Tandem Autologous Stem Cell Transplantation for Multiple Myeloma Patients Based on Response to Their First Transplant-A Prospective Phase II Study.

In this prospective phase II clinical trial, multiple myeloma (MM) patients were randomized to receive a second (tandem) autologous stem cell transplantation (ASCT) based on whether they achieved a partial response or worse (≤PR) following initial ASCT (ASCT1). Patients who achieved a very good partial response or better (≥VGPR) had salvage ASCT at relapse. Seventy-five patients received conditioning therapy and ASCT1. A total of 44 patients (59%) achieved ≥VGPR, whereas 31 patients entered ≤PR and were offered tandem ASCT. In all, 20 patients agreed to tandem ASCT. Demographic and clinical characteristics were similar between the two cohorts except for median lactate dehydrogenase (LDH) (P = 0.0141) and percentage of marrow plasma cells before ASCT1 (P = 0.0047), both lower in the ≥VGPR group. Intent to treat analysis showed that patients who achieved ≥VGPR to ASCT1 had a trend toward improved progression-free survival (PFS) (37 vs. 26 months, P = 0.078) and superior overall survival (OS) (not reached vs. 50 months, P = 0.0073). Patients with ≤PR who declined tandem transplantation had shortened PFS (20 vs. 28 months, P = 0.05) but similar OS (53 vs. 57.5 months, P = 0.29) compared to those who received it. Thus, a favorable clinical response to ASCT1 identifies a low-risk group with superior long-term prognosis despite similar PFS.

Designs for randomized phase II clinical trials with two treatment arms.

The most common primary statistical end point of a phase II clinical trial is the categorization of a patient as either a 'responder' or 'nonresponder'. The primary objective of typical randomized phase II anticancer clinical trials is to evaluate experimental treatments that potentially will increase response rate over a historical baseline and select one to consider for further study. We propose single-stage and two-stage designs for randomized phase II clinical trials, precisely defining various type I error rates and powers to achieve this objective. We develop a program to compute these error rates and powers exactly, and we provide many design examples to satisfy pre-fixed requirements on error rates and powers. Finally, we apply our method to a randomized phase II trial in patients with relapsed non-Hodgkin's disease.

Effect of bevacizumab on angiogenesis and growth of canine osteosarcoma cells xenografted in athymic mice.

Objective-To investigate the effects of bevacizumab, a human monoclonal antibody against vascular endothelial growth factor, on the angiogenesis and growth of canine osteosarcoma cells xenografted in mice. Animals-27 athymic nude mice. Procedures-To each mouse, highly metastasizing parent osteosarcoma cells of canine origin were injected into the left gastrocnemius muscle. Each mouse was then randomly allocated to 1 of 3 treatment groups: high-dose bevacizumab (4 mg/kg, IP), low-dose bevacizumab (2 mg/kg, IP), or control (no treatment). Tumor growth (the number of days required for the tumor to grow from 8 to 13 mm), vasculature, histomorphology, necrosis, and pulmonary metastasis were evaluated. Results-Mice in the high-dose bevacizumab group had significantly delayed tumor growth (mean ± SD, 13.4 ± 3.8 days; range, 9 to 21 days), compared with that for mice in the low-dose bevacizumab group (mean ± SD, 9.4 ± 1.5 days; range, 7 to 11 days) or control group (mean ± SD, 7. 2 ± 1.5 days; range, 4 to 9 days). Mice in the low-dose bevacizumab group also had significantly delayed tumor growth, compared with that for mice in the control group. Conclusions and Clinical Relevance-Results indicated that bevacizumab inhibited growth of canine osteosarcoma cells xenografted in mice, which suggested that vascular endothelial growth factor inhibitors may be clinically useful for the treatment of osteosarcoma in dogs. Impact for Human Medicine-Canine osteosarcoma is used as a research model for human osteosarcoma; therefore, bevacizumab may be clinically beneficial for the treatment of osteosarcoma in humans.

Increased IL-6 detection in adult and pediatric lymphoid tissue harboring parvovirus B19.

BACKGROUND: Parvovirus B19 (B19V) is a common pathogenic virus infecting humans. Previous studies have shown evidence of B19V infection in patients with non-Hodgkin's lymphoma (NHL) and Hodgkin's lymphoma using ELISA and PCR on serum specimens. B19V nonstructural protein is known to alter the expression of cellular factors including interleukin-6 (IL-6), which can increase the risk for and worsen the prognosis of lymphomas. OBJECTIVE: The objective of this study was to detect B19V capsid protein and IL-6 expression in normal and malignant lymphoid tissue, as well as any correlation between the two. STUDY DESIGN: IHCs for B19V capsid protein, IL-6, and B19V co-receptors P-antigen and α5ß1 integrin were performed on a tissue array containing 70 duplicated pediatric and adult lymphoma tissues and 5 duplicated benign lymph node sections. Cases were identified as normal, B-cell NHL, diffuse large B-cell NHL, Hodgkin's lymphoma, extranodal NK/T cell lymphoma, anaplastic large cell lymphoma, or mantle cell lymphoma. IL-6 and B19V capsid staining were quantified using a positive pixel count algorithm, and P-antigen and α5ß1 staining using a membrane quantification algorithm. RESULTS: B19V capsid protein was detected in both benign and malignant lymphoid tissue. The Spearman rank correlation coefficient analysis was performed to determine the relationship between the level of positivity for B19V and IL-6 staining, yielding an overall correlation coefficient of 0.679 (p-value<0.0001). CONCLUSIONS: Our results show a moderate correlation between the levels of positive B19V and IL-6 staining by IHC, indicating a possible role for B19V in the pathogenesis of lymphomas.

Improved two-stage tests for stratified phase II cancer clinical trials.

In a single-arm, two-stage, phase II cancer clinical trial for efficacy screening of cytotoxic agents, a common primary endpoint is a binary (yes/no) patient response to treatment. Usually, fixed decision boundaries are used in binomial tests to determine whether the study treatment is promising enough to be studied in a large-scale, randomized phase III trial. We may know in advance that the patient response distribution for a phase II clinical trial will be heterogeneous, making it advisable to stratify patients into subgroups, each with a different prognosis. In this case, fixed decision boundaries may be inappropriate. In this article, we propose two-stage tests based on the Neyman-Pearson lemma. The proposed test statistic is a linear combination of the observed number of responders in each stratum. The test allows adjustment of the decision boundaries to the observed numbers of patients in each stratum and permits sample sizes to be increased adaptively after the originally planned number of patients is observed at each of the two stages. Our numerical results show that the proposed test is more powerful than an existing test in many cases. Finally, we present an application to a Children's Oncology Group phase II clinical trial in patients who relapsed after initial treatment for neuroblastoma.

Phase II cancer clinical trials with heterogeneous patient populations.

The patient population for a Phase II trial often consists of multiple subgroups in terms of risk level. In this case, a popular design approach is to specify the response rate and the prevalence of each subgroup, to calculate the response rate of the whole population by the weighted average of the response rates across subgroups, and to choose a standard Phase II design such as Simon's optimal or minimax design to test the response rate for the whole population. In this case, although the prevalence of each subgroup is accurately specified, the observed prevalence among the accrued patients to the study may be quite different from the expected one because of the small sample size, which is typical in most Phase II trials. The fixed rejection value for a chosen standard Phase II design may be either too conservative (i.e., increasing the false rejection probability of the experimental therapy) if the trial accrues more high-risk patients than expected, or too anti-conservative (i.e., increasing the false acceptance probability of the experimental therapy) if the trial accrues more low-risk patients than expected. We can avoid such problems by adjusting the rejection values, depending on the observed prevalence from the trial. In this paper, we investigate the performance of the flexible designs compared with the standard design with fixed rejection values under various settings.

Randomized, controlled trial of standard, large-capacity versus jumbo biopsy forceps for polypectomy of small, sessile, colorectal polyps.

BACKGROUND: Polypectomy with cold biopsy forceps is a frequently used technique for removal of small, sessile, colorectal polyps. Jumbo forceps may lead to more effective polypectomy because of the larger size of the forceps cup. OBJECTIVE: To evaluate the efficiency of cold jumbo biopsy forceps compared with standard forceps for polypectomy of small, sessile, colorectal polyps. DESIGN: Randomized, controlled trial. SETTING: Outpatient endoscopy center. PATIENTS: This study involved 140 patients found to have at least one eligible polyp defined as a sessile polyp measuring ≤6 mm. INTERVENTION: Polypectomy with cold biopsy forceps. MAIN OUTCOME MEASUREMENTS: Complete visual polyp eradication with one forceps bite. RESULTS: In 140 patients, a total of 305 eligible polyps were detected (151 removed with jumbo forceps and 154 with standard forceps). Complete visual eradication of the polyp with one forceps bite was achieved in 78.8% of the jumbo forceps group and 50.7% of the standard forceps group (P < .0001). Biopsies from the polypectomy sites of adenomatous polyps thought to be visually completely eradicated with one bite showed a trend toward a higher complete histologic eradication rate with the jumbo forceps (82.4%) compared with the standard forceps (77.4%), but the difference did not reach statistical significance (P = .62). The withdrawal time for visual inspection of the colon and time to perform polypectomies were significantly shorter in the jumbo forceps group (mean 21.43 vs 18.23 minutes; P = .02). LIMITATIONS: Lack of blinding to the type of forceps used. CONCLUSION: The jumbo biopsy forceps is superior to the standard forceps in removing small, sessile polyps. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT00855790.).

A statistical design for testing transgenerational genomic imprinting in natural human populations.

Genomic imprinting is a phenomenon in which the same allele is expressed differently, depending on its parental origin. Such a phenomenon, also called the parent-of-origin effect, has been recognized to play a pivotal role in embryological development and pathogenesis in many species. Here we propose a statistical design for detecting imprinted loci that control quantitative traits based on a random set of three-generation families from a natural population in humans. This design provides a pathway for characterizing the effects of imprinted genes on a complex trait or disease at different generations and testing transgenerational changes of imprinted effects. The design is integrated with population and cytogenetic principles of gene segregation and transmission from a previous generation to next. The implementation of the EM algorithm within the design framework leads to the estimation of genetic parameters that define imprinted effects. A simulation study is used to investigate the statistical properties of the model and validate its utilization. This new design, coupled with increasingly used genome-wide association studies, should have an immediate implication for studying the genetic architecture of complex traits in humans.

Phase I study of valspodar (PSC-833) with mitoxantrone and etoposide in refractory and relapsed pediatric acute leukemia: a report from the Children's Oncology Group.

BACKGROUND: Valspodar, a non-immunosuppressive analog of cylosporine, is a potent P-glycoprotein (MDR1) inhibitor. As MDR1-mediated efflux of chemotherapeutic agents from leukemic blasts may contribute to drug resistance, a phase 1 study of valspodar combined with mitoxantrone and etoposide in pediatric patients with relapsed or refractory leukemias was performed. PROCEDURE: Patients received a valspodar-loading dose (2 mg/kg) followed by a 5-day continuous valspodar infusion (8, 10, 12.5, or 15 mg/kg/day) combined with lower than standard doses of mitoxantrone and etoposide. The valspodar dose was escalated using a standard 3 + 3 phase I design. RESULTS: Twenty-one patients were evaluable for toxicity and 20 for response. The maximum tolerated dose (MTD) of valspodar was 12.5 mg/kg/day, combined with 50% dose-reduced mitoxantrone and etoposide. The clearance of mitoxantrone and etoposide was decreased by 64% and 60%, respectively, when combined with valspodar. Dose-limiting toxicities included stomatitis, ataxia, and bone marrow aplasia. Three of 11 patients with acute lymphoblastic leukemia (ALL) had complete responses while no patient with acute myeloid leukemia (AML) had an objective response. In vitro studies demonstrated P-glycoprotein expression on the blasts of 5 of 14 patients, although only 1 had inhibition of rhodamine efflux by valspodar. CONCLUSIONS: While this regimen was tolerable, responses in this heavily pretreated population were limited to a subset of patients with ALL.

Biologic behavior and clinical outcome of 25 dogs with canine appendicular chondrosarcoma treated by amputation: a Veterinary Society of Surgical Oncology retrospective study.

OBJECTIVE: To characterize biologic behavior, clinical outcome, and effect of histologic grade on prognosis for dogs with appendicular chondrosarcoma treated by amputation alone. STUDY DESIGN: Case series. ANIMALS: Dogs (n=25) with appendicular chondrosarcoma. METHODS: Medical records were searched to identify dogs with appendicular chondrosarcoma treated by limb amputation alone. Information recorded included signalment, anatomic location, radiographic appearance, and development of metastasis. Histopathologic diagnosis was confirmed and graded (1, 2, or 3). Survival curves were generated by the Kaplan-Meier method and the association between covariates (gender, age, weight, and tumor grade) and survival were evaluated using the univariate proportional hazards model. RESULTS: Histopathology slides were available for 25 dogs. Rates of pulmonary metastasis were as follows: grade 1-0%, grade 2-31%, and grade 3-50%. Overall median survival time (MST) was 979 days. Age, weight, and sex were not significantly associated with survival (P=.16; .33; and .31, respectively). Survival was significantly associated with tumor grade (P=.008), with dogs with tumor grade of 1, 2, and 3 having MSTs of 6, 2.7, and 0.9 years, respectively. CONCLUSION: Canine appendicular chondrosarcoma can be treated effectively with amputation alone. Low to intermediate grade chondrosarcoma has a good prognosis, whereas high-grade tumors appear to behave aggressively. CLINICAL RELEVANCE: The overall prognosis for appendicular chondrosarcoma is better than that of appendicular osteosarcoma treated by amputation alone or in combination with chemotherapy.

A statistical model for genetic mapping of viral infection by integrating epidemiological behavior.

Large-scale studies of genetic variation may be helpful for understanding the genetic control mechanisms of viral infection and, ultimately, predicting and eliminating infectious disease outbreaks. We propose a new statistical model for detecting specific DNA sequence variants that are responsible for viral infection. This model considers additive, dominance and epistatic effects of haplotypes from three different genomes, recipient, transmitter and virus, through an epidemiological process. The model is constructed within the maximum likelihood framework and implemented with the EM algorithm. A number of hypothesis tests about population genetic structure and diversity and the pattern of genetic control are formulated. A series of closed forms for the EM algorithm to estimate haplotype frequencies and haplotype effects in a network of genetic interactions among three genomes are derived. Simulation studies were performed to test the statistical properties of the model, recommending necessary sample sizes for obtaining reasonably good accuracy and precision of parameter estimation. By integrating, for the first time, the epidemiological principle of viral infection into genetic mapping, the new model shall find an immediate application to studying the genetic architecture of viral infection.

Score statistics for mapping quantitative trait loci.

We propose a method to detect the existence of quantitative trait loci (QTL) in a backcross population using a score test. Since the score test only uses the MLEs of parameters under the null hypothesis, it is computationally simpler than the likelihood ratio test (LRT). Moreover, because the location parameter of the QTL is unidentifiable under the null hypothesis, the distribution of the maximum of the LRT statistics, typically the statistic of choice for testing H0: no QTL, does not have the standard chi-square distribution asymptotically under the null hypothesis. From the simple structure of the score test statistics, the asymptotic null distribution can be derived for the maximum of the square of score test statistics. Numerical methods are proposed to compute the asymptotic null distribution and the critical thresholds can be obtained accordingly. We show that the maximum of the LR test statistics and the maximum of the square of score statistics are asymptotically equivalent. Therefore, the critical threshold for the score test can be used for the LR test also. A simple backcross design is used to demonstrate the application of the score test to QTL mapping.

The feasibility of expectant management with inner-city men with newly diagnosed localized prostate cancer.

OBJECTIVE: To determine the compliance rate for treatment recommendations consistent with expectant management of inner-city men with prostate cancer. METHODS: Twenty-seven out of 560 men who underwent biopsy of the prostate were found to harbor cancer and opted for expectant management. Clinic and hospital records were reviewed for adherence to follow-up schema. RESULTS: Of the 27 men on expectant management, 22 men (82%) adhered to strict follow-up schema. At 6-month follow-up, there were no significant changes in clinicopathologic features (e.g., prostate specific antigen (PSA), Gleason score, and stage). With a median follow-up of 12 months, only 2 men demonstrated a rise of more than 30% from baseline PSA (repeat biopsy demonstrated persistent low grade, low stage disease). CONCLUSIONS: Our findings imply that expectant management may be feasible in inner-city settings. Thus, in subsequent expectant management trials, inner-city men should be actively recruited.

Cardiomyopathy in children with Down syndrome treated for acute myeloid leukemia: a report from the Children's Oncology Group Study POG 9421.

PURPOSE: To determine the outcomes, with particular attention to toxicity, of children with Down syndrome (DS) and acute myeloid leukemia (AML) treated on Pediatric Oncology Group (POG) protocol 9421. PATIENTS AND METHODS: Children with DS and newly diagnosed AML (n = 57) were prospectively enrolled onto the standard-therapy arm of POG 9421 and were administered five cycles of chemotherapy, which included daunorubicin 135 mg/m(2) and mitoxantrone 80 mg/m(2). Outcomes and toxicity were evaluated prospectively and were compared with the non-DS-AML cohort (n = 565). A retrospective chart review was performed to identify adverse cardiac events. RESULTS: In the DS-AML group, 54 patients (94.7%) entered remission. One experienced induction failure and two died. Of the 54 who entered remission, three relapsed and six died as a result of other causes. The remission induction rate was similar in the non-DS-French-American-British (FAB) M7 (91.7%) and non-DS-non-M7 (89.3%) groups. The 5-year overall survival was significantly better in the DS-AML group (78.6%) than in the non-DS-M7 (36.3%) or the non-DS-non-M7 (51.8%) groups (P < .001). No age-related difference in 5-year, event-free survival was seen between patients younger than 2 years (75.8%) and those aged 2 to 4 years (78.3%). Symptomatic cardiomyopathy developed in 10 patients (17.5%) with DS-AML during or soon after completion of treatment; three died as a result of congestive heart failure. CONCLUSION: The POG 9421 treatment regimen was highly effective in both remission induction and disease-free survival for patients with DS-AML. However, there was a high incidence of cardiomyopathy, which supports current strategies for dose reduction of anthracyclines in this patient population.

One- and two-stage designs for phase II window studies.

The primary goal of phase II window studies in cancer is testing new single agents or combination therapies for newly diagnosed patients who are less likely to have multiple-drug-resistant tumours than the typical phase II patients who have failed one or more chemotherapeutic regimens. In addition, by utilizing newly diagnosed patients, one can assess the responsiveness in a population more representative of where the phase II agent might be applied in a true phase III setting. In general, the outcome of a patient on a phase II window study can be categorized as response, stable disease, or early disease progression. Phase II window studies sometimes require early stopping rules for both insufficient response rate and excessive early progression rates. In this paper, one-stage and two-stage designs for phase II window studies are developed, requiring the monitoring of two rates. It is shown that the power function is monotone in response rate and early disease progression rate. Consequently, the significance level and power are easy to compute. Computational procedures are described and examples are provided. The proposed method can be applied to other studies with categorical outcomes.

A prospective study of the natural history of transient leukemia (TL) in neonates with Down syndrome (DS): Children's Oncology Group (COG) study POG-9481.

A unique transient leukemia (TL) has been described in newborns with Down syndrome (DS; or trisomy 21 mosaics). This leukemia has a high incidence of spontaneous remission; however, early death and subsequent development of acute megakaryoblastic leukemia (AMKL) have been reported. We prospectively evaluated 48 infants with DS and TL to determine the natural history and biologic characteristics of this disease, identify the clinical characteristics associated with early death or subsequent leukemia, and assess the incidence of subsequent leukemia. Blast cells associated with TL in DS infants exhibited FAB M(7) morphology and phenotype. Most infants (74%) had trisomy 21 (or mosaicism) as the only cytogenetic abnormality in the blast cells. Most children were able to spontaneously clear peripheral blasts (89%), normalize blood counts (74%), and maintain a complete remission (64%). Early death occurred in 17% of infants and was significantly correlated with higher white blood cell count at diagnosis (P < .001), increased bilirubin and liver enzymes (P < .005), and a failure to normalize the blood count (P = .001). Recurrence of leukemia occurred in 19% of infants at a mean of 20 months. Development of leukemia was significantly correlated with karyotypic abnormalities in addition to trisomy 21 (P = .037). Ongoing collaborative clinical studies are needed to determine the optimal role of chemotherapy for infants at risk for increased mortality or disease recurrence and to further the knowledge of the unique biologic features of this TL.

Randomized use of cyclosporin A (CsA) to modulate P-glycoprotein in children with AML in remission: Pediatric Oncology Group Study 9421.

Relapse is a major obstacle in the cure of acute myeloid leukemia (AML). The Pediatric Oncology Group AML Study 9421 tested 2 different strategies to improve event-free survival (EFS) and overall survival (OS). Patients were randomized to receive standard-dose DAT (daunorubicin, cytarabine, and thioguanine) or high-dose DAT during induction. To interfere with P-glycoprotein (P-gp)-dependent drug efflux, the second randomization tested the benefit of cyclosporine (CsA) added to consolidation chemotherapy. Of the 282 children randomly assigned to receive standard DAT induction, 248 (87.9%) achieved remission compared to 253 (91%) of the 278 receiving high-dose DAT (P = ns). Children with HLA-identical sibling donors who achieved a complete remission received an allogeneic bone marrow transplant as consolidation. For the 83 patients receiving a matched related donor bone marrow transplantation (BMT), the 3-year disease-free survival (DFS) is 67%. Of the 418 children who achieved remission and went on to consolidation with and without CsA, the DFS was 40.6% and 33.9%, respectively (P = .24). Overexpression of P-gp was infrequent (14%) in this pediatric population. In this study, intensifying induction with high-dose DAT and the addition of CsA to consolidation chemotherapy did not prolong the durations of remission or improve overall survival for children with AML.

One- and two-stage designs for stratified phase II clinical trials.

A global one-sample test for response rates for stratified phase II clinical trials is proposed. Such a test is analogous to that of a stratified log-rank test for time-to-event data. Both one- and two-stage tests are developed, and conditional and unconditional approaches are introduced in each case, where the conditional approach involves conditioning on the observed samples sizes within the strata. The methodology generates samples sizes and stopping boundaries that provide designs with the desired power and type I error probability. These methods are useful for designing stratified phase II clinical trials. An application to a Children's Oncology Group phase II clinical trial in relapsed neuroblastoma patients is presented.

Improved confidence intervals for a binomial parameter following a group sequential phase II clinical trial.

Group sequential procedures are widely employed in phase II clinical trials. It is often desirable to provide an interval estimate of the true response rate upon termination of a group sequential phase II clinical trial. The confidence intervals proposed by Jennison and Turnbull (Technometrics 1983; 25: 49-58) are conservative. Utilization of auxiliary statistics based on the overall disease status is proposed to reduce the discreteness of the underlying distribution. Confidence intervals generated by the proposed methods have confidence coefficients closer to the nominal level and have shorter average lengths than JT.

Gene expression profiles at diagnosis in de novo childhood AML patients identify FLT3 mutations with good clinical outcomes.

Fms-like tyrosine kinase 3 (FLT3) mutations are associated with unfavorable outcomes in children with acute myeloid leukemia (AML). We used DNA microarrays to identify gene expression profiles related to FLT3 status and outcome in childhood AML. Among 81 diagnostic specimens, 36 had FLT3 mutations (FLT3-MUs), 24 with internal tandem duplications (ITDs) and 12 with activating loop mutations (ALMs). In addition, 8 of 19 specimens from patients with relapses had FLT3-MUs. Predictive analysis of microarrays (PAM) identified genes that differentiated FLT3-ITD from FLT3-ALM and FLT3 wild-type (FLT3-WT) cases. Among the 42 specimens with FLT3-MUs, PAM identified 128 genes that correlated with clinical outcome. Event-free survival (EFS) in FLT3-MU patients with a favorable signature was 45% versus 5% for those with an unfavorable signature (P = .018). Among FLT3-MU specimens, high expression of the RUNX3 gene and low expression of the ATRX gene were associated with inferior outcome. The ratio of RUNX3 to ATRX expression was used to classify FLT3-MU cases into 3 EFS groups: 70%, 37%, and 0% for low, intermediate, and high ratios, respectively (P < .0001). Thus, gene expression profiling identified AML patients with divergent prognoses within the FLT3-MU group, and the RUNX3 to ATRX expression ratio should be a useful prognostic indicator in these patients.