1. What is the purpose of this report and who created it?

This report provides an update on the trends in cancer incidence (new cases reported) and death rates in the United States. It also features a section on a dozen cancers with upward trends compared to the majority of cancers which are decreasing. The North American Association of Central Cancer Registries (NAACCR); the Centers for Disease Control and Prevention (CDC), including the National Center for Health Statistics (NCHS); the American Cancer Society (ACS); and the National Cancer Institute (NCI) collaborated to create this report. These reports are issued annually.

2. What are the sources of the data?

Information on newly diagnosed cancer cases occurring in the United States is based on data collected by registries in the NCI's Surveillance, Epidemiology, and End Results (SEER) Program and the CDC's National Program of Cancer Registries (NPCR), which are put together annually and published by the North American Association of Central Cancer Registries (NAACCR). The SEER Program, which began in 1973, collects cancer incidence data from geographic areas comprising 14 percent of the U.S. population. The NPCR, authorized in 1992, expands data collection and operations in existing cancer incidence registries and plans and implements new registries in states and U.S. territories where ones did not previously exist. NAACCR evaluates and publishes data annually from registries in both programs. Cancer mortality information in the United States is based on causes of death reported by physicians on death certificates. The mortality information is processed and consolidated into a national database by the NCHS through the National Vital Statistics System.

3. What is happening with cancer rates overall?

Cancer incidence rates increased from 1973 to 1982 and the increase accelerated from 1982 to 1992. Incidence rates for all cancer sites combined decreased on average 1.1 percent per year from 1992 to 1998. This confirms the continued downward trend that has been reported to the nation for the past four years.

Cancer death rates increased from 1973 to 1991, were level from 1991 to 1994, and declined 1.4 percent per year from 1994 to 1998.

4. How is the cancer burden monitored among ethnic and racial groups?

In this report, cancer incidence and death rates are described for whites, blacks, Asian and Pacific Islanders, American Indians/Alaska Natives, and Hispanics. Hispanic is not mutually exclusive from whites, blacks, and Asian and Pacific Islanders. Supplemental information on the report can be found at http://seer.cancer.gov. Additional information on trends can be found on SEER's Cancer Statistics Review at http://seer.cancer.gov/Publications/CSR1973_1998/.

5. What is happening with cancer among ethnic and racial groups?

Continued higher incidence and death rates among some racial and ethnic groups suggest that not all populations have benefitted equally from cancer prevention and treatment control efforts. Such disparities may be due to multiple factors, such as late stage of disease at diagnosis, barriers to health care access, history of other diseases, biologic and genetic differences in tumors, health behaviors, and the presence of risk factors.

The four leading cancer incidence sites for the five racial and ethnic populations were: lung and bronchus, prostate, female breast, and colorectum. Together these four sites account for over half of all new diagnoses. When these four cancer sites were examined by race and ethnicity, it was found that except for female breast cancer, blacks had higher incidence and death rates than the other racial and ethnic populations. Some cancer sites tended to be unique to a specific population. For example, melanoma and leukemia were among the top 10 sites only in whites; liver cancer was among the top 10 sites only in Asian and Pacific Islanders; kidney and renal pelvis cancers were among the top 10 only in American Indian/Alaska Natives; and bladder cancer was among the top 10 only in whites and Hispanics.

The four leading cancer death sites from 1992 to 1998 for the racial and ethnic groups were the same sites as for incidence: lung and bronchus, prostate, female breast, and colorectum. When these four mortality sites were examined by race and ethnicity, blacks had higher cancer death rates than whites, Asian and Pacific Islanders, American Indians/Alaska Natives, or Hispanics.

In April 2000, the NCI established Special Populations Networks, which will distribute a total of $60 million in grants over five years to address some of these disparities. In collaboration with other state and nonprofit organizations, CDC and NCI support various activities aimed toward reducing disparities in cancer, including the CDC's Initiative to Eliminate Racial and Ethnic Disparities and the National Institutes of Health Disparities Plan.

6. What is happening with lung and bronchus cancer rates?

Lung cancer is the number one cause of cancer death among men and women in all racial and ethnic groups except for Hispanic women. Female lung cancer is one of the 12 cancers showing increasing trends. Due to a lag in smoking cessation trends, death rates for women have increased 0.8 percent per year between 1992 to 1998, although there has been a gradual slowing in female lung cancer death rates over the past three decades. Death rates for men decreased 1.9 percent per year from 1992 to 1998. Lung cancer mortality began to decrease in 1990 in men but the increase in mortality continued until at least 1998 in women.

After long-term increases, female lung cancer incidence rates have leveled off since 1991. Incidence rates in white men steadily increased between 1973 and 1981, leveled off around 1981, then declined steadily after 1991.

7. What is happening with breast cancer rates in women?

Female breast cancer represents one of the dozen cancers with an upward statistical trend, showing a 1.2 percent per year increase in incidence rates from 1992 to 1998. Long-term trends in invasive breast cancer incidence rates show an increase of more than 40 percent, from 82.6 per 100,000 to 118.1 per 100,000 from 1973 to 1998. Increases were limited to early stage (I and II) cancers. In addition, in situ cancer is also increasing in women over the age of 50. These trends may be related to increased screening during this period, particularly with mammograms. The extent to which other factors, such as increases in obesity and post-menopausal hormone use, may contribute to the increase is unknown.

Breast cancer death rates decreased 1.6 percent annually from 1989 to 1995, then declined more rapidly to 3.4 percent per year between 1995 and 1998, probably due to improvements in early detection and treatment. Breast cancer was the leading cause of cancer deaths in Hispanic women and the death rate was highest among black women.

8. What is happening with prostate cancer rates?

Prostate cancer incidence rates have fluctuated dramatically. Incidence rates increased rapidly between 1988 and 1992 with the introduction of Prostate Specific Antigen testing and then decreased after 1992. Prostate cancer is the most commonly diagnosed cancer incidence site in men for all racial and ethnic groups. Incidence rates varied from 101.0 per 100,000 for white men in Kentucky to 262.6 per 100,000 for black men in the Atlanta metropolitan area. Prostate cancer death rates have also varied over time, and death rates for blacks and whites have steadily declined since the mid-1990s. Death rates in black men are double those of other racial and ethnic groups.

9. What is happening with colorectum cancer rates?

Incidence rates for white men declined 1.3 percent per year from 1992 to 1998 and remained stable for black males, black females, and white females. Long-term trends show incidence rates for all people increased until 1985, decreased 1.8 percent per year through 1995, and stabilized through 1998. Death rates decreased in all groups form 1992 to 1998, except for black females where rates remained stable. The long-term decrease in death rates began earlier in women than in men and was larger in white than in black populations.

10. What are the 10 other cancers that are showing upward trends?

In addition to the recent rise in female breast cancer incidence rates and the long-term increase in female lung cancer death rates, an increase in either incidence or death rates between 1992 to 1998 has been observed for ten other cancer sites. Below is a list of those less common cancers, in descending order of their contribution to total cancer deaths:

• Non-Hodgkin's Lymphoma (4.4 percent of deaths, 4.0 percent of cases in 1998) - Incidence rates increased in black females and those under age 65 while death rates increased for white males and black females. The origin of most cases of this cancer are unknown, although infectious agents, medications, and pollutants that affect the immune system are a few of the primary suspects.

• Liver and intrahepatic bile duct (2.3 percent of deaths, 1.2 percent of cases in 1998) - Although incidence rates increased for both sexes, rates were higher in men and in black populations. Death rates also increased, but not for black women. Liver cancer is the fifth most common cancer in the world but it is not common in the United States. Chronic infection with hepatitis B virus increases the risk of liver cancer.

• Esophagus (2.2 percent of deaths, 0.9 percent of cases in 1998) - Death rates rose overall due mainly to a 1.6 percent yearly increase in white men. Incidence rates varied by gender and race. The increase was due primarily to increases in new cases of adenocarcinoma of the lower esophagus.

• Melanoma (1.4 percent of deaths, 3.5 percent of cases in 1998) - Incidence rates showed sharp increases until the 1980s and have slowed somewhat recently. Death rates rose slowly for white men and were stable for white women. Melanoma is rare among other racial and ethnic populations. Sporadic overexposure to the sun is the main risk factor for melanoma.

• Acute Myeloid Leukemia (1.3 percent of deaths, 0.8 percent of cases in 1998) - Incidence rates increased 1.8 percent for men, with most of the increase in men age 65 and older. This cancer occurs mainly in young children and the elderly, with cigarette smoking and exposure to chemicals such as benzene associated with increased risk of the disease.

• Soft (connective) Tissue including Heart (0.7 percent of deaths, 0.6 percent of cases in 1998) - Incidence rates increased 3.3 percent per year among white women with other race and gender groups remaining stable. Mortality trends have slowed to a 1.3 percent annual increase since 1980. Most of these cancers are sarcomas that are fairly rare, which makes identification of risk factors difficult.

• Thyroid (0.4 percent of deaths, 1.5 percent of cases in 1998) - Incidence rates increased 2.7 percent per year and were 2.5 times higher in women than men. All racial and ethnic groups had low death rates.

• Small intestine (0.2 percent of deaths, 0.3 percent of cases in 1998) - Long-term increases in both incidence and death rates were seen in both sexes from 1973 to 1998, with increases in incidence rates being five times higher than increases in death rates. While the small intestine comprises 75 percent of the length and 90 percent of the absorptive area of the GI tract, it contributes to only 2 percent of digestive tract cancers in the United States.

• Vulva (0.1 percent of deaths, 0.3 percent of cases in 1998) - Incidence rates increased 2.4 percent, primarily among women younger than 65. Death rates have remained stable overall from the mid-1980s to 1998. Most cancers are squamous cell and occur in older women and women of low socioeconomic status.

• Peritoneum, Omentum, and Mesentery (0.1 percent of deaths, 0.1 percent of cases in 1998) - White women showed a similar 14.9 percent per year incidence and death rate increase. The increase in incidence rates may be due to improved diagnostic techniques resulting in better visualization of tumors during surgery.

11. What strategies did the authors identify to help reduce cancer incidence and mortality rates?

A number of strategies were identified, with reduction in tobacco use being the most significant since tobacco smoking causes an estimated 30 percent of all cancer deaths. Other prevention programs, such as sunscreen education to reduce melanoma rates, immunization against hepatitis B to prevent chronic hepatitis B virus (HBV) infection
(to reduce liver cancer incidence), and development of a vaccine against hepatitis C virus (HCV) to reduce liver cancer associated with hepatitis C, were examples put forth by the authors of this report.

A second strategy identified was improved use of effective but underutilized screening techniques, such as colonoscopy for colorectal cancer and mammography for breast cancer. Coupled with this strategy is the need to develop more effective screening and detection tools.

Thirdly, development of state-of-the-art diagnostic tests and treatments and the use of these tests to more accurately guide and direct treatment were suggested. This is particularly important in the drive to develop and use molecularly targeted drug regimens.

The fourth strategy was identifying and reducing disparities across diverse populations by disseminating cancer treatment to all populations to increase survival, improve quality of life, and decrease mortality. Training programs to increase the diversity of scientists in biomedical research and to enhance existing careers were offered as viable strategies.

Finally, support of a national cancer surveillance system that collects information across the entire life cycle was seen as important. Information could be used to target populations with prevention and early detection initiatives, to focus research, and to improve access to treatment and palliative care for all cancer patients and survivors.

How to Read the Report

12. How are cancer incidence and death rates presented?

Cancer incidence rates and cancer death rates are measured as the number of cases or deaths per 100,000 people and are age-adjusted to the 1970 U.S. standard million population. When a cancer affects only one gender -- for example, prostate cancer -- then the number is per 100,000 persons of that gender.

13. How is progress against cancer being measured in this report?

This report primarily includes two measures of cancer -- the incidence rate and the death rate. In addition to the rates, the annual percent change in those rates has been calculated for 1992 to 1998, as well as for other intervals, to measure the amount of increase or decrease in trends. Short-term as well as long-term trends were also examined.

14. What is an annual percent change or APC?

The annual percent change (APC) is the average rate of change in a cancer rate per year in a given time frame; i.e., how fast or slowly a cancer rate has increased or decreased each year over a period of years. Annual percent change was calculated for both incidence and death rates. The number is given as a percent -- such as the 1.1 percent per year decrease in incidence of all cancers diagnosed between 1992 to 1998. A negative APC describes a decreasing trend, and a positive APC describes an increasing trend. The rates are age-adjusted, which allows for comparison of different populations over various age structures and times.

15. What is joinpoint analysis?

Joinpoint analysis is a statistical method that describes changing trends over successive segments of time and the amount of increase or decrease within each segment. This statistical method chooses the best fitting point or points, which are called joinpoints, and these points are where the rate of increase or decrease changes significantly. Joinpoint analyses were performed for incidence and mortality trends for 1973 to 1998.

16. Where is this report being published?

The report is published in the June 6, 2001, issue of the Journal of the National Cancer Institute (Vol. 93, Issue 11, page 824-842). The authors are Holly L. Howe, Ph.D. (NAACCR), Phyllis A. Wingo, Ph.D. (CDC), Michael J. Thun, M.D. (ACS), Lynn A.G. Ries, M.S. (NCI), Harry M. Rosenberg, Ph.D. (CDC), Ellen G. Feigal, M.D. (NCI), and Brenda K. Edwards, Ph.D. (NCI).

17. What Internet sites have more information on cancer?

NCI's SEER home page: http://www.seer.cancer.gov. (This Web site contains all data points for graphs in the manuscript as well as supplementary data and charts. Click on the icon "1973-1998 Report to the Nation")

National Cancer Institute: http://www.cancer.gov

American Cancer Society: http://www.cancer.org

CDC's Division of Cancer Prevention and Control: http://www.cdc.gov/cancer

CDC's National Center for Health Statistics mortality page: http://www.cdc.gov/nchs/about/major/dvs/mortdata.htm

NAACCR: http://www.naaccr.org