While cancer's precise causes remain unknown, here's what we do

April 11, 2005|by Dr. Michael McCormack

Cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells. If the spread is not successfully controlled, the condition results in death.

Cancer is the second-leading cause of death in the United States behind cardiovascular diseases and it can occur in essentially any organ in the human body as well as the blood and lymphatic systems. The site of origin (i.e., breast, lung, etc.) is the most important factor in determining prognosis and treatment.

The precise cause of most cancers remains unknown. Cancer is associated with internal factors such as heredity or immune system problems or by external factors such as tobacco or chemicals.

While cancer can occur at any age, it is more common in the elderly. With rare exceptions (i.e., testicular cancer, and Hodgkin's disease), cancer risk increases as we age. For example, a woman is more likely to develop breast cancer at age 70 than at age 40. More than three quarters of all cancers are diagnosed after the age of 55.


Overall, blacks are more likely to develop cancer than whites or hispanics. The reasons for this are unclear, but the good news is that over the past 10 years the mortality rate for black patients has declined more rapidly than for other racial or ethnic groups.

Lifestyle and, in particular, smoking is clearly a risk factor for cancer. Smokers are 20 times more likely to develop lung cancer than nonsmokers, Smokers also are at higher risk for other cancers such as head and neck cancers and esophageal cancer.

The cause of most other cancers is unknown. Heredity plays some role but usually less than most people think. If a member of your immediate family has had breast, ovarian, colon or prostate cancer, this does increase your risk for these diseases but, in general, only 10 percent to 20 percent.

Approximately 1.4 million Americans are diagnosed with cancer every year. More than 20 million Americans have been diagnosed with cancer since 1990. In Maryland, there are 24,000 to 25,000 cases per year. In Washington County, about 1,000 patients per year are diagnosed.

The most common cancer in women is breast cancer, while in men it is prostate cancer. However, the most lethal cancer in both sexes is lung cancer, which ranks third in number of new cases. Other frequently diagnosed cancers include colorectal cancer, gynecologic cancers and lymphomas.

Cancer rates in Washington County tend to reflect national averages; there is a slightly higher rate of lung cancer locally than in the nation as a whole.

Many people think that cancer is a death sentence. However, if found early and treated with current therapies, a large number of cancers are curable. Even if not cured, many cancers can be treated with effective therapies that can allow patients to lead productive lives for several years or more.

The National Cancer Institute estimates that there are about 9 million Americans who have had cancer or are living with cancer.

With the exception of cancers caused by smoking, most cancers cannot be prevented. Simple measures such eating well, exercising regularly and limiting sun exposure (a risk factor for skin cancer) will be helpful.

The more important issue is usually early detection. It is important for all individuals to be screened for those cancers that can be detected early and thus more easily cured.

It generally is recommended that women be screened for breast, cervical, and colon cancer, and that men be screened for colon and prostate cancer. If everyone was vigilant about getting these tests, the death rate from cancer could be substantially reduced.

In subsequent articles, my colleagues and I will discuss more in depth particular kinds of cancer as well as new treatments. Also, we will deal with some of the emotional issues faced by cancer patients.

Dr. Michael McCormack is an oncologist in Hagerstown.

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