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Biomedical subjects

N Urban

Publications and source records attributed to N Urban.

At least 19 recordsLinked to original sources
PubMed2004

Combining CA 125 and SMR serum markers for diagnosis and early detection of ovarian carcinoma.

OBJECTIVES: The serum tumor marker CA 125 is elevated in most clinically advanced ovarian carcinomas. Because these elevations may precede clinical detection by a year or more, CA 125 is potentially useful for early detection as part of an ovarian cancer screening program. However, CA 125 is often not elevated in clinically detected cancer and is frequently elevated in women with benign ovarian tumors. CA 125 may be more useful in conjunction with one or more other tumor biomarkers. Additional markers could play a role if, when used with CA 125, they identify some carcinomas missed by CA 125 (i.e., they improve sensitivity), rule out false positives (i.e., improve specificity), or are able to detect the same cancers earlier. METHODS: We have evaluated a composite marker (CM) that combines CA 125 and a previously described soluble mesothelin related (SMR) marker in sera from 52 ovarian cancer cases, 43 controls with benign ovarian tumors, and 220 normal risk controls who participated in a screening program, including 25 healthy women having two serum samples collected 1 year apart. CA 125, SMR, and CM were evaluated for their ability to identify clinical disease and for their temporal stability, which assesses their ability to obtain even greater sensitivity when used in a longitudinal screening program. RESULTS: CM has the best sensitivity, with specificity equal to CA 125. Importantly, CM has temporal stability at least as high as CA 125. CONCLUSION: The CM may outperform CA 125 alone in a longitudinal screening program as well as in a diagnostic setting.

CA-125 Antigen↗
PubMed2003

Current research and treatment for epithelial ovarian cancer. A Position Paper from the Helene Harris Memorial Trust.

In March 2003, an international mulltidisciplinary group of scientists and clinicians with a specific interest in ovarian cancer met for 4 days to discuss research into and treatment of this challenging disease. Under the headings of molecular genetics, molecular biology, the biology of ovarian cancer, old therapies, new targets and the early detection of the disease, this Position Paper summarises the presentations and discussion from the 9th Biennial Helene Harris Memorial Trust Forum on Ovarian Cancer. In particular, we highlight the potential of international collaborations in translating laboratory science into useful clinical interventions.

Antineoplastic Agents↗
PubMed2003

Breast cancer worry and mammography use by women with and without a family history in a population-based sample.

Worry about breast cancer risk has been found to be a barrier to mammography use by women with a family history of breast cancer in some studies, although worry is generally found to increase mammography use among average risk women. Our study sought to examine the association of worry with mammography use in a population-based sample of women stratified by family history associated risk for breast cancer. A population-based sample of 6512 women completed a telephone interview. Fourteen percent (n = 948) of these reported a family history suggestive of elevated risk, including at least one affected first-degree relative. To examine the effects of worry on mammography use in women, a logistic regression model, including family history associated risk, age, and worry, was tested. Although family history was a significant predictor of mammography use in bivariate examinations, in the multivariate model it was not significant after adjustment for age and worry, which remained statistically significant predictors of mammography (P < 0.05). The association between worry and mammography use was best described by a quadratic term. Interaction terms for family history-associated risk and worry were not statistically significant predictors of mammography use. Worry about breast cancer risk appears to be associated with mammography use in an inverted u-shaped pattern. Women reporting moderate levels of worry were more likely to use mammography annually than those who were either mildly or severely worried. Severe worry may be a barrier to mammography use for all women not only those with a family history.

Aged↗
PubMed2002

Worry about ovarian cancer risk and use of ovarian cancer screening by women at risk for ovarian cancer.

OBJECTIVE: This study examined reports of perceived risk of ovarian cancer, worry, and screening use in a large sample of women. While screening for asymptomatic women is not generally recommended, in 1994 a consensus conference concluded that women with multiple affected relatives are at high risk for ovarian cancer and should be encouraged to participate in screening. The consensus report also suggested that women with a single affected first-degree relative are at elevated risk and while these women were not encouraged to get screening it was suggested that they may choose to pursue screening outside of a randomized trial [NIH Consensus Conference. JAMA 1995;273(6) 491-7]. METHODS: A total of 3257 women participated in this research by completing a mailed survey on ovarian cancer risk, worry, and use of screening. One hundred forty-two of these women were at high risk for this disease due to a strong family history. An additional 144 women were at elevated risk due to a single first-degree affected relative with ovarian cancer. RESULTS: Family history did predict perceived risk, difficulties due to worry, and use of ovarian cancer screening. However, the group of women most likely to report high levels of perceived risk and to have received screening for ovarian cancer were women with a single affected relative rather than those at high risk, for whom screening is recommended. CONCLUSIONS: These results suggest that many women need additional education about ovarian cancer risk. Most women overestimated their risk for this disease. Some average-risk women get screening although it is not recommended outside of randomized trials, and a significant percentage of women at high risk fail to get recommended screening.

Adolescent↗
PubMed2001

Cost-effectiveness of microsatellite instability screening as a method for detecting hereditary nonpolyposis colorectal cancer.

BACKGROUND: The National Cancer Institute has published consensus guidelines for universal screening for hereditary nonpolyposis colorectal cancer (HNPCC) in patients with newly diagnosed colorectal cancer. OBJECTIVE: To determine the cost-effectiveness of screening compared with standard care in eligible patients with colorectal cancer and their siblings and children. DESIGN: Cost-effectiveness analysis. DATA SOURCES: National colorectal cancer registry data, the Creighton International Hereditary Colorectal Cancer Registry, Medicare claims records, and published literature. TARGET POPULATION: Patients with newly diagnosed colorectal cancer and their siblings and children. TIME HORIZON: Lifetime (varies depending on age at screening). PERSPECTIVE: Societal. INTERVENTIONS: Initial office-based screening to determine eligibility (based on personal and family cancer history), followed by tumor testing for microsatellite instability. Those with microsatellite instability were offered genetic testing for HNPCC. Siblings and children of patients with cancer and the HNPCC mutation were offered genetic testing, and those who were found to carry the mutation received lifelong colorectal cancer screening. MEASUREMENTS: Life-years gained. RESULTS OF BASE-CASE ANALYSIS: When only the patients with cancer were considered, cost-effectiveness of screening was $42 210 per life-year gained. When patients with cancer and their siblings and children were considered together, cost-effectiveness increased to $7556 per life-year gained. RESULTS OF SENSITIVITY ANALYSIS: The model was most sensitive to the estimated survival gain from screening siblings and children, to the prevalence of HNPCC mutations among patients with newly diagnosed cancer, and to the discount rate. In probabilistic analysis, the 90% CI for the cost-effectiveness of screening patients with cancer plus their relatives was $4874 to $21 576 per life-year gained. CONCLUSION: Screening patients with newly diagnosed colorectal cancer for HNPCC is cost-effective, especially if the benefits to their immediate relatives are considered.

Age Distribution↗
PubMed2001

MAGE-F1, a novel ubiquitously expressed member of the MAGE superfamily.

Most known members of the MAGE superfamily are expressed in tumors, testis and fetal tissues, which has been described as a cancer/testis or "CT" expression pattern. We have identified a novel member of this superfamily, MAGE-F1, which is expressed in all adult and fetal tissues tested. In addition to normal tissues, MAGE-F1 is expressed in many tumor types including ovarian, breast, cervical, melanoma and leukemia. MAGE-F1 is encoded on chromosome 3, identifying a sixth chromosomal location for a MAGE superfamily gene. The coding region of MAGE-F1 is contained within a single exon and includes a microsatellite repeat. Sequence analysis and expression profiles define a new class of ubiquitously expressed MAGE superfamily genes that includes MAGE-F1, MAGE-D1, MAGE-D2/JCL-1 and NDN. The finding that several MAGE genes are ubiquitously expressed suggests a role for MAGE encoded proteins in normal cell physiology. Furthermore, potential cross-reactivity to these ubiquitously expressed MAGE gene products should be considered in the design of MAGE-targeted immunotherapies for cancer.

Adult↗
PubMed2001

Parameter solicitation for planning cost effectiveness studies with dichotomous outcomes.

When economic endpoints are included alongside clinical effectiveness measures in randomized clinical trials (RCT), they are summarized together by the incremental cost effectiveness ratio (ICER). Adding economic endpoints to an RCT complicates the planning of experiments because investigators must now solicit their beliefs about costs, but even more challenging, they must also specify their association with effectiveness. Solicitation of correlations between costs and effects can be unintuitive, and so potentially highly inaccurate. This is unfortunate because power is highly sensitive to the association between costs and effects. Mis-specification in this association may lead to substantially underpowered or overpowered studies. We show that when clinical effectiveness measures are dichotomous, specification of the correlation between costs and effects can be avoided by instead describing their association with a mixture model. This representation leads to simple and highly intuitive parameter specifications. It may also be used to generate realistic raw data that can be used to evaluate experiment power with simulation. We give particular attention to evaluating and interpreting power when Fieller's theorem method (FTM) is used to calculate confidence for, and test hypotheses about, the ICER. Data from a previously published clinical trial are used to demonstrate the use of this new method to calculate sample size for a cost effectiveness study.

Cost-Benefit Analysis↗
PubMed2000

Performance of screening mammography among women with and without a first-degree relative with breast cancer.

BACKGROUND: Although it is recommended that women with a family history of breast cancer begin screening mammography at a younger age than average-risk women, few studies have evaluated the performance of mammography in this group. OBJECTIVE: To compare the performance of screening mammography in women with a first-degree family history of breast cancer and women of similar age without such history. DESIGN: Cross-sectional. SETTING: Mammography registries in California (n = 1), New Hampshire (n = 1), New Mexico (n = 1), Vermont (n = 1), Washington State n = 2), and Colorado (n = 1). PARTICIPANTS: 389 533 women 30 to 69 years of age who were referred for screening mammography from April 1985 to November 1997. MEASUREMENTS: Risk factors for breast cancer; results of first screening examination captured for a woman by a registry; and any invasive cancer or ductal carcinoma in situ identified by linkage to a pathology database, the Surveillance, Epidemiology, and End Results program, or a state tumor registry. RESULTS: The number of cancer cases per 1000 examinations increased with age and was higher in women with a family history of breast cancer than in those without (3.2 vs. 1.6 for ages 30 to 39 years, 4.7 vs. 2.7 for ages 40 to 49 years, 6.6 vs. 4.6 for ages 50 to 59 years, and 9.3 vs. 6.9 for ages 60 to 69 years). The sensitivity of mammography increased significantly with age (P = 0.001 [chi-square test for trend]) in women with a family history and in those without (63.2% [95% CI, 41. 5% to 84.8%] vs. 69.5% [CI, 57.7% to 81.2%] for ages 30 to 39 years, 70.2% [CI, 61.0% to 79.5%] vs. 77.5% [CI, 73.3% to 81.8%] for ages 40 to 49 years, 81.3% [CI, 73.3% to 89.3%] vs. 80.2% [CI, 76.5% to 83.9%] for ages 50 to 59 years, and 83.8% [CI, 76.8% to 90.9%] vs. 87.7% [CI, 84.8% to 90.7%] for ages 60 to 69 years). Sensitivity was similar for each decade of age regardless of family history. The positive predictive value of mammography was higher in women with a family history than in those without (3.7% vs. 2.9%; P = 0.001). CONCLUSIONS: Cancer detection rates in women who had a first-degree relative with a history of breast cancer were similar to those in women a decade older without such a history. The sensitivity of screening mammography was influenced primarily by age.

Adult↗
PubMed2000

Current medicolegal and confidentiality issues in large, multicenter research programs.

The convenience of fast computers and the Internet have encouraged large collaborative research efforts by allowing transfers of data from multiple sites to a single data repository; however, standards for managing data security are needed to protect the confidentiality of participants. Through Dartmouth Medical School, in 1996-1998, the authors conducted a medicolegal analysis of federal laws, state statutes, and institutional policies in eight states and three different types of health care settings, which are part of a breast cancer surveillance consortium contributing data electronically to a centralized data repository. They learned that a variety of state and federal laws are available to protect confidentiality of professional and lay research participants. The strongest protection available is the Federal Certificate of Confidentiality, which supersedes state statutory protection, has been tested in court, and extends protection from forced disclosure (in litigation) to health care providers as well as patients. This paper describes the careful planning necessary to ensure adequate legal protection and data security, which must include a comprehensive understanding of state and federal protections applicable to medical research. Researchers must also develop rules or guidelines to ensure appropriate collection, use, and sharing of data. Finally, systems for the storage of both paper and electronic records must be as secure as possible.

Confidentiality↗
PubMed2000

Quality of life in survivors of colorectal carcinoma.

BACKGROUND: Colon carcinoma is a common malignancy that accounts for a substantial share of all cancer-related morbidity and mortality. However, little is known with regard to general and disease specific quality of life in survivors of colorectal carcinoma, particularly from community-based samples of cases across stage and survival times from diagnosis. METHODS: Subjects with colorectal carcinoma were recruited from the National Cancer Institute's Surveillance, Epidemiology, and End Results cancer registry. Subjects completed two self-administered surveys: the Functional Assessment of Cancer Therapy Scales for Colorectal Cancer (FACT-C) and the Health Utilities Index (HUI) Mark III. RESULTS: One hundred seventy-three respondents (average age: 70.4 years, 71.4% female) completed the survey. In the first 3 years after diagnosis, quality of life was lower and varied substantially among respondents. After 3 years, respondents in all TNM stages of disease except Stage IV reported a relatively uniform and high quality of life. Pain, functional well-being, and social well-being were affected most substantially across all stages and times from diagnosis. Low income status was associated with worse outcomes for pain, ambulation, and social and emotional well-being. Only emotional well-being scores improved significantly over time in both surveys. CONCLUSIONS: Those individuals who achieve a long term remission from colorectal carcinoma may experience a relatively high quality of life, although deficits remain for several areas, particularly in those of low socioeconomic status. Sampling design may have excluded the most severely ill patients.

Activities of Daily Living↗
PubMed2000

Reported ovarian cancer screening among a population-based sample in Washington state.

OBJECTIVE: To assess the prevalence of reported ovarian cancer screening among a population-based sample of women from Washington state and identify factors that influence the decision to be screened. METHODS: A population-based sample of 6749 women aged 54-84 years, living in 40 predominately rural communities in Washington state, was surveyed about their utilization of ultrasonography and CA 125 for ovarian cancer screening. We also assessed relevant demographic, family history, psychosocial, and health behavior variables. RESULTS: After exclusions, data from 4938 respondents were available. Two percent (n = 96) reported having been screened. Multiple logistic regression identified ovarian cancer worry, contact with an obstetrician-gynecologist, and family history of ovarian cancer as independently associated with screening. Based on self-reported family histories, 27 women had pedigrees consistent with high risk of ovarian cancer, but none of those women reported having been screened. CONCLUSION: Ovarian cancer screening is rare. Women at high risk of it might not be getting recommended screening.

Aged↗
PubMed2000

The effectiveness of mammography promotion by volunteers in rural communities.

INTRODUCTION: The Community Trial of Mammography Promotion assessed the effectiveness of mammography promotion by community volunteer groups in rural areas. Three interventions were tested. One used an individual counseling strategy, one used a community activities strategy, and a third combined the two strategies. METHODS: The effects of the interventions were tested by randomizing 40 communities either to the study interventions or to a control group. A cohort of 352 women from each community was randomly selected and used to evaluate the interventions' effectiveness. Of these, 6592 women were eligible for screening mammography at baseline and follow-up and were successfully interviewed prior to and after study intervention activities. RESULTS: Although the interventions did not significantly increase women's overall use of mammography, the community activities intervention increased use at follow-up by regular users over baseline by 2.9% (p = 0.01). Intervention appears to have increased the use of mammography among certain groups of women who were not regular users at baseline, including those in communities without female physicians (10% to 16%; p < 0.05), and among women with no health insurance (10% to 23%; p </= 0.05). CONCLUSION: Volunteers can effectively promote mammography in rural communities.

Adult↗
PubMed2000

Simulation modeling of outcomes and cost effectiveness.

Modeling will continue to be used to address important issues in clinical practice and health policy issues that have not been adequately studied with high-quality clinical trials. The apparent ad hoc nature of models belies the methodologic rigor that is applied to create the best models in cancer prevention and care. Models have progressed from simple decision trees to extremely complex microsimulation analyses, yet all are built using a logical process based on objective evaluation of the path between intervention and outcome. The best modelers take great care to justify both the structure and content of the model and then test their assumptions using a comprehensive process of sensitivity analysis and model validation. Like clinical trials, models sometimes produce results that are later found to be invalid as other data become available. When weighing the value of models in health care decision making, it is reasonable to consider the alternatives. In the absence of data, clinical policy decisions are often based on the recommendations of expert opinion panels or on poorly defined notions of the standard of care or medical necessity. Because such decision making rarely entails the rigorous process of data collection, synthesis, and testing that is the core of well-conducted modeling, it is usually not possible for external audiences to examine the assumptions and data that were used to derive the decisions. One of the modeler's most challenging tasks is to make the structure and content of the model transparent to the intended audience. The purpose of this article is to clarify the process of modeling, so that readers of models are more knowledgeable about their uses, strengths, and limitations.

Computer Simulation↗
PubMed2000

Effect of variations in operational definitions on performance estimates for screening mammography.

RATIONALE AND OBJECTIVES: The Mammography Quality Standards Act requires practices to measure limited aspects of their performance. The authors conducted this study to calculate the differences in measurements of sensitivity and specificity due only to differences in the definitions used in the analysis. This included definitions for case inclusion. MATERIALS AND METHODS: Data from the New Mexico Mammography Project for January 1991 to December 1995 on 136,540 women who underwent screening mammography were analyzed. A starting definition was created for each performance measure. The components of the definition were varied, and estimates of sensitivity and specificity for the different definitions were calculated. RESULTS: Sensitivity was lower and specificity was higher when assessed on the basis of the results of all imaging performed in the screening work-up rather than on the initial screening examination alone. Sensitivity was higher and specificity was lower in women who did not undergo rather than in women who did recently undergo a previous examination. When the definition of a positive examination included cases that were recommended for short-term follow-up, the work-up sensitivity was slightly higher and the work-up specificity was considerably lower. Longer follow-up times for determining the diagnosis of cancer were associated with decreasing sensitivity, particularly when the follow-up period extended beyond 12 months. CONCLUSION: Variations in the operational definitions for measures of mammographic performance affect these estimates. To facilitate valid comparisons, reports need to be explicit regarding the definitions and methods used.

Adult↗
PubMed2000

Ovarian cancer tumor marker behavior in asymptomatic healthy women: implications for screening.

Ovarian cancer screening protocols generally have been limited by inadequate recognition of the normal behavior of tumor markers in women at risk of ovarian cancer. We have characterized the behavior of five serum tumor markers in a large cohort of healthy women and examined the implications for screening. Serial measurements of CA125, HER-2/neu, urinary gonadotropin peptide, lipid-associated sialic acid, and Dianon marker 70/K were obtained during 6 years of follow-up of 1257 healthy women at high risk of ovarian cancer. We analyzed individual-specific tumor marker behavior and explored methods that can exploit this information to develop individual-specific screening rules. These five tumor markers behaved approximately independently. Substantial heterogeneity was observed among women in the behavior of each tumor marker, particularly CA125. Intraclass correlation (ICC), or the proportion of total variability that occurs between individuals, was approximately 0.6 for log-transformed CA125 and urinary gonadotropin peptide, and less than 0.4 for the other markers. This degree of tumor marker heterogeneity among healthy women, and the relative independence of these markers, has important implications for screening and diagnostic tests. Independence of markers results in the clinically useful fact that the combined false positive rate from screening with multiple markers may be estimated by the sum of individual false positive rates. Heterogeneity of tumor marker patterns in healthy women implies that a fixed screening cutoff level is suboptimal to a degree that depends strongly on ICC. Using information on longitudinal measurements and ICC, individual-specific screening rules may be developed with the potential to improve early detection of ovarian cancer.

Adult↗
PubMed1999

Involvement in decision-making and breast cancer survivor quality of life.

Advances in treatment for breast cancer have improved women's chances of surviving this disease, while giving patients more treatment options than in the past. This study examined the influence of patient involvement in decision-making on survivor quality of life. A prevalence sample of breast cancer survivors were interviewed about their involvement in decision-making about their cancer treatment and follow-up care. A series of multivariate regression analyses were then conducted to examine how involvement in decision-making about cancer treatment and follow-up care contributed to survivor quality of life. Analyses revealed involvement in decision-making about the use of testing for recurrent disease (TFR) as part of follow-up care is associated with improved quality of life in several domains (p < 0.05). This association of improved quality of life with involvement in decision-making about follow-up TFR was independent of associations of quality of life with surgical treatment received, involvement in decision-making about surgical treatment, frequency of TFR, use of mammography, age, income, education, and years since diagnosis. This suggests that efforts to increase patient involvement in decision-making about follow-up care may improve quality of life for breast cancer survivors.

Aged↗
PubMed1999

Prostate-specific antigen for prostate cancer screening. Do physician characteristics affect its use?

PURPOSE: Screening for prostate cancer with the prostate-specific antigen (PSA) test remains controversial. This controversy is reflected in a lack of consensus in the medical literature and among professional and policy organizations regarding routine screening by PSA. It is not known how physicians respond when recommendations from experts are inconsistent. METHODS: A questionnaire was mailed to 1369 primary care physicians in active practice in Washington State in 1994. Response rate to the survey was 63%. Chi-square tests and multivariate logistic regression analysis were used to examine the effects of physician characteristics on physicians' self report of use of the PSA test for screening asymptomatic male patients, aged 50 to 80, for prostate cancer. RESULTS: Of the 714 physicians included in the analysis, 68% reported routine use of PSA. Use of PSA varied among physicians on the basis of practice setting, years since medical school graduation, and whether compensation was fee-for-service or salaried. Male physicians trained before 1974 and physicians receiving fee-for-service were significantly more likely than other physicians to recommend screening by PSA. CONCLUSIONS: Results suggest that physicians' personal characteristics such as year of medical school graduation, gender, and mode of reimbursement are related to self-reported PSA use.

Chi-Square Distribution↗