Annual Report to the Nation on the Status of Cancer 1975-2001, with a Special Feature on Survival: Questions and Answers
- What is the purpose of this report and who created it? This report provides an update of cancer death rates, incidence rates (new cases), and trends in the United States. It also includes a special feature on survival rate changes over time. (Question 1)
- What are the sources of the data? Cancer mortality information in the United States is based on causes of death reported by physicians on death certificates and filed by state vital statistics offices. The mortality information is processed and consolidated in a national database by CDC through the National Vital Statistics System, which covers the entire United States. (Question 2)
- What reporting periods were chosen as a main focus of the report? The period from 1992 through 2001 was used for describing the cancer burden and trend among the five major racial and ethnic populations. The period from 1975 through 2001 was chosen to represent the best perspective on long-term trends in cancer incidence, death, and survival rates among all races combined. (Question 3)
- What is the purpose of this report and who created it?
This report provides an update of cancer death rates, incidence rates (new cases), and trends in the United States. It also includes a special feature on survival rate changes over time. The American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), which is part of the National Institutes of Health, and the North American Association of Central Cancer Registries (NAACCR) collaborated to create this report. These reports have been issued annually since 1998.
- What are the sources of the data?
Cancer mortality information in the United States is based on causes of death reported by physicians on death certificates and filed by state vital statistics offices. The mortality information is processed and consolidated in a national database by CDC through the National Vital Statistics System, which covers the entire United States.
Information on newly diagnosed cancer cases occurring in the United States is based on data collected by registries in NCI's Surveillance, Epidemiology, and End Results (SEER) Program and CDC's National Program of Cancer Registries (NPCR). NAACCR evaluates and publishes data annually from registries in both programs. Incidence rates are for invasive cancers, except for bladder cancer, which includes in situ cancer.
Long-term (1975-2001) incidence trends are reported by NCI SEER and cover 10 percent of the U.S. population. Trend data (1992-2001) for the five major racial and ethnic populations (non-Hispanic white, Hispanic white, black, Asian and Pacific Islander (API), and American Indian/Alaska Native (AI/AN)) are also from SEER and cover 14 percent of the U.S. population.
Survival data are derived from the SEER database.
- What reporting periods were chosen as a main focus of the report?
The period from 1992 through 2001 was used for describing the cancer burden and trend among the five major racial and ethnic populations. The period from 1975 through 2001 was chosen to represent the best perspective on long-term trends in cancer incidence, death, and survival rates among all races combined. All rates are adjusted to the 2000 U.S. standard million population as determined by the U.S. Census Bureau.
Update On Incidence and Mortality Trends for All Cancer Sites Combined and the Top Major Cancers
- What is happening with cancer death rates overall?
Overall, cancer death rates for all racial and ethnic populations combined declined by 1.1 percent per year from 1993 to 2001 and also declined for many of the top 15 cancers in both men and women. The decline was more pronounced in men (1.5 percent per year from 1993-2001) than in women (0.8 percent per year from 1992-2001). Importantly, lung cancer death rates among women leveled off for the first time between 1995 and 2001 after increasing continuously for many decades.
- Last year it was reported that death rates were stabilizing after declining in previous years. Is this no longer the situation?
With an extra year of population and mortality data now available, it appears that death rates have actually been steadily declining since the early 1990s and that last year's report of stabilization was due to statistical uncertainties related to changes in data collection.
One factor contributing to the overall appearance of stabilization of death rates was the introduction of the International Classification of Diseases, 10th revision (ICD-10), beginning with 1999 mortality data, which affected mortality trends included in last year's report. The ICD-10 replaced ICD-9, which was used from 1979 through 1998. Only 0.7 percent of deaths reported were due to changes in rules for selecting underlying causes of death with ICD-10.
- What is happening with cancer incidence rates overall?
Cancer incidence rates for all cancer sites combined declined by 0.5 percent per year from 1991 to 2001 in both men and women. Using a statistical method to adjust for delays in reporting (see question #14), rates stabilized for men from 1995 to 2001 while incidence rates increased for women from 1987 to 2001. Delay adjusted rates are included for long-term incidence trends, but most analyses focus on observed rates which are not delay adjusted.
- What is happening with incidence and death rates for some of the top 15 cancers?
The top four cancers represent more than half of all new cancer cases or deaths. Men and women of different racial and ethnic populations showed considerably different rates and trends for each of the top cancer sites:
- Lung cancer incidence rates have been declining since the early 1980s and death rates have been declining since the early 1990s in men. Incidence rates for women have declined since 1998 and mortality rates stabilized since 1995 after decades of increase, demonstrating the impact of smoking cessation efforts in the past few decades.
- Breast cancer incidence rates increased 0.4 percent per year from 1987-2001, which is a slower rate of increase than before 1987. Death rates from breast cancer decreased beginning in the early 1990s, with steeper declines reported among white women than among black women. Rising breast cancer incidence rates during the 1990s have been attributed, in part, to increased mammography screening.
- Prostate cancer death rates have been declining since the early 1990s and incidence rates declined dramatically between the years of 1992 and 1995. Since 1995, prostate cancer incidence rates have been rising. The introduction of the prostate specific antigen (PSA) test is thought to have contributed to the very steep increase in prostate cancer incidence rates of 16.4 percent per year from 1988-1992. With the PSA test, prostate cancers were likely to be diagnosed several years earlier than they would have been diagnosed without the test. The increase of 1.4 percent per year in prostate cancer incidence rates from 1995-2001 is now similar to the increase noted prior to the introduction of the PSA test.
- Colon cancer death rates have been on the decline for both whites and blacks for the time period covered in this report. Incidence rates are also declining.
- Non-Hodgkin Lymphoma rates have been affected by a rise in AIDS-related cases since the 1980s, which stabilized in the 1990s. Mortality declines may be due to improved treatments.
- Leukemia incidence rates were stable from 1975 to 2001 in women, but decreased after 1988 in men. Long-term decreases in leukemia death rates reflect dramatic improvements in survival for childhood leukemia, as well as modest improvements in survival for some types of leukemias in adults.
- Kidney cancer incidence rates have been rising, perhaps due to newer diagnostic techniques or increased prevalence of obesity. Mortality rates have been stable since 1991 for men and since 1992 for women.
- What is the overall cancer burden among racial and ethnic groups or populations?
In this report, cancer incidence and death rates are described for white, black, Asian and Pacific Islander (API), American Indian/Alaska Native (AI/AN), and Hispanic persons (Hispanic persons are not mutually exclusive from persons who are white, black, API, or AI/AN.) While overall cancer incidence rates declined from 1992 through 2001 among each racial and ethnic population of men, overall incidence rates decreased only among AI/AN women. Overall cancer death rates decreased in every racial and ethnic population, except in AI/AN men and women.
Among men, cancers of the prostate, lung and colon/rectum were the three most common ncident cancers for every racial and ethnic population except Hispanics, for whom colorectal cancer ranked ahead of lung cancer. Among women, the three leading incident cancers were breast, colon, and lung, in that order, except for white women, for whom lung cancer ranked second.
Data on the cancer burden for these populations are covered and monitored by two federal programs, all of the states and the District of Columbia: CDC's National Program of Cancer Registries (NPCR) and NCI's Surveillance, Epidemiology, and End Results (SEER) Program.
- What are some specific examples of racial/ethnic disparities included in this Report?
An examination of black and white populations revealed growing differences for colorectal and breast cancer death rates. By 2001, death rates for white populations were substantially lower than those for black populations, an indication that black men and women may not have experienced the same benefits from screening and/or treatment as white men and women.
Additionally, prostate cancer incidence was 62 percent higher in black men than in white. Black women had the highest death rates for all cancer sites combined. API incidence rates for stomach, liver, and thyroid (women only) cancers were higher than the rates of other racial/ethnic populations. For AI/AN, kidney cancer death rates were higher than the rates of other racial/ethnic populations for both men and women. Hispanic/Latino women had higher cervical and gallbladder cancer incidence rates and gallbladder cancer death rates than other racial/ethnic populations.
- How is survival measured in this report?
Progress in survival was measured by comparing survival rates of cancer patients diagnosed during two five-year time periods: 1975-1979 and 1995-2000. Patients diagnosed with the top 15 cancers and childhood cancers were followed for vital status through Dec. 31, 2001. In addition, survival rates by race/ethnicity were described.
- What are some key survival trends?
Substantial improvements in five-year relative survival rates over the last two decades were bserved for many of the top 15 cancers for both men and women. However, improvement in survival was limited for most highly fatal cancers -- including those of the lung, pancreas, and liver. In general, the improvements in survival rates over the two diagnostic periods were higher in men than in women.
Five-year survival rates for childhood cancers have increased 20 percent over the past 20 years for boys, but only 13 percent for girls.
Five-year survival rates varied across racial and ethnic populations. For example, the five-year survival rate for female patients diagnosed with leukemia ranged from 39.1 percent in API to 53.3 percent in non-Hispanic whites. In general, survival rates were lower and the risk of dying was higher from many cancers in other racial and ethnic populations, compared to white populations.
Note that gains in survival rate over time do not always reflect progress against cancer. The introduction of new diagnostic techniques may lead to improved survival by advancing the time of diagnosis of disease without affecting the time at death, i.e., without prolonging life.
How to Read This Report
- 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 per year and are age-adjusted to the 2000 U.S. standard population. When a cancer affects only one gender -- for example, prostate cancer -- then the number is per 100,000 persons of that gender.
- 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 approximate one percent per year decrease.
A negative APC describes a decreasing trend, and a positive APC describes an increasing trend. In this Report, trends are reported as increasing and decreasing only if they are significant. The rates are age-adjusted, which allows for comparison of rates from different populations with varying age composition over time and regions.
- Why were rates adjusted for delays in reporting incidence data to SEER?
This report presents analyses of long-term trends in cancer incidence rates with and without adjustment for reporting delays. Adjusting for these delays provides the basis for a potentially more accurate assessment of incidence rates and trends in the most recent years for which data are available. Cancer registries routinely take two to three years to compile their current cancer statistics. An additional one to two years may be required to have more complete incidence data on certain cancers, such as prostate and breast cancers, particularly when they are diagnosed in outpatient settings. Cancer registries continue to update incidence rates to include these cases. Consequently, the initial data reported for certain cancer incidence rates may be an underestimate. Long-term reporting patterns in SEER registries have been analyzed, and it is now possible to adjust site-specific and all cancers combined incidence rates to correct for expected reporting delays.
- Where is this report published?
The report was published online June 3, 2004, in Cancer. The article, "Annual Report to the Nation on the Status of Cancer, 1975-2001, with a Special Feature Regarding Survival," will appear in the July 1, 2004, print issue (Vol.101 No. 1). The authors of this year's report are Ahmedin Jemal, Ph.D. (ACS), Limin X. Clegg, Ph.D. (NCI), Elizabeth Ward, Ph.D. (ACS), Lynn A.G. Ries, M.S. (NCI), Xiaocheng Wu, M.D. (NAACCR), Patricia M. Jamison (CDC), Phyllis A. Wingo, Ph.D. (CDC), Holly L. Howe, Ph.D. (NAACCR), Robert N. Anderson, Ph.D. (CDC), and Brenda K. Edwards, Ph.D. (NCI).
- Where can I find out more about the report?
For more information, visit the following Web sites:
Report to the Nation press release: http://www.cancer.gov/newscenter/pressreleases/ReportNation2004release
CDC (Division of Cancer Prevention and Control): http://www.cdc.gov/cancer
CDC (National Center for Health Statistics' mortality report): http://www.cdc.gov/nchs/about/major/dvs/mortdata.htm
For more information about cancer, please visit NCI's Web site at www.cancer.gov.