alphabet are a guide to help you recognize the

warning signs of melanoma.

A is for Asymmetry. Most melanomas are asymmetrical. If you draw a line through the middle of the lesion, the two halves don’t match, so it looks different from a round to oval and symmetrical common mole.

B is for Border. Melanoma borders tend to be uneven and may have scalloped or notched edges, while common moles tend to have smoother, more even borders.

C is for Color. Multiple colors are a warning sign. While benign moles are usually a single shade of brown, a melanoma may have different shades of brown, tan or black. As it grows, the colors red, white or blue may also appear.

D is for Diameter or Dark. While it’s ideal to detect a melanoma when it is small, it’s a warning sign if a lesion is the size of a pencil eraser (about 6 mm, or ¼ inch in diameter) or larger. Some experts say it is also important to look for any lesion, no matter what size, that is darker than others.

E is for Evolving. Any change in size, shape, color or elevation of a spot on your skin, or any new symptom in it, such as bleeding, itching or crusting, may be a warning sign of melanoma.





3. CAUSES OF SKIN CANCER:

Skin cancer occurs when errors (mutations) occur in the DNA of skin cells. The mutations cause the cells to grow out of control and form a mass of cancer cells. The major cause of skin cancer is as follows;

3.1 Ultraviolet light or exposure to Ultraviolet light: Much of the damage to DNA in skin cells results from ultraviolet (UV) radiation found in sunlight and in the lights used in tanning beds.

But sun exposure doesn't explain skin cancers that develop on skin not ordinarily exposed to sunlight. This indicates that other factors may contribute to your risk of skin cancer, such as being exposed to toxic substances or having a condition that weakens your immune system.

Exposure to Ultraviolet radiation is the major cause, however, there are several risk factors associated with diagnosis of skin cancer.

3.2 Risk Factors:

The risk factors for causing skin cancers is as follows;

  • Fair skin. Anyone, regardless of skin color, can get skin cancer. However, having less pigment (melanin) in your skin provides less protection from damaging UV radiation. If you have blond or red hair and light-colored eyes, and you freckle or sunburn easily, you're much more likely to develop skin cancer than is a person with darker skin.

  • A history of sunburns. Having had one or more blistering sunburns as a child or teenager increases your risk of developing skin cancer as an adult. Sunburns in adulthood also are a risk factor.

  • Excessive sun exposure. Anyone who spends considerable time in the sun may develop skin cancer, especially if the skin isn't protected by sunscreen or clothing. Tanning, including exposure to tanning lamps and beds, also puts you at risk. A tan is your skin's injury response to excessive UV radiation.

  • Sunny or high-altitude climates. People who live in sunny, warm climates are exposed to more sunlight than are people who live in colder climates. Living at higher elevations, where the sunlight is strongest, also exposes you to more radiation.

  • Moles. People who have many moles or abnormal moles called dysplastic nevi are at increased risk of skin cancer. These abnormal moles — which look irregular and are generally larger than normal moles — are more likely than others to become cancerous. If you have a history of abnormal moles, watch them regularly for changes.

  • Precancerous skin lesions. Having skin lesions known as actinic keratoses can increase your risk of developing skin cancer. These precancerous skin growths typically appear as rough, scaly patches that range in color from brown to dark pink. They're most common on the face, head and hands of fair-skinned people whose skin has been sun damaged.

  • A family history of skin cancer. If one of your parents or a sibling has had skin cancer, you may have an increased risk of the disease.

  • A personal history of skin cancer. If you developed skin cancer once, you're at risk of developing it again.

  • A weakened immune system. People with weakened immune systems have a greater risk of developing skin cancer. This includes people living with HIV/AIDS and those taking immunosuppressant drugs after an organ transplant.

  • Exposure to radiation. People who received radiation treatment for skin conditions such as eczema and acne may have an increased risk of skin cancer, particularly basal cell carcinoma.

  • Exposure to certain substances. Exposure to certain substances, such as arsenic, may increase your risk of skin cancer.




4. DIAGNOSIS AND TREATMENT:

4.1 Diagnosis: To diagnose skin cancer, your doctor may:

  • Examine your skin. Your doctor may look at your skin to determine whether your skin changes are likely to be skin cancer. Further testing may be needed to confirm that diagnosis.

Remove a sample of suspicious skin for testing (skin biopsy). Your doctor may remove the suspicious-looking skin for lab testing. A biopsy can determine whether you have skin cancer and, if so, what type of skin cancer you have. 4.2 Determining the extent of the skin cancer If your doctor determines you have skin cancer, you may have additional tests to determine the extent (stage) of the skin cancer. Because superficial skin cancers such as basal cell carcinoma rarely spread, a biopsy that removes the entire growth often is the only test needed to determine the cancer stage.

But if you have a large squamous cell carcinoma, Merkel cell carcinoma or melanoma, your doctor may recommend further tests to determine the extent of the cancer. Additional tests might include imaging tests to examine the nearby lymph nodes for signs of cancer or a procedure to remove a nearby lymph node and test it for signs of cancer (sentinel lymph node biopsy). Doctors use the Roman numerals I through IV to indicate a cancer's stage. Stage I cancers are small and limited to the area where they began. Stage IV indicates advanced cancer that has spread to other areas of the body. The skin cancer's stage helps determine which treatment options will be most effective. 4.3 Treatment: Your treatment options for skin cancer and the precancerous skin lesions known as actinic keratoses will vary, depending on the size, type, depth and location of the lesions. Small skin cancers limited to the surface of the skin may not require treatment beyond an initial skin biopsy that removes the entire growth. If additional treatment is needed, options may include:

  • Freezing. Your doctor may destroy actinic keratoses and some small, early skin cancers by freezing them with liquid nitrogen (cryosurgery). The dead tissue sloughs off when it thaws.

  • Excisional surgery. This type of treatment may be appropriate for any type of skin cancer. Your 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.

  • Mohs surgery. This procedure is for larger, recurring or difficult-to-treat skin cancers, which may include both basal and squamous cell carcinomas. It's often used in areas where it's necessary to conserve as much skin as possible, such as on the nose. During Mohs surgery, your 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.

  • Curettage and electrodesiccation or cryotherapy. After removing most of a growth, your doctor scrapes away layers of cancer cells using a device with a circular blade (curet). An electric needle destroys any remaining cancer cells. In a variation of this procedure, liquid nitrogen can be used to freeze the base and edges of the treated area. These simple, quick procedures may be used to treat basal cell cancers or thin squamous cell cancers.

  • Radiation therapy. Radiation therapy uses high-powered energy beams, such as X-rays, to kill cancer cells. Radiation therapy may be an option when cancer can't be completely removed during surgery.

  • Chemotherapy. In chemotherapy, drugs are used to kill cancer cells. For cancers limited to the top layer of skin, creams or lotions containing anti-cancer agents may be applied directly to the skin. Systemic chemotherapy can be used to treat skin cancers that have spread to other parts of the body.

  • Photodynamic therapy. This treatment destroys skin cancer cells with a combination of laser light and drugs that makes cancer cells sensitive to light.

  • Biological therapy. Biological therapy uses your body's immune system to kill cancer cells.




5. CONCLUSION:

Skin Cancer is a common condition in many countries due to exposure to Ultraviolet radiation and other associated risk factors. It is very essential to understand the causes and treatment of skin condition, so that it can be better in coping with such conditions. So, the above article gives an overview of skin cancer its types causes and treatment.



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