What is cancer?
The body is made up of trillions of living cells. Normal body cells grow, divide into new cells, and die in an orderly way. During the early years of a person’s life when they are growing, normal cells divide faster. After the person becomes an adult, most cells divide only to replace worn-out, damaged, or dying cells.
Cancer begins when cells in a part of the body start to grow out of control. There are many kinds of cancer, but they all start because of this out-of-control growth of abnormal cells. Cancer cell growth is different from normal cell growth. Instead of dying, cancer cells keep on growing and form new cancer cells. These cancer cells can grow into (invade) other tissues, something normal cells can’t do. Being able to grow out of control and invade other tissues are what makes a cell a cancer cell.
In most cases the cancer cells form a tumor. But some cancers, like leukemia, rarely form tumors. Instead, these cancer cells are in the blood and bone marrow. Sometimes cancer cells travel to other parts of the body. There they begin to grow and form new tumors. This process is called metastasis.
No matter where a cancer spreads, it is named (and treated) based on the place where it started. For instance, breast cancer that has spread to the liver is still breast cancer, not liver cancer. Likewise, prostate cancer that has spread to the bones is still prostate cancer, not bone cancer. Different types of cancer can behave very differently. They grow at different rates and respond to different treatments. That is why people with cancer need treatment that is aimed at their own kind of cancer. Not all tumors are cancer. Tumors that aren’t cancer are called benign. Benign tumors can cause problems – they can grow very large and press on healthy organs and tissues. But they can’t grow into other tissues. Because of this, they also can’t spread to other parts of the body (metastasize). These tumors are almost never life threatening.
What is melanoma skin cancer?
Melanoma is a cancer that begins in the melanocytes. Because most of these cells still make melanin, melanoma tumors are often brown or black. But this is not always the case, and melanomas can also appear pink, tan, or even white. elanoma most often starts on the trunk (chest or back) in men and on the legs of women, but it can start in other places, too. Having dark skin lowers the risk of melanoma, but a person with dark skin can still get melanoma. Melanoma is much less common than basal cell and squamous cell skin cancers, but it is far more dangerous. It can almost always be cured in its early stages. But it is likely to spread to other parts of the body if it is not caught early.
How many people get melanoma skin cancer?
The American Cancer Society’s estimates for melanoma skin cancer in the United States for 2014 are:
• About 76,100 new cases of melanoma
• About 9,710 deaths from melanoma
Skin cancer is the most common of all cancers. Melanoma accounts for less than 5% of skin cancers. But it causes most skin cancer deaths. The number of new cases of melanoma in the United States has been increasing for at least 30 years. Overall, the lifetime risk of getting melanoma is about 1 in 50 for whites, 1 in 1,000 for blacks, and 1 in 200 for Hispanics. Unlike many other common cancers, melanoma occurs in both younger and older people. Rates keep on going up with age.
What are the risk factors for melanoma skin cancer?
We do not yet know exactly what causes melanoma skin cancer. But we do know that certain risk factors are linked to this disease. A risk factor is anything that affects your chance of getting a disease. Different cancers have different risk factors. Some risk factors, like smoking, can be changed. Others, like a person’s age or family history, can’t be changed.
But having a risk factor, or even several risk factors, does not mean that you will get the disease. And some people who get the disease may have few or no known risk factors. Even if a person with melanoma has a risk factor, it’s often very hard to know what part that risk factor may have played in getting the cancer. Scientists have found several risk factors that could make a person more likely to get melanoma.
UV (ultraviolet) light
Too much exposure to UV rays is a major risk factor for most melanomas. The main source of UV rays is the sun. Tanning lamps and beds are also sources of UV rays. People with high levels of UV exposure from these sources are at greater risk for all types of skin cancer. The amount of UV exposure a person gets depends on the strength of the light, how long the skin is exposed, and whether the skin is covered with clothing or sunscreen.
A mole is a benign (not cancer) skin tumor. The chance of any single mole turning into cancer is very low. But certain types of moles increase a person’s chance of getting melanoma. People who have many abnormal moles are more likely to develop melanoma. These people should have very thorough skin exams by a dermatologist. Many doctors also suggest these people should be shown how check their own skin every month. Good sun protection is always important.
Light-colored skin, freckles, and light hair
The risk of melanoma is more than 10 times higher for whites than for African Americans. Whites with red or blond hair, blue or green eyes, or fair skin that freckles or burns easily are at increased risk.
Family history of melanoma
Your risk of melanoma is higher if you have a close relative (parent, brother, sister, or child) who has had the disease. This could be because the family tends to spend more time in the sun, or because the family members have fair skin, or both. It may also be because of a gene change (mutation) that runs in the family.
People with a strong family history of melanoma should do these things:
• Have regular skin exams by a dermatologist
• Look closely at their own skin once a month and report any changes to the doctor
• Be very careful about sun exposure and avoid tanning beds
Having had melanoma in the past
A person who has already had melanoma has a higher risk of getting another one.
Weak immune system
People who have been treated with medicines that suppress the immune system, such as organ transplant patients, have an increased risk of melanoma.
Melanoma is more likely to happen in older people. But it is a cancer that is also found in younger people. In fact, it is one of the most common cancers in people under 30.
In the United States, melanoma is generally more common in men than in women. But this varies by age. Before age 40, the risk is higher for women; after age 40 the risk is higher in men.
Can melanoma skin cancer be prevented?
Not all melanomas can be prevented, but there are things you can do that might reduce your risk.
Limit UV exposure
The best way to lower the risk of melanoma is to limit your exposure to strong sunlight and other sources of UV light. Simply staying in the shade is one of the best ways to limit being exposed to UV rays.
Use sunscreen and lip balm. Broad spectrum products (which protect against different types of UV rays) with a sun protection factor (SPF) of 30 or more are recommended. Be sure to use enough – about a shot glass or a palmful to cover your arms, legs, face, and neck. And put it on again at least every 2 hours and after swimming or sweating. Use sunscreen even on days with light or broken cloud cover because UV rays still come through. Don’t make the mistake of thinking that because you’re using sunscreen, you can stay out in the sun as long as you want. Sunscreens are a filter – they do not block all UV rays. If you spend enough time in the sun you will still end up with damage to your skin.
Avoid tanning beds and sunlamps
Many people believe the UV rays of tanning beds are harmless. This is not true. Tanning lamps give out UVA and often UVB rays as well. Both of these can cause long-term skin damage and are linked to skin cancer. Tanning bed use has been linked with an increased risk of melanoma, especially if it’s started before the age of 30. Most skin doctors and health groups advise against using tanning beds and sun lamps. If you want a tan, one option is a sunless tanning lotion. These can make you look tan without the danger. You do not have to go out in the sun for these to work. The color tends to wear off after a few days. Most sunless tanning lotions don’t protect very much against UV rays. If you use one, you should still take other measures mentioned above to protect your skin when you are outside. Some tanning salons offer a spray-on tan. A concern here is that the spray should not be inhaled or sprayed in or on the mouth, eyes, or nose. People who choose to get a spray tan should make sure to protect these areas.
Check for abnormal moles and have them removed
If you have many moles or abnormal moles, your doctor may want to watch them closely with regular exams and may advise you to do monthly skin self-exams. The doctor may want to remove some of them if they have certain features that suggest they might change into a melanoma. If you find a new, unusual, or changing mole, you should have it checked by your doctor.
Possible signs and symptoms of melanoma
The most important warning sign for melanoma is a new spot on the skin or a spot that is changing in size, shape, or color. A spot that looks different from all of the other spots on your skin can also be a warning. If you have any of these warning signs, have your skin checked by a doctor.
The ABCDE rule can help you tell a normal mole from an abnormal mole. Moles that have any of these signs should be checked by a doctor. ABCDE stands for the following:
• A is for Asymmetry: One half of a mole or birthmark does not match the other.
• B is for Border: The edges are irregular, ragged, notched, or blurred
• C is for Color: The color is not the same all over and may include shades of brown or black, or even patches of pink, red, white, or blue.
• D is for Diameter: The spot is larger than about ¼ inch across (the size of a pencil eraser), but melanomas can be smaller than this.
• E is for Evolving: The mole is changing in size, shape, or color.
Some melanomas doesn’t fit the “rules” above. It may be hard to tell if the mole is normal or not, so you should show your doctor anything that you are unsure of.
Other warning signs are:
• A sore that does not heal
• Spread of color from the border of a spot to the skin around it
• Redness or a new swelling beyond the border
• Itchiness, tenderness, or pain
• Change in the surface of a mole – scaliness, oozing, bleeding, or a new bump or nodule
Be sure to show your doctor any areas that concern you and ask your doctor to look at areas that may be hard for you to see. Sometimes it’s hard to tell the difference between melanoma and an ordinary mole, so it’s important to show your doctor any mole that you are unsure of.
For more information contact your American Cancer Society at 1-800-227-2345 or www.cancer.org