Biomedical subjects

K R Abrams

Publications and source records attributed to K R Abrams.

At least 37 records · Page 2Linked to original sources

PubMed2002

Determination of gestational age after the 24th week of gestation from fetal kidney length measurements.

OBJECTIVE: To evaluate the application of kidney length measurement to the determination of gestational age between the 24th and 38th weeks and to compare its accuracy with that of other fetal biometric indices. STUDY DESIGN: Seventy-three women with singleton uncomplicated pregnancies underwent standard ultrasound fetal biometry and kidney length measurement every 2 weeks between 24 and 38 weeks' gestation. These measurements were used to date the pregnancies relative to crown-rump length dating between 8 and 10 weeks' gestation. Linear regression models for estimation of gestational age were derived from the biometric indices and kidney length. In addition, stepwise regression models were constructed to determine the best model for determining gestational age between 24 and 38 weeks. Comparisons were then made between the accuracy of these models in the determination of gestational age. RESULTS: The best model for estimating gestational age in late pregnancy included the variables kidney length, biparietal diameter, head circumference, femur length and abdominal circumference. This model accurately predicted gestational age with a standard error of +/- 8.48 days. A model including kidney length, biparietal diameter, head circumference and femur length accurately predicted gestational age with a standard error of +/- 8.57 days. These models were slightly more accurate than models derived from the biometric indices of biparietal diameter, head circumference and femur length (+/- 9.87 days), biparietal diameter, head circumference, femur length and abdominal circumference (+/- 9.45 days) and biparietal diameter and femur length (+/- 9.9 days). Kidney length and femur length were the most accurate single parameters for predicting gestational age using simple linear regression models (+/- 10.29 and 10.96 days, respectively); the abdominal circumference was the least accurate (+/- 14.54 days). CONCLUSION: Kidney length is a more accurate method of determining gestational age than the fetal biometric indices of biparietal diameter, head circumference, femur length and abdominal circumference between 24 and 38 weeks' gestation. When combined with biparietal diameter, head circumference and femur length, the precision of dating is improved by 2 days. This measurement is easy to make and could therefore be easily incorporated into the model for dating pregnancies after 24 weeks of gestation, in particular when measurements of the biparietal diameter and head circumference are difficult.

Crown-Rump Length↗

PubMed2002

Simultaneous analysis of quality of life and survival data.

In many phase III clinical trials, particularly in the field of cancer, the comparison of treatments is based on both length of survival and quality of life. Subjects are followed over time until death and during this period, quality of life is assessed on a number of occasions. Simultaneous analysis of these two outcomes supplements the comparison of treatments in terms of each outcome independently with an assessment of the net effect. In addition, it provides a means of accounting for the informative dropout due to death of patients within the time frame of the quality of life study. The methods also have the potential to be extended to allow for informative dropout from the quality of life study prior to death. There are a number of broad approaches for the simultaneous analysis of quality of life and survival data. The most widely used approach in clinical research is quality-adjusted survival analysis, where treatments are compared in terms of a composite measure of quality and quantity of life. The paper reviews the different techniques for quality-adjusted survival analysis, illustrating the methodology by application to data from a phase III clinical trial in pancreatic cancer. In addition, alternative approaches using multistate survival analysis and joint modelling methods are also discussed.

Clinical Trials, Phase III as Topic↗

PubMed2002

Decision analytical economic modelling within a Bayesian framework: application to prophylactic antibiotics use for caesarean section.

Economic evaluation of health care interventions based on decision analytic modelling can generate valuable information for health policy decision makers. However, the usefulness of the results obtained depends on the quality of the data input into the model; that is, the accuracy of the estimates for the costs, effectiveness, and transition probabilities between the different health states of the model. The aim of this paper is to review the use of Bayesian decision models in economic evaluation and to demonstrate how the individual components required for decision analytical modelling (i.e., systematic review incorporating meta-analyses, estimation of transition probabilities, evaluation of the model, and sensitivity analysis) may be addressed simultaneously in one coherent Bayesian model evaluated using Markov Chain Monte Carlo simulation implemented in the specialist Bayesian statistics software WinBUGS. To illustrate the method described, a simple probabilistic decision model is developed to evaluate the cost implications of using prophylactic antibiotics in caesarean section to reduce the incidence of wound infection. The advantages of using the Bayesian statistical approach outlined compared to the conventional classical approaches to decision analysis include the ability to: (i) perform all necessary analyses, including all intermediate analyses (e.g., meta-analyses) required to derive model parameters, in a single coherent model; (ii) incorporate expert opinion either directly or regarding the relative credibility of different data sources; (iii) use the actual posterior distributions for parameters of interest (opposed to making distributional assumptions necessary for the classical formulation); and (iv) incorporate uncertainty for all model parameters.

Antibiotic Prophylaxis↗

PubMed2001

Analysis of ambulatory blood pressure monitor data using a hierarchical model incorporating restricted cubic splines and heterogeneous within-subject variances.

Hypertensive disorders of pregnancy are associated with significant maternal and foetal morbidity. Measurement of blood pressure remains the standard way of identifying individuals at risk. There is growing interest in the use of ambulatory blood pressure monitors (ABPM), which can record an individual's blood pressure many times over a 24-hour period. From a clinical perspective interest lies in the shape of the blood pressure profile over a 24-hour period and any differences in the profile between groups. We propose a two-level hierarchical linear model incorporating all ABPM data into a single model. We contrast a classical approach with a Bayesian approach using the results of a study of 206 pregnant women who were asked to wear an ABPM for 24 hours after referral to an obstetric day unit with high blood pressure. As the main interest lies in the shape of the profile, we use restricted cubic splines to model the mean profiles. The use of restricted cubic splines provides a flexible way to model the mean profiles and to make comparisons between groups. From examining the data and the fit of the model it is apparent that there were heterogeneous within-subject variances in that some women tend to have more variable blood pressure than others. Within the Bayesian framework it is relatively easy to incorporate a random effect to model the between-subject variation in the within-subject variances. Although there is substantial heterogeneity in the within-subject variances, allowing for this in the model has surprisingly little impact on the estimates of the mean profiles or their confidence/credible intervals. We thus demonstrate a powerful method for analysis of ABPM data and also demonstrate how heterogeneous within-subject variances can be modelled from a Bayesian perspective.

Bayes Theorem↗

PubMed2001

Circulating neuroblastoma cells detected by reverse transcriptase polymerase chain reaction for tyrosine hydroxylase mRNA are an independent poor prognostic indicator in stage 4 neuroblastoma in children over 1 year.

PURPOSE: In this prospective, multicenter study, the independent prognostic power of neuroblastoma cells detected by reverse transcriptase polymerase chain reaction (RT-PCR) for tyrosine hydroxylase (TH) mRNA was evaluated. PATIENTS AND METHODS: The clinical significance of disease detected by RT-PCR in peripheral blood from children at diagnosis was compared with established prognostic markers [ie, age, lactate dehydrogenase (LDH), neuron-specific enolase, ferritin, and MYCN gene amplification] by multivariate analysis. The value of disease detection by RT-PCR during treatment and follow-up was also examined. RESULTS: TH mRNA was detected in peripheral blood from 33 of 49 (67%) children with stage 4 neuroblastoma > 1 year old at diagnosis and was a significant predictive factor for overall survival [hazard ratio (HR) = 2.40, 95% confidence interval (CI) 1.19 to 4.84, P =.014) and event-free survival (HR = 2.09, 95% CI 1.06 to 4.17, P =.034) in a multivariate analysis. Detection of disease in blood from clinically disease-free children was related to increased risk of death (HR 2.54, 95% CI 1.42 to 4.55, P =.0014). CONCLUSION: TH mRNA in peripheral blood of children with neuroblastoma is a poor prognostic indicator, reflecting the propensity for dissemination via the bloodstream. When combined with a serum LDH > 1500 IU/L, this is the most powerful poor prognostic model at diagnosis for children > 1 year old with stage 4 disease. The detection of TH mRNA in peripheral blood from clinically disease-free children is related to increased risk of relapse and death.

Age Factors↗

PubMed2001

Bcl-2 is an independent prognostic factor and adds to a biological model for predicting outcome in operable non-small cell lung cancer.

INTRODUCTION: The underlying biology of a tumour may hold the key to predicting the outcome for an individual patient as well as identifying potential therapeutic targets. Using epidermal growth factor receptor (EGFR) and matrix metalloproteinase (MMP)-9 immunoexpression combined with microvessel counts we have developed a prognostic model for operable non-small cell lung cancer (NSCLC) which predicts outcome independent of stage (Thorax, 56 (2001) 561-566). The aim of this study was to evaluate the impact of bcl-2 expression upon survival in this model. METHODS: This was a retrospective analysis of 167 patients with resected stage I-IIIa NSCLC and >60 days post-operative survival. Minimum follow-up was 2 years. Immunohistochemistry was performed on paraffin-embedded tissue sections for bcl-2, EGFR, MMP-9 and the microvessel marker CD34 to evaluate the relationships between, and impact on survival of these biological markers. RESULTS: Tumour cell MMP-9 (P=0.002), microvessel count > median (P=0.01), bcl-2 (P=0.02) and stage (P=0.02) were independent prognostic factors. Bcl-2 expression was associated with an improved survival in all sub-groups of our prognostic model. CONCLUSION: bcl-2, EGFR and MMP-9 expression and angiogenesis provide prognostic information independent of TNM stage. Prognostic models offer the potential of tailoring the therapeutic management for an individual patient.

Adult↗

PubMed2001

An illustrated guide to the methods of meta-analysis.

Meta-analysis is now accepted as a necessary tool for the evaluation of health care. Such analyses have been carried out in virtually every area of medicine to evaluate a wide spectrum of health care interventions and policies. This paper has three broad aims: (1) to describe the basic principles of meta-analysis, using a meta-analysis of interventions intended to reduce hospital re-admission rates for illustration; (2) to consider threats to the internal validity of meta-analysis, and the measures which can be taken to minimize their impact; and (3) to present an overview of more specialist and developing methods for synthesizing data, with the intention of outlining the directions meta-analysis may take in the future. The methods used to synthesize studies, which take 'weighted averages' of effect sizes have been refined to a high degree, while the methods for dealing with threats to the validity of meta-analyses such as publication bias, and variations in quality of the primary studies, are at a less advanced stage. However, many consider this standard 'weighted average' approach to meta-analysis not to be 'state of the art' in at least some situations, where the use of more sophisticated methods, generally to explain variation in estimates from different studies and synthesize a broader base of evidence, would be advantageous. Currently, approaches which attempt to do this are mainly still in the experimental stage and, unfortunately, ideas which sound natural and appealing are often difficult to implement in practice. Clearly, it will be some time before they are used routinely, but significant steps have been made.

Bayes Theorem↗

PubMed2001

Involving patients in treatment decisions: can we learn from clinical trials?

The delivery of information to patients with cancer is a primary responsibility of health professionals and it may improve patients' satisfaction with their involvement in treatment decisions. Clinical trials often involve more written and verbal information for patients. All patients who were receiving chemotherapy in Leicestershire during a 2-week period were asked to complete a questionnaire. The responses of clinical trial and non-trial patients were compared. Clinical trial patients were significantly more likely to have been informed about alternative treatment options and to feel that they had taken part in the decision to undergo chemotherapy. They were also significantly more likely to have received written and verbal information about diagnosis and treatment from a hospital nurse, and were more willing to approach a nurse with future questions. If greater patient participation in treatment decisions is advocated, more written and verbal information and closer involvement of hospital nurses should be considered for all forms of chemotherapy.

Adult↗

PubMed2001

How discriminatory is the objective structured clinical examination (OSCE) in the assessment of clinical competence of medical students?

A prospective collection and analysis of examination marks for three consecutive academic years was undertaken to determine the correlation between the objective structured clinical examination (OSCE) and various other components of medical students' examination, and also to examine how discriminatory the OSCE examination is in the assessment of clinical competence. Out of 388 students, 96.3% passed the examination at the first attempt. Of those who passed, 15.5% had merit while 1.0% had a distinction. When the OSCE component was excluded from the analysis, 11.6% and 2.8% had merits and distinctions, respectively, but when the clinical examination was excluded, there were 17.8% and 6.2% merits and distinctions, respectively. Correlations between the various components of the examination were significant except for that between the clinical examination and the project. Although the OSCE and clinical components of examinations for clinical students are complementary, the OSCE component awards more merit and distinction categories. Although there were statistically significant correlations between the various components of the examination, only 11% of the variability in clinical examination scores could be explained by the performance in OSCE suggesting that the different components are testing different aspects of the student's clinical competence. Completely replacing clinicals with an OSCE may not necessarily be the best way of assessing medical students' clinical competence.

Journal Article↗

PubMed2001

The risk of colorectal cancer in ulcerative colitis: a meta-analysis.

BACKGROUND AND AIMS: Controversy surrounds the risk of colorectal cancer (CRC) in ulcerative colitis (UC). Many studies have investigated this risk and reported widely varying rates. METHODS: A literature search using Medline with the explosion of references identified 194 studies. Of these, 116 met our inclusion criteria from which the number of patients and cancers detected could be extracted. Overall pooled estimates, with 95% confidence intervals (CI), of cancer prevalence and incidence were obtained using a random effects model on either the log odds or log incidence scale, as appropriate. RESULTS: The overall prevalence of CRC in any UC patient, based on 116 studies, was estimated to be 3.7% (95% CI 3.2-4.2%). Of the 116 studies, 41 reported colitis duration. From these the overall incidence rate was 3/1000 person years duration (pyd), (95% CI 2/1000 to 4/1000). The overall incidence rate for any child was 6/1000 pyd (95% CI 3/1000 to 13/1000). Of the 41 studies, 19 reported results stratified into 10 year intervals of disease duration. For the first 10 years the incidence rate was 2/1000 pyd (95% CI 1/1000 to 2/1000), for the second decade the incidence rate was estimated to be 7/1000 pyd (95% CI 4/1000 to 12/1000), and in the third decade the incidence rate was 12/1000 pyd (95% CI 7/1000 to 19/1000). These incidence rates corresponded to cumulative probabilities of 2% by 10 years, 8% by 20 years, and 18% by 30 years. The worldwide cancer incidence rates varied geographically, being 5/1000 pyd in the USA, 4/1000 pyd in the UK, and 2/1000 pyd in Scandinavia and other countries. Over time the cancer risk has increased since 1955 but this finding was not significant (p=0.8). CONCLUSIONS: Using new meta-analysis techniques we determined the risk of CRC in UC by decade of disease and defined the risk in pancolitics and children. We found a non-significant increase in risk over time and estimated how risk varies with geography.

Australia↗

PubMed2001

Methods for exploring heterogeneity in meta-analysis.

In meta-analysis, when the difference in results between studies is greater than would be expected by chance, one needs to investigate whether the observed variation in results across studies is associated with clinical and/or methodological differences between studies. This article reviews methods used in meta-analysis for exploring heterogeneity, including statistical tests for homogeneity, methods for visually displaying results of primary studies, methods for reducing heterogeneity, methods for investigating sources of heterogeneity, and identification of moderator variables or effect modifiers. The investigation of sources of heterogeneity in meta-analysis is by nature exploratory, and therefore its results should always be interpreted with caution. However, careful investigation of heterogeneity may provide an important second level of evidence that can be useful in suggesting direction of future research. Sometimes, it may provide clinically important results by indicating who might benefit more or less from a treatment or how an intervention should be applied.

Data Interpretation, Statistical↗

PubMed2001

Bayesian methods in meta-analysis and evidence synthesis.

This paper reviews the use of Bayesian methods in meta-analysis. Whilst there has been an explosion in the use of meta-analysis over the last few years, driven mainly by the move towards evidence-based healthcare, so too Bayesian methods are being used increasingly within medical statistics. Whilst in many meta-analysis settings the Bayesian models used mirror those previously adopted in a frequentist formulation, there are a number of specific advantages conferred by the Bayesian approach. These include: full allowance for all parameter uncertainty in the model, the ability to include other pertinent information that would otherwise be excluded, and the ability to extend the models to accommodate more complex, but frequently occurring, scenarios. The Bayesian methods discussed are illustrated by means of a meta-analysis examining the evidence relating to electronic fetal heart rate monitoring and perinatal mortality in which evidence is available from a variety of sources.

Bayes Theorem↗

PubMed2000

Hierarchical models in generalized synthesis of evidence: an example based on studies of breast cancer screening.

Evidence regarding the potential benefits of a particular health care intervention is often available from a variety of disparate sources. However, formal synthesis of such evidence has traditionally concentrated almost exclusively on that derived from randomized studies, although for a range of conditions the randomized evidence will be less than adequate due to economic, organizational or ethical considerations. In such situations a formal synthesis of the evidence that is available from observational studies can be valuable whilst awaiting higher quality evidence from randomized trials. Consideration of randomized studies alone may be appropriate when assessing the efficacy of an intervention, but assessment of the effectiveness of such an intervention within a more general target population may be improved by consideration of evidence from non-randomized studies as well. Standard meta-analysis methods may allow for both within- and between-study heterogeneity; however when multiple sources of evidence are considered an extra level of complexity is introduced, namely study type. One possible solution to the problem of making inferences, particularly regarding an overall population effect, in such situations is to model the heterogeneity, both quantitative and qualitative, using a Bayesian hierarchical model. The hierarchical nature of such models specifically allows for the quantitative within and between sources of heterogeneity, whilst the Bayesian approach can accommodate a priori beliefs regarding qualitative differences between the various sources of evidence. The use of such methods in practice is illustrated in the context of screening for breast cancer; in this example evidence is available from both randomized clinical trials and observational studies. A particular appeal of a Bayesian approach for this type of problem lies in the prediction of future benefits likely to be observed in a target population. This approach to health service monitoring in general is discussed.

Aged↗

PubMed2000

Endometrial protection from tamoxifen-stimulated changes by a levonorgestrel-releasing intrauterine system: a randomised controlled trial.

INTRODUCTION: Tamoxifen is currently the most commonly used adjuvant treatment for breast cancer, however, it frequently causes episodes of unscheduled uterine bleeding, which could be associated with proliferative changes of the endometrium, or even endometrial cancer. We aimed to assess whether a levonorgestrel intrauterine system could modulate the uterine responses to tamoxifen. We also aimed to assess women's tolerance of the screening procedures, the insertion, removal, and potential side-effects of the device. METHODS: We did a randomised controlled trial, in which postmenopausal women who had had at least 1 year of adjuvant tamoxifen treatment and who were undergoing regular follow-up for breast cancer were randomly assigned to either endometrial surveillance alone, or endometrial surveillance before and after insertion of the levonorgestrel intrauterine system for 12 months. We assessed tolerance of the surveillance procedures and the device with visual analogue scales. FINDINGS: Baseline assessment showed only benign uterine changes in all women (n=122). Hysteroscopic assessment indicated a uniform decidual response (confirmed histologically in 40 of 41 cases) in all women fitted with the intrauterine system; there were no new polyps in these women and 13% had fewer fibroids than in controls. Both screening procedures and device were well tolerated. There was an excess of bleeding in the women fitted with intrauterine systems but this resolved to a baseline similar to those receiving surveillance only. INTERPRETATION: The levonorgestrel-releasing intrauterine system had a protective action against the uterine effects of tamoxifen. The effectiveness of this device in preventing uterine changes in the endometrium needs to be assessed in the context of decreasing the need for repeated investigations of postmenopausal bleeding in women taking tamoxifen.

Aged↗

PubMed2000

Empirical assessment of effect of publication bias on meta-analyses.

OBJECTIVE: To assess the effect of publication bias on the results and conclusions of systematic reviews and meta-analyses. DESIGN: Analysis of published meta-analyses by trim and fill method. STUDIES: 48 reviews in Cochrane Database of Systematic Reviews that considered a binary endpoint and contained 10 or more individual studies. MAIN OUTCOME MEASURES: Number of reviews with missing studies and effect on conclusions of meta-analyses. RESULTS: The trim and fill fixed effects analysis method estimated that 26 (54%) of reviews had missing studies and in 10 the number missing was significant. The corresponding figures with a random effects model were 23 (48%) and eight. In four cases, statistical inferences regarding the effect of the intervention were changed after the overall estimate for publication bias was adjusted for. CONCLUSIONS: Publication or related biases were common within the sample of meta-analyses assessed. In most cases these biases did not affect the conclusions. Nevertheless, researchers should check routinely whether conclusions of systematic reviews are robust to possible non-random selection mechanisms.

Clinical Trials as Topic↗

PubMed2000

Does immunointensity account for the differences in prognostic significance of Bcl-2 expression in non-small cell lung cancer?

Bcl-2 is an oncogenic protein that plays a central role in apoptosis. The association of Bcl-2 expression and prognosis in non-small cell lung cancer (NSCLC) is unclear, with some studies showing improved outcome whilst others show no survival advantage. We evaluated 178 surgically resected NSCLC specimens for Bcl-2 and p53 immunoexpression. Bcl-2 staining was present in 34.9% of cases (weakly staining 24.2%, strongly staining 10.7%), nuclear p53 in 43. 3% and cytoplasmic p53 in 10.7%. There was no association between p53 and survival. Bcl-2 immunoexpression correlated with improved outcome (p=0.04). A sub-group of strongly Bcl-2 staining cases had a poor survival compared to those that stained weakly (p=0.01). The strongly staining cases had a similar survival to negative cases. Immunointensity may therefore account for the disparity in results regarding the prognostic significance of Bcl-2 demonstrated in previous studies.

Adult↗

PubMed2000

Inhibition of vascular smooth muscle cell adhesion and migration by c7E3 Fab (abciximab): a possible mechanism for influencing restenosis.

OBJECTIVES: Brief intravenous administration of chimeric antibody c7E3 Fab during coronary angioplasty has been shown in some studies to provide long term protection against coronary events. Smooth muscle cell (SMC) adhesion and migration are key initial steps in the development of restenosis. The purpose of this study was to investigate the effect of c7E3 Fab on adhesion and migration of SMC to the extracellular matrix (ECM) proteins osteopontin (Opn) and vitronectin (Vn). METHODS: Adhesion of human vascular SMCs to ECM proteins was quantified using a CyQUANT assay kit. Migration of SMCs to Vn, Opn and PDGF was studied using a modified Boyden's chamber migration assay. Integrin expression was determined by immunoprecipitation. RESULTS: c7E3 Fab reduced SMC adhesion on Vn and Opn to 69.2+/-3.3% (P<0.001) and 52.5+/-4.8% (P<0.001) respectively, compared to adhesion without antibody present. This reduction was the same as that for anti-alpha(v)beta(3) integrin antibody LM609 (P=0.5). The combination of anti-alpha(v)beta(5) integrin antibody and c7E3 Fab had a greater effect than either antibody alone (P<0.001). c7E3 Fab reduced SMC migration to Vn and Opn to 51.6+/-8.9% (P<0.001) and 20.3+/-6.1% (P<0.001) respectively, compared to migration in the absence of antibodies. Again, similar results were seen with LM609. PDGF-induced SMC migration was also inhibited by c7E3 Fab (P=0.004) and LM609 (P=0.001), but to much less an extent. The migration SMCs from a culture found not to express the alpha(v)beta(3) integrin was unaffected by these antibodies, strengthening the argument that c7E3 Fab inhibits SMC function via this integrin. CONCLUSIONS: c7E3 Fab inhibits the adhesion and migration of SMCs via the alpha(v)beta(3) integrin. The inhibition, however, is partial, and varied depending on type of ECM protein and alpha(v)beta(3) integrin expression. Some of the clinical benefits of c7E3 Fab may be due to its effect on SMCs.

Abciximab↗

PubMed2000

Platelet-derived endothelial cell growth factor expression and angiogenesis in cervical intraepithelial neoplasia and squamous cell carcinoma of the cervix.

Growth and metastatic spread of invasive carcinoma depends on angiogenesis, the formation of new blood vessels. Platelet-derived endothelial cell growth factor (PD-ECGF) is an angiogenic growth factor for a number of solid tumors, including lung, bladder, colorectal, and renal cell cancer. Cervical intraepithelial neoplasia (CIN) is the precursor to squamous cell cervical carcinoma (SCC). Mean vessel density (MVD) increases from normal cervical tissue, through low- and high-grade CIN to SCC. We evaluated PD-ECGF immunoreactivity and correlated its expression with MVD in normal, premalignant, and malignant cervical tissue. PD-ECGF expression was assessed visually within the epithelial tissues and scored on the extent and intensity of staining. MVD was calculated by counting the number of vessels positive for von Willebrand factor per unit area subtending normal or CIN epithelium or within tumor hotspots for SCC. Cytoplasmic and/or nuclear PD-ECGF immunoreactivity was seen in normal epithelium. PD-ECGF expression significantly increased with histologic grade from normal, through low- and high-grade CIN, to SCC (P < .02). A progressive significant increase in the microvessel density was also seen, ranging from a mean of 28 vessels for normal tissue to 57 for SCC (P < .0005). No correlation was found between PD-ECGF expression and MVD (P = .45). We conclude that PD-ECGF expression and MVD increase as the cervix transforms from a normal to a malignant phenotype. PD-ECGF is thymidine phosphorylase, a key enzyme in the activation of fluoropyrimidines, including 5-fluorouracil. Evaluation of PD-ECGF thymidine phosphorylase expression may be important in designing future chemotherapeutic trials in cervical cancer.

Carcinoma, Squamous Cell↗