Search PubMed⌕ Search

Biomedical subjects

E J Feuer

Publications and source records attributed to E J Feuer.

At least 37 records · Page 2Linked to original sources
PubMed1998

Estimating lifetime and age-conditional probabilities of developing cancer.

Lifetime and age-conditional risk estimates of developing cancer provide a useful summary to the public of the current cancer risk and how this risk compares with earlier periods and among select subgroups of society. These reported estimates, commonly quoted in the popular press, have the potential to promote early detection efforts, to increase cancer awareness, and to serve as an aid in study planning. However, they can also be easily misunderstood and frightening to the general public. The Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute and the American Cancer Society have recently begun including in annual reports lifetime and age-conditional risk estimates of developing cancer. These risk estimates are based on incidence rates that reflect new cases of the cancer in a population free of the cancer. To compute these estimates involves a cancer prevalence adjustment that is computed cross-sectionally from current incidence and mortality data derived within a multiple decrement life table. This paper presents a detailed description of the methodology for deriving lifetime and age-conditional risk estimates of developing cancer. In addition, an extension is made which, using a triple decrement life table, adjusts for a surgical procedure that removes individuals from the risk of developing a given cancer. Two important results which provide insights into the basic methodology are included in the discussion. First, the lifetime risk estimate does not depend on the cancer prevalence adjustment, although this is not the case for age-conditional risk estimates. Second, the lifetime risk estimate is always smaller when it is corrected for a surgical procedure that takes people out of the risk pool to develop the cancer. The methodology is applied to corpus and uterus NOS cancers, with a correction made for hysterectomy prevalence. The interpretation and limitations of risk estimates are also discussed.

Adolescent↗
PubMed1998

Improvement in the prognosis of breast cancer from 1965 to 1984.

PURPOSE: The prognosis of breast cancer has improved over the past three decades. It is uncertain, however, whether this improvement results from an increase in the cure rate, extension of the life span of uncured patients, or some combination. METHODS: From the Connecticut Tumor Registry, we obtained data on 25,091 patients with localized (node-negative) and regionally metastatic (node-positive) breast cancer who were diagnosed over the two decades between 1965 and 1984, with follow-up through 1993. The data for these patients were analyzed using a variety of parametric models to quantitate likelihood of cure and median survival time among uncured patients. These models incorporate the assumption that time to death from breast cancer follows a specific distribution. RESULTS: For patients with node-negative disease, parametric analysis revealed no significant difference in cured-fraction or median survival time over the two decades studied. For patients with node-positive disease, however, a significant increase in median survival time (P < .001) was found during the second decade (1970 to 1979). There was also a trend toward a higher cured-fraction over time, but this was not statistically significant. CONCLUSION: This study confirms that patients with node-positive disease had an improved prognosis over the two decades studied. Parametric analysis suggests that this improvement reflects primarily an increase in the median survival time for uncured patients, although there is a trend toward an increase in the likelihood of cure.

Breast Neoplasms↗
PubMed1997

A semi-parametric estimate of extra-Poisson variation for vital rates.

We introduce a method for estimating overdispersion in Poisson models for vital rates. We assume smoothness conditions on the counts to obtain pointwise variance estimates that we combine to obtain an estimate of the overdispersion parameter. We create confidence intervals about the observed rates using this estimate and an approximation based on the gamma distribution. The advantage of this method is that the estimates of the superpopulation rates do not depend on the smoothness assumption, yet when this assumption is met we obtain approximately unbiased estimates of the overdispersion parameter. Thus, we may calculate confidence intervals for vital rates under an overdispersed Poisson model without making parametric assumptions on the mean rates.

Adult↗
PubMed1997

Breast cancer clusters in the northeast United States: a geographic analysis.

High breast cancer mortality rates have been reported in the northeastern part of the United States, with recent attention focused on Long Island, New York. In this study, the authors investigate whether the high breast cancer mortality is evenly spread over the Northeast, in the sense that any observed clusters of deaths can be explained by chance alone, or whether there are clusters of statistical significance. Demographic data and age-specific breast cancer mortality rates for women were obtained for all 244 counties in 11 northeastern states and for the District of Columbia for 1988-1992. A recently developed spatial scan statistic is used, which searches for clusters of cases without specifying their size or location ahead of time, and which tests for their statistical significance while adjusting for the multiple testing inherent in such a procedure. The basic analysis is adjusted for age, with further analyses examining how the results are affected by incorporating race, urbanicity, and parity as confounding variables. There is a statistically significant and geographically broad cluster of breast cancer deaths in the New York City-Philadelphia, Pennsylvania, metropolitan area (p = 0.0001), which has a 7.4% higher mortality rate than the rest of the Northeast. The cluster remains significant when race, urbanicity, and/or parity are included as confounding variables. Four smaller subclusters within this area are also significant on their own strength: Philadelphia with suburbs (p = 0.0001), Long Island (p = 0.0001), central New Jersey (p = 0.0001), and northeastern New Jersey (p = 0.0001). The elevated breast cancer mortality on Long Island might be viewed less as a unique local phenomenon and more as part of a more general situation involving large parts of the New York City-Philadelphia metropolitan area. The several known and hypothesized risk factors for which we could not adjust and that may explain the detected cluster are most notably age at first birth, age at menarche, age at menopause, breastfeeding, genetic mutations, and environmental factors.

Breast Neoplasms↗
PubMed1997

Confidence intervals for directly standardized rates: a method based on the gamma distribution.

We offer an approximation to central confidence intervals for directly standardized rates, where we assume that the rates are distributed as a weighted sum of independent Poisson random variables. Like a recent method proposed by Dobson, Kuulasmaa, Eberle and Scherer, our method gives exact intervals whenever the standard population is proportional to the study population. In cases where the two populations differ non-proportionally, we show through simulation that our method is conservative while other methods (the Dobson et al. method and the approximate bootstrap confidence method) can be liberal.

Chi-Square Distribution↗
PubMed1997

Impact of changes in catheter management on infectious complications among children with central venous catheters.

OBJECTIVES: To characterize and enumerate central venous catheter (CVC)-related complications among children with chronic illnesses, and to reduce the complication rate through changes in CVC management and education. DESIGN: A prospective observational study followed by an educational program and a nonrandomized interventional trial. SETTING: The Children's Hospital of Philadelphia, a tertiary, pediatric facility. PATIENTS: 268 children with Broviac, Hickman, or Infusaport catheters in place during 58,290 catheter days. INTERVENTIONS: Development and implementation of protocols for cleaning insertion site and hub, use of nonocclusive dressings, and manipulation of access; formal staff and parental education about protocols. RESULTS: CVC-related infections fell from 4.58/1,000 catheter-days preintervention to 3.83 postintervention (risk ratio [RR], 0.20; 95% confidence interval [CI95], 0.89-1.622; P = .25); exit-site infections fell from 0.58 to 0.11 (CI95, 1.22-45.64; P = .02); rates among infants on the surgical service fell from 15.46 to 6.67 (RR, 2.31; CI95, 1.10-4.30; P = .02). CONCLUSIONS: Education and changes in management protocols reduced the incidence of exit-site infections among all patients and reduced the overall infectious complication rate among the infants receiving parenteral nutrition on the surgical service. Other interventions are needed to decrease further the infectious complications in these children.

Catheterization, Central Venous↗
PubMed1997

Estimating medical costs from incomplete follow-up data.

Estimation of the average total cost for treating patients with a particular disease is often complicated by the fact that the survival times are censored on some study subjects and their subsequent costs are unknown. The naive sample average of the observed costs from all study subjects or from the uncensored cases only can be severely biased, and the standard survival analysis techniques are not applicable. To minimize the bias induced by censoring, we partition the entire time period of interest into a number of small intervals and estimate the average total cost either by the sum of the Kaplan-Meier estimator for the probability of dying in each interval multiplied by the sample mean of the total costs from the observed deaths in that interval or by the sum of the Kaplan-Meier estimator for the probability of being alive at the start of each interval multiplied by an appropriate estimator for the average cost over the interval conditional on surviving to the start of the interval. The resultant estimators are consistent if censoring occurs solely at the boundaries of the intervals. In addition, the estimators are asymptotically normal with easily estimated variances. Extensive numerical studies show that the asymptotic approximations are adequate for practical use and the biases of the proposed estimators are small even when censoring may occur in the interiors of the intervals. An ovarian cancer study is provided.

Aged↗
PubMed1997

The lifetime risk of developing prostate cancer in white and black men.

Two factors help explain increases in the lifetime risk of developing cancer: (a) decreasing overall mortality rates such that people are now living to older ages when cancer rates rise rapidly; and (b) increasing numbers of cancer cases discovered by new medical procedures, screening tests, and changes in the population risk factors. Prostate cancer lifetime risk estimates are particularly influenced by improved mortality rates and increased detection of asymptomatic disease. In this study, we report trends in lifetime risk estimates of developing prostate cancer in white and black men in the United States, from 1975 to 1993, and focus on the effects of changing mortality and screening. For the study period 1975-1977 to 1991-1993, the lifetime risk of developing invasive prostate cancer increased from 7.3 to 19.6% for whites and from 8.5 to 18.6% for blacks. When we recalculated these estimates using age-specific incidence trends from 1975 through 1989 (thereby controlling for the effect of prostate-specific antigen serum testing on prostate cancer incidence rates), the lifetime risk estimates in 1991-1993 fell to 13.8% for whites and 12.5% for blacks. When we made an additional assumption, basing lifetime risk estimates on higher 1975-1977 mortality rates, the lifetime risk estimates in 1991-1993 became 11.3% for whites and 11.8% for blacks. It is also shown that although mortality rates have improved for white and black men over the study period, they are much larger for blacks than whites in younger age groups, when the prevalence of prostate cancer is relatively low. As a result, fewer blacks survive to older ages when age-specific prostate cancer rates are large. It is of note that blacks have higher incidence rates for prostate cancer than do whites at every age-specific interval. Hence, increasing trends in lifetime risk of prostate cancer suggest, in large part, longer life expectancy and better detection methods.

Adult↗
PubMed1996

Prognostic significance of in situ carcinoma associated with invasive breast carcinoma. A natural experiment in cancer immunology?

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.

Aged↗
PubMed1996

Risk-adjusted cancer-incidence rates (United States).

A risk-adjusted method is proposed for estimating cancer incidence rates from data collected by the Surveillance, Epidemiology, and End Results (SEER) program of the US National Cancer Institute. Unlike the conventional incidence-rate estimates reported by SEER, this method considers only the first primary cancer, and adjusts for population-based cancer prevalence, as well as for surgical procedures which remove an individual from risk of developing a given cancer. Thus, risk-adjusted incidence-rates more accurately reflect the average cancer risk for individuals in the cancer-free, at-risk population. The results of the analysis indicate that, in general, incidence-rate estimates are fairly similar between the conventional and risk-adjusted methods. However, this is not the case for certain cancer sites which may have: (i) a high number of subsequent primary cancers (e.g., melanomas-skin); (ii) a high cancer prevalence proportion (e.g., prostate cancer); (iii) a high number of subsequent primary cancers and prevalence proportion (e.g., female breast); or (iv) a high prevalence of removal of the organ in question (e.g., cervical and uterine cancers). For example, by applying the risk-adjusted incidence method for in situ and invasive cervical cancer, we found that in the period 1990-92 the age-adjusted incidence-rate estimate increased from 57.8 to 66.3 (15 percent) per 100,000 person-years; the greatest increase in the incidence-rate estimate occurred for women aged 65 to 69 years, from 40.1 to 63.2 (58 percent) per 100,000 person-years; and the lifetime risk of developing cervical cancer increased from 4.6 (1 in 22) to 5.5 (1 in 18) percent.

Adolescent↗
PubMed1996

Disenrollment of Medicare cancer patients from health maintenance organizations.

OBJECTIVES: There is concern that financial incentives in health maintenance organizations (HMOs) might result in pressures to induce sicker members to disenroll. The authors compared disenrollment rates of Medicare HMO enrollees with cancer with disenrollment rates for cancer-free enrollees, using Medicare enrollment files linked to population-based tumor registry data from the Surveillance, Epidemiology, and End Results (SEER) Program. METHODS: The authors identified all aged Medicare beneficiaries who enrolled in an HMO located in a SEER reporting area during 1985 to 1989. Time to disenrollment was analyzed using a proportional hazards model. RESULTS: Overall, cancer patients were no more likely to disenroll than others. However, persons diagnosed with cancer after enrollment were less likely to disenroll than other persons in Independent Practice Association (IPA) mode HMOs (relative risk [RR] = 0.79). Persons diagnosed with cancer after enrollment in group- and staff-model HMOs were about equally likely to disenroll as other persons (RR = 0.91). Persons diagnosed with cancer less than 18 months before enrollment were at high risk for disenrollment from both IPA and group-/staff-model HMOs (RR = 1.47 and 1.35). There was substantial variation among HMOs in overall disenrollment rates and in RRs for disenrollment by cancer patients. CONCLUSIONS: The low disenrollment rates of patients diagnosed after enrollment do not support the contention that features intrinsic to managed care make HMOs unattractive to the seriously ill. Monitoring of selective disenrollment could be used as a screen for possible access and quality problems.

Aged↗
PubMed1996

Increasing incidence of childhood cancer: report of 20 years experience from the greater Delaware Valley Pediatric Tumor Registry.

As little is known about the aetiology of cancer in children, analysis of time trends may be useful. Recent data on time trends for paediatric cancers are very limited. We report here on trends in the incidence of 15 categories of cancer in children under 15 years of age from 1970 to 1989, using data from the Greater Delaware Valley Pediatric Tumor Registry in the US. Total cancer incidence increased 1% per year (P < 0.001). Neither acute lymphocytic leukaemia, acute myelocytic leukaemia, nor total leukaemia incidence changed significantly. In contrast, the incidence of central nervous system (CNS) tumours rose 2.7% per year (P < 0.001). All three subgroups of this category, glioma, primitive neuroectodermal tumor (PNET)/medulloblastoma, and other CNS tumours, showed increases. For glioma and PNET/medulloblastoma, trends differed by age, race, and/or gender. Among the other childhood cancers, significant increases were observed for non-Hodgkin lymphoma and neuroblastoma. For osteosarcoma and retinoblastoma, no overall change in incidence was observed, although decreases were observed in some age and race subgroups. The rise in CNS tumour incidence confirms previous reports from the US and Great Britain. The lack of change for acute lymphocytic leukaemia conflicts with other data from the US, but diagnostic changes appear to explain at least part of the discrepancy. The increase in neuroblastoma has also been observed in Great Britain. In contrast to our finding, investigators in the US and Great Britain have reported no rise in non-Hodgkin lymphoma. Analyses for more of the childhood cancers from other registries would aid in detecting and interpreting incidence trends in recent years.

Adolescent↗
PubMed1995

Are increases in mammographic screening still a valid explanation for trends in breast cancer incidence in the United States?

A number of studies have attributed much of the sharp increase in breast cancer incidence in the United States during the 1980s to the increased detection through mammography. The most recent breast cancer data from the US National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program show that the incidence trend has slowed, while results from the National Health Interview Survey (NHIS) of 1987 and 1990 indicate that the percentage of women receiving mammograms continues to increase. This phenomenon suggested the need to reassess the relationship between increasingly early detection of breast cancer and overall incidence trends. A polynomial age-cohort model was used to establish the secular trend in incidence rates excluding the impact of recent increases in detection due to the rising use of mammography. Based on the model, the incidence trend in the youngest age group (40 to 49 years) would peak and then begin to decline in the early 1980s. This pattern would manifest itself later in successively older age groups as these younger cohorts age. Breast cancer trends are seen to be generally consistent with the impact of the increased use of mammography when its effect is superimposed upon the background of declining or slowing secular trends. These results support previous reports linking incidence rates with the increase in screening-mammography.

Adult↗
PubMed1994

Projection of incidence rates to a larger population using ecologic variables.

There is wide acceptance of direct standardization of vital rates to adjust for differing age distributions according to the representation within age categories of some referent population. One can use a similar process to standardize, and subsequently project vital rates with respect to continuous, or ratio scale ecologic variables. We obtained from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) programme, a 10 per cent subset of the total U.S. population, country-level breast cancer incidence during 1987-1989 for white women aged 50 and over. We applied regression coefficients that relate ecologic factors to SEER incidence to the full national complement of county-level information to produce an age and ecologic factor adjusted rate that may be more representative of the U.S. than the simple age-adjusted SEER incidence. We conducted a validation study using breast cancer mortality data available for the entire U.S. and which supports the appropriateness of this method for projecting rates.

Age Factors↗
PubMed1994

A method for partitioning cancer mortality trends by factors associated with diagnosis: an application to female breast cancer.

U.S. cancer mortality data derived from information recorded on death certificates are frequently relied upon as an indicator of progress against cancer. A limitation of this measure is the lack of information pertaining to the onset of disease, such as year-of-diagnosis, age-at-diagnosis, stage of disease at diagnosis and histology of lesions. However, population-based cancer registries collect these types of data and allow the calculation of an incidence-file based mortality rate. This incidence-based mortality rate allows a partitioning of mortality by variables associated with the cancer onset. Breast cancer incidence-based mortality measures are created and compared to mortality rates based on death certificates over a comparable time period. Novel mortality measures, such as mortality rates by stage-at-diagnosis, age-at-diagnosis and year-of-diagnosis, are used to illustrate the value of this approach.

Adult↗
PubMed1994

Cohort-specific risks of developing breast cancer to age 85 in Connecticut.

Previous estimates of the lifetime risk of developing breast cancer have used cross-sectional estimates of incidence. Cross-sectional rates, however, yield a biased picture of cohort risks when rates are unstable, as breast cancer trends have been. We developed cohort life tables for Connecticut women born from 1888-1892 to 1948-1952 to generate more specific estimates of breast cancer risk to age 85. Multiple decrement life tables were produced for each birth cohort. We included as cases only the first reports of breast cancer in women with no earlier malignancy. Our results indicate that widely circulated lifetime risks of 1 in 9 may be inflated slightly owing to changing incidence. We estimate that of those women 40-44 years old in 1992, 1 woman in 10 will develop breast cancer by age 85. For women born between 1928 and 1932, 1 in 13 will be diagnosed with breast cancer by age 85. The results are insensitive to mortality trends in the past. Errors in the estimates are more likely to arise from changes in incidence and mortality in the future.

Adult↗
PubMed1994

After a treatment breakthrough: a comparison of trial and population-based data for advanced testicular cancer.

PURPOSE: To determine to what extent the benefits of cisplatin-based combination chemotherapy have been disseminated to all American men diagnosed with advanced testicular cancer. PATIENTS AND METHODS: One hundred seventy-two advanced testicular cancer cases from five population-based registries of the Surveillance, Epidemiology, and End Results (SEER) Program diagnosed from 1978 to 1984 were compared with 133 diagnostically comparable cases from the Memorial Sloan-Kettering Cancer Center (MSKCC) vinblastine, dactinomycin, and bleomycin (VAB) regimens 7 through 9. Exclusions were made in both series for cases with elevated markers only, abdominal disease only, or extragonadal tumors. Ratings of extent of disease using the Indiana University system (minimal/moderate or advanced) were available for the MSKCC cases, and were determined retrospectively on the SEER cases based on information abstracted from medical records. RESULTS: Among the SEER cases, 89% reported receiving chemotherapy, and 95% of these received cisplatin-containing regimens. Survival among the MSKCC patients was significantly better than for the SEER cases in the minimal/moderate extent of disease category (95% and 73% 3-year survival rate, respectively); however, the difference for advanced cases was only marginally significant (52% and 40% 3-year survival rates, respectively). Survival did not vary significantly by year of diagnosis in either series. CONCLUSION: Although most of the patients in the SEER series received cisplatin-based chemotherapy, this alone did not produce results equivalent to that in the MSKCC series. Since the patients were selected to be as diagnostically comparable as possible at baseline, remaining differences in survival may be due to adherence to a fixed regimen and level of dose-intensity, adequacy of diagnostic work-up, implementation of salvage therapies and debulking surgery, and unknown factors related to who is willing and able to travel to a tertiary care center for treatment. Whatever the reason for not achieving optimal results in the SEER series, the very modest survival improvements over the time period 1978 to 1984 indicates that the differences in outcome between the two series were basically stable over the study period.

Adolescent↗