Prostate cancer and consistency of reporting sexual histories in men over age 50.

We conducted an in-person interview to examine the reliability of reported sexual histories among men over age 50 y with and without prostate cancer. Marriage and cohabitation were used as memory cues to recall sexual activity. High correlations on test-retest for questions evaluating sexual histories suggest reliable answers for most factors, and specifically for age at first sexual activity, and lifetime number of sexual partners. Low correlations were seen for ill-defined and socially undesirable items. These data suggest that men consistently report most measures of sexual activity when using marriage and cohabitation as memory cues to recall sexual histories.

Vasectomy and the risk of prostate cancer: a meta-analysis examining vasectomy status, age at vasectomy, and time since vasectomy.

The aim of this study was to conduct a quantitative review of prostate cancer studies to pool relative risk (RR) estimates on the association between prostate cancer and vasectomy, in an attempt to determine whether there is an association, and if so, its magnitude. Random-effects models were examined along with a linear model for time since vasectomy. The pooled RR estimate was 1.37 (95% CI=1.15-1.62) based on five cohort studies and 17 case-control studies. The RR estimate varied by study design with the lowest risk for population-based case-control studies. No difference was seen in risk by age at vasectomy. A linear trend based on the 16 studies reporting time since vasectomy suggested an 10% increase for each additional 10 y or a RR of 1.32 (95% CI=1.17-1.50) for 30 y since vasectomy. When null effects were assumed for the six studies not reporting information, the linear RR for the 22 studies was 1.07 (1.03-1.11) and 1.23 (1.11-1.37) for 10 and 30 y since vasectomy, respectively. These results suggest that men with a prior vasectomy may be at an increased risk of prostate cancer, however, the increase may not be causal since potential bias cannot be discounted. The overall association was small and therefore could be explained by bias. The latency effect shown here for time since vasectomy should be examined further.

Analysis of recent trends in prostate cancer incidence and mortality.

BACKGROUND: There is debate over whether the recent increases seen in prostate cancer are due to lead-time bias from screening, or identification of clinically insignificant lesions. METHODS: Population-based incidence rates for 1973-1996 were calculated, based on the Surveillance, Epidemiology, and End Results Program (SEER) tumor registries. Relative incidence rates for prostate cancer by stage, fatal incidence, and lymph nodes were calculated, adjusted for age. RESULTS: Localized and regional stage prostate cancer increased through 1992 and then dropped. The rate of distant-stage disease was relatively stable from 1973-1991, with a decrease in distant stage starting in 1992. The 2-year mortality rates were constant for 1973-1989. A decline in the 2-year mortality among cases (fatal incidence) also began in 1992. CONCLUSIONS: These data show large increases in early disease, followed by a drop and leveling off along with a decrease in advanced disease (distant stage, 2-year mortality, positive lymph nodes). This indicates that the increasing incidence rates for prostate cancer are largely due to lead-time bias from increased early detection and treatment of prostate cancer. However, since incidence rates have not declined to rates seen in the 1970s, the additional cases may also reflect length bias from insignificant lesions or a true increase in incidence over time.

Meta-analysis for combining relative risks of alcohol consumption and prostate cancer.

BACKGROUND: Prostate cancer has become the most common cancer among men in the United States, but little is known about factors associated with prostate cancer incidence. METHODS: A meta-analysis of studies published prior to July 1998 was conducted to pool relative risk (RR) estimates from the existing literature on the association between prostate cancer and alcohol consumption, in an attempt to determine whether there is an association, and if so, what its magnitude is. RESULTS: The overall pooled RR estimate was 1. 05 for both fixed and random effects models, based on six cohort studies and 27 case-control studies. The RR estimate varied little by study design. Among types of consumption, the highest risk was found for beer (RR = 1.27), but this was based on only eight studies that reported type of alcohol consumed. A linear dose-response was fit to the 15 studies reporting amount of alcohol consumed, finding a RR of 1.05 (95% confidence interval (CI), 0.91-1.20) for each additional drink of alcohol per day or a RR of 1.21 for 4 drinks per day. When the average drinks per day consumed in the 15 studies were used to estimate the overall risk for all 33 studies, a RR of 1.02 was found for each additional drink of alcohol per day. CONCLUSIONS: Overall, no association between prostate cancer and alcohol consumption was seen. While some categories of consumption showed an increased risk, the studies reporting such categories appeared to be biased towards reporting a positive association among the categories.

Agreement of Medicare claims and tumor registry data for assessment of cancer-related treatment.

BACKGROUND: Although health claims data are increasingly used in evaluating variations in patterns of cancer care and outcomes, little is known about the comparability of these data with tumor registry information. OBJECTIVES: To evaluate the agreement between Medicare claims and tumor registry data in measuring patterns of diagnostic and therapeutic procedures for older cancer patients. RESEARCH DESIGN: Analysis of a database linking Surveillance, Epidemiology and End Results (SEER) registry data and Medicare claims in patients aged > or =65 years with cancer. SUBJECTS: 361,255 Medicare patients with invasive breast, colorectal, endometrial, lung, pancreatic, and prostate cancer diagnosed between 1984 and 1993. MEASURES: Concordance of SEER files with corresponding Medicare claims. RESULTS: Medicare claims generally identified patients who underwent resection and radical surgery according to SEER (ie, concordance > or =85%-90%) but less likely biopsy or local excision (ie, concordance < or =50%). In some instances, claims also categorized patients as having more invasive surgery than was listed in SEER and also provided incremental information about the use of surgical treatment after 4 months. SEER files and, to a lesser degree, Medicare claims identified radiation therapy not included in the other data source, and Medicare files also captured a significant number of patients with codes for chemotherapy. CONCLUSIONS: Medicare files may be appropriate for studies of patterns of use of surgical treatment, but not for diagnostic procedures. The potential benefit of Medicare claims in identifying delayed surgical intervention and chemotherapy deserves further study.

A meta-analysis of risk estimates for prostate cancer related to tire and rubber manufacturing operations.

Studies investigating the association between prostate cancer and exposure to the tire and rubber manufacturing environment have reported weak and inconsistent results. A meta-analysis of nine cohort studies that used standard mortality ratios and three case-control studies that used odds ratios was conducted. The pooled results from the nine cohort studies showed a standard mortality ratio of 101 (95% confidence interval [CI] = 93,110), whereas the pooled results from the three case-control studies showed on odds ratio of 1.10 (95% CI = 0.94, 1.29). The standard mortality ratios were converted to odds ratios by dividing by 100. The overall pooled risk estimate from all 12 studies was 1.03 (95% CI = 0.96, 1.11). The conclusion of this meta-analysis is that work exposure in a rubber and tire manufacturing environment does not result in an increased risk of prostate cancer.

The utility of Medicare claims data for measuring cancer stage.

BACKGROUND: The validity of using claims data for measuring tumor stage, one of the most important determinants of choice of therapy and long-term survival, is unknown. OBJECTIVES: To determine the relative accuracy of both inpatient and hospital Outpatient Medicare claims for measuring the stage of disease of six commonly diagnosed cancers. RESEARCH DESIGN: Analysis of a database linking Surveillance, Epidemiology, and End Results (SEER) registry data and Medicare claims in patients aged 65 years with cancer. SUBJECTS: Three hundred twenty thousand, six hundred and thirty seven cases of invasive breast, colorectal, endometrial, lung, pancreatic, and prostate cancers diagnosed between 1984 and 1993. MEASURES: Using SEER files as the "gold standard," concordance with Medicare claims, as well as sensitivity and positive predictive value of coding for each stage was measured. RESULTS: Although Medicare data correctly categorized local, regional, and distant stage tumors in 97%, 33%, and 65%, respectively, the data substantially overestimated the proportion of localized tumors and underestimated the rate of regional stage disease. The highest concordance was observed for breast and colorectal cancer. However, the sensitivity and positive predictive values were never simultaneously 80% within one stage of a specific cancer. The accuracy of coding for stage in Outpatient files was inferior to inpatient data. CONCLUSIONS: With few exceptions, Medicare claims have limited utility as a measure of cancer stage. If tumor registry data are not available, investigators should consider the trade offs in sensitivity and predictive value when considering a study that will use claims data.

The sensitivity of Medicare claims data for case ascertainment of six common cancers.

BACKGROUND: Although Medicare claims data have been used to identify cases of cancer in older Americans, there are few data about their relative sensitivity. OBJECTIVES: To investigate the sensitivity of diagnostic and procedural coding for case ascertainment of breast, colorectal, endometrial, lung, pancreatic, and prostate cancer. SUBJECTS: Three hundred and eighty nine thousand and two hundred and thirty-six patients diagnosed with cancer between 1984 and 1993 resided in one of nine Surveillance Epidemiology and End Results (SEER) areas. MEASURES: The sensitivity of inpatient and Part B diagnostic and cancer-specific procedural codes for case finding were compared with SEER. RESULTS: The sensitivity of inpatient and inpatient plus Part B claims for the corresponding cancer diagnosis was 77.4% and 91.2%, respectively. The sensitivity of inpatient claims alone was highest for colorectal (86.1%) and endometrial (84.1%) cancer and lowest for prostate cancer (63.6%). However, when Part B claims were included, the sensitivity for diagnosis of breast cancer was greater than for other cancers (93.6%). Inpatient claim sensitivity was highest for earlier years of the study, and, because of more complete data and longer follow up, the highest sensitivity of combined inpatient and Part B claims was achieved in the late 1980s or early 1990s. CONCLUSIONS: Medicare claims provide reasonably high sensitivity for the detection of cancer in the elderly, especially if inpatient and Part B claims are combined. Because the study did not measure other dimensions of accuracy, such as specificity and predictive value, the potential costs of including false positive cases need to be assessed.

Analysis of the melanoma epidemic, both apparent and real: data from the 1973 through 1994 surveillance, epidemiology, and end results program registry.

BACKGROUND: The incidence of melanoma has been increasing faster than that of any other cancer in the United States. It is unclear whether the increase is related to increased surveillance or other changes in the disease. OBJECTIVE: To examine changes in melanoma rates by several measures of severity of disease and to review the ways in which increased surveillance may cause lead-time bias through early detection or length bias through detection of clinically insignificant lesions as a basis for interpreting these changing rates. DESIGN: Population-based incidence rates for 1973 through 1994. SETTING: United States Surveillance, Epidemiology, and End Results Program tumor registries. PATIENTS: A total of 47,638 cases of melanoma among white patients aged 20 years and older. MAIN OUTCOME MEASURES: Relative incidence rates for melanoma by stage, and tumor thickness adjusted for age and sex. RESULTS: Localized-stage melanoma increased, but no significant change for distant-stage melanomas was seen. Among those diagnosed from 1988 through 1994, there were 22%, 26%, and 31% increases for tumor thickness less than 1.0 mm, between 1.0 and 3.0 mm, and 3.0 mm or greater, respectively. The 2-year mortality rates also increased over time. CONCLUSIONS: While these data show large increases in early disease (localized stage, thin tumors), they also suggest some increase in advanced disease (thick tumors, 2-year mortality). This indicates that the increasing incidence rates of melanoma are not solely caused by increased early detection and diagnosis of clinically insignificant melanomas, but may also represent a true increase in cancer rates.

An ecological study of the effectiveness of mammography in reducing breast cancer mortality.

OBJECTIVES: The purpose of this study was to determine the relation of screening mammography to breast cancer incidence and case fatality. METHODS: In a sample of White female Medicare beneficiaries hospitalized in 1990-1991, age-adjusted breast cancer incidence and 2-year case fatality rates were estimated and compared with the frequency of mammographic screening from a population-based survey. RESULTS: The average rates for incidence, case fatality, and mammography within 5 years in 29 states were 414/100,000, 18.8%, and 59.2%, respectively. There was a positive state-level correlation between mammography rates and incidence and an inverse correlation between mammography and case fatality. CONCLUSIONS: High screening mammography rates in some states are associated with reduced breast cancer case fatality rates, presumably as a result of diagnosis of earlier stage cancers.

Nevi and migration within the United States and Canada: a population-based cross-sectional study.

A survey to ascertain factors associated with benign melanocytic nevi or moles was conducted among randomly-selected White adults (aged 18 to 50 years) in Washington State (United States). Participants of the telephone interview in 1990-91 were questioned about lifetime places of residence and constitutional factors. Subjects counted raised nevi on their arms at the end of the survey. Logistic regression was used to examine the risk for two or more nevi compared with no nevi. Individuals who resided in warmer areas and lower latitudes than Washington State were at higher risk of having multiple nevi. This association held for residence at birth, during childhood, adolescence, and over lifetime: an odds ratio (OR) of 2.3 (95 percent confidence interval = 1.2-4.3) for lifetime average daily maximum temperature of > or = 64 degrees F compared with 58.9 degrees F, and similar ORs of 2.1 for adolescence and 1.8 for childhood. These associations remained significant after adjusting for potential confounding effects of constitutional factors and for childhood sunburns as a potential mechanism. Risk of multiple nevi was reduced for both early age at migration and longer duration of stay in Washington. These data are consistent with the importance of childhood and adolescent sun exposure in the etiology of nevi, but also suggest an effect of lifetime sun exposure.

Constitutional factors and sun exposure in relation to nevi: a population-based cross-sectional study.

A survey of benign melanocytic nevi (moles), suspected precursors or markers for melanoma, was conducted in Washington State among 717 randomly selected 18- to 50-year-old white adults who participated in a telephone interview in 1990-1991. Participants were questioned about constitutional factors, time spent in the sun, and severe sunburns over three time periods and were asked to count the raised nevi on both their arms. Logistic regression was used to examine the risk for 2+ nevi compared with none. An odds ratio (OR) of 2.0 (95% confidence interval (CI) 1.3-3.1) was seen for current freckling. Skin color, tendency to burn, and inability to tan were important risk factors but were not independent of each other. Individuals with a history of severe sunburns had an increased risk of nevi: OR = 1.9 (95% CI 0.9-3.9) for 3+ severe sunburns compared with none in the last 5 years; OR = 2.0 (95% CI 1.2-3.1) for 4+ severe teenage sunburns; and OR = 3.1 (95% CI 1.7-5.3) for 4+ severe childhood sunburns. Furthermore, childhood sunburns were related to nevi independently of sun sensitivity and teenage and recent sunburns: OR = 2.0 (95% CI 1.0-4.0) for 4+ severe sunburns. These data suggest that childhood sunburns are important in the etiology of nevi. This study supports prior studies of the relation between melanoma and early sun exposure.

Firearm injury risk among primary care patients.

BACKGROUND: Firearm injuries are the eighth leading cause of death in the United States. Evidence suggests that availability of guns in the home is associated with an increased risk of homicide, suicide, and unintentional injuries and fatalities. Our study examined five demographically diverse primary care practices in Oregon to determine the extent to which patients and members of their households might be at risk for firearm injuries. METHODS: Six hundred and four consecutive English-speaking patients who were at least 18 years old and seeking care at the five different practices were surveyed. Participants were asked about the presence of firearms in the home, methods of storage, history of firearm safety training, and history of firearm counseling by their physicians. RESULTS: Forty-two percent of respondents reported having at least one firearm in the home. In homes with firearms, 48% contained at least one firearm that was stored unlocked, and 26% contained at least one firearm stored loaded. Twenty percent of homes with children contained at least one unlocked firearm, and 10% contained a loaded firearm. Forty-five percent [corrected] of those homes with both children and firearms had at least one gun that was stored unlocked, and 25% [corrected] contained at least one loaded firearm. Those who reported having had formal firearm safety training were no more likely to store their firearms safely than those without such training. Only 3% of respondents reported that their physician had ever talked with them about gun safety. CONCLUSIONS: Our data indicate that a substantial number of patients cared for by primary care physicians are at risk for firearm injuries.

Cancer survival among American Indians in western Washington State (United States).

Cancer survival among American Indians is worse than among other races in some regions of the United States, but has not been studied among American Indians in Washington state. Our purpose was to evaluate cancer survival among American Indians included in the Seattle-Puget Sound Cancer Registry. We compared site-specific survival among American Indians (n = 551) and Whites (n = 110,899) diagnosed from 1974 to 1989 for five cancer sites. For all sites except prostate, the distribution of cancer stage at diagnosis for American Indians was not significantly different from the distribution for Whites, and a similar proportion of American Indians and Whites received cancer treatment. After adjustment for age differences between American Indians and Whites, American Indians experienced poorer survival from prostate, breast, cervical, and colorectal cancer. Poorer survival among American Indians persisted after adjustment for differences in cancer stage at diagnosis, lack of cancer treatment, and residence in a non-urban county. The survival experience among American Indians who were recorded as non-American Indians in the cancer registry but who were listed as American Indians in Indian Health Service records was more favorable than that among persons initially coded as American Indians in the cancer registry. We conclude that cancer survival among American Indians in western Washington is poorer than that among Whites in the same region, and that factors other than age, differences in stage at diagnosis, lack of cancer treatment, and residence in non-urban counties account for this.