What is Cancer
Cancer is a group of more than 100 diseases caused by the uncontrolled growth and spread of abnormal cells. Tumors, or abnormal growth of tissue, may be benign or malignant. Benign tumors are usually slow-growing and not life-threatening, whereas malignant tumors (or cancers) are made up of cells with abnormal genetic material (or DNA) and grow more rapidly. Malignant tumors have a tendency to invade neighboring tissues or organs and to travel and grow in other areas of the body (i.e. to metastasize). If the spread of the cancer is not stopped, cancer cells invade vital organs which can result in death. Cancer cells may remain at their original site (local stage), spread to an adjacent area of the body or into surrounding lymph nodes (regional stage), or spread throughout the body (distant stage). Cancers at the local, regional or distant stage are considered invasive. A very early cancer found in only a few layers of cells, called in situ cancer, is considered non-invasive. (Please see the Glossary for definitions of many of these terms.)
What Causes Cancer
Cancers are caused by a variety of factors working alone or in combination. Some cancers are caused by external factors such as tobacco, diet, certain chemicals, radiation, and viruses and some by factors such as hormones, immune conditions, and inherited genetic mutations. Usually ten or more years pass between exposure to a factor that causes cancer and the detectable disease.
Cancer Incidence and Mortality in the U.S.
Cancer is the second leading cause of death in the U.S. with about 1,221,800 new cases and 563,100 deaths estimated for 1999. Over the past 50 years, the overall death rate from cancer has increased due partially to a large rise in lung cancer death rates resulting from smoking. During the past few years cancer rates have begun to decrease, possibly as a result of healthier lifestyles, particularly decreases in smoking. Cancer occurs in people of all ages, but its occurrence increases steadily in people over 45 years of age. However, in the U.S. cancer is also the leading cause of non-injury death among children under 15. In this country, men have about a 1 in 2 lifetime risk of developing cancer and women have about a 1 in 3 lifetime risk. These proportions do not include the majority of skin cancers which are not reportable to most cancer registries. In the U.S., men have higher cancer mortality rates than women, and blacks have the highest cancer mortality rate of any major racial group. Fortunately, a much higher percentage of people diagnosed with cancer are now surviving compared with people diagnosed in earlier years. More than six of every ten people diagnosed with cancer in recent years will survive for at least five years from the time of diagnosis.
Incidence in the U.S. (American Cancer Society (ACS), 1999; American Agency for Cancer Research (AACR), 1998; United States Department of Health and Human Services, 1999)
Prostate cancer is the most common type of cancer among men in the U.S., accounting for about 30 percent of all newly diagnosed cases of cancer among men each year (excluding skin cancer). Approximately one in six men in the U.S. will be diagnosed with prostate cancer at some time in his life, according to the American Cancer Society. The age-adjusted incidence rate of prostate cancer among men in the U.S. steadily increased between 1973 and 1992, especially between 1989 and 1992, after which prostate cancer incidence declined. Many researchers believe that some of the increase, especially from 1989 to 1992, is due to an increased use of screening procedures that identify prostate cancer at early stages. Another possible reason is the increase in life span; most prostate cancers are diagnosed in men over age 65 and more men are now living well beyond 65, thereby increasing the chances that they will develop prostate cancer that is clinically diagnosed.
Mortality in the U.S. (ACS, 1999)
Prostate cancer is the second most common cause of death due to cancer in the U.S. (following lung cancer) with about 37,000 deaths estimated nationwide for 1999. The mortality rate of prostate cancer is declining, but the rate for black men remains twice that of white men. The declining mortality rate is believed to be due in part to earlier detection which enables more successful treatment. During the most recent interval (1989-1994) which was evaluated nationally, the five-year survival rate for prostate cancer diagnosed at the local or regional stages was about 99 percent, but for men with distant metastases at diagnosis, five-year survival was about 33 percent.
Risk Factors for Prostate Cancer
The known risk factors include the following:
* Age - The risk of prostate cancer increases sharply after age 65. This is the single most important risk factor.
The following factors are under investigation regarding their role in increasing the risks of prostate cancer.
* Hormones - Male hormones or androgens, specifically testosterone and dihydrotestosterone, may act as factors which promote prostate cancer development. (AACR, 1998)
Other potential risk factors under investigation include smoking, alcohol consumption, physical activity, occupational exposures, socio-economic status, urban living, religion, sexual activity, and marital status.
Until the preventable risk factors for prostate cancer are better defined, early detection and treatment are the best means to increase survival and reduce mortality due to prostate cancer. However, low dietary fat intake and maintenance of normal body weight, which are under investigation regarding prevention of prostate cancer, are also preventive of other health problems and are therefore recommended.
Consensus has not been reached on screening guidelines. Although men with prostate cancer diagnosed at the early stages have better survival rates, screening programs have not been proven to be beneficial for all men. In particular, diagnoses are made earlier through screening and thus may appear to prolong survival only because men are followed for a longer period prior to their death, irrespective of the effect of therapy. It is also not yet clear for which groups of men the medical risks of diagnostic and treatment procedures which are often used following a positive screening test are outweighed by the benefits of earlier detection (see the Discussion section). There are numerous investigations currently underway to address these issues. Appendix I contains a list of screening recommendations and guidelines from several key organizations.
For additional free information on prostate and other cancers these organizations may be contacted:
* Cancer Epidemiology Services, New Jersey Department of Health and Senior Services - phone 1-609-588-3500 or access the Internet at www.state.nj.us/health. The Cancer Epidemiology Services has incidence data on cancer in New Jersey from the New Jersey State Cancer Registry and informational materials from a variety of other organizations.
* American Cancer Society - phone 1-973-331-9300 or access the Internet at www.cancer.org. The American Cancer Society is a nationwide, community-based, voluntary health organization dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives and diminishing suffering from cancer, through research, education, advocacy, and service.
* National Cancer Institute - phone 1-800- 4-CANCER (or 1-800-422-6237) or access the Internet at www.nci.nih.gov. The Cancer Information Service (CIS) of the National Cancer Institute provides a nationwide telephone service for the public, cancer patients and their families. Health care professionals can answer questions in English and Spanish and send printed materials. People with TTY equipment for the hearing-impaired may call 1-800-332-8615.
* American Urological Association - is a national organization representing most of the urologists in the U.S. They provide education, professional training, and screening recommendations. Their website is www.auanet.org.
* Man to Man - is a non-profit organization associated with the American Cancer Society dedicated to education, support, and awareness for the patient and his family. Members meet to share and support one another in coping with prostate cancer. Their telephone is 1-973-331-9300. Their website is www.cancer.org/m2m/m2pro.
* US-TOO International - is one of the largest patient-organized support groups dedicated exclusively to prostate disease. It has local chapters all across America and is primarily focused on patient support, fellowship, and counseling. Their telephone is 1-800-808-7866. Their website is www.ustoo.com and it contains a link to New Jersey chapters.
* Cancer Hope Network - puts patients in touch with other patients for support and fellowship. Their telephone is 1-877-467-3638.
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