The lead time distribution when lifetime is subject to competing risks in cancer screening.

This paper extends the previous probability model for the distribution of lead time in periodic cancer screening exams, namely, in that the lifetime T is treated as a random variable, instead of a fixed value. Hence the number of screens for a given individual is a random variable as well. We use the actuarial life table from the Social Security Administration to obtain the lifetime distribution, and then use this information to project the lead time distribution for someone with a future screening schedule.

Bayesian Estimation of Combined Accuracy for Tests with Verification Bias.

This presentation will emphasize the estimation of the combined accuracy of two or more tests when verification bias is present. Verification bias occurs when some of the subjects are not subject to the gold standard. The approach is Bayesian where the estimation of test accuracy is based on the posterior distribution of the relevant parameter.

Bayesian Methods for Medical Test Accuracy.

Bayesian methods for medical test accuracy are presented, beginning with the basic measures for tests with binary scores: true positive fraction, false positive fraction, positive predictive values, and negative predictive value. The Bayesian approach is taken because of its efficient use of prior information, and the analysis is executed with a Bayesian software package WinBUGS®. The ROC (receiver operating characteristic) curve gives the intrinsic accuracy of medical tests that have ordinal or continuous scores, and the Bayesian approach is illustrated with many examples from cancer and other diseases.

Bayesian inference for the lead time in periodic cancer screening.

This article develops a probability distribution for the lead time in periodic cancer screening examinations. The general aim is to allow statistical inference for a screening program's lead time, the length of time the diagnosis is advanced by screening. The program's lead time is distributed as a mixture of a point mass and a piecewise continuous distribution.

Preoperative risk stratification using gated myocardial perfusion studies in patients with cancer.

Unlabelled: Cancer patients frequently have anemia or an altered coagulation state that may affect their risk stratification for perioperative cardiac events. We performed this study to investigate the incidence of perioperative cardiac events in cancer patients who had abnormal stress myocardial perfusion imaging (MPI) results versus cancer patients with normal MPI results.

Methods: We included 394 consecutive cancer patients with normal (n = 201) or abnormal (n = 193) results on MPI studies performed for preoperative risk stratification.

The reliability of measuring physical characteristics of spiculated masses on mammography.

The goal of this study was to assess the reliability of measurements of the physical characteristics of spiculated masses on mammography. The images used in this study were obtained from the Digital Database for Screening Mammography. Two experienced radiologists measured the properties of 21 images of spiculated masses.

Novel in vivo imaging shows up-regulation of death receptors by paclitaxel and correlates with enhanced antitumor effects of receptor agonist antibodies.

Susceptibility to apoptosis by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is mediated through cognate death receptor signaling. We hypothesized that auto-amplification of this apparatus would enhance antitumor effects in vivo and could be optimized using the results obtained from novel imaging techniques. We therefore imaged mice bearing human colorectal cancer (Colo205) tumor xenografts with HGS-ETR1 and HGS-ETR2 agonist antibodies to TRAIL receptor-1 (TRAIL-R1) and TRAIL-R2, respectively, after radiolabeling the antibodies.

The prevalence of myocardial ischemia after concurrent chemoradiation therapy as detected by gated myocardial perfusion imaging in patients with esophageal cancer.

Unlabelled: The detection of myocardial perfusion abnormalities after radiation therapy (RT) has been investigated previously in patients with lymphoma and breast cancer. However, the prevalence and association of such abnormalities with RT in esophageal cancer patients have not been investigated previously.

Methods: The prevalence of myocardial perfusion abnormalities detected using gated myocardial perfusion imaging (GMPI) in patients with esophageal cancer after RT (RT group) was compared with that in patients with esophageal cancer who did not undergo RT (NRT group).

Interobserver and intraobserver variability of standardized uptake value measurements in non-small-cell lung cancer.

Objectives: To assess interobserver and intraobserver variabilities in measuring the maximal standardized uptake value (SUV) of non-small-cell lung cancer.

Methods: Positron emission tomography-computed tomography examinations of 20 consecutive patients referred for initial evaluation of newly diagnosed non-small-cell lung cancer were retrospectively reviewed by 5 experienced positron emission tomography-computed tomography readers, who independently measured the maximal SUV/body weight of the primary tumors. Interobserver and intraobserver variabilities were assessed by using 4 statistical methods: correlation, regression analysis, Bland-Altman analysis, and analysis of variance.

Effect of transcatheter hepatic arterial embolization on angiogenesis in an animal model.

Objectives: Transcatheter arterial embolization (TAE) is used for the treatment of patients with malignant liver tumors. However, the proangiogenesis effect of TAE-associated hypoxia has not been adequately studied. The goal of this study was to determine angiogenic activity in tumors subjected to TAE by evaluating the tumor microvessel density (MVD).

Incidental pulmonary emboli in oncology patients: prevalence, CT evaluation, and natural history.

Purpose: To retrospectively determine the prevalence and natural history of incidental pulmonary emboli in oncology patients, the number of such cases reported at initial thoracic computed tomographic (CT) image interpretation, and the factors that contribute to underdiagnosis.

Materials And Methods: Institutional review board approval, which included HIPAA-compliant access to protected health information and waived patient consent requirements, was obtained for this retrospective study. Four hundred three consecutive oncology patients (199 male, 204 female; age range, 14-87 years; mean age, 55 years) in whom adequate-quality multidetector thoracic CT was performed within a 10-day period for indications other than pulmonary emboli assessment were identified.

Tumor iNOS predicts poor survival for stage III melanoma patients.

Inducible nitric oxide synthase (iNOS) produces nitric oxide, which has growth promoting activity in melanoma. A preliminary study of tumors from patients with Stage III melanoma who had received neo-adjuvant therapy revealed an association of tumor iNOS expression with shortened survival. The objective of the present study was to determine whether iNOS expression in tumors of newly diagnosed, untreated Stage III patients is predictive of survival.

MLE and Bayesian inference of age-dependent sensitivity and transition probability in periodic screening.

This article extends previous probability models for periodic breast cancer screening examinations. The specific aim is to provide statistical inference for age dependence of sensitivity and the transition probability from the disease free to the preclinical state. The setting is a periodic screening program in which a cohort of initially asymptomatic women undergo a sequence of breast cancer screening exams.

Integrated computed tomography-positron emission tomography in patients with potentially resectable malignant pleural mesothelioma: Staging implications.

Background: Integrated computed tomography-positron emission tomography imaging with coregistration of anatomic and functional imaging data may improve the accuracy of malignant pleural mesothelioma staging. We evaluate the use of integrated computed tomography-positron emission tomography in patients with malignant pleural mesothelioma who are being considered for extrapleural pneumonectomy.

Methods: Twenty-nine patients with malignant pleural mesothelioma who were judged to be candidates for extrapleural pneumonectomy after clinical and conventional radiologic evaluation underwent whole-body integrated computed tomography-positron emission tomography and pathologic staging.

The value of 99mTc-sestamibi SPECT/CT over conventional SPECT in the evaluation of parathyroid adenomas or hyperplasia.

Unlabelled: As SPECT/CT technology evolves, its applications and indications need to be evaluated clinically for more efficient and cost-effective use. This retrospective study evaluated the clinical value of simultaneously acquired (99m)Tc-sestamibi SPECT/CT versus conventional SPECT in diagnosing and locating parathyroid adenomas or hyperplasia in patients with primary hyperparathyroidism.

Methods: Immediately and 60 minutes after intravenous administration of 740-925 MBq of (99m)Tc-sestamibi, static planar images of the neck and chest were obtained.

Small (

Purpose: To retrospectively compare the diagnostic yield and complications associated with the use of short versus long needle paths for computed tomography (CT)-guided biopsy of small subpleural lung lesions.

Materials And Methods: The study was approved by the institutional review board, and the requirement for informed patient consent was waived. The medical and imaging records of patients who underwent CT-guided biopsy of subpleural pulmonary nodules measuring up to 2 cm in diameter were reviewed.

Radiation dosimetry of 99mTc-labeled C225 in patients with squamous cell carcinoma of the head and neck.

Unlabelled: This study assessed the radiation dosimetry of 99mTc-labeled ethylene dicysteine (EC) C225 (EC-C225), a promising radioligand for functional tumor imaging.

Methods: Whole-body scanning was performed on 6 patients with head and neck squamous cell carcinoma up to 24 h after administration of 99mTc-EC-C225. Alternate patients who had been randomized to receive C225 in a phase III trial received 99mTc-EC-C225 before their 20-mg test dose or after their 400 mg/m2 loading dose of unlabeled C225 (patients 1/3/5 and 2/4/6, respectively).

NHERF (Na+/H+ exchanger regulatory factor) gene mutations in human breast cancer.

Yeast two-hybrid screening was used to explore novel proteins that interact with a breast tumor or metastasis suppressor, SYK (spleen tyrosine kinase). The screening yielded NHERF (Na+/H+ exchanger regulatory factor, also known as NHERF1 or EBP-50) that binds to the interdomain B of SYK. NHERF is an estrogen-responsive gene that encodes an inhibitory factor for epithelial Na+/H+ exchanger isoform 3 (NHE3).

Biochemotherapy in patients with metastatic anorectal mucosal melanoma.

Background: Patients with metastatic anorectal melanoma generally have an unfavorable prognosis, but no effective systemic therapy has been reported.

Methods: The authors retrospectively evaluated the medical records of all patients with metastatic anorectal melanoma treated with biochemotherapy between January 1991 and December 2001 at the University of Texas M. D.

Detection of small pancreatic tumors with multiphasic helical CT.

Objective: The purpose of this study was to evaluate the sensitivity and specificity of helical CT in the detection of adenocarcinomas of the pancreas measuring 2 cm or smaller at pathologic examination.

Materials And Methods: Thin-section triple phase (20, 40, and 70 sec after the start of injection) contrast-enhanced helical CT scans of the abdomen in 18 patients with a pancreatic carcinoma that was 2 cm or smaller and 18 patients with a normal pancreas were retrospectively reviewed by two senior radiologists who specialized in oncologic abdominal imaging. Discrepancies were resolved by consensus.

Cyclooxygenase-2 is essential for HER2/neu to suppress N- (4-hydroxyphenyl)retinamide apoptotic effects in breast cancer cells.

We reported that HER2/neu reduces the sensitivity of breast cancer cells to N-(4-hydroxyphenyl)retinamide (4-HPR) by suppressing nitric oxide production. We show that HER2/neu uses Akt to induce cyclooxygenase-2 (COX-2) expression and that inhibition of Akt or COX-2 increases 4-HPR-induced apoptosis and nitric oxide production. Apoptosis induced by the 4-HPR and COX-2 inhibitor combination, although unaffected by an anti-HER2/neu antibody, was reversed by the COX-2 product prostaglandin E(2), indicating that COX-2 is a major mechanism by which HER2/neu suppresses 4-HPR apoptosis in breast cancer cells.

HER2/neu reduces the apoptotic effects of N-(4-hydroxyphenyl)retinamide (4-HPR) in breast cancer cells by decreasing nitric oxide production.

The retinoid N-(4-hydroxyphenyl)retinamide (4-HPR also known as fenretinide) is a potent inducer of apoptosis in breast cancer cells. We observed a 4.5-fold reduction in 4-HPR-mediated apoptosis in MCF-7 breast cancer cells transfected with HER2/neu (MCF-7/HER2) as compared with the parental MCF-7 (MCF-7/WT) cells.

Importance of predosing of recombinant human thrombopoietin to reduce chemotherapy-induced early thrombocytopenia.

Purpose: Recombinant human thrombopoietin (rhTPO) increases platelets, and the peak response of rhTPO is delayed and is, therefore, not uniformly effective when administered after chemotherapy. The purpose of this study was to identify an effective schedule of rhTPO to best attenuate early thrombocytopenia.

Patients And Methods: Cohorts of six patients with sarcoma (66 assessable patients) were treated sequentially with doxorubicin and ifosfamide (AI), with rhTPO by a fixed dose and varying schedules being administered before and/or after chemotherapy in cycle 2 and subsequent cycles.

High prevalence of hypothyroidism among patients with cutaneous melanoma.

We have previously reported a high prevalence of hypothyroidism among patients with uveal melanoma. The objectives of the present study were to determine if a similar pattern of thyroid pathology exists among patients with cutaneous melanoma as well. To address this question, the medical records of all patients registered at the University of Texas M.

Interobserver and intraobserver variability in measurement of non-small-cell carcinoma lung lesions: implications for assessment of tumor response.

Purpose: Response of solid malignancies to therapy is usually determined by serial measurements of tumor size. The purpose of our study was to assess the consistency of measurements performed by readers evaluating lung tumors.

Materials And Methods: The study group was composed of 33 patients with lung tumors more than 1.