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Prevention of palmoplantar erythrodysesthesia (PPE) with an antiperspirant in breast cancer patients treated with pegylated liposomal doxorubicin (PLD), a placebo-controlled, double blinded, phase lll trial (SAKK 92/08). J Clin Oncol 2012. [DOI: 10.1200/jco.2012.30.15_suppl.9059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
9059 Background: PPE, also known as hand-foot syndrome, is a distinctive adverse drug reaction of PLD treatment. PLD has been detected in elevated concentrations in eccrine sweat glands in palms and soles. We postulated that prophylactic administration of an antiperspirant (F511 cream) prior and during treatment with PLD could decrease the incidence of PPE. Methods: Patients (pts) with metastatic breast cancer treated with PLD monotherapy ≥10mg/m2 per week applied an antiperspirant to the left or right hand and foot and a corresponding placebo to the opposite site with double-blinding for the content of the cream applied to either side (intra-patient randomization). The creams were applied once daily during the first week, then three times per week. The primary endpoint was the rate of PPE grade (G) ≥ 2 in the antiperspirant or placebo treated side. Pts were evaluable if they developed PPE G ≥ 2 or had received cumulatively at least 160mg/m2 PLD. Patient-reported extent of symptom burden was a secondary endpoint. Using McNemar’s matched pairs design 53 pts were needed to detect a difference of 20% between the sides with a significance level of 5% and power of 90%. Results: 52 of 90 pts from 11 Swiss centers included were evaluable. Median age was 64.5 years; median duration of PLD treatment was 12 weeks. 30 pts developed PPE G ≥ 2. In 3 pts PPE G ≥ 2 occurred on the placebo side but not on the antiperspirant side (p=0.097; table). PPE G ≥ 2 was borderline significantly more frequent in placebo foot than antiperspirant foot (p=0.048). Patient-reported extent of symptom burden showed a trend in favor of the antiperspirant side for skin problems (peeling, blistering, bleeding) in the group of pts with PPE G ≥ 2 (p=0.051). Conclusions: In this double-blind trial with intra-patient randomization we observed a trend towards less PPE G ≥ 2 with application of the antiperspirant cream F511 in pts treated with PLD as determined by the treating physician and reported by the pts. [Table: see text]
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Weekly x 4 induction therapy with the anti-CD20 antibody rituximab: effect on circulating t(14;18)(+) follicular lymphoma cells. CLINICAL LYMPHOMA 2001; 1:293-7. [PMID: 11707844 DOI: 10.3816/clm.2001.n.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Rituximab 375 mg/m(2) weekly x 4 has been reported to induce a 60% response rate in patients with relapsed follicular lymphomas (FL). Our aim was to examine the effect of this rituximab schedule on circulating FL cells in an ongoing multicenter study. One hundred fifty-four patients with FL were examined by nested polymerase chain reaction (PCR) at baseline for the presence of t(14;18) translocation-carrying lymphoma cells in bone marrow and/or blood. Sixty-four patients (42%) had PCR-detectable t(14;18)(+) FL cells. Pretreatment characteristics of these 64 patients were as follows: one had stage I, nine had stage II, 14 had stage III, and 40 had stage IV disease. Thirty-five patients had bulky disease (> or = 5 cm) and 25 patients had an elevated serum lactate dehydrogenase (LDH) level. Bone marrow was morphologically assessed in 64 patients, and 39 of these patients had an infiltration with FL cells. Blood samples from 51 patients were available for PCR analysis between weeks 8-12 after induction therapy, and 28 of these patients (55%) were PCR negative. Paired blood and bone marrow samples were available for PCR analysis from 39 patients between weeks 8-12 after induction therapy with rituximab. Thirteen of these patients (33%) did not have PCR-detectable cells in blood and bone marrow, while 26 patients (67%) still had circulating t(14;18)(+) cells in either bone marrow (eight patients), blood (one patient), or both (17 patients). PCR negativity in blood and bone marrow in 13 patients was statistically significantly associated with partial or complete response after induction therapy with rituximab (P = 0.006). However, clearance of PCR-detectable t(14;18)(+) cells in bone marrow and/or blood could not be associated with any low tumor burden pretreatment characteristics such as stages I/II, absence of morphological bone marrow infiltration or tumor bulk of > or = 5 cm, and normal serum LDH.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Murine-Derived
- Antigens, CD20/immunology
- Antineoplastic Agents/therapeutic use
- Chromosomes, Human, Pair 14/genetics
- Chromosomes, Human, Pair 18/genetics
- Cytogenetic Analysis
- Drug Administration Schedule
- Female
- Humans
- L-Lactate Dehydrogenase/metabolism
- Lymphoma, B-Cell/blood
- Lymphoma, B-Cell/drug therapy
- Lymphoma, B-Cell/enzymology
- Lymphoma, B-Cell/genetics
- Lymphoma, Follicular/blood
- Lymphoma, Follicular/drug therapy
- Lymphoma, Follicular/enzymology
- Lymphoma, Follicular/genetics
- Male
- Middle Aged
- Neoplasm Staging
- Neoplastic Cells, Circulating/drug effects
- Polymerase Chain Reaction
- Rituximab
- Translocation, Genetic
- Treatment Outcome
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The effect of Rituximab on patients with follicular and mantle-cell lymphoma. Swiss Group for Clinical Cancer Research (SAKK). Ann Oncol 2000; 11 Suppl 1:123-6. [PMID: 10707793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND Clinical activity of the anti CD-20 monoclonal antibody Rituximab has been reported in patients with follicular lymphoma (FL) and mantle-cell lymphoma (MCL). PATIENTS AND METHODS 120 patients with bi-dimensionally measurable FL or MCL (R.E.A.L. Classification) were treated with Rituximab 375 mg/m2/week for 4 weeks. A central pathology review confirmed the diagnosis of FL in 76 of 78 and of MCL in 39 of 42 cases. The response was evaluated after 8 weeks and confirmed after 12 weeks from the start of treatment. RESULTS The toxicity of the treatment was, as expected, grade 1-2 fever and rigors during the first infusion and mild asthenia during the treatment period. Serious adverse events, probably or possibly related to the study treatment, included four deaths (3 of cardiac origin, 1 caused by P. carinii pneumonia) and 10 further nonfatal cases, including a permanent agranulocytosis and one case of heart failure. Response rate at week 12 was 52% for FL and 22% for MCL. After treatment, the BCL-2 rearrangement disappeared in 15 of 29 blood but only in 5 of 23 bone marrow samples; BCL-1 disappeared in 5 of 12 blood and 0 of 7 bone marrow specimens, as determined by PCR. CONCLUSIONS Rituximab is an active agent for the treatment of FL, while its efficacy is modest in MCL. The effect in reducing minimal residual disease is more pronounced on the blood than it is on the bone marrow.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/adverse effects
- Antibodies, Monoclonal, Murine-Derived
- Antineoplastic Agents/administration & dosage
- Antineoplastic Agents/adverse effects
- Cardiovascular Diseases/chemically induced
- Female
- Fever/chemically induced
- Humans
- Logistic Models
- Lymphoma, Follicular/diagnosis
- Lymphoma, Follicular/drug therapy
- Lymphoma, Follicular/mortality
- Lymphoma, Mantle-Cell/diagnosis
- Lymphoma, Mantle-Cell/drug therapy
- Lymphoma, Mantle-Cell/mortality
- Male
- Middle Aged
- Predictive Value of Tests
- Prognosis
- Rituximab
- Severity of Illness Index
- Survival Analysis
- Survival Rate
- Treatment Outcome
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Saturable metabolism of continuous high-dose ifosfamide with mesna and GM-CSF: a pharmacokinetic study in advanced sarcoma patients. Swiss Group for Clinical Cancer Research (SAKK). Ann Oncol 1999; 10:1087-94. [PMID: 10572607 DOI: 10.1023/a:1008386000547] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The aim of this study was to assess the pharmacology, toxicity and activity of high-dose ifosfamide mesna +/- GM-CSF administered by a five-day continuous infusion at a total ifosfamide dose of 12-18 g/m2 in adult patients with advanced sarcomas. PATIENTS AND METHODS Between January 1991 and October 1992 32 patients with advanced or metastatic sarcoma were entered the study. Twenty-seven patients were pretreated including twenty-three with prior ifosfamide at less than 8 g/m2 total dose/cycle. In 25 patients (27 cycles) extensive pharmacokinetic analyses were performed. RESULTS The area under the plasma concentration-time curve (AUC) for ifosfamide increased linearly with dose while the AUC's of the metabolites measured in plasma by thin-layer chromatography did not increase with dose, particularly that of the active metabolite isophosphoramide mustard. Furthermore the AUC of the inactive carboxymetabolite did not increase with dose. Interpatient variability of pharmacokinetic parameters was high. Dose-limiting toxicity was myelosuppression at 18 g/m2 total dose with grade 4 neutropenia in five of six patients and grade 4 thrombocytopenia in four of six patients. Therefore the maximum tolerated dose was considered to be 18 g/m2 total dose. There was one CR and eleven PR in twenty-nine evaluable patients (overall response rate 41%). CONCLUSION Both the activation and inactivation pathways of ifosfamide are non-linear and saturable at high-doses although the pharmacokinetics of the parent drug itself are dose linear. Ifosfamide doses greater than 14-16 g/m2 per cycle appear to result in a relative decrease of the active metabolite isophosphoramide mustard. These data suggest a dose-dependent saturation or even inhibition of ifosfamide metabolism by increasing high dose ifosfamide and suggest the need for further metabolic studies.
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Quality of life in postmenopausal patients with breast cancer after failure of tamoxifen: formestane versus megestrol acetate as second-line hormonal treatment. Swiss Group for Clinical Cancer Research (SAKK). Eur J Cancer 1999; 35:913-20. [PMID: 10533471 DOI: 10.1016/s0959-8049(99)00028-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Swiss Group for Clinical Cancer Research (SAKK) compared efficacy and toxicity of formestane (250 mg intramuscularly (i.m.) every 2 weeks) versus megestrol acetate (MGA; 160 mg orally daily) as second-line treatment in postmenopausal patients with advanced breast cancer and disease progression while on tamoxifen treatment in a randomised trial (Thürlimann B, Castiglione M, Hsu Schmitz SF, et al. Eur J Cancer 1997, 33, 1017-1024). Quality of life (QL) was evaluated as a secondary endpoint (n = 177). Overall, 83% (669/805) of expected QL forms were received, 88% (155/177) at baseline, 88% (402/457) on study treatment, and 65% (112/171) at treatment failure. Patients with no impairment in performance status reported better physical well-being (P = 0.0001), mood (P = 0.0007) and coping (P = 0.03), and less tiredness (P = 0.0001) and appetite/sense of taste disturbance (P = 0.0001) at baseline. After adjustment for baseline, there was no statistically significant difference in QL by treatment. Baseline QL was strongly predictive for QL under treatment but not for time to treatment failure. In conclusion, the question of whether oestrogen deprivation (e.g. formestane) or addition of progesterone (MGA) has a more beneficial impact on QL needs further investigation. The subjective experience of second-line endocrine treatment varies considerably as a consequence of the large variation in the individual course of the disease and has to be judged on an individual basis.
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Defining clinical benefit in postmenopausal patients with breast cancer under second-line endocrine treatment: does quality of life matter? J Clin Oncol 1999; 17:1672-9. [PMID: 10561203 DOI: 10.1200/jco.1999.17.6.1672] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE In endocrine therapy trials in advanced breast cancer, patients with response (complete response/partial response [CR/PR]) and patients with stable disease for at least 6 months (SD(6m)) have shown similar survival and therefore are often defined as a population with clinical benefit (patients with CR/PR or SD(6m)). We evaluated the impact of response and/or clinical benefit on quality of life (QL) in postmenopausal patients under second-line endocrine treatment after failure of tamoxifen. PATIENTS AND METHODS One hundred twenty-eight of 177 eligible patients of a randomized trial (Swiss Group for Clinical Cancer Research 20/90) receiving either formestane (250 mg intramuscularly biweekly) or megestrol acetate (160 mg orally daily) were analyzed. The baseline characteristics (with the exception of site of metastases) were balanced among patients with CR/PR, SD(6m), and progressive disease (PD). Patients completed QL indicators at baseline and at 1, 3, 5, 7, 9, and 11 months. Responders were separately compared with nonresponders (patients with SD(6m) or PD) and with patients with SD(6m), and patients with clinical benefit were compared with patients with PD by analysis of covariance with adjustment for baseline scores. RESULTS Overall, 88% (557 of 634) of expected QL forms were received. In the comparison of responders versus patients with both SD(6m) and PD, responders indicated better physical well-being (P =. 004) and mood (P =.02) at month 3. Compared only with patients with SD(6m), responders showed no significant difference in baseline QL and time to treatment failure (328.5 v 340 days). While under treatment, responders reported significantly better physical well-being (months 3 to 11), mood (months 5 to 11), coping (months 5 to 9), and appetite (months 7 to 11) and less dizziness (month 9) than patients with SD(6m). The changes between baseline and months 5 and 7, respectively, indicated improvement in responders but heterogeneous patterns in patients with SD(6m). CONCLUSION Although the CR/PR and SD(6m) groups had similar times to treatment failure, patients with CR/PR reported better QL, suggesting more beneficial response to second-line endocrine treatment. Patients' subjective perspective should be taken into account in this mainly palliative setting. Future trials should be designed so that the CR/PR and SD(6m) groups are investigated separately.
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Prognostic value of beta1,6-branched oligosaccharides in human colorectal carcinoma. Cancer Res 1998; 58:5559-64. [PMID: 9850094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Increase of beta1,6-branched oligosaccharides is possibly associated with tumor progression and lymph node metastasis. The aim of this study was to determine the prognostic value of beta1,6 branches in human colorectal carcinoma. Expression of beta1,6 branches was histochemically evaluated using the leukoagglutinating Phaseolus vulgaris lectin, PHA-L, in 92 clinically documented colorectal carcinomas, of which 31 had formed lymph node metastases. The follow-up time ranged between 4 and 14 years (median, 10.3 years). A PHA-L staining index (SI), taking into account staining intensity and its percentage of tumor cut surface area, was established. The carcinoma SI was highly associated with the disease-free survival (P = 0.004) and overall survival (P = 0.005). Patients with a carcinoma SI of >1, as compared to those with a SI of < or =1, were at significantly higher risk for tumor recurrence, with a shorter disease-free survival (hazard ratio = 2.59, P = 0.005) and significant higher risk of death with shorter overall survival (hazard ratio = 2.51, P = 0.007). The carcinoma SI was also associated with the presence of lymph node metastases. We conclude that PHA-L staining in human colorectal carcinoma sections provides an independent prognostic indicator for tumor recurrence and patient survival and is associated with the presence of lymph node metastases.
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Effect of carboplatin on response and palliation in hormone-refractory prostate cancer. Swiss Group for Clinical Cancer Research (SAKK). Support Care Cancer 1998; 6:462-8. [PMID: 9773464 DOI: 10.1007/s005200050195] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
To assess the efficacy of carboplatin in patients with hormone-refractory prostate cancer in terms of response rate and palliation, the Swiss Group for Clinical Cancer Research (SAKK) conducted this phase II clinical trial (SAKK 08/91). Carboplatin 400 mg/m2 was administered i.v. every 28 days to 27 patients. The prostate-specific antigen (PSA) level was monitored and compared with the clinical response. Tumour response was evaluated according to EORTC criteria. For patients with nonmeasurable disease, response was defined as the absence of progression in any tumour localization, with no increase in PSA and a decrease of at least 2 points in the WHO pain score. Selected aspects of quality of life (QL) and use of analgesics were assessed to describe patients' experience of toxicity and palliation. Only 1 patient with measurable and 2 patients with nonmeasurable disease achieved partial remission or a response according to our criteria. However, 13 of the 27 evaluable patients had some benefit from carboplatin therapy, as indicated by an improvement in performance status, reduction of pain, and stabilization of metastases. There was no clear-cut association between clinical response and PSA level. QL data suggested that carboplatin was relatively well tolerated and confirmed the clinically documented palliation. In particular, from baseline, for at least two consecutive cycles 7 patients reported either an improvement in pain by 1 point or more on a 4-point scale (> or = 33%) without an increase in analgesic intake or a decrease by 50% or more in analgesic intake without an increase in pain. With the dose and schedule used in this study, carboplatin had only limited objective activity in advanced prostate cancer, but induced palliation in about half the patients.
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Abstract
This paper discusses methods of identifying the types of missingness in quality of life (QOL) data in cancer clinical trials. The first approach involves collecting information on why the QOL questionnaires were not completed. Based on the reasons provided one may be able to distinguish the mechanisms causing missing data. The second approach is to model the missing data mechanism and perform hypothesis testing to determine the missing data processes. Two methods of testing if missing data are missing completely at random (MCAR) are presented and applied to incomplete longitudinal QOL data obtained from international multi-centre cancer clinical trials. The first method (Ridout, 1991) is based on a logistic regression and the second method (Park and Davis, 1993) is based on an adaptation of weighted least squares. In one application (advanced breast cancer) missing data was not likely to be MCAR. In the second application (adjuvant breast cancer) the missing mechanism was dependent on the QOL scale under study. MCAR and missing at random (MAR) have distinct consequences for data analysis. Therefore it is relevant to distinguish between them. However, if either MCAR or MAR hold, likelihood or Bayesian inferences can be based solely on the observed data, although for MAR, depending on the research question, modelling the dropout mechanism may still be necessary. Distinguishing between MAR and missing not at random (MNAR) is not trivial and relies on fundamentally untestable assumptions.
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Fewer infections, but maintained antitumor activity with lower-dose versus standard-dose cladribine in pretreated low-grade non-Hodgkin's lymphoma. J Clin Oncol 1998; 16:850-8. [PMID: 9508165 DOI: 10.1200/jco.1998.16.3.850] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE To study the efficacy and the safety of cladribine (2-chlorodeoxyadenosine [2-CDA]) administered at two different dosages. PATIENTS AND METHODS In this two-cohort study, patients with low-grade refractory/relapsing non-Hodgkin's lymphoma (NHL) received 2-CDA at a dose of 0.7 mg/kg per cycle as a continuous intravenous (i.v.) infusion (group 1, n = 44) or at a reduced dose of 0.5 mg/kg per cycle as a subcutaneous (s.c.) bolus injection (group 2, n = 60). Three 2-CDA cycles at > or = 4-week intervals were planned, then treatment could be pursued until six cycles. RESULTS A total of 300 cycles were administered (group 1, 114 cycles; group 2, 186). Patient characteristics in both groups were comparable. The median dose-intensities were 0.17 mg/kg/wk and 0.13 mg/kg/wk for groups 1 and 2, respectively (P < or = .0001). The overall response rate for all 104 patients was 54% (95% confidence interval [CI], 45% to 66%; 15% complete response [CR] and 39% partial response [PR]). Response was similar in both patient groups (57% in group 1 and 53% in group 2; P = .72), and no association between 2-CDA dose-intensity and response rate was found (P = .35). Median remission duration was 7 and 12 months in groups 1 and 2, respectively (P = .21). Toxicity, in particular opportunistic infections (> or = grade 2, 30% in group 1 v 7% in group 2; P = .003) and myelosuppression (> or = grade 3 neutropenia, 33% v 8% of 2-CDA cycles, P < .0001), were more frequent in group 1. Multiple logistic regression analysis showed that the infection risk (grade > or = 2) was decreased by 81% with 2-CDA dose reduction in group 2 after adjusting for number of pretreatment regimens and time since diagnosis (P = .01). CONCLUSION When administered as a s.c. bolus injection, 2-CDA at 0.5 mg/kg per cycle is safe and this dose level should not be exceeded in this patient population.
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2-chlorodeoxyadenosine (2-CDA) therapy in previously untreated patients with follicular stage III-IV non-Hodgkin's lymphoma. Ann Oncol 1996; 7:793-9. [PMID: 8922192 DOI: 10.1093/oxfordjournals.annonc.a010757] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
PURPOSE This phase II multi-institutional trial was designed to assess response and toxicity of 2-chlorodeoxyadenosine (2-CDA) in patients with previously untreated follicular lymphoma. The clinical significance of detecting cells carrying the t(14;18) translocation (bcl-2/JH rearrangement) in peripheral blood and bone marrow by polymerase chain reaction (PCR) before, during and after treatment was also examined. PATIENTS AND METHODS Between May 1993 and October 1995, 37 patients were accrued: male/female: 15/22, median age 51 years (range: 20-78), stage III/IV: 9/28. Patients received a total 2-CDA dose of 0.7 mg/kg as continuous s.c. or i.v. infusions over 7 days, every 28 days for a maximum of 5 cycles. A total of 165 cycles were administered. In 25 patients, blood and bone marrow before, during and after treatment were available for PCR analysis of the bcl-2/JH rearrangements. RESULTS All 37 patients were evaluable for response and toxicity. The overall response rate was 84% (95% confidence interval, 68%-94%) with 14% CR (n = 5) and 70% PR (n = 26) and a median time to treatment failure of 15.7 months. bcl-2/JH rearrangement in peripheral blood and/or bone marrow was found in 10/25 of patients (40%) before treatment and 5 of these became repeatedly negative after 2-CDA therapy. There was no apparent association between bcl-2/ JH result and response. In 11 patients, 2-CDA was stopped because of progressive disease (n = 4), myelotoxicity (grade 2-3, n = 4), and other causes (n = 3, pulmonary embolism, metabolic disorder, and patient's decision). Four patients (11%) suffered from infections (grade 2-3). In 6 patients, persistent thrombocytopenia of 7.5 months (range: 3-21) occurred after completion of the 5 cycles. CONCLUSION 2-CDA is active in untreated follicular lymphomas, but time to treatment failure suggests no advantage compared with standard treatment and toxicity on haematopoietic stem cells appears to be more pronounced. Molecular remission is induced in a considerable proportion of patients with disappearance of the bcl-2/JH rearrangement, and its possible significance as a predictive factor for quality of response and relapse warrants further study.
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Determining the minimum sample size required to obtain sufficient progeny with a desired genotype at two quantitative trait loci. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1993; 87:136-144. [PMID: 24190205 DOI: 10.1007/bf00223757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/1992] [Accepted: 03/01/1993] [Indexed: 06/02/2023]
Abstract
In this paper we determine the minimum progeny sample size n needed to obtain, with probability α, at least m individuals of a desired two-locus genotype [Symbol: see text] affecting quantitative traits. The two quantitative trait loci (QTLs) of interest may be linked or independent, with or without epistatic interaction between them. Parental genotypes may be known or unknown, and gene action at either locus may range from additive to overdominance. To reduce the required sample size, mating patterns that will produce a high proportion of desired progeny are suggested for different progeny genotypes and dominance levels. Based on the assumption of normally distributed quantitative trait expression, individuals can be classified into a genotype or genotypic group according to their phenotypic expressions. This technique is used to select both parents and progeny with unknown genotypes. Choice of parental classification criteria for a given quantitative trait affects classification accuracy, and hence the probability of obtaining progeny of the desired genotype. The complexity of this probability depends on the dominance level at each locus, the recombination fraction, and the awareness of parental genotypes. The procedure can be expanded to deal with more than two loci.
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