Thursday, 16 August 2007

Cancer By The Numbers: Basal Cell Carcinoma

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My sister has skin cancer -- the basal cell variety. She has two spots, both on her chest, each one scheduled to be surgically removed in a few weeks. If it were me with this new diagnosis, I'm sure I'd be freaking out, maybe because I've already had breast cancer and tend to panic about any cancer or maybe just because I'm a worrier by nature. But my sister is taking her cancer news in stride, and I am too -- because now that I've done a little research, it seems this type of cancer is pretty easy to beat.

Here's a little refresher lesson on the skin: The skin is the largest organ in the body, and is made of three layers -- the epidermis (top layer), dermis (middle layer), and subcutis (deepest layer). For the purpose of this post, let's focus on the epidermis.

The epidermis has three layers -- an upper, middle, and a bottom layer. This bottom layer is comprised of basal cells. This is where basal cell cancer begins.

Skin cancers are divided into two groups -- melanomas and non-melanomas. Basal cell cancer is one of the most common forms of non-melanoma skin cancer. The other is squamous cell cancer. Basal cell cancers usually begin on areas exposed to the sun, such as the head or neck (or chest, in my sister's case) and while once found mostly on middle-aged and older people, it is now seen more and more on younger people, probably because they are spending more time in the sun without protecting their skin.

The Numbers

Skin cancers are the most common of all cancers, and it's estimated there are at least as many non-melanoma skin cancer cases found each year as all other cancers combined (about one million each year). Most of these cancers are basal cell and number about 800,000 to 900,000 annually. About three out every four skin cancers are basal cell carcinomas.

People do not typically die of basal cell cancer. About 1,000 to 2,000 people die of non-melanoma skin cancer each year, nearly all of them older and characterized by a lack of early treatment.

After treatment, basal cell carcinoma can return in the same place. New basal cell cancers can also start on other places on the skin. Within five years of diagnosis, about 35 to 50 percent of patients develop a new skin cancer.

Risk Factors

Ultraviolet (UV) light is the major risk factor for skin cancer. Sunlight, tanning beds, and tanning booths account for most UV damage. Those who live in places with year-round, bright sunlight are most at risk -- the highest rate of skin cancer in the world in Australia -- and people with fair skin are more at risk than those with darker skin. Men are twice as likely as women to develop basal cell cancers, and exposure to chemicals may also increase risk. People who have received radiation treatment and anyone who has had one or more skin cancers are also at increased risk. Smoking is not a risk factor for this type of cancer -- but some rare skin conditions and HPV infection are.

Prevention


It's easy -- just limit UV exposure, protect your skin with clothing, wear a hat and sunglasses, slather on sunscreen, seek shade, protect children, and avoid harmful chemicals and you'll keep pretty darn safe.

Detection

Basal cell skin cancer can be caught very early. Unlike some cancers, buried in the body and without symptoms for extended periods of time, this cancer can be seen. Many will discover these suspicious lesions on their skin during self-exams; others will learn of their existence during clinical self exams. Basal cell cancers are usually flat, firm, and pale. They can be pink, red, even translucent and are shiny, waxy areas that can bleed and hurt. Larger ones may have oozing and crusted spots.

To determine if a suspicious area is basal cell cancer, a doctor will complete a surgical biopsy. If the biopsy reveals cancer, treatment will follow. Typically, this type of cancer is not staged because it is so rare for basal cell cancer to spread to other organs. If it has spread (lymph node biopsies and lymph node removal will be necessary in this case), the Roman numerals 0-IV are used for staging. The lower the number, the less the cancer has spread.

Treatment

Most basal cell cancers can be completely cured by fairly minor surgery. There's a simple excision where the skin is numbed and the tumor, along with some healthy skin around it, is removed. The remaining skin is stitched back together. This surgery leaves a scar.

The cancer can also be scraped with a long, thin tool called a curette in a process called Curettage and Electrodessication. The area is then treated with an electric needle to destroy remaining cancer cells. This process, often done more than once, also leaves a scar.

Mohs surgery involved removing a layer of skin that the tumor has spread to and checking the sample under a microscope right away. If it's cancer, more pieces of the tumor are removed and examined until the skin samples come up clean. It's a slow process but but allows normal skin next to the tumor to be saved, ensuring the skin looks better after surgery. Only doctors with special training should perform this procedure.

If it's not possible to stretch the remaining skin after surgery, skin grafts and reconstructive surgery may be necessary.

Sometimes, traditional surgery is not necessary. Cancer cells can also be frozen and killed (cryosurgery) or can be destroyed using laser surgery. Chemotherapy lotions are available -- 5-fluorouracil (5-FU) is often used -- as are chemicals that can be applied to the skin or injected into the blood. Chemicals make the cancer sensitive to light and then a light source is used to kill cells.

Finally, radiation therapy can be used to kill or shrink cancer cells. Older individuals who cannot tolerate surgery might use this method.

About Vitamin D

It only takes 15 minutes per day, three days per week, to capitalize on the vitamin D made by our skin when we are in the sun. This is the maximum amount of time the American Cancer Society recommends we spend in the sun.

Source: American Cancer Society

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