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Medical records are generally accepted as the most accurate source of information documenting cancer treatments. However, as the health care system becomes more decentralized and more cancer care is delivered in outpatient settings, it is increasingly difficult and expensive to review records from the many surgeons and medical/radiation oncologists who administer cancer therapies in the community setting. Using 1994-1995 data, the authors compared initial treatment for prostate cancer self-reported (from a mailed questionnaire or telephone/in-person interview) by 3,196 US men in the population-based Prostate Cancer Outcomes Study with information obtained from medical records. Agreement between self-reports and medical records varied by type of treatment. Generally, agreement was excellent for more invasive procedures such as prostatectomy or radiation (kappa values > 0.8), with decreasing agreement for hormone shots and pills (kappa values < 0.7). If the medical record abstract is assumed to be the "gold standard," the estimated sensitivity was generally high (>80%) for prostatectomy and radiation but low (68%) for hormone pills, although the estimated specificity was 90% or greater for all treatments. These results can serve as a useful guide to researchers contemplating the use of surveys as an alternative to medical record abstraction to ascertain treatment in studies of patient outcomes.

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BACKGROUND: Age-adjusted rates and statistical measures used to assess these rates are commonly used in cancer research to monitor progress against this disease. Trends in age-adjusted rates and related summary statistics may depend on the standard population used for age adjustment. Hence, knowledge of how the selected standard population influences such rates is essential for analysis and interpretation of the results. METHODS: The current paper evaluates age-specific and age-adjusted trends for the three leading causes of cancer mortality in the United States: lung and prostate cancers for males, and lung and breast cancers for females. RESULTS, CONCLUSIONS: The analysis shows that the choice of the standard population for age adjustment of the rates can influence one's perception of the progress being made against cancer.

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OBJECTIVE: Surveillance of chronic diseases includes monitoring trends in age-adjusted rates in the general population. Statistics that are calculated to describe and compare trends include the annual percent change and the percent change for a specified time period. However, it is also of interest to determine the contribution specific diseases make to an overall trend in order to better understand the impact of interventions and changes in the prevalence of risk factors. The objective here is to provide a method for partitioning a linear trend in age-adjusted rates into disease-specific components. METHODS: The method presented is based on linear regression. The decreasing trend in age-adjusted cancer mortality rates for the total United States during the period 1991-96 is analyzed to illustrate the method. RESULTS: Trends in mortality for cancers of the colon/rectum, breast, lung/bronchus, and prostate are found to be responsible for 75% of the decreasing trend in cancer mortality. CONCLUSIONS: It is possible to partition an overall trend in age-adjusted rates under the assumption that it and the trends for all mutually exclusive and exhaustive subgroups of interest are linear.

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BACKGROUND: The prostate-specific antigen test was approved by the U.S. Food and Drug Administration in 1986 to monitor the disease status in patients with prostate cancer and, in 1994, to aid in prostate cancer detection. However, after 1986, the test was performed on many men who had not been previously diagnosed with prostate cancer, apparently resulting in the diagnosis of a substantial number of early tumors. Our purpose is to provide insight into the effect of screening on prostate cancer rates. Detailed data are presented for whites because the size of the population allows for calculating statistically reliable rates; however, similar overall trends are seen for African-Americans and other races. METHODS: Prostate cancer incidence data from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program and mortality data from the National Center for Health Statistics were analyzed. RESULTS/CONCLUSIONS: The following findings are consistent with a screening effect: 1) the recent decrease since 1991 in the incidence of distant stage disease, after not having been perturbed by screening; 2) the decline in the incidence of earlier stage disease beginning the following year (i.e., 1992); 3) the recent increases and decreases in prostate cancer incidence and mortality by age that appear to indicate a calendar period effect; and 4) trends in the incidence of distant stage disease by tumor grade and trends in the survival of patients with distant stage disease by calendar year that provide suggestive evidence of the tendency of screening to detect slower growing tumors. IMPLICATIONS: The decline in the incidence of distant stage disease holds the promise that testing for prostate-specific antigen may lead to a sustained decline in prostate cancer mortality. However, population data are complex, and it is difficult to confidently attribute relatively small changes in mortality to any one cause.

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BACKGROUND: The rise and fall of prostate cancer mortality correspond closely to the rise and fall of newly diagnosed cases. To understand this phenomenon, we explored the role that screening, treatment, iatrogenic (i.e., treatment-induced) deaths, and attribution bias (incorrect labeling of death from other causes as death from prostate cancer) have played in recent mortality trends. METHODS: Join point regression is utilized to assess the recent rise and fall in mortality and the relationship of total U.S. trends to those areas served by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Cancer Registry Program. Incidence-based mortality (IBM) is estimated with the use of prostate cancer data from the SEER Program to partition (from overall prostate cancer mortality trends) the contribution of cases diagnosed since the widespread use of prostate-specific antigen (PSA) testing starting in 1987. IBM is also used to examine the contribution of stage at diagnosis to the recent prostate cancer mortality trends. RESULTS: IBM for cases diagnosed since 1987 rose above the pre-1987 secular (i.e., background) trend, peaked in the early 1990s, and almost returned to the secular trend by 1994. This rise and fall of IBM track with the pool of prevalent cases diagnosed within the prior 2 years. IBM for cases diagnosed with metastatic disease fell starting in 1991, while IBM for those diagnosed with localized/regional disease was relatively flat. CONCLUSIONS: The rise and fall in prostate cancer mortality observed since the introduction of PSA testing in the general population are consistent with a hypothesis that a fixed percent of the rising and falling pool of recently diagnosed patients who die of other causes may be mislabeled as dying of prostate cancer. The decline in IBM for distant stage disease and flat IBM trends for localized/regional disease provide some evidence of improved prognosis for screen-detected cases, although alternative interpretations are possible.

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BACKGROUND: The objective of this study was to investigate the circumstances under which dissemination of prostate-specific antigen (PSA) testing, beginning in 1988, could plausibly explain the declines in prostate cancer mortality observed from 1992 through 1994. METHODS: We developed a computer simulation model by use of information on population-based PSA testing patterns, cancer detection rates, average lead time (the time by which diagnosis is advanced by screening), and projected decreased risk of death associated with early diagnosis of prostate cancer through PSA testing. The model provides estimates of the number of deaths prevented by PSA testing for the 7-year period from 1988 through 1994 and projects what prostate cancer mortality for these years would have been in the absence of PSA testing. RESULTS: Results were generated by assuming a level of screening efficacy similar to that hypothesized for the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Under this assumption, the projected mortality in the absence of PSA testing continued the increasing trend observed before 1991 only when it was assumed that the mean lead time was 3 years or less. Projected mortality trends in the absence of PSA screening were not consistent with pre-1991 increasing trends for lead times of 5 years and 7 years. CONCLUSIONS: When screening is assumed to be at least as efficacious as hypothesized in the PLCO trial, it is unlikely that the entire decline in prostate cancer mortality can be explained by PSA testing based on current beliefs concerning lead time. Only very short lead times would produce a decline in mortality of the magnitude that has been observed.

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BACKGROUND: Clinical trials have demonstrated that use of mammographic screening and advances in therapy can improve prognosis for women with breast cancer. PURPOSE: We determined the trends in breast cancer mortality rates, as well as incidence and survival rates by extent of disease at diagnosis, for white women in the United States and considered whether these trends are consistent with widespread use of such beneficial medical interventions. METHODS: We examined mortality data from the National Center for Health Statistics and incidence and survival data by extent of disease from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, all stratified by patient age, using statistical-regression techniques to determine changes in the slope of trends over time. RESULTS: The age-adjusted breast cancer mortality rate for U.S. white females dropped 6.8% from 1989 through 1993. A significant decrease in the slope of the mortality trend of approximately 2% per year was observed in every decade of age from 40 to 79 years of age. Trends in incidence rates were also similar among these age groups: localized disease rates increased rapidly from 1982 through 1987 and stabilized or increased more slowly thereafter; regional disease rates decreased after 1987; and distant disease rates have remained level over the past 20 years. Three-year relative survival rates increased steadily and significantly for both localized and regional disease from 1980 through 1989 in all ages, with no evidence of an increase in slope in the late 1980s. IMPLICATIONS: The decrease in the diagnosis of regional disease in the late 1980s in women over the age of 40 years likely reflects the increased use of mammography earlier in the 1980s. The increase in survival rates, particularly for regional disease, likely reflects improvements in systemic adjuvant therapy. Statistical modeling indicates that the recent drop in breast cancer mortality is too rapid to be explained only by the increased use of mammography; likewise, there has been no equivalent dramatic increase in survival rates that would implicate therapy alone. Thus, indications are that both are involved in the recent rapid decline in breast cancer mortality rates in the United States.

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BACKGROUND: Our previous studies indicate that the in situ phase of mammary carcinogenesis is characteristically associated with cell-mediated immunity (CMI against an immunogen shared by most breast carcinomas. Such reactivity is inversely correlated with stage and appears to impede in situ-to-invasive progression and lethality from invasive breast carcinoma. If in situ carcinomas are indeed associated with ambient, prognostically favorable immunity against such an immunogen, one would expect lethality from invasive breast carcinoma to be reduced in patients with a diagnosis of a prior, simultaneous, or subsequent in situ breast carcinoma. The present study provides a test of such relationships. METHODS: Patient survival was analyzed for 129,394 female patients with invasive breast carcinoma diagnosed in areas covered by the Surveillance, Epidemiology, and End Results (SEER) Program based at the National Cancer Institute (NCI). Patients were classified according to whether they had a prior, simultaneous, or subsequent in situ breast carcinoma and survival was examined for up to 15 years subsequent to diagnosis using life tables and the Cox regression model. RESULTS: The findings indicate that patients with an invasive breast carcinoma who had a prior, simultaneous, or subsequent in situ breast carcinoma did experience significantly better survival than comparison groups of patients who either did not have an associated cancer of any type, had an associated invasive breast carcinoma, or had an in situ or invasive cancer of non-breast origin. CONCLUSIONS: Our prior and current observations warrant more direct studies of the prognostic, therapeutic, and prophylactic significance of the in situ carcinoma-associated type of specific CMI in breast cancer patients.

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We elected to examine available information from several sources to approximate the annual number of cases of vaginal adenocarcinoma in the United States for recent years. Data were obtained from the Registry of Hormonal Transplacental Carcinogenesis, the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute, the National Cancer Databank of the American College of Surgeons Commission on Cancer, and a survey of gynecologic oncologists practicing in the United States. In 1990 a total of 33 new cases and 11 recurrences were reported, while in 1991 23 new cases and 8 recurrences were reported. Neither SEER nor the Registry appear to provide adequate surveillance for this rare disease. Phase III clinical trials are not feasible, given the small number of patients. Statistically effective phase II one-armed studies to investigate new agents in the treatment of advanced or recurrent vaginal clear cell cancer may be possible. Effective mobilization of patients and physicians will be required for such trials to be completed in a timely manner.

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Second malignant neoplasms were evaluated among 32,251 women with ovarian cancer, including 4,402 10-year survivors, within the nine population-based registries of the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute (1973-1992) and the Connecticut Tumor Registry (1935-1972). Overall, 1,296 second cancers occurred against 1,014 expected [observed/expected (O/E), 1.28; 95% confidence interval (CI), 1.21-1.35]. Sites contributing 25 or more excess cancers included leukemia (O/E, 4.17; O, 111; 95% CI, 3.43-5.03) and malignancies of colon (O/E, 1.33; O, 188; 95% CI, 1.15-1.54), rectum (O/E, 1.43; O, 76; 95% CI, 1.13-1.79), breast (O/E, 1.18; O, 404; 95%, CI 1.07-1.30), and bladder (O/E, 2.07; O, 65; 95% CI, 1.59-2.63). Ocular melanoma (O/E, 4.45; O, 8; 95% CI, 1.92-8.77) was also significantly increased. Second cancer risk was high during all follow-up intervals, and cumulative risk at 20 years was 18.2%, compared with a population expected risk of 11.5%. Statistically significant relationships existed between serous adenocarcinoma of the ovary and breast cancer (O/E, 1.29; 95% CI, 1.06-1.56) and mucinous ovarian adenocarcinoma and rectal cancer (OE/E, 1.95; 95% CI, 1.09-3.22). Secondary leukemia appeared linked with antecedent chemotherapy, whereas radiotherapy was associated with cancers of connective tissue, bladder, and possibly pancreas. Genetic and reproductive factors predisposing to ovarian cancer may have contributed to the elevated risk of breast and colorectal neoplasms and possibly ocular melanoma. Thus, excess malignancies following ovarian cancer represent complications of curative therapies and/or underlying susceptibility states that have etiological and clinical ramifications.

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BACKGROUND: To ascertain the quality of data entering a population-based reporting system, an essential requirement is to study levels of completeness of case-ascertainment and reporting. This study represents an effort to quantify completeness of case reporting in the SEER (Surveillance, Epidemiology, and End Results) Program of the National Cancer Institute. METHODS: Hospitals in each of the participating SEER areas were stratified according to their annual hospital cancer caseload for the year 1987. Within each caseload stratum, a random sample of hospitals was selected for inclusion in this study. Files in the medical record, pathology, and radiation oncology departments in each hospital were reviewed for SEER reportable cases. These cases were then matched against SEER case listings to identify unreported cases. RESULTS: The crude estimated completeness of reporting for 1987 in the six participating SEER areas was 97.7% and the registry-caseload standardized rate was 96.8%. Variation was noted by SEER registry, hospital cancer caseload, and casefinding source (hospital department). Three-quarters of unreported cases were of invasive disease and one-fourth were in situ, primarily of the cervix uteri. CONCLUSIONS: There is variation in completeness of casefinding among SEER registries, hospital size, and hospital department source. Additional factors that appear to be related to case ascertainment are cancer site or type and who performs the casefinding function (hospital registry or central registry staff).

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BACKGROUND: The pattern of second cancers after treatment for cervical cancer provides important information on the risk of radiation-induced malignancies. Large numbers of women survive many years and can be studied for late effects. METHODS: Incident second cancers in 86,193 patients with cervical cancer reported to 13 population-based cancer registries in 5 countries were evaluated to estimate the risk of second cancer among very long term survivors. RESULTS: Overall, 7543 second cancers were observed versus 6015 cancers expected based on population rates (observed/expected = 1.2). Lung cancer accounted for nearly half of the excess cancers. Among the 49,828 women treated with radiation, 3750 survived 30 or more years and a two-fold risk of cancers of heavily irradiated organs was seen. Most of the excess cancers were of the rectum, vagina, vulva, ovary, and bladder. Patterns of risk over time since treatment were consistent with a radiation etiology. Significant increases of nonchronic lymphocytic leukemia and cancers of the bone and kidney were also linked to radiotherapy. Women treated surgically were also at significant risk of second cancers, in all likelihood related to cigarette smoking and risk factors similar to those of cervical cancer. CONCLUSIONS: Curative therapy for cervical cancer results in large numbers of long term survivors who develop second cancers very late in life. Radiation is an important cause of this increase and there is no evidence that risk returns to normal levels.

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PURPOSE: Black patients with colon cancer are more likely to have poorer survival from colon cancer than are white patients. To determine whether anatomic site differences might contribute to survival differences, we compared anatomic site distributions of black and white patients. METHODS: As part of the Black/White Cancer Survival Study, we collected medical record data for 1,045 patients from Atlanta, New Orleans, and San Francisco/Oakland, newly diagnosed in 1985 or 1986 and interviewed 745 of them. RESULTS: In polychotomous logistic regression analysis, site was related to stage, grade, and histologic type and among women with age, parity, and possibly smoking. However, it was not related to race, except perhaps among men age 65 and older, among whom blacks were somewhat likely to have more transverse and distal, not proximal, cancer. These relations were consistent across subgroups and were independent of other factors examined. CONCLUSION: Results suggest that site differences are unlikely to contribute to poorer survival commonly observed among black colon cancer patients in the United States.

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This supplement presents the study of various histologic types of cancers diagnosed in the populations covered by the Surveillance, Epidemiology, and End Results (SEER) Program. It describes the SEER program and the coding of histologic type by the International Classification of Diseases for Oncology. Each of the 19 articles deals with the histologic types of cancer found in major sites or with specific histologic types, such as lymphomas or melanomas. Histologic types have been grouped based on those developed by Dr. John Berg. Data presented in this supplement are based on more than one million microscopically proven invasive cancers and 98,000 in situ cancers diagnosed during the period 1973-1987 in areas covered by the SEER Program.

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