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R T Silver

Publications and source records attributed to R T Silver.

At least 37 records · Page 2Linked to original sources
PubMed1997

Value of molecular monitoring during the treatment of chronic myeloid leukemia: a Cancer and Leukemia Group B study.

PURPOSE: Disappearance of the Philadelphia chromosome during treatment for chronic myeloid leukemia (CML) has become an important therapeutic end point. To determine the additional value of molecular monitoring during treatment for CML, we performed a prospective, sequential analysis using quantitative Southern blot monitoring of BCR gene rearrangements of blood and marrow samples from Cancer and Leukemia Group B (CALGB) study 8761. PATIENTS AND METHODS: Sixty-four previously untreated adults with chronic-phase CML who were enrolled onto CALGB 8761, a molecular-monitoring companion study to a treatment study for adults with chronic-phase CML (CALGB 9013). Treatment consisted of repetitive cycles of interferon alfa and low-dose subcutaneous cytarabine. Blood and marrow Southern blot quantitation of BCR gene rearrangements was compared with marrow cytogenetic analysis before the initiation of treatment and of specified points during therapy. Reverse-transcriptase polymerase chain reaction (RT-PCR) analysis was performed to detect residual disease in patients who achieved a complete response by Southern blot or cytogenetic analysis. RESULTS: Quantitative molecular monitoring by Southern blot analysis of blood samples was found to be equivalent to marrow monitoring at all time points. Twelve of 62 (19%) follow-up samples studied by Southern blot analysis had a complete loss of BCR gene rearrangement in matched marrow and blood specimens. Southern blot monitoring of blood samples was also found to be highly correlated to marrow cytogenetic evaluation at all points, although there were four discordant cases in which Southern blot analysis of blood showed no BCR gene rearrangement, yet demonstrated from 12% to 20% Philadelphia chromosome-positive metaphase cells in the marrow. RT-PCR analysis detected residual disease in five of six patients in whom no malignant cells were detected using Southern blot or cytogenetic analyses. CONCLUSION: Quantitative Southern blot analysis of blood samples may be substituted for bone marrow to monitor the response to therapy in CML and results in the need for fewer bone marrow examinations. To avoid overestimating the degree of response, marrow cytogenetic analysis should be performed when patients achieve a complete response by Southern blot monitoring. This approach provides a rational, cost-effective strategy to monitor the effect of treatment of individual patients, as well as to analyze large clinical trials in CML.

Adult↗
PubMed1996

Postsurgical adjuvant chemotherapy of stage II breast carcinoma with or without crossover to a non-cross-resistant regimen: a Cancer and Leukemia Group B study.

PURPOSE: To compare two cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone (CMFVP) regimens with a doxorubicin-based regimen--vinblastine, doxorubicin, thiotepa, and Halotestin (Upjohn, Kalamazoo, MI) (VATH)--in patients with stage II node-positive breast carcinoma. METHODS: Nine hundred forty-five women were treated with a 6-week induction course of CMFVP. They were then randomized to receive one of two consolidation CMFVP regimens: 6-week courses or 2-week courses. Following completion of CMFVP consolidation, patients were again randomized to either continue the CMFVP regimen or to receive six escalating doses of VATH. RESULTS: Among all patients, with a median follow-up time of 11.5 years, there is no statistically significant difference in disease-free survival (DFS) between the two consolidation CMFVP regimens. VATH intensification treatment is statistically significantly superior to CMFVP in terms of DFS (P = .0040). For patients with one to three involved nodes, there is currently no significant difference between VATH and CMFVP; however, among those with four or more positive lymph nodes, there is a significant difference in favor of VATH (P = .0037). There is also improved overall survival with VATH (P = .043; median, > 14 years v 10 years). This difference is also statistically significant in patients with four or more involved lymph nodes, among postmenopausal patients, and among postmenopausal estrogen receptor-positive patients. CONCLUSION: Chemotherapy with crossover to escalating doses of VATH following CMFVP was well tolerated and effective. Inauguration of VATH as a treatment intensification at the eighth month produced a major increase in relapse-free and overall survival. The observation that sensitivity to VATH is retained so long after mastectomy raises questions about the proper duration of adjuvant chemotherapy and lends support to further investigation of cross-over designs in future trials to postoperative adjuvant chemotherapy regimens.

Adult↗
PubMed1995

Clinical pharmacology of cytarabine in patients with acute myeloid leukemia: a cancer and leukemia group B study.

The pharmacokinetics of cytarabine (ara-C) were determined in 265 patients with acute myeloid leukemia (AML) receiving ara-C (200 mg/m2 per day for 7 days as a continuous infusion) and daunorubicin during induction therapy. The mean (standard deviation) ara-C concentration at steady-state (Css) and systemic clearance (Cl) were 0.30 (0.13) microM and 134 (71) l/h per m2 respectively. Males had a significantly faster ara-C Cl (139 vs 131 l/h per m2, P = 0.025) than females. Significant correlations were noted between ara-C Cl and the pretreatment, peripheral white blood cell count (P = 0.005) and pretreatment blast count (P = 0.020). No significant differences in ara-C Css or Cl were noted in patients achieving complete remission compared with those failing therapy (P = 0.315, P = 0.344, respectively). No significant correlations were observed between ara-C pharmacokinetic parameters and several indices of patient toxicity. Our findings indicate that variability in ara-C disposition in plasma at this dosage level does not correlate with remission status or toxicity in patients with AML receiving initial induction therapy with ara-C and daunorubicin.

Acute Disease↗
PubMed1995

Characterization of chromosome 11 with a complex inversion and deletion in an AML [M2] using fluorescence in situ hybridization.

We report on a new case of AML [M2] where chromosome 11 was rearranged in a highly complex manner involving band 11q23. Routine G banding failed to identify the nature of this aberration which later was accomplished using whole chromosome 11-specific painting probe by the FISH technique. Chromosome 11 band q23 is frequently involved in reciprocal translocations with various chromosomes, but to have sole morbidity of such a complex nature is an atypical finding in AML [M2]. The band q23 of chromosome 11 involves the mixed lineage leukemia gene and rearrangement of this chromosomal region has been found in a variety of neoplasias. Henceforth, its precise identification has become imperative for classification of hematological malignancies and in turn to devise therapeutic strategies.

Bone Marrow↗
PubMed1995

Recombinant alpha-2b-interferon in therapy of previously untreated hairy cell leukemia: long-term follow-up results of study by Cancer and Leukemia Group B.

In 1985, Cancer and Leukemia Group B initiated a multi-institutional study to define the role of interferon alpha in therapy of previously untreated active hairy cell leukemia (HCL). This is a long-term follow-up report of the study. Fifty-five evaluable patients were treated with recombinant interferon-2b 2 million units/m2 subcutaneously three times a week for 1 year. Treatment was well tolerated; toxicity mainly consisted of flu-like syndrome and pancytopenia, both of a transient nature. Seventy-three percent of patients had objective beneficial responses with 8.3 months median time to achieve at least a partial response (PR). After 1 year of therapy, the patients have been observed for a median of 5 years. There was a continual trend towards relapse throughout this period but 28% have remained in remission beyond 6 years. Forty-six patients (83%) are alive at 6 years. Among the 40 patients who achieved at least a PR, there were 28 with splenomegaly at the beginning of study: the spleen size was reduced in all with interferon alpha therapy and none required splenectomy. This study confirms the results of other investigators, and demonstrates that recombinant alpha interferon-2b is an effective agent for treatment of hairy cell leukemia.

Adult↗
PubMed1994

Prognostic importance of mutations in the ras proto-oncogenes in de novo acute myeloid leukemia.

Mutations of the N- and K-ras genes are the most frequent genetic aberrations in acute myeloid leukemia (AML) and their detection in preleukemic conditions such as the myelodysplastic syndrome (MDS) suggests a role in the earliest phases of leukemogenesis. Despite these observations, little is known about the clinical importance of ras mutations in AML. We studied the clinical impact of ras mutations in 99 patients with de novo AML. All patients were treated in two prospective multicenter trials. The polymerase chain reaction was used to amplify areas surrounding the codons 12, 13, and 61 of the three ras genes N-, K-, and H-ras from DNA from bone marrow cells, ras mutations were detected by an algorithm based on allele-specific oligonucleotide hybridization. Eighteen of 99 (18%) patients harbored mutations in either N- or K-ras. All of the observed mutations occurred in N-ras (N = 10) and K-ras (N = 5) or concurrently in both N- and K-ras (N = 3). There were no significant differences between ras-negative and ras-positive patients according to age, sex, blood counts, cytogenetic abnormalities, or French-American-British classification. However, univariate analysis suggested a longer survival in ras-positive patients (P = .11). When adjusted for age, which was the most important factor affecting outcome, the presence of a ras mutation emerged as a significant predictor for improved survival (P = .03) and along with lower bone marrow blast counts (P = .02) and better cytogenetic category (P = .01). However, the presence of an aberrant ras allele was strongly correlated with lower bone marrow blast counts (P = .007). Thus, whether a mutation in the N-ras or K-ras proto-oncogenes directly affects treatment outcome or indirectly through an association with lower leukemic burden remains to be determined. Nevertheless, these findings counter the prevailing bias that oncogene mutations lead to more aggressive behavior in human malignancies.

Adult↗
PubMed1994

Combination trial of subcutaneous recombinant alpha 2 b interferon and oral cyclophosphamide in follicular low-grade non-Hodgkin's lymphoma.

The follicular non-Hodgkin's lymphomas (NHL) have been among those tumors demonstrated to show frequent responses to alpha interferon in phase I and II clinical trials. In addition, there are data suggesting that alpha interferon demonstrates synergistic antitumor activity with alkylating agents in animal models for a number of tumors. Based on these data, Cancer and Leukemia Group B (CALGB) undertook a phase II pilot study of the combination of interferon rIFN alpha 2b (2 x 10(6) IU/m2 s.c. tiw) and cyclophosphamide (100 mg/m2 per day orally) with the ultimate purpose of examining this combination as long-term therapy of follicular lymphoma in comparison to oral cyclophosphamide alone. One hundred five advanced stage III or IV eligible patients with pathologically diagnosed International Working Formulation B or C histology were entered on CALGB 8553 to determine toxicity and response rates to the combination. Both previously chemotherapy-treated patients (32) and patients without prior chemotherapy (73) were entered on study. For patients without prior chemotherapy the overall response rate to the combination regimen was 86% with 58% of chemotherapy-treated patients achieving complete response. Chemotherapy-treated patients had a total response rate of 62% with only 25% complete responders. Complete responses in patients without prior chemotherapy were positively correlated with absence of B symptoms, and good performance status and negatively correlated with the histological subtype of follicular mixed small-cleaved and large cell histology (IWF C); only performance status was significantly correlated with response in patients who had previously had chemotherapy. Survival at 5 years is estimated to be 63% for those without chemotherapy and 39% for those previously treated with chemotherapy patients. The maximum toxicities experienced during therapy with the combination regimen of cyclophosphamide and interferon alpha were primarily related to myelosuppression. Sixty-seven percent of patients without prior chemotherapy and 65% of patients receiving prior chemotherapy experienced severe leukopenia while severe thrombocytopenia and anemia occurred in 6-31% of these patients. Non-myelosuppressive toxicities were less frequently seen. These response rates are similar to those achieved in a previous CALGB trial with oral cyclophosphamide as a single agent, although severe myelotoxicity was increased to approximately 60% of patients from less than 10% with the single-agent therapy. The combination of alpha interferon and cyclophosphamide administered in this fashion is safe when peripheral counts are carefully monitored. Randomized studies of this regimen in comparison to oral cyclophosphamide are currently in progress.

Administration, Oral↗
PubMed1993

Cigarette smoking and risk of acute leukemia: associations with morphology and cytogenetic abnormalities in bone marrow.

BACKGROUND: Cigarette smoking may be a risk factor for leukemia. No detailed biological mechanism has been proposed, but a causal link is made plausible by evidence of systemic effects of cigarette smoke and the presence in cigarette smoke of chemicals that have been associated with leukemia risk. PURPOSE: Our purpose was to investigate the leukemia risk associated with cigarette smoking in a multicenter case-control study of acute leukemias in adults. METHODS: Adults aged 18-79 with newly diagnosed leukemia were contacted to participate in this epidemiologic study when they entered a clinical trial to be treated under protocols sponsored by Cancer and Leukemia Group B. Smoking histories for 610 patients with acute leukemia and 618 population control subjects were obtained by telephone interviews. We examined bone marrow samples and classified patients by morphology of leukocyte precursor cells according to the French-American-British (FAB) classification system and, for 378 patients, by the presence or absence of specific clonal chromosome abnormalities. We calculated odds ratios (ORs) for risk of leukemia associated with smoking cigarettes. ORs were adjusted for age, race, and sex. RESULTS: Smoking was associated with only a modest increase in risk for leukemia overall (adjusted OR = 1.13; 95% confidence interval [CI] = 0.89-1.44). However, among participants aged 60 and older, smoking was associated with a twofold increase in risk for acute myeloid leukemia (AML) (OR = 1.96; 95% CI = 1.17-3.28) and a threefold increase in risk for acute lymphocytic leukemia (ALL) (OR = 3.40; 95% CI = 0.97-11.9). Among older persons, risks increased with amount and duration of smoking. Smoking was associated with increased risk for AML classified as FAB type M2 at all ages, with ORs of 1.70 (95% CI = 1.00-2.90) for those younger than 60 and 3.50 (95% CI = 1.53-8.03) for those aged 60 and older. Smoking was also associated with ALL type L2 at all ages, with ORs of 1.72 (95% CI = 0.90-3.27) for those younger than 60 and 5.34 (95% CI = 1.03-27.6) for those who were older. Smoking was more common among patients with specific chromosome abnormalities in AML [-7 or 7q-, -Y, +13] and in ALL [t(9;22)(q34;q11)]. CONCLUSIONS: Cigarette smoking is associated with increased risk for leukemia and may lead to leukemias of specific morphologic and chromosomal types. The association varies with age. IMPLICATION: Examining discrete subtypes of disease may permit more accurate assessment of risk. As standardized morphologic classification and cytogenetic and molecular evaluation of leukemia patients becomes more common, epidemiologic studies that take advantage of these advances will begin to contribute to the identification of additional risk factors and mechanisms in acute leukemia.

Acute Disease↗
PubMed1992

Hodgkin disease survivors at increased risk for problems in psychosocial adaptation. The Cancer and Leukemia Group B.

BACKGROUND: The long-term psychosocial adaptations of 273 survivors of advanced Hodgkin disease were assessed to determine the nature and extent of problems experienced and to identify those at high risk for maladaptation. METHODS: Hodgkin disease survivors were identified who initially had been treated in clinical trials within the Cancer and Leukemia Group B from 1966 to 1986, were currently disease free, and had completed treatment for a minimum of 1 year. All survivors had advanced Hodgkin disease (with disease diagnosed at a mean age of 28 years). Survivors were at a mean age of 37 years at the time of interview (6.3 years after treatment completion), and 60% were male. Survivors were interviewed over the telephone 7-10 days after questionnaires were mailed to them concerning their psychological, social, vocational, and sexual functioning. RESULTS: Psychological distress was found to be elevated by one standard deviation (SD) above that of healthy subjects on the Brief Symptom Inventory, and 22% met the criterion suggested for a psychiatric diagnosis. In addition, the following problems were reported by survivors to be a consequence of having had Hodgkin disease: denial of life (31%) and health (22%) insurance, sexual problems (37%), conditioned nausea in response to reminders of chemotherapy (39%), and a negative socioeconomic effect (36%). Survivors found to be at high risk for maladaptation were: men earning less than $15,000 per year or who were currently unemployed; unmarried individuals; those with serious illnesses since treatment completion; and those who were less educated. CONCLUSIONS: These findings suggest that including a routine assessment of these factors would help to target survivors in need of additional evaluation and treatment.

Adaptation, Psychological↗
PubMed1992

Disappearance of a highly unusual clone, 46,XY,del(7)(p12),t(9;22)(q34;q11) in chronic myeloid leukemia after treatment with recombinant interferon and cytosine arabinoside.

A patient with the typical features of the stable phase of chronic myeloid leukemia (CML) displayed two karyotypically related subclones. In addition to the t(9;22), cells from one clone contained a deletion of the short arm of chromosome 7, del(7)(p12), [46,XY,del(7)(p12),t(9;22)(q34;q11)]; the other contained only the standard translocation [46,XY,t(9;22)(q34;q11)]. Cells with a deletion of the short arm of chromosome 7 at band p12 as the only additional abnormality have not been observed previously in CML. Conventional chemotherapy with hydroxyurea and then with recombinant interferon-alpha (rIFN-alpha) did not reduce the population of either subclone. However, after treatment with a combination of rIFN-alpha and low-dose cytosine arabinoside (LoDac) continuously infused subcutaneously (s.c.), cells from the clone with the deleted chromosome 7 disappeared and normal metaphases were demonstrable.

Adult↗
PubMed1992

Chronic myeloid leukemia.

Chronic myeloid leukemia is an enigma in origin and a source of frustration in treatment because until recently no real progress had been made in altering its natural history. Nevertheless, recent advances in cell biology and molecular genetics, and a plethora of morphologic, biochemical, and cytogenetic data of potential clinical relevance have yielded new data regarding this disease. The use of marrow transplantation and recombinant interferon have been of significant clinical importance, although their roles in the overall treatment of the disease remain to be determined.

Bone Marrow Transplantation↗
PubMed1992

Attempted prevention of blast crisis in chronic myeloid leukemia by the use of pulsed doses of cytarabine and lomustine. A Cancer and Leukemia Group B study.

An attempt to prevent the blast crisis in chronic myeloid leukemia by the use of pulsed doses of (cytarabine cytosine arabinoside) and lomustine was attempted as a cooperative group study by Cancer and Leukemia Group B. The basis for this study was to delay the development of blast crisis by pulsing dose of drugs known to be effective against emerging "blast" cells. The experimental arm which consisted of cytarabine and lomustine did not produce overall results superior to conventional treatment with busulfan. This was related to the non-hematologic effects of the combination which produced significant gastrointestinal toxicity leading to relatively early discontinuation of the combination. Nevertheless, the trial design allowed relatively prompt discontinuation of experimental arm and cross-over to conventional treatment with either hydrea or busulfan. No evidence existed that the use of new drug combinations in CML prejudiced the patient's chance to response to conventional chemotherapy. Thus, a role model for future trials in this disease was developed. With the development of the interferons and other experimental forms of therapy this conceptual development may be of significance.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Lymphomatoid papulosis: case report of a patient managed with radiation therapy and review of the literature.

Lymphomatoid papulosis is an elusive and very rare skin disorder. It is clinically benign but histologically "atypical," and about 20% of affected patients go on to develop a lymphoreticular malignancy, usually Hodgkin's disease, or mycosis fungoides. A wide variety of treatments to prevent recurrence and improve local control have been suggested, but the results have been poor. We report on a patient with two nonhealing lymphomatoid papulosis lesions treated successfully with electron beam therapy and describe our technique. The need for close follow-up of all patients with this condition cannot be overemphasized.

Humans↗
PubMed1991

The effects of postinduction intensification treatment with cytarabine and daunorubicin in adult acute lymphocytic leukemia: a prospective randomized clinical trial by Cancer and Leukemia Group B.

Cancer and Leukemia Group B undertook a randomized trial of intensification treatment in adults aged 15 to 79 years with acute lymphocytic leukemia (ALL) in complete remission (CR). Daunorubicin (DNR), prednisone, vincristine (VCR), intrathecal (IT) methotrexate (MTX), and asparaginase produced 177 CRs in 277 patients. One hundred fifty-one patients were randomly assigned to receive treatment as follows: 74 received intensive cytarabine and DNR, and 77 received cycles of mercaptopurine (6-MP) and MTX, followed by 6MP, MTX, VCR, and prednisone for 3 years in all. One hundred twelve patients received CNS prophylaxis. Intensification produced major myelosuppression but did not improve remission duration (median, 21 months). Of the 151 patients with CRs who entered the intensification phase, 29% remain in continuous CR (43 to 117 months); in 19 patients, CRs have lasted for longer than 7 years. No relapses occurred after 60 months. Median survival from the time of randomization was 30 months. Those under 30 years of age responded more frequently, with longer CR and survival. While 53% of those aged 15 to 19 years remain in continuous CR, 92% of patients over 59 years have relapsed. The presence of a myeloid antigen on the leukemic cells was adversely prognostic for CR achievement and for survival. Pretreatment WBC and platelet levels independently affected CR duration and survival. Early M1 marrow development presaged longer remissions. CNS relapse occurred in 47 of 256 patients with normal CSF before treatment, in 29 before CNS prophylaxis. CNS disease occurred after CNS prophylaxis in 18 patients: 13 of 61 who had received standard premaintenance and five of 51 who received intensification. No advantage in CR duration or survival resulted from intensive treatment with DNR and cytarabine following induction of CR.

Adolescent↗