Skin Cancer

Cancer is a word used to describe a group of diseases. Each has its own

name, its own treatment, and its own chances of being cured. Each is

different from the others in many ways, but every cancer, whatever its called

or whatever part of the body it is located in, is a disease of the body’s

cells. The millions of tiny cells that make up the human body are so small

that they can be seen only by looking through a microscope. There are

different kinds of cells, but they all make new cells by dividing into two.

This is how worn-out, old cells are replaced with strong new ones. When a

cell changes and doesn’t do the job it should do for the body, it divides into

more cells like itself, then these cells keep dividing into more cells. A

group of these cells is a tumor. There are two kinds of tumors. A benign

tumor is not cancer. The cells of a benign tumor can crowd out healthy cells,

but they cannot spread to other parts of the body. A malignant tumor is

cancer. Like a benign tumor, it can take over other healthy cells around it,

but it can also spread to other parts of the body. To do this, a cell or

group of cells from the tumor breaks away and moves, usually though the blood,

to other parts of the body. There they divide and start tumors made of

malignant cells like the ones that made up the first tumor. When this

happens, it is called metastasis.

Skin cancer is the most prevalent of all cancers, and it’s increasingly

common. About a million Americans will develop skin cancer this year. It is a

disease in which cancer cells are found in the outer layers of skin. Skin

protects the body against heat, light, infection, and injury. It also stores

water, fat, and vitamin D.

The skin has two main layers and several kinds of cells. The top layer of

skin is called the epidermis. It contains three kinds of cells: flat, scaly

cells on the surface called squamous cells, round cells called basal cells,

and cells called melanocytes, which give skin its color.

The inner layer of skin is called the dermis. This layer is thicker, and

contains blood vessels, nerves, and sweat glands. The hair on skin also grows

from tiny pockets in the dermis, called follicles. The dermis makes sweat,

which helps cool the body, and oils that keep the skin from drying out.

Skin cancer is viewed as an undeclared epidemic by dermatologists. "Skin

cancer is now about as common as all other cancers combined," says Martin A.

Weinstock, M.D., Ph.D., director of Brown University’s Dermatoepidemiology

Unit and Chief of Dermatology at the Providence Veteran’s Affairs Medical

Center. He also says there’s no evidence the epidemic has peaked, which means

it could get worse.

Skin cancer is quite curable when treated early. More than ninety percent of

skin cancers are completely cured. It’s also largely preventable, simply by

avoiding sun and sunlamp exposure.

Sunscreen is the most common defense against skin cancer. However, only two

in five people consistently use sunscreen whenever they’re in the sun. Few

people say they sunbathe, but about one in five adults still does.

There are three main types of skin cancer. Melanoma is the least common but

most serious because this killer is responsible for three-quarters of the

nearly 10,000 skin cancer deaths per year. The other two types, basal cell

and squamous cell carcinomas, are often referred to together as non-melanoma

skin cancer. Basal cell cancer is by far the most common skin cancer,

followed by squamous cell carcinoma, which can also become a killer. Between

1980 and 1989, the incidence of non-melanoma skin cancers increased sixty-five

percent and melanoma twenty-one percent. Skin cancer is also striking at

younger ages than before. One-quarter of the more than 30,000 people expected

to develop melanoma this year will be thirty-nine or younger. Other kinds of

cancers that may affect the skin include cutaneous T-cell lymphoma, a cancer

of the lymph system, and Kaposi’s sarcoma.

Melanoma is the fastest-growing type of cancer, affecting about 32,000

Americans in 1993. The skin cancer is triggered by UV rays from the sun