Biomedical subjects

J Sayre

Publications and source records attributed to J Sayre.

At least 37 records · Page 2Linked to original sources

PubMed1998

Predictors of aneurysmal occlusion in the period immediately after endovascular treatment with detachable coils: a multivariate analysis.

BACKGROUND AND PURPOSE: Complete intracranial aneurysmal occlusion by endovascular techniques is required for successful treatment and is presumably influenced by several parameters. The purpose of this study was to investigate whether operator experience and angiographic characteristics of intracranial aneurysms correspond to the degree of endovascular occlusion in the period immediately after treatment with Guglielmi detachable coils (GDCs). METHODS: Pre- and posttreatment angiograms of 72 patients undergoing GDC treatment were reviewed retrospectively. The following angiographic characteristics of the aneurysms were evaluated: largest diameter of the sac, volume, neck size, shape, type, cerebrovascular site, surroundings, and likely direction of aneurysmal inflow as judged by a score developed by measuring aneurysm/parent artery angulation. The chronological sequence in which the aneurysms were treated was used as a measure of operator experience. A chi2-test was used to identify parameters that correlated with outcomes of total (100%) or partial (<100%) occlusion. A multivariate analysis was used to determine the factors most predictive of aneurysmal occlusion at therapy. RESULTS: Parameters that correlated with the unsatisfactory result of partial occlusion were large aneurysmal diameter, volume, and neck size, more direct inflow (ie, increasingly obtuse aneurysm/parent artery angulation), and early chronological presentation in the series. The three factors most predictive of partial occlusion were large aneurysmal diameter, more direct inflow, and early chronological order of treatment. CONCLUSION: Several morphologic features of aneurysms were identified to help predict the immediate outcome of occlusion with GDCs. This study underscores the existence of a steep learning curve associated with GDC use in treating aneurysms and the importance of operator experience in achieving optimal therapeutic results.

Cerebral Angiography↗

PubMed1997

Vitamin D-receptor gene polymorphisms and bone density in prepubertal American girls of Mexican descent.

BACKGROUND: Bone mass is under strong genetic control, and recent studies in adults have suggested that allelic differences in the gene for the vitamin D receptor may account for inherited variability in bone mass. We studied the relations of the vitamin D-receptor genotype to skeletal development and variation in the size, volume, and density of bone in children. METHODS: We identified three allelic variants of the vitamin D-receptor gene using the polymerase chain reaction and three restriction enzymes (ApaI, BsmI, and TaqI) in 100 normal prepubertal American girls of Mexican descent. We then determined the relations of the different vitamin D-receptor genotypes (AA, Aa, aa, BB, Bb, bb, TT, Tt, and tt) to the cross-sectional area, cortical area, and cortical bone density of the femoral shaft and the cross-sectional area and density of the lumbar vertebrae. RESULTS: The vitamin D-receptor genotype was associated with femoral and vertebral bone density. Girls with aa and bb genotypes had 2 to 3 percent higher femoral bone density (P=0.008 and P=0.04, respectively) and 8 to 10 percent higher vertebral bone density (P=0.01 and P=0.03, respectively) than girls with AA and BB genotypes. There was no association between the cross-sectional area of the vertebrae or the cross-sectional or cortical area of the femur and the vitamin D-receptor genotype. The chronologic age, bone age, height, weight, body-surface area, and body-mass index did not differ significantly among girls with different vitamin D-receptor genotypes. CONCLUSIONS: Vitamin D-receptor gene alleles predict the density of femoral and vertebral bone in prepubertal American girls of Mexican descent.

Alleles↗

PubMed1997

Differential effect of gender on the sizes of the bones in the axial and appendicular skeletons.

Recent observations suggest that throughout life the size of the vertebral bodies in females is smaller than that in males even after accounting for differences in body size. To confirm these reports and to determine whether similar differences exist in the appendicular skeleton, detailed measurements of the sizes of the vertebrae and the femur were obtained using computed tomography in 30 pairs of prepubertal boys and girls matched for age, height, and weight. Anthropometric parameters as well as gender influenced the cross-sectional area of the vertebrae. Heavier children had greater vertebral cross-sectional area than slender children regardless of gender, and the vertebral bodies were found to be significantly smaller in girls than in matched boys (approximately 11%), both using Student's t test (P < 0.0001) and its multivariate analog, the Hotelling's T2 test (P < 0.0001). In contrast to these findings in the axial skeleton, gender status did not influence the size of the bones in the appendicular skeleton, and neither the cross-sectional area (3.28 +/- 0.84 vs. 3.10 +/- 0.56 cm2) nor the cortical bone area (1.80 +/- 0.37 vs. 1.85 +/- 0.36 cm2) at the midshaft of the femur differed between boys and girls. These values, however, correlated strongly with all anthropometric indexes, and multiple regression analyses indicated that both measurements were primarily related to weight. The results suggest that although increases in mechanical loading associated with growth are the main determinant of the cross-sectional properties of the appendicular skeleton in children, factors other than body mass and related to gender have a significant role in the regulation of the sizes of the bones in the axial skeleton.

Body Weight↗

PubMed1997

Chest teleradiology in a teaching hospital emergency practice.

OBJECTIVE: New standards for hospital accreditation and health care reimbursement may require that faculty subspecialists be more available after regular working hours to supervise residents in academic radiology departments. We designed a receiver operating characteristic study to determine whether a thoracic radiologist who evaluated computed radiography (CR) images of the chest at a home-based teleradiology workstation could add significant value to a junior resident's interpretations of films within the hospital for acutely ill patients. SUBJECTS AND METHODS: Using a hybrid cassette, we obtained analog chest films and CR images simultaneously for each of 252 acutely ill patients in the emergency department and in an intensive care unit. Interpretations of the analog films by three first-year residents were analyzed for 11 parameters deemed critical for patient management. Likewise, CR images of the same chest studies were viewed on a home teleradiology workstation by a faculty thoracic radiologist who analyzed the images for these 11 interpretive parameters. All interpretations by radiology residents and by the home-based thoracic radiologist were then compared with the interpretations of a consensus panel consisting of another thoracic radiologist and a full-time emergency department radiologist. RESULTS: Analysis of the pooled results from the three junior residents as a group failed to show significant differences between their interpretations of chest films and the interpretations of CR images by a thoracic radiologist at a home workstation. However, we observed significant differences for several image interpretation parameters between individual residents and the home-based radiology subspecialist. CONCLUSION: The data confirm that significant value can be added to the interpretations of chest films by individual junior residents when a home-based thoracic radiologist uses teleradiology to provide expert interpretations. Accordingly, it is reasonable to infer that on-line supervision by faculty subspecialists via teleradiology could be used to complement the scheduled visits that are being made now by individual faculty members of our institution to interpret films periodically with a radiology resident during overnight and weekend periods.

Emergency Service, Hospital↗

PubMed1997

Local staging of pancreatic cancer: criteria for unresectability of major vessels as revealed by pancreatic-phase, thin-section helical CT.

OBJECTIVE: This study was conducted to determine the criteria for unresectability of major peripancreatic vessels in patients with pancreatic carcinoma as revealed by optimally enhanced, pancreatic-phase thin-section helical CT. SUBJECTS AND METHODS: Twenty-five patients with pancreatic adenocarcinoma who underwent local dissection during curative or palliative surgery also underwent preoperative pancreatic-phase thin-section helical CT (40- to 70-sec delay, 2.5- to 3-mm collimation). Tumor involvement of the portal and superior mesenteric veins and the celiac, hepatic, and superior mesenteric arteries was prospectively graded on a 0-4 scale based on circumferential contiguity of tumor to vessel. Subsequent surgical results were then correlated with the CT grades. RESULTS: At surgery, definitive evaluation was possible for 80 vessels. Forty-eight of 48 vessels graded 0 and three of three vessels graded 1 were resectable. Four of seven vessels graded 2, seven of eight vessels graded 3, and 14 of 14 vessels graded 4 were unresectable. A threshold of between grades 2 and 3, which corresponded to tumor involvement of one-half circumference of the vessel, yielded the lowest number of false-negatives and an acceptable number of false-positives for unresectability. Such a threshold would have yielded a sensitivity of 84%, a specificity of 98%, a positive predictive value of 95%, and a negative predictive value of 93% for unresectability of the vessels studied. CONCLUSION: A grading system for tumor involvement of the major vessels in patients with pancreatic adenocarcinoma can be based on the degree of circumferential contiguity of tumor to vessel. Involvement of vessel to tumor that exceeds one-half circumference of the vessel is highly specific for unresectable tumor.

Adenocarcinoma↗

PubMed1997

Transcranial color Doppler imaging of brain arteriovenous malformations in adults.

This study was performed to investigate the utility of transcranial color Doppler sonography in evaluating adult cerebral arteriovenous malformations. Twelve patients with such malformations underwent sonography. Spectral Doppler sonographic assessment included peak systolic velocity, end diastolic velocity, and resistive index within the intracranial and extracranial vessels. Color Doppler sonography was used to visualize the site of shunting. Paired and unpaired Student's t-tests were used to determine significance of spectral findings. The nidus was seen in eight of 10 pial malformations. The nidi in two patients were located in the parietal region and not visualized. When compared with the corresponding contralateral artery, feeding arteries (identified in all 10 of the pial lesions) demonstrated diminished resistive indices (P = 0.09). Similarly, the end diastolic velocity was increased in all feeding arteries (P = 0.03). When compared with published normal values, the peak systolic and end diastolic velocities were significantly elevated and the resistive indices were low (P < 0.0003). Transcranial color Doppler sonography depicted the nidi of pial arteriovenous malformations in 80% of cases. Feeding arteries demonstrated abnormal peak systolic velocity, end diastolic velocity, and resistive index in all cases when compared with published values. Transcranial color Doppler sonography is not a good screening tool due to limited acoustical window, but it may be useful for noninvasive study of the physiology of arteriovenous malformations as they are treated.

Adult↗

PubMed1996

Validation of volume flow measurements in blood vessels with quantitative color velocity imaging using a physiologic model of the circulation.

RATIONALE AND OBJECTIVES: Color velocity imaging-quantitative (CVI-Q) is a new sonographic technique designed to measure volume flow (VF) in blood vessels. We attempted to validate VF measurements with CVI-Q in an in vitro model of the circulation. METHODS: We validated CVI-Q in a flow phantom mimicking physiologic conditions by connecting isolated porcine arteries 4-14 mm in diameter to a calibrated perfusion roller pump generating pulsatile flow with porcine blood. Pump flow was varied stepwise from 0 to 1,000 ml/min. CVI-Q VF measurements were performed using a 7.5-MHz linear array transducer. VF results then were compared with pump flow calibration values through linear regression. RESULTS: A good correlation (r2 = .98-.99, slope = 0.88-1.02) was obtained from 0 to 400-600 ml/min. The degree of correlation depended on vessel diameter, with linearity being maintained over a somewhat larger range in medium-sized vessels. At higher flows, variability increased significantly. CONCLUSION: VF measurements with CVI-Q are accurate in a physiologic flow range. At supraphysiologic flow rates, as are encountered within arteriovenous fistulae, CVI-Q may give inaccurate results. Awareness of possible pitfalls and limitations of the technique is important for obtaining accurate and reproducible results.

Animals↗

PubMed1996

Mammography fixed grid versus reciprocating grid: evaluation using cadaveric breasts as test objects.

In this study we use unfixed cadaveric breasts to obtain mammography images with fixed and reciprocating grids. Sheets of acrylic, containing one or more clusters of simulated calcifications and masses, were superimposed on two fresh cadaveric breasts (3.4 and 6.5 cm thick), and were imaged with a fixed grid and a reciprocating grid. Six radiologists, working independently, attempted to identify the number of clusters and/or masses in 114 images containing 139 clusters of simulated calcifications and 42 simulated masses. Thirty-four of these images were normal, containing no lesions. For the thinner breast, no statistically significant difference was found in the detection of clusters of calcifications in the images produced with the fixed grid compared to those produced with the reciprocating grid. However, for the detection of calcifications in images of the thicker breast, sensitivity of 74% for detection of calcifications when a fixed grid was used was significantly less than sensitivity of 86% when a reciprocating grid was used (P = 0.006). The mass detection sensitivity was 91% for images made with a fixed grid compared to 96% for images made with a reciprocating grid, but the difference was not statistically significant (P = 0.346). The use of cadaveric breasts as test objects was well accepted by radiologists. Only for the thick cadaveric breast were differences between the two grids significant, and these differences were restricted to the task of finding calcifications.

Biophysical Phenomena↗

PubMed1995

Dietary intake and counseling, weight maintenance, and the course of HIV infection.

OBJECTIVE: To define relationships among dietary intake and counseling, weight maintenance, and the clinical course of patients infected with the human immunodeficiency virus (HIV). DESIGN: A prospective cohort study in an HIV clinic in a county hospital. SUBJECTS: HIV-infected patients (68 with and 40 without acquired immunodeficiency syndrome [AIDS]) who had a good performance status and no chronic diarrhea were assessed at entry to the study and after 6 months. The following assessments were made: energy and nutrient intake based on 7-day food records, anthropometric measurements, immunologic function as lymphocyte T-cell subpopulations (ratio of CD4 to CD8), and serum cholesterol level. Patients were monitored to determine clinical outcome. INTERVENTION: All patients received standardized dietary counseling designed to address identified intake deficiencies and maintain body weight. MAIN OUTCOME MEASURES: Changes in energy and nutrient intake, body weight, and clinical outcome (ie, time to AIDS-defining illness and overall survival time). STATISTICAL ANALYSES PERFORMED: Group differences (HIV group vs AIDS group) were sought using chi 2 analyses and Student's t test. A multivariate regression model was used to determined the best predictors of clinical outcome. RESULTS: At baseline, total energy intake (based on 30 kcal/kg usual body weight) was adequate in both HIV and AIDS patients (101 +/- 4% and 103 +/- 5% [mean +/- standard deviation] of need, respectively). Despite dietary counseling and continued maintenance of energy intake, body weight, serum cholesterol level, and CD4 level progressively decreased. Consequently, saturated fat intake was found to be inversely related (P < .01) to serum cholesterol level. Clinical outcome (after 3.5 years) was associated with baseline ratio of CD4 to CD8 (P < .001), weight (P < .01), and serum cholesterol level (P < .001). Multivariate analysis related ratio of CD4 to CD8 (P < .001) and weight maintenance (P < .001) to favorable outcome in the final model. APPLICATIONS: Weight loss in patients with HIV infection is independently prognostic of clinical outcome, and development of hypocholesterolemia is not favorable for clinical outcome. Because weight loss progresses despite conventional dietary counseling to identify energy need, interventions earlier in the disease course should be considered along with increased target levels for energy intake.

Adult↗

PubMed1995

Communication of mammography results to women by radiologists: attitudes of referring health care providers.

PURPOSE: To understand the attitudes of referring physicians about the communication of mammography results directly to women by radiologists. MATERIALS AND METHODS: Questionnaires were mailed to 87 health care providers (85 physicians and two nurse practitioners) who regularly refer women to the authors' mammographic facility. Responses were answered by assigning a score of 1-5 (strongly agree to strongly disagree). RESULTS: Seventy-one (82%) referring providers responded to the survey. For normal results, 85% agreed that radiologists should report directly to women; for abnormal results, 58% agreed. For a radiologist to send a written report directly to women, 75% agreed for normal results and 73% for abnormal results. For follow-up reminders, 67% agreed the radiologist should do it, 25% agreed both the radiologist and referring physician should be both responsible, and 8% agreed the referring physician should do it. CONCLUSION: Referring physicians were receptive to the direct communication of mammography results to women by radiologists. Use of this type of survey is recommended for radiologists planning to change their communication protocols.

Attitude of Health Personnel↗

PubMed1995

Vertebral size in elderly women with osteoporosis. Mechanical implications and relationship to fractures.

Reductions in bone density are a major determinant of vertebral fractures in the elderly population. However, women have a greater incidence of fractures than men, although their spinal bone densities are comparable. Recent observations indicate that women have 20-25% smaller vertebrae than men after accounting for differences in body size. To assess whether elderly women with vertebral fractures have smaller vertebrae than women who do not experience fractures, we reviewed 1,061 computed tomography bone density studies and gathered 32-matched pairs of elderly women, with reduced bone density, whose main difference was absence or presence of vertebral fractures. Detailed measurements of the dimensions of unfractured vertebrae and the moment arm of spinal musculature from T12 to L4 were calculated from computed tomography images in the 32 pairs of women matched for race, age, height, weight, and bone density. The cross-sectional area of unfractured vertebrae was 4.9-11.5% (10.5 +/- 1.4 vs 9.7 +/- 1.5 cm2; P < 0.0001) smaller and the moment arm of spinal musculature was 3.2-7.4% (56.4 +/- 5.1 vs 53.1 +/- 4.4 mm; P < 0.0001) shorter in women with fractures, implying that mechanical stress within intact vertebral bodies for equivalent loads is 5-17% greater in women with fractures compared to women without fractures. Such significant variations are very likely to contribute to vertebral fractures in osteoporotic women.

Aged↗

PubMed1995

Comparison of hard- and soft-copy digital chest images with different matrix sizes for managing coronary care unit patients.

OBJECTIVE: This study was to determine whether different digital display formats for portable chest radiographs of coronary care unit patients would provide comparable information for clinical care. In particular, we tried to ascertain whether 1024 x 1024 pixel (1K) images on a picture archiving and communication system (PACS) workstation would be comparable to 1760 x 2140 pixel (2K) images on workstations or to digital films. If comparability could be proved, we hypothesized that 1K workstations could considerably lower equipment and film costs and facilitate image transmission from point to point. MATERIALS AND METHODS: Four chest radiologists read a panel of chest studies assembled from 98 coronary care unit patients, comparing 1K and 2K soft-copy images with digital hard copies. For all three image types for the 98 patients, the readers evaluated nine image parameters that the cardiologists deemed essential for clinical decision making. Two other chest radiologists reviewed each patient's three image types, historical chest images, current and prior radiologic reports, and medical record to determine the consensus, or "truth findings." RESULTS: With one exception (small pleural effusions), the receiver operating characteristic analysis showed no significant differences in the clinical information derived from the three image types. CONCLUSION: For clinical management in a coronary care unit, comparable information can be obtained from digital radiologic chest studies using a 1K x 1K soft-copy format, a 2K x 2K soft-copy format, or a hard copy (film). Substantial savings in cost and time are therefore possible by using soft-copy images and lower resolution (1K x 1K) workstations and, when necessary, by transmitting images on regular telephone lines.

Coronary Care Units↗

PubMed1994

Late mortality and levamisole adjuvant therapy in colorectal cancer.

Beginning in 1975, 78 patients with resected stage B and C colorectal carcinoma were randomly assigned (2:1) to receive either levamisole 2.5 mg kg-1 day-1 given for 2 days every week for 18 months or placebo therapy in the same schedule. Pretreatment characteristics (age, gender, disease site, CEA and stage) and the pattern of follow-up were similar in both groups. For the first 5 years following randomisation, relapse-free survival and overall survival were similar in the two treatment groups. Subsequently, excess late mortality was associated with levamisole group assignment. Consequently, overall survival was somewhat greater in the placebo group than in the levamisole group, 68% vs 38% (P < 0.08). For patients surviving 5 years from randomisation, subsequent survival favoured placebo over levamisole (100% vs 57%; P < 0.03). The absolute numbers of deaths were 27 in the levamisole group (19 definitely cancer related) and seven in the group placebo (five definitely cancer related). This long-term result seen with a more intensive adjuvant levamisole dose and schedule suggests: (1) other levamisole adjuvant trials in patients with colorectal cancer should be examined for long-term outcome; (2) future trials utilising the even higher levamisole dosage required for clinical immunomodulation should proceed cautiously.

Aged↗

PubMed1994

Evaluation of myocardial motion tracking with cine-phase contrast magnetic resonance imaging.

RATIONALE AND OBJECTIVES: The accuracy of myocardial motion measurements, computed from cine-phase contrast (cine-PC) magnetic resonance (MR) velocity data, was compared with directly visualized motion of MR signal voids caused by implanted tantalum markers in anesthetized dogs. METHODS: Magnetic resonance imaging (MRI) data were electrocardiogram-gated and divided into 16 phases per cardiac cycle. Myocardial trajectories as a function of time in the cardiac cycle were measured using both methods for four to seven markers in each of eight animals. RESULTS: The peak observed in-plane excursion was 4.0 +/- 2.1 mm. The average deviation between displacements derived from velocity data versus displacements visualized directly was 1.1 +/- 0.7 mm (27.5% of the peak displacement). The difference was less if three separate MR scans were used to measure each velocity component in the cine-PC method. This improvement is probably caused by improved temporal resolution. CONCLUSIONS: Cine-PC MRI offers a noninvasive method for accurate quantification of myocardial motion.

Animals↗

PubMed1994

Women's attitudes about receiving mammographic results directly from radiologists.

PURPOSE: To learn what women think about the communication of mammographic results directly to them by radiologists. MATERIALS AND METHODS: Three hundred seven women completed a survey at the time of mammographic examination. The women were asked to indicate the strength of their agreement with seven statements about the communication of mammographic results directly to them by the radiologist. RESULTS: The majority agreed that the radiologist should give them normal (286 women [93%]) or abnormal (277 women [90%]) results directly on site. They also agreed that the radiologist should send a report written in lay language of normal (268 women [87%]) or abnormal (280 women [91%]) results directly to them and that the radiologist should inform them of recommendations for short-term follow-up examinations (93%) and monitor their compliance (88%). CONCLUSION: Because these results reflect findings for only these patients, the authors suggest that additional investigation be performed to determine what women in diverse socioeconomic backgrounds and geographic locations think about these issues.

Breast Neoplasms↗

PubMed1994

The UCLA population studies of chronic obstructive respiratory disease: XI. Impact of air pollution and smoking on annual change in forced expiratory volume in one second.

We assessed the relative impact of residential exposure to community air pollution and habitual cigarette smoking on lung function by comparing the annualized rate of change in forced expiratory volume in 1 s (FEV1) in current, former, and never-smokers 25 to 59 yr of age residing in three demographically similar areas of the Southern California air basin who had been chronically exposed to (1) moderate levels of photochemical oxidants and very low levels of other pollutants (Lancaster); (2) very high levels of photochemical oxidants, sulfates, and particulate matter (Glendora); and (3) high levels of sulfates, oxides of nitrogen, and probably hydrocarbons (Long Beach), together with moderate levels of sulfur dioxide. Of the 621 to 763 nonsmokers, 317 to 479 former smokers and 472 to 691 continuing smokers residing in the three areas who were studied initially, 53 to 64, 49 to 59, and 43 to 54%, respectively, were retested. For male residents, area of residence and smoking category each had highly significant effects on FEV1 decline (two-way ANCOVA; p < 0.001) without significant interaction (p > 0.4). After adjustment for baseline FEV1, age, height, and a history of allergy, the mean decline in FEV1 attributable to living in Long Beach compared with living in Lancaster was 23.6 ml/yr, which was 71% of the rate of decline in FEV1 (33.3 ml/yr), attributable to smoking > 1 pack of cigarettes per day. For female residents, a significant interaction was noted between area and smoking (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Age-related changes in cortical and cancellous vertebral bone density in girls: assessment with quantitative CT.

OBJECTIVE: Bone mass increases during growth, but little information is available about the changes in cortical and cancellous bone densities during skeletal development or their relative contributions to age-related increases in bone mass. Accordingly, separate measurements of cancellous and cortical bone density were done at each stage of sexual development in white girls during childhood and adolescence. SUBJECTS AND METHODS: Quantitative CT was used to measure the densities of cortical and cancellous bone of the lumbar spine in 96 healthy white girls 4-20 years old. The relationships among various anthropometric indexes, pubertal status, and corresponding densities of cortical and cancellous bone were then examined. RESULTS: Cortical bone density increased with age, and values were significantly correlated with the anthropometric indexes of height (r = .61), weight (r = .62), body mass index (r = .61), and muscle volume (r = .58). In contrast, cancellous vertebral bone density increased only during the later stages of puberty. Moreover, cancellous bone density in prepubertal girls was inversely related to age (r = -.27) as well as to both the volume (r = -.20) and the height (r = -.15) of the vertebral body. CONCLUSION: The results suggest that weight bearing and/or mechanical stresses are important determinants of cortical bone density in the lumbar spine throughout growth, whereas cancellous vertebral bone density is more strongly influenced by hormonal and/or metabolic factors associated with sexual development during late adolescence.

Adolescent↗

PubMed1992

Current attitudes and practice of American Society of Clinical Oncology-member clinical oncologists regarding cancer prevention and control.

PURPOSE AND METHODS: A nationwide needs assessment survey including a validated Cancer Prevention and Early Detection Attitude Inventory of 1,500 randomly selected American Society of Clinical Oncology (ASCO)-member clinical oncologists was conducted via a 67-item, mailed questionnaire to assess practice and attitudes regarding cancer prevention and control. RESULTS: Responses of 729 physicians from 48 states representing medical (57%), radiation (17%), surgical (16%), and pediatric oncology (6%), and hematology/other (4%) fields were obtained. Except for ambivalence regarding an important role for diet in cancer causation, cancer prevention and control recommendations were widely endorsed despite skepticism about their impact on reducing deaths from cancer. Surprisingly, a significantly (P less than .001) more favorable attitude for cancer prevention and control issues was found in physicians with greater than 20 years practice compared with younger oncology colleagues, as measured by a 22-item Cancer Prevention and Early Detection Attitude Inventory. Among all physicians, participation in cancer therapy trials exceeded that in cancer prevention and control trials (91% v 27%, P less than .01). Formal instruction during postgraduate training in cancer screening (34%) or prevention (23%) was received by few oncologists; nonetheless, 69% considered themselves a resource for cancer prevention and control issues in their practice communities. Of potential barriers to cancer prevention and control activity, only lack of patients without cancer (53%) and difficulty in including such activity economically into clinical practice (65%) were majority selections. Importantly, 64% agreed they could "motivate their patients to change lifestyle to reduce cancer risk." CONCLUSION: Clinical oncologists may represent a potential resource for implementation of cancer prevention and control objectives if economically feasible models for their use in practice settings can be identified.

Adult↗