Biomedical subjects

Andrew N Freedman

Publications and source records attributed to Andrew N Freedman.

9 recordsLinked to original sources

PubMed2005

Cancer risk prediction models: a workshop on development, evaluation, and application.

Cancer researchers, clinicians, and the public are increasingly interested in statistical models designed to predict the occurrence of cancer. As the number and sophistication of cancer risk prediction models have grown, so too has interest in ensuring that they are appropriately applied, correctly developed, and rigorously evaluated. On May 20-21, 2004, the National Cancer Institute sponsored a workshop in which experts identified strengths and limitations of cancer and genetic susceptibility prediction models that were currently in use and under development and explored methodologic issues related to their development, evaluation, and validation. Participants also identified research priorities and resources in the areas of 1) revising existing breast cancer risk assessment models and developing new models, 2) encouraging the development of new risk models, 3) obtaining data to develop more accurate risk models, 4) supporting validation mechanisms and resources, 5) strengthening model development efforts and encouraging coordination, and 6) promoting effective cancer risk communication and decision-making.

Breast Neoplasms↗

PubMed2005

Physician exposure to and attitudes toward advertisements for genetic tests for inherited cancer susceptibility.

Commercial marketing materials may serve as a source of information for physicians about genetic testing for inherited cancer susceptibility (GTICS) in addition to medical guidelines, continuing education, and journal articles. The primary purposes of this study were to: (1) determine the percentage of physicians who received advertisements for GTICS early in the diffusion of commercial GTICS (1999-2000); (2) assess associated characteristics; and (3) measure the perceived importance of commercial advertisements and promotions in physicians' decisions to recommend testing to patients. A nationally representative, stratified random sample of 1,251 physicians from the American Medical Association (AMA) Physician Masterfile completed a 15-20 min mixed mode questionnaire that assessed specialty, previous use of genetic tests, practice characteristics, age, and receipt of advertising materials (response rate = 71%). Overall, 27.4% (n = 426) had received advertisements. In multivariate analysis, factors associated with receipt of advertisements included: specialties in obstetrics/gynecology, oncology, or gastroenterology; past GTICS use, and age 50+. One of four felt that advertisements would be important in their decision to recommend GTICS. Study results indicate that physicians, particularly in oncology, obstetrics/gynecology, and gastroenterology, began receiving GTICS advertisements commensurate with the early diffusion of commercially available tests into clinical practice. At that time, one-quarter of the physicians considered advertisements to play an important role in their clinical decision making, suggesting attention to other sources of information and additional factors.

Advertising↗

PubMed2005

Prognostic implications of molecular and immunohistochemical profiles of the Rb and p53 cell cycle regulatory pathways in primary non-small cell lung carcinoma.

PURPOSE: Many studies have highlighted the aberrant expression and prognostic significance of individual proteins in either the Rb (particularly cyclin D1, p16INK4A, and pRb) or the p53 (p53 and p21Waf1) pathways in non-small cell lung cancer. We hypothesize that cumulative abnormalities within each and between these pathways would have significant prognostic potential regarding survival. EXPERIMENTAL DESIGN: Our study population consisted of 106 consecutive surgically resected cases of predominantly early-stage non-small cell lung cancer from the National Cancer Institute-Mayo Clinic series, and assessment of proteins involved both immunohistochemical (cyclin D1, p21Waf1, pRb, p16INK4A, and p53) and mutational analysis (p53) in relationship to staging and survival. RESULTS: Cyclin D1 overexpression was noted in 48% of the tumors, p16INK4A negative in 53%, pRb negative in 17%, p53 immunopositive in 50%, p53 mutation frequency in 48%, and p21(Waf1) overexpression in 47%, none with prognostic significance. Cyclin D1 overexpression in pRb-negative tumors revealed a significantly worse prognosis with a mean survival of 2.3 years (P = 0.004). A simultaneous p53 mutation dramatically reduced the mean survival time to 0.9 years (P = 0.007). Cyclin D1 overexpression with either a p53 mutation or a p53 overexpression was also associated with a significantly poorer prognosis (P = 0.0033 and 0.0063, respectively). CONCLUSIONS: Some cumulative abnormalities in the Rb and p53 pathways (e.g., cyclin D1 overexpression and p53 mutations) significantly cooperate to predict a poor prognosis; however, the complexity of the cell cycle protein interaction in any given tumor warrants caution in interpreting survival results when specific protein abnormalities are taken in isolation.

Aged↗

PubMed2004

Revised Bethesda Guidelines for hereditary nonpolyposis colorectal cancer (Lynch syndrome) and microsatellite instability.

Hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome, is a common autosomal dominant syndrome characterized by early age at onset, neoplastic lesions, and microsatellite instability (MSI). Because cancers with MSI account for approximately 15% of all colorectal cancers and because of the need for a better understanding of the clinical and histologic manifestations of HNPCC, the National Cancer Institute hosted an international workshop on HNPCC in 1996, which led to the development of the Bethesda Guidelines for the identification of individuals with HNPCC who should be tested for MSI. To consider revision and improvement of the Bethesda Guidelines, another HNPCC workshop was held at the National Cancer Institute in Bethesda, MD, in 2002. In this commentary, we summarize the Workshop presentations on HNPCC and MSI testing; present the issues relating to the performance, sensitivity, and specificity of the Bethesda Guidelines; outline the revised Bethesda Guidelines for identifying individuals at risk for HNPCC; and recommend criteria for MSI testing.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Prevalence and correlates of repeat mammography among women aged 55-79 in the Year 2000 National Health Interview Survey.

BACKGROUND: Utilization of mammography has increased steadily since the early 1990s. It is now important to expand the attention given to obtaining repeat examination. This study examines the prevalence and cross-sectional correlates of repeat mammography, among women aged 55-79, using a 12-month (N = 3,502) and a 24-month interval (N = 3,491). METHODS: Data were from the Year 2000 Cancer Control Module of the National Health Interview Survey (NHIS-CCM). The NHIS-CCM asked about the most recent mammogram and the total number of mammograms over the prior 6 years. An algorithm estimated repeat mammography for the two intervals. RESULTS: Prevalence estimates were 49% for the 12-month interval, and 64.1% for the 24-month interval. Correlates of lower likelihood of repeat mammography for both indicators were: no regular source of care, having public or no health insurance, less than a college education, household income less than $45K, not being married, current or never smoking, age 65-79, and lower absolute risk of breast cancer (Gail Model score). CONCLUSIONS: A substantial percentage of women do not receive repeat mammography. The correlates of repeat mammography were similar to those often found for ever-had and recent mammography. There is probably some imprecision in the prevalence estimates due to the nature of NHIS-CCM questions. Issues pertinent to the definition of repeat examination are addressed.

Aged↗

PubMed2004

What factors are associated with diagnostic follow-up after abnormal mammograms? Findings from a U.S. National Survey.

The purpose of this study was to identify factors associated with diagnostic follow-up after an abnormal mammogram in a national sample of women in the U.S. The sample was selected from the year 2000 National Health Interview Survey and included 1901 women aged 30 and above who reported ever having an abnormal mammogram. The outcome measure was receipt of at least some diagnostic follow-up after an abnormal mammogram. Bivariate and multivariate logistic regression analyses were used to explore the associations between sociodemographic characteristics, general health and health behaviors, cancer risk and risk perceptions, and health care utilization characteristics and follow-up. Approximately 9% of women who reported ever having abnormal mammograms reported not completing any additional diagnostic follow-up. Controlling for all other factors, women with less than a high school education were less likely to report follow-up after an abnormal mammogram than were women who had at least completed college (odds ratio = 0.56; 95% confidence interval: 0.32, 0.98). Younger women and women in poorer health were also less likely to report follow-up. Women who perceived a high versus low level of cancer in their family were more likely to report follow-up (odds ratio = 1.65; 95% confidence interval: 1.04, 2.62), controlling for all other factors. In a national sample of women with abnormal mammograms, a substantial number did not complete any diagnostic follow-up, potentially reducing the effectiveness of mammography screening programs in the U.S. Additional research on subsequent screening behaviors for women with incomplete follow-up and in-depth exploration of the roles of patient-provider interactions and health care system factors related to the index abnormal mammogram is warranted.

Adult↗

PubMed2003

Estimates of the number of US women who could benefit from tamoxifen for breast cancer chemoprevention.

BACKGROUND: The Breast Cancer Prevention Trial demonstrated that tamoxifen treatment produced a 49% reduction in the risk of invasive breast cancer among women at elevated risk for the disease. The U.S. Food and Drug Administration (FDA) subsequently approved tamoxifen for women aged 35 years or older with a 5-year breast cancer risk of 1.67% or higher for breast cancer chemoprevention. However, tamoxifen use has been associated with adverse outcomes, and not all eligible women have a positive benefit/risk ratio. METHODS: We used weighted data from the year 2000 National Health Interview Survey Cancer Control Module to estimate the total number of U.S. women, aged 35-79 years, who were eligible for tamoxifen chemoprevention based on the FDA eligibility criteria. We also estimated the numbers of white and black women who would benefit from tamoxifen chemoprevention on the basis of a positive benefit/risk index developed by Gail et al. RESULTS: Of the 65,826,074 women aged 35-79 years without reported breast cancer in the United States in 2000, 10,232 816 women (15.5%, 95% confidence interval [CI] = 14.7% to 16.3%) would be eligible for tamoxifen chemoprevention. The percentage of U.S. women who would be eligible varied dramatically by race, with 18.7% (95% CI = 17.8% to 19.7%) of white women, 5.7% (95% CI = 4.3% to 7.5%) of black women, and 2.9% (95% CI = 2.1% to 3.9%) of Hispanic women being eligible. Of the 50,104,829 white U.S. women aged 35-79 years, 2,431,911 (4.9%, 95% CI = 4.3% to 5.4%) would have a positive benefit/risk index for tamoxifen chemoprevention. Of the 7,481,779 black U.S. women aged 35-79 years, only 42,768 (0.6%, 95% CI = 0.2% to 1.3%) would have a positive benefit/risk index. Among white women, 28,492 (95% CI = 24,693 to 32,292) breast cancers would be prevented or deferred if those women who have a positive net benefit index took tamoxifen over the next 5 years. CONCLUSION: A substantial percentage of U.S. women would be eligible for tamoxifen chemoprevention according to FDA criteria, but a much smaller percentage would have an estimated net benefit. Nevertheless, this latter percentage corresponds to more than two million women.

Adult↗

PubMed2003

Awareness of genetic testing for increased cancer risk in the year 2000 National Health Interview Survey.

OBJECTIVES: This study explores factors associated with differential awareness of genetic tests for increased cancer risk in the US. METHODS: 27,405 respondents from the 2000 National Health Interview Survey, ages 25+, were asked if they had heard of these tests. RESULTS: 44.4% said 'yes', including 49.9% of whites, 32.9% of African-Americans, 32.3% of American Indians/Alaskan Natives, 28.0% of Asian/Pacific Islanders, and 20.6% of Hispanics. In multivariate analysis, test awareness was significantly associated with higher education, white race, age <60 years, female gender, private health insurance, personal or parent's history of certain cancers, physical activity, and vitamin/supplement use, among other factors. CONCLUSIONS: The survey showed which population subgroups may lack access to cancer genetics information and may therefore benefit from targeted strategies to ensure risk-appropriate utilization of genetic counseling and testing.

Adult↗

PubMed2003

Physician use of genetic testing for cancer susceptibility: results of a national survey.

Genetic testing for inherited germ-line mutations associated with cancer susceptibility is an emerging technology in medical practice. Limited information is currently available about physician use of cancer susceptibility tests (CSTs). In 1999-2000, a nationally representative survey was conducted to estimate prevalence of CST use by United States physicians and assess demographic, training, practice setting, and practice patterns associated with use. A stratified random sample of clinicians in eight specialties was selected from a file of all licensed physicians. In total, 1251 physicians, including 820 in primary care and 431 in tertiary care, responded to a 15-min questionnaire by mail, telephone, fax, or Internet (response rate = 71.0%). In the previous 12 months, 31.2% [95% confidence interval (CI), 28.5-33.9] overall, including 30.6% (95% CI, 27.5-33.7) in primary care and 33.4% (95% CI, 27.9-38.9) in tertiary care, had ordered CSTs or referred patients elsewhere for risk assessment or testing. More physicians referred patients elsewhere [26.7% (95% CI, 24.2-29.2)] than directly ordered tests [7.9% (95% CI, 6.3-9.5)]. Factors associated with ordering or referring included practice location in the Northeast [odds ratio (OR), 2.30; 95% CI, 1.46-3.63%], feeling qualified to recommend CSTs (OR, 1.96; 95% CI = 1.41-2.72), receiving CST advertising materials (OR, 1.97; 95% CI, 1.40-2.78%), and most notably, having patients who asked whether they can or should get tested (OR, 5.52; 95% CI, 3.97-7.67%). Lower CST use was associated with not knowing if there were local testing and counseling facilities (OR, 0.39; 95% CI, 0.23-0.66%). These findings underscore the importance of establishing effective clinical approaches to test use and promoting physician education to facilitate communication with patients about cancer genetics.

Adult↗