Biomedical subjects

M LeBlanc

Publications and source records attributed to M LeBlanc.

At least 19 recordsLinked to original sources

PubMed2002

Binary partitioning for continuous longitudinal data: categorizing a prognostic variable.

We investigate a binary partitioning algorithm in the case of a continuous repeated measures outcome. The procedure is based on the use of the likelihood ratio statistic to evaluate the performance of individual splits. The procedure partitions a set of longitudinal data into two mutually exclusive groups based on an optimal split of a continuous prognostic variable. A permutation test is used to assess the level of significance associated with the optimal split, and a bootstrap confidence interval is obtained for the optimal split.

Adolescent↗

PubMed2001

Phase III randomized intergroup trial of subtotal lymphoid irradiation versus doxorubicin, vinblastine, and subtotal lymphoid irradiation for stage IA to IIA Hodgkin's disease.

PURPOSE: The management of early-stage Hodgkin's disease in the United States is controversial. To evaluate whether staging laparotomy could be safely avoided in early-stage Hodgkin's disease and whether chemotherapy should be a part of the treatment of nonlaparotomy staged patients, a phase III intergroup trial was performed. PATIENTS AND METHODS: Three hundred forty-eight patients with clinical stage IA to IIA supradiaphragmatic Hodgkin's disease were randomized without staging laparotomy to treatment with either subtotal lymphoid irradiation (STLI) or combined-modality therapy (CMT) consisting of three cycles of doxorubicin and vinblastine followed by STLI. RESULTS: The study was closed at the second, planned, interim analysis because of a markedly superior failure-free survival (FFS) rate for patients on the CMT arm (94%) compared with the STLI arm (81%). With a median follow-up of 3.3 years, 10 patients have experienced relapse or died on the chemoradiotherapy arm, compared with 34 on the radiotherapy arm (P <.001). Few deaths have occurred on either arm (three deaths on CMT and seven deaths on STLI). Treatment was well tolerated, with only one death on each arm attributed to treatment. CONCLUSION: These results demonstrate that it is possible to obtain a high FFS rate in a large group of stage IA to IIA patients without performing staging laparotomy and that three cycles of chemotherapy plus STLI provide a superior FFS compared with STLI alone. Extended follow-up is necessary to assess freedom from second relapse, overall survival, late toxicities, patterns of treatment failure, and quality of life.

Adolescent↗

PubMed2001

Understanding neural networks using regression trees: an application to multiple myeloma survival data.

Neural networks are becoming very popular tools for analysing data. It is however quite difficult to understand the neural network output in terms of the original covariates or input variables. In this paper we provide, using readily available software, an easy way of understanding the output of the neural network using regression trees. We focus on the problem in the context of censored survival data for patients with multiple myeloma, where identifying groups of patients with different prognosis is an important aspect of clinical studies. The use of regression trees to help understand neural networks can be easily applied to uncensored situations.

Age Factors↗

PubMed2001

Infusional CHOP chemotherapy (CVAD) with or without chemosensitizers offers no advantage over standard CHOP therapy in the treatment of lymphoma: a Southwest Oncology Group Study.

PURPOSE: Two phase II studies were conducted to evaluate infusional cyclophosphamide, doxorubicin, vincristine, and dexamethasone chemotherapy, termed the CVAD regimen, alone (Southwest Oncology Group [SWOG] 9240) and with the chemosensitizers verapamil and quinine (SWOG 9125) to assess effects on response, survival, and toxicity in intermediate- and high-grade advanced-stage non-Hodgkin's lymphoma (NHL). The results were compared with the historic group of patients randomized to CHOP chemotherapy on Intergroup (INT) 0067 (SWOG 8516). PATIENTS AND METHODS: All patients had biopsy-proven intermediate- or high-grade NHL (lymphoblastic histology excluded), were ambulatory and previously untreated, and had bulky stage II, III, or IV disease. One hundred twelve patients were registered on SWOG 9240 and received cyclophosphamide 750 mg/m(2) by intravenous bolus day 1, doxorubicin 12.5 mg/m(2)/d and vincristine 0.5 mg/d delivered as a continuous 96-hour infusion on days 1 through 4, and dexamethasone 40 mg/d orally on days 1 through 4 (CVAD). Cycles were repeated every 21 days for eight cycles. One hundred patients on SWOG 9125 received the same chemotherapy and the chemosensitizers verapamil 240 mg bid and quinine 40 mg tid. Chemosensitizers were begun 24 hours before chemotherapy and continued for a total of 6 days. RESULTS: Eighty-one patients were eligible for each study. The complete response (CR) rates were 39% on SWOG 9125 and 31% on SWOG 9240. With a median follow-up of 5.8 years on SWOG 9125 and 4.5 years on SWOG 9240, the 2-year failure-free survival (FFS) rate was 42% on SWOG 9125 and 41% on SWOG 9240. Two-year overall survival (OS) rate was 64% on SWOG 9125 and 58% on SWOG 9240. These results are comparable to a 44% CR rate, a 2-year FFS of 46%, and 2-year OS of 63% observed in 225 patients treated with CHOP on INT 0067 (SWOG 8516). CONCLUSION: CVAD combination chemotherapy alone or with the chemosensitizers verapamil and quinine is not promising therapy with respect to improved response or OS in intermediate- and high-grade advanced-stage NHL.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2000

Phase II evaluation of interleukin-4 in patients with non-Hodgkin's lymphoma: a Southwest Oncology Group trial.

We performed a phase II, Southwest Oncology Group (SWOG) clinical trial of recombinant human interleukin-4 (rhuIL-4) in patients with previously treated non-Hodgkin's lymphoma (NHL). We studied 18 eligible patients with low-grade and 21 patients with intermediate- or high-grade NHL. All patients had received prior chemotherapy. A protocol amendment after the first four patients reduced the frequency of s.c. rhuIL-4 administration from daily to 3 times per week at 3 microg/kg and limited the number of prior chemotherapy regimens allowed. We documented no complete or partial responses in the low-grade NHL group [0%; 95% confidence interval (CI) 0-19%]. One patient in the intermediate/high-grade NHL group developed a partial response lasting longer than 15 months (5%; 95% CI 0-24%). Median survivals for the low- and intermediate/high-grade NHL groups were 15 and 13 months, respectively. Common toxicities included: arhralgia/myalgia, fatigue/malaise/lethargy, fever, headache, nausea and rigors/chills. Cardiac toxicity, gastrointestinal ulceration and nasal congestion due to rhuIL-4 were not prominent toxicities in our patients. Our previously treated NHL patients tolerated s.c. rhuIL-4 at a dose of 3 microg/kg given 3 times per week, but objective response rarely occurred. Further evaluation of rhuIL-4 in these patient populations does not appear warranted.

Adult↗

PubMed2000

Interferon alpha consolidation after intensive chemotherapy does not prolong the progression-free survival of patients with low-grade non-Hodgkin's lymphoma: results of the Southwest Oncology Group randomized phase III study 8809.

PURPOSE: S8809 is a randomized phase III trial determining whether intensive cytoreductive treatment, followed by interferon consolidation at the time of minimal residual disease, prolongs the progression-free survival (PFS) or overall survival (OS) of indolent lymphoma patients. PATIENTS AND METHODS: Five hundred seventy-one patients with previously untreated stage III or IV low-grade non-Hodgkin's lymphoma were registered. Patients received six to eight cycles of prednisone, methotrexate, doxorubicin, cyclophosphamide, and etoposide/mechlorethamine, vincristine, procarbazine, and prednisone (ProMACE[day 1]-MOPP[day 8]) chemotherapy or chemotherapy plus radiotherapy. Responding patients were randomized to observation alone or to interferon consolidation. Interferon alpha-2b 2 mU/m(2) was given subcutaneously three times weekly for 2 years. RESULTS: Two hundred sixty-eight eligible patients were randomized to interferon alpha consolidation (n = 144) or observation alone (n = 124). With a median follow-up time from randomization among patients still alive of 6.2 years, the median PFS time was 4.1 years for patients who received interferon consolidation therapy and 3.2 years for patients who were observed after ProMACE-MOPP induction (P =.25). The adjusted hazard ratio for relapse for observation to interferon was 0.83 (95% confidence interval [CI], 0.61 to 1.13). The median OS has not been reached in either group. At 5 years, OS is 78% for the interferon group and 77% for the observation group (P =.65). The adjusted hazard ratio for survival for observation to interferon is 1.11 (95% CI, 0.69 to 1. 79). CONCLUSION: Interferon alpha consolidation therapy after intensive treatment with anthracycline-containing combination chemotherapy and involved-field radiation therapy does not prolong the PFS or OS of patients with low-grade non-Hodgkin's lymphoma.

Adult↗

PubMed1999

Using the bootstrap for estimation in group sequential designs: an application to a clinical trial for nasopharyngeal cancer.

We investigate a resampling method for bias correction in group sequential designs with censored survival data using logrank testing. The method draws nested bootstrap samples of different sizes from the observed data in order to mimic the large sample independent increment property of statistics resulting from sequential designs. The motivation for this problem came from the very positive results and early termination of a randomized clinical trial for nasopharyngeal cancer co-ordinated by the Southwest Oncology Group.

Antimetabolites, Antineoplastic↗

PubMed1999

False positive rates of randomized phase II designs.

The randomized Phase II design for the purpose of selecting a treatment for eventual Phase III testing has recently gained popularity in cancer clinical research. Unfortunately, along with its wider use also come frequent misapplications. The major misuse of the design is the treatment of the Phase II results as ends in themselves without further, definitive evaluation. For binary and censored exponential survival data, we quantify the chance of observing "impressive" between-group differences when underlying distributions are exactly the same in 2-, 3-, and 4-arm selection designs. Depending on one's view of what is impressive, the "false-positive" rates range from 20% to over 40%. We stress that randomized Phase II results are pilots to Phase III evaluations. One should not regard them as conclusive. We caution especially against the inclusion of control arms in such designs because of the propensity for erroneous inferences. We also discuss the inappropriate practice of performing post-hoc hypothesis testing and presenting p-values that are less than 0.05.

Clinical Trials, Phase II as Topic↗

PubMed1999

Phase II trial of menogaril in non-Hodgkin's lymphomas: a Southwest Oncology Group trial.

PURPOSE: To assess the efficacy and toxicity of menogaril against non-Hodgkin's lymphoma (NHL) in a group of previously treated patients. PATIENTS AND METHODS: Sixty-two eligible patients with a histologic diagnosis of NHL were enrolled, 35 of who had intermediate or high-grade histologies and 27 of who had low-grade lymphomas. Patients with intermediate or high-grade lymphomas had received only 1 prior chemotherapy regimen, while patients with low-grade histologies had received 1 or 2 prior chemotherapy regimens. Menogaril was administered at 160 mg/m2 intravenously over 1 hour, once every 28 days. RESULTS: Among the 35 patients with intermediate or high-grade lymphomas who were evaluable for response, 6 of 35 patients achieved a partial response (PR) for a response rate of 17% (95% confidence interval: 7%-34%). Median survival in this group of patients was 13 months. For those patients with low-grade lymphoma, 5 of 26 patients achieved a PR for a response rate of 19% (95% confidence interval: 6%-38%). No complete responses were observed in either patient group. The incidence of serious (grade 3 or 4) toxicity for those with intermediate/high-grade and low-grade lymphomas was 43% and 44%, respectively. Most of these toxic effects consisted of reversible myelosuppression. Menogaril was discontinued in 2 patients due to prolonged neutropenia. Cardiotoxicity was observed in 4 patients, requiring discontinuation of the drug in 1 patient. No treatment-related deaths occurred and the overall toxicity was felt to be acceptable. CONCLUSION: The observed antitumor activity of single agent menogaril against both intermediate/high-grade and low-grade lymphomas was modest. Further exploration of this agent in patients with non-Hodgkin's lymphomas does not seem warranted.

Aged↗

PubMed1999

Adaptive regression splines in the Cox model.

We develop a method for constructing adaptive regression spline models for the exploration of survival data. The method combines Cox's (1972, Journal of the Royal Statistical Society, Series B 34, 187-200) regression model with a weighted least-squares version of the multivariate adaptive regressi on spline (MARS) technique of Friedman (1991, Annals of Statistics 19, 1-141) to adaptively select the knots and covariates. The new technique can automatically fit models with terms that represent nonlinear effects and interactions among covariates. Applications based on simulated data and data from a clinical trial for myeloma are presented. Results from the myeloma application identified several important prognostic variables, including a possible nonmonotone relationship with survival in one laboratory variable. Results are compared to those from the adaptive hazard regression (HARE) method of Kooperberg, Stone, and Truong (1995, Journal of the American Statistical Association 90, 78-94).

Biometry↗

PubMed1998

Chemotherapy alone compared with chemotherapy plus radiotherapy for localized intermediate- and high-grade non-Hodgkin's lymphoma.

BACKGROUND: Patients with clinically localized, intermediate- or high-grade non-Hodgkin's lymphoma usually receive initial treatment with a doxorubicin-containing regimen such as cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Pilot studies suggest that eight cycles of CHOP alone or three cycles of CHOP followed by involved-field radiotherapy are effective in such patients. METHODS: We compared these two approaches in a prospective, randomized, multi-institutional study. The end points were progression-free survival, overall survival, and life-threatening or fatal toxic effects. Two hundred eligible patients were randomly assigned to receive CHOP plus radiotherapy, and 201 received CHOP alone. RESULTS: Patients treated with three cycles of CHOP plus radiotherapy had significantly better progression-free survival (P=0.03) and overall survival (P=0.02) than patients treated with CHOP alone. The five-year estimates of progression-free survival for patients receiving CHOP plus radiotherapy and for patients receiving CHOP alone were 77 percent and 64 percent, respectively. The five-year estimates of overall survival for patients receiving CHOP plus radiotherapy and for patients receiving CHOP alone were 82 percent and 72 percent, respectively. The adverse effects included one death in each treatment group. Life-threatening toxic effects of any type were seen in 61 of 200 patients treated with CHOP plus radiotherapy and in 80 of 201 patients treated with CHOP alone (P=0.06). The left ventricular function was decreased in seven patients who received CHOP alone, whereas no cardiac events were recorded in the group receiving CHOP plus radiotherapy (P=0.02). CONCLUSIONS: Three cycles of CHOP followed by involved-field radiotherapy are superior to eight cycles of CHOP alone for the treatment of localized intermediate- and high-grade non-Hodgkin's lymphoma.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1998

The Purpose-in-Life Test and religious denomination: Protestant and Catholic scores in an elderly population.

The Purpose-in-Life Test (PIL) was administered to a group of 118 elderly persons from three senior citizen centers. Data were obtained on religious denomination. Results suggested that whether a person was Protestant or Catholic had no significant effect on PIL scores, with mean scores almost identical. What seemed to be important was how meaningful spirituality was to the person. Those who scored high on an index of spirituality also scored high on the PIL.

Aged↗

PubMed1998

Mobilized CD34+ cells selected as autografts in patients with primary light-chain amyloidosis: rationale and application.

BACKGROUND: Concern about tumor cell contamination in stem cell preparations has led to the use of CD34+ cell selection as a means of purging. Increasing the number of CD34+ cells per leukapheresis may help to provide an adequate dose of CD34+ cells. STUDY DESIGN AND METHODS: The reverse transcriptase polymerase chain reaction (RT-PCR) was employed to clone overexpressed clonotypic immunoglobulin light-chain variable region genes (Ig VL) from bone marrows of patients with primary light-chain amyloidosis (AL). Patient-specific primers were designed to evaluate stem cell collections for contamination. CD34+ cell selection was performed on components from AL patients who underwent mobilization with granulocyte-colony-stimulating factor (G-CSF) (filgrastim; 16 microg/kg/d for 4 days) and collection by large-volume leukapheresis (LVL;25L) on Days 4 and 5. The selected cells alone were transfused after patients received mephalan (200 mg/m2). RESULTS: Contamination was found in collections from 4 to 7 patients, which provided the rationale for a subsequent trial of CD34+ cell selection. The median number of CD34+ cells per kg collected on Days 4 and 5, and in toto, was 4.0 x 10(6)(1.1-12.7), 7.9 x 10(6)(1.8-12.7), and 10.7 x 10(6)(2.9-25.4), respectively (n = 9 patients). The median yield per selection was 38 percent, with a purity of 85 percent (45-97%), and the viability of CD34+ cells averaged 96.4 +/- 3.6 percent (n = 18 selections). The median number of CD34+ cells infused was 5.9 x 10(6) per kg (2.1-10.1). In comparison with AL patients given unselected autografts, patients receiving selected CD34+ cells experienced similar reconstitution of neutrophils and platelets but slower lymphocyte recovery. CONCLUSION: Patients with AL often have contamination with clonotypic cells in their blood autografts. G-CSF mobilization and LVL provide components that allow the selection of adequate doses of CD34+ cells. The use of CD34+ cells in patients with AL achieves rapid neutrophil and platelet recovery but delayed lymphocyte recovery. CD34+ cell selection is feasible in the treatment of AL, but its effectiveness in purging clonotypic cells remains to be ascertained.

Adult↗

PubMed1998

Autologous bone marrow transplantation for patients with relapsed or refractory diffuse aggressive non-Hodgkin's lymphoma: value of augmented preparative regimens--a Southwest Oncology Group trial.

PURPOSE: To determine the toxicity and prognosis of patients with relapsed and refractory diffuse aggressive non-Hodgkin's lymphoma (NHL) who underwent an autologous bone marrow transplant (ABMT) using augmented preparative regimens, treated in a major cooperative group setting, and to examine prognostic factors for outcome. PATIENTS AND METHODS: Ninety-four patients with either chemosensitive (50 patients) or chemoresistant (44 patients) relapse, including 22 who failed induction chemotherapy, were treated with high-dose cyclophosphamide and etoposide with total-body irradiation (TBI) (67 patients) or an augmented carmustine (BCNU), cyclophosphamide, and etoposide (BCV) preparative regimen (27 patients) and an ABMT at 16 Southwest Oncology Group (SWOG) transplant centers. All relapsing patients were required to undergo a minimum of two courses of salvage therapy to determine chemosensitivity before transplant. Overall (OS) and progression-free survival (PFS) were determined and a Cox regression model was used to assess potential prognostic variables. RESULTS: Of the 94 eligible patients, there were 10 (10.6%) deaths before day 50 posttransplant because of infection (six deaths), hemorrhagic alveolitis (three deaths), or bleeding (one death). The median 3-year PFS and OS for the entire group was 33% and 44%. For those with chemosensitive disease the PFS and OS were 42% and 55%, whereas for those with chemoresistant disease the PFS and OS were 22% and 29%. The PFS and OS for those failing induction chemotherapy were 27% and 32%. The relapse rates within the first 3 years for the chemosensitive relapse, chemoresistant, and induction failure groups were 61%, 40%, and 59%, respectively. For both PFS and OS, only disease status at transplant was a significant factor in the multivariate Cox model. CONCLUSION: These results single institutional pilot trials exploring augmented preparative regimens. Patients undergoing transplantation for resistant disease, particularly those failing induction chemotherapy, appear to have an improved prognosis as compared with reports using standard preparative regimens. Therapies other than manipulation of standard preparative regimens appear to be required to decrease relapses following autotransplantation.

Adult↗

PubMed1998

Phase II trial of paclitaxel by 24-hour continuous infusion for relapsed non-Hodgkin's lymphomas: Southwest Oncology Group trial 9246.

PURPOSE: The Southwest Oncology Group (SWOG) recently conducted a multiinstitutional phase II trial to determine the complete response (CR) and partial response (PR) rates, toxicities, and progression-free and overall survivals of patients with relapsed non-Hodgkin's lymphomas (NHLs) treated with a 24-hour continuous infusion of paclitaxel at a dose of 175 mg/m2. PATIENTS AND METHODS: Sixty-six patients with relapsed NHL who had received minimal prior therapy (one prior chemotherapy regimen for intermediate- to high-grade NHL [44 patients] or one or two prior regimens for low-grade NHL [22 patients]) were premedicated with dexamethasone, diphenhydramine, and cimetidine and then treated with continuous intravenous infusion paclitaxel over 24 hours every 21 days. RESULTS: Eleven of 66 patients (17%) achieved rigorously documented objective remissions, including two CRs (3%) and nine PRs (14%). In addition, another five patients (8%) achieved apparent PRs on a single computed tomographic (CT) scan. Responses were brief, lasting a median of 3 months (5 months for indolent lymphomas and 3 months for intermediate- to high-grade lymphomas). Grade 4 or 5 granulocytopenia was the only common serious toxicity, and occurred in 42 of 66 patients (64%). CONCLUSION: Paclitaxel is generally well tolerated when given as a continuous infusion of 175 mg/m2 over 24 hours, despite predictable granulocytopenia. However, single-agent paclitaxel has modest clinical efficacy compared with other available treatments for relapsed NHL.

Adult↗

PubMed1998

Chemoradiotherapy versus radiotherapy in patients with advanced nasopharyngeal cancer: phase III randomized Intergroup study 0099.

PURPOSE: The Southwest Oncology Group (SWOG) coordinated an Intergroup study with the participation of Radiation Therapy Oncology Group (RTOG), and Eastern Cooperative Oncology Group (ECOG). This randomized phase III trial compared chemoradiotherapy versus radiotherapy alone in patients with nasopharyngeal cancers. MATERIALS AND METHODS: Radiotherapy was administered in both arms: 1.8- to 2.0-Gy/d fractions Monday to Friday for 35 to 39 fractions for a total dose of 70 Gy. The investigational arm received chemotherapy with cisplatin 100 mg/m2 on days 1, 22, and 43 during radiotherapy; postradiotherapy, chemotherapy with cisplatin 80 mg/m2 on day 1 and fluorouracil 1,000 mg/m2/d on days 1 to 4 was administered every 4 weeks for three courses. Patients were stratified by tumor stage, nodal stage, performance status, and histology. RESULTS: Of 193 patients registered, 147 (69 radiotherapy and 78 chemoradiotherapy) were eligible for primary analysis for survival and toxicity. The median progression-free survival (PFS) time was 15 months for eligible patients on the radiotherapy arm and was not reached for the chemo-radiotherapy group. The 3-year PFS rate was 24% versus 69%, respectively (P < .001). The median survival time was 34 months for the radiotherapy group and not reached for the chemo-radiotherapy group, and the 3-year survival rate was 47% versus 78%, respectively (P = .005). One hundred eighty-five patients were included in a secondary analysis for survival. The 3-year survival rate for patients randomized to radiotherapy was 46%, and for the chemoradiotherapy group was 76% (P < .001). CONCLUSION: We conclude that chemoradiotherapy is superior to radiotherapy alone for patients with advanced nasopharyngeal cancers with respect to PFS and overall survival.

Adolescent↗

PubMed1998

The design and development of a gloveless endoskeletal prosthetic hand.

Current prosthetic hands, although functional, have the potential of being improved significantly. We report here the design and development of a novel prosthetic hand that is lighter in weight, less expensive, and more functional than current hands. The new prosthesis features an endoskeleton embedded in self-skinning foam that provides a realistic look and feel and obviates the need for a separate cosmetic glove. The voluntary-closing mechanism offers variable grip strength. Placement of joints at three locations (metacarpophalangeal and proximal and distal interphalangeal) within each of four fingers affords realistic finger movement. High-strength synthetic cable attached to the distal phalanx of each finger is used to effect flexion. A multiposition passive thumb provides both precision and power grips. The new prosthesis can securely grasp objects with various shapes and sizes. Compared to current hands, weight has been reduced by approximately 50%, and cable excursion required for full finger flexion by more than 50%. The new endoskeletal prosthesis requires approximately 12-24% less force input to grasp a variety of everyday objects, largely due to its adaptive grip. Production cost estimates reveal the new prosthesis to be significantly less expensive than current prosthetic hands.

Activities of Daily Living↗

PubMed1997

Follicular lymphomas: do histologic subtypes predict outcome?

There has been a long history of debate as to whether histologic subtypes of follicular lymphoma are associated with unique outcomes. The controversy has been fueled by studies of small patient groups having heterogeneous prognostic factors followed for short intervals, and by a new proposal for the classification of lymphomas (REAL). The current report provides insight into the controversy by using a large group of patients of similar stage and treatment followed for up to 25 years.

Adult↗