Cancer statistics, 1998

Cancer is an important public health concern in the United States and around the world. To provide an up-to-date perspective on the occurrence of cancer, the American Cancer Society presents an overview of cancer burden, incidence, mortality, and survival statistics for 1998. Because the United States does not have a nationwide cancer registry and because the quality of case reporting varies among state cancer registries, investigators have no way of knowing exactly how many new cases of cancer are diagnosed in the United States as a whole and in selected states each year. Consequently, we estimated the number of new cancer cases expected to be diagnosed in 1998 using population data collected by the US Bureau of the Census and cancer incidence rates collected by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. 1-3 Estimates were calculated using a three-step procedure. First, we multiplied annual age-specific cancer incidence rates for 1979 through 1994 by the age-appropriate US Census Bureau population projections for the same years to estimate the number of cancer cases diagnosed annually from 1979 to 1994. Second, we fitted these annual cancer case estimates to an autoregressive quadratic model using the SAS procedure PROC FORECAST. 4, 5 Finally, we used the model to forecast the number of cancer cases expected to be diagnosed in 1998. Some additional adjustments were made for sites (or types of cancer) with recently changing incidence rates or with widely varying year-to-year estimates. These sites (or types) included rectum, pancreas, chronic lymphocytic leukemia, acute lymphocytic leukemia, and lung and bronchus in men and women; other respiratory tract, bones and joints, other leukemia, and prostate in men; and colon, gallbladder and other biliary passages, other digestive tract, endometrium (uterus), and brain and other nervous system in women. Between 1987 and 1992, the incidence rate of prostate cancer increased 84%, followed by a decline of 46% between 1992 and 1994. 3 Preliminary data for 1995 show a continued decline (personal communication with Lynn A. G. Ries of the National Cancer Institute's Cancer Control Research Program). The sharp increase in incidence followed by the decline in recent years probably reflects extensive use of prostate-specific antigen (PSA) screening in the late 1980s and the subsequent increase in earlier diagnoses. 6 Assuming that the number of prostate cancer cases will continue to decline until it approaches rates in effect before widespread use of PSA screening, we estimated new cases of prostate cancer for 1998 using a linear projection based on data from 1979 to 1989. Because cancer incidence rates and case counts for 1979 through 1994 were not available for many states, we used state-specific data on cancer deaths to calculate new cases in individual states. We calculated the proportion of cancer deaths forecasted for each state in 1998 among cancer deaths forecasted for the United States in 1998; we then multiplied this proportion by the 1998 forecast of new cancer cases for the United States. This method assumes that the ratio of cancer deaths to cancer cases for each state is the same as the ratio for the United States as a whole. We estimated the number of cancer deaths expected to occur in the United States in 1998 using data on underlying cause of death from death certificates reported to the National Center for Health Statistics (NCHS). 7 The numbers of cancer deaths occurring annually from 1979 to 1994 were fitted to an autoregressive quadratic model using PROC FORECAST. 4, 5 This model was used to forecast the number of cancer deaths expected to occur in the United States in 1998. Some estimates were adjusted slightly to compensate for the effects of recently changing mortality rates or large year-to-year variations in estimates. These sites included colon and prostate in men and colon, stomach, and cervix (uterus) in women. The estimated number of cancer deaths for each state was calculated with the same modeling procedure used to estimate cancer deaths for the United States as a whole. Mortality statistics for the leading causes of death, the probability of developing cancer, and cancer survival are also presented in this report (Figs. Figure 3-Figure 6, Tables 5–13). These statistics have been assembled from a variety of sources, and the methods used to calculate them were described previously. 8 We computed mortality rates for cancer around the world (Table 14) using data compiled by the World Health Organization; we included countries that had populations of 500, 000 or more, death registration of at least 82%, and a proportion of deaths with a medically certified cause of death of at least 95%. 9 We estimate that about 1, 228, 600 new cases of invasive cancer are expected to be diagnosed in the United States in 1998 (Table 1). This estimate does not include carcinoma in situ of any site except urinary bladder, and it does not include basal and squamous cell cancers of the skin. Approximately 1 million cases of basal and squamous cell skin cancers, 36, 900 cases of breast carcinoma in situ, and 21, 100 cases of melanoma carcinoma in situ are expected to be diagnosed in 1998. Among men, the most common cancers in 1998 are expected to continue to be cancers of the prostate, lung and bronchus, and colon and rectum (Fig. 1). Prostate is the leading cancer site, accounting for 29% of new cancer cases in men. This year 184, 500 new diagnoses of prostate cancer are expected (Table 1). Among women, the three mostly commonly diagnosed cancers are expected to be cancers of the breast, lung and bronchus, and colon and rectum (Fig. 1). Approximately 325, 800 new cancers are expected to occur at these sites (Table 1), accounting for more than 50% of new cancer cases in women. Breast cancer alone is expected to account for about 30% of new cancer cases, with approximately 178, 700 cases in 1998 (Table 1). In 1998, we estimate that about 564, 800 Americans can be expected to die of cancer—more than 1, 500 people a day (Table 2). Although most 1998 cancer deaths in men (54%) are expected to be from cancers of the lung and bronchus, prostate, and colon and rectum (Fig. 2), the number of deaths from these three sites appears to be leveling off and may be beginning to decline. This change is consistent with the continuing declines in overall cancer mortality rates. 3, 10 Between 1990 and 1994, mortality rates for men decreased about 1. 4% per year for lung cancer, 0. 5% per year for prostate cancer, and 1. 9% per year for colorectal cancers. 3 Among women, cancers of the lung and bronchus, breast, and colon and rectum are expected to account for more than half of all cancer deaths in 1998 (Fig. 2). In 1987, lung cancer surpassed breast cancer as the leading cause of cancer death in women, and it is expected to account for 25% of all cancer deaths in women in 1998. Although lung cancer mortality in men is leveling off, the mortality rate and the number of deaths from lung cancer in women are steadily increasing. Between 1990 and 1994, the lung cancer mortality rate in women increased about 1. 7% per year. 3 Conversely, the numbers of deaths of women from breast and colorectal cancers appear to be leveling off and may be beginning to decline. These sites account for 16% and 11%, respectively, of cancer deaths in women (Fig. 2). Between 1990 and 1994, mortality rates in women decreased about 1. 8% per year for breast cancer and 1. 5% per year for colorectal cancers. 3 Our estimated numbers of new cancer cases and cancer deaths should be interpreted with caution when used to study trends in cancer incidence and mortality. These are estimates that can vary considerably from year to year, particularly for less common cancers and for smaller states. For this reason, we discourage the use of our estimates to track year-to-year changes in cancer occurrence and cancer deaths. NCHS mortality rates and SEER cancer incidence rates are generally more informative statistics to use for tracking cancer trends. For example, breast cancer incidence rates increased about 1% per year between 1979 and 1982, increased 4% per year between 1982 and 1987, and were approximately constant between 1987 and 1994. Despite the stabilization of rates during the latter period, our estimates for new breast cancer cases increased between 1988 and 1996. Our estimates are based on the most currently available cancer incidence and mortality data; however, these data are 4 years old at the time that the estimates are calculated. As such, the effects of large changes occurring in the 4-year interval between 1994 and 1998 cannot be captured by our modeling efforts. Reports of the direction of such changes in different geographic locations during the 4-year interval may help in determining appropriate interpretations. Finally, our estimates of new cancer cases are based on incidence rates for the geographic locations that participate in the SEER program and therefore may not be representative of the United States as a whole. Despite these limitations, our estimates do provide an indication of current patterns of cancer in the United States. Such estimates will assist our continuing efforts to reduce the burden of cancer in the US and world populations as the 21st century approaches. Estimated New Cancer Cases* 10 Leading Sites by Sex, United States, 1998 Estimated Cancer Deaths* 10 Leading Sites by Sex, United States, 1998 Age-Adjusted Cancer Death Rates* for Females by Site, United States, 1930–1994 Age-Adjusted Cancer Death Rates* for Males by Site, United States, 1930–1994 Percent Distribution of Cancer Cases by Race and Stage at Diagnosis, United States, 1986–1993 Five-Year Relative Survival Rates by Race and Stage at Diagnosis, United States, 1986–1993 The American Cancer Society is earmarking 1. 5 million for this grant cycle for each of two areas of research in prostate cancer (1) health policy and outcomes research and (2) behavioral, psychosocial, and quality-of-life research. Application is open to independent investigators at any stage of their careers. The next deadline for applications for both grants is April 1, 1998. Subsequent deadlines will be October 15, 1998, April 1, 1999, and October 1, 1999. The grants will be for 3 years, up to 250, 000 per year, including 25% indirect costs, and will be renewable as long as this remains a targeted priority area. At least two grants will be awarded in each research area during each grant cycle, contingent on the quality of the applications. Please contact the grants administration or development office at your institution for a special application form, or download it from http: //www. cancer. org. Questions concerning this request for applications should be directed to Dr. Ralph Vogler at 404–329–7542 or to Dr. Frank Baker at 404–329–7795.