Combination chemotherapy with mitoguazon, ifosfamide, MTX, etoposide (MIME) and G-CSF can efficiently mobilize PBPC in patients with Hodgkin's and non-Hodgkin's lymphoma

A nonparametric two-sample comparison for skewed data with unequal variances

OBJECTIVE

The aim of the study was to recommend a statistical test for the situation in which unequal variances are accompanied by skewed distributions. A previous publication in this journal could not recommend any test; instead, transformations were suggested.

STUDY DESIGN AND SETTING

A recently introduced generalized Wilcoxon test is presented, which can be applied when variances may be unequal and the distribution may be skewed. This test examines the null hypothesis that the relative effect is 0.5. Its type I error rate was investigated in a simulation study.

RESULTS

The generalized Wilcoxon test was already recommended for various areas of life sciences and, very recently, it was shown that a permutation test could be performed with the generalized test statistic. Simulation results indicate an acceptable control of the type I error rate even for extreme variance ratios.

CONCLUSION

The generalized Wilcoxon test should be applied when it cannot be assumed that variances are equal and that the distribution is symmetric. This test is preferable to a transformation, because the use of transformations can be problematic, in particular when sample sizes are small.

Ifosfamide, Epirubicin and Etoposide (IEV) Regimen as Salvage and Mobilization Therapy for Refractory or Early Relapsing Patients with Aggressive Non-Hodgkin's Lymphoma

The prognosis of early relapsing or refractory aggressive non-Hodgkin's lymphoma (NHL) is still poor. Effective salvage therapy should be able to induce high response rate as well as to mobilize hematopoietic precursors. A combination of ifosfamide, epirubicin and etoposide (IEV) was given to 28 patients with refractory or relapsing high grade NHL (4 lymphoblastic lymphoma and 24 large cell lymphoma). All patients were evaluated for response. After 2 courses of IEV, the overall and complete response rate were 64% and 39%, respectively. All patients were controlled for mobilization of peripheral blood stem cells, which was successful in 26 out of 28 (93%). Overall, 25 out of 26 patients proceeded to autologous stem cell transplantation (ASCT). Toxicity was mild, with no occurrence of severe persisting extra-hematologic side-effects. Following the entire therapeutic program, including IEV and ASCT, median progression free survival has not yet been reached and 21 patients are alive (18 in continuous complete remission) after a median follow-up of 18 months. Our results demonstrate that treatment with IEV regimen is effective in refractory or relapsing aggressive NHL, resulting in a high percentage of successful stem cell mobilization and feasibility of ASCT.

Successful mobilization of peripheral blood stem cells with the DHAP regimen (dexamethasone, cytarabine, cisplatinum) plus granulocyte colony-stimulating factor in patients with relapsed Hodgkin's disease

High-dose chemotherapy followed by autologous stem cell transplantation can improve the outcome of relapsed and refractory Hodgkin's disease (HD) patients. The objective of the trial was to determine the mobilizing potential of the DHAP salvage regimen (dexamethasone, cytarabine, cisplatin) for the collection of peripheral blood stem cells (PBSC) in patients with relapsed HD. The target yield of harvesting CD34 + cells was > or =2 x 10(6)/kg in order to support the subsequent myeloablative chemotherapy. Most of the 105 patients included were intensively pre-treated with different combination chemotherapy regimens prior to mobilization. The use of DHAP followed by granulocyte colony-stimulating factor (G-CSF; 10 microg/kg) resulted in the successful collection of adequate numbers of PBSC in 97.1% of patients (102 of 105) with a median harvest of CD34+ cells of 13 x 10(6)/kg (range 2.6 - 85.1). More than 2.0 x 10(6) CD34+ cells/kg were achieved in 65 of 103 (63%) patients after 1 apheresis, the maximum number of aphereses for all patients was 3. It was found that the optimal time of PBSC harvest was at days 13 - 16 after initiating the mobilization regimen. These results demonstrate that the salvage chemotherapy regimen, such as DHAP combined with G-CSF, can be successfully used to mobilize PBSC in HD patients.

A phase II study of dexamethasone, ifosfamide, cisplatin and etoposide (DICE) as salvage chemotherapy for patients with relapsed and refractory lymphoma

The 4-day combination of dexamethasone, ifosfamide, cisplatin, and etoposide (DICE) is a salvage regimen for lymphoma. We report a prospective phase II multi-center trial of a modified DICE regimen in relapsed or refractory Hodgkin (HL) or non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL), constituting a single day of intravenous administration followed by 3 days of oral administration, aimed at reducing inpatient days without losing efficacy. Forty patients (median age 56, range 25 - 79) were included: 28 (70%) NHL, 9 (23%) HL and 3 (8%) CLL. Fifty-three per cent had received 2 prior treatment regimens. International Prognostic Index (IPI) was 2 in 75% of NHL patients. Patients aged 55 and those with previous autologous stem cell transplantation (ASCT) started on a lower-dose regimen, with dose escalation possible in 2 patients. Overall response rate was 41%. Thirty-eight per cent of patients had stable disease. With a median of 3.1 years of follow-up, estimated progression-free survival (PFS) and overall survival (OS) rates at 3 years were 15% and 43% respectively. OS was longer in the < 55 compared to the 55 age cohort (P = 0.0091), longer for HL than NHL (P = 0.59 and 0.039 respectively) and longer for Low/Low-Int IPI than High/High-Int IPI (P = 0.0074 and 0.0009 respectively). Median duration of inpatient stay was 3 days. There were no treatment-related deaths. In conclusion, this modification of DICE is an effective and well tolerated salvage regimen, even in this poor prognosis group of patients. Further clinical studies of DICE in first relapse and in older patients, possibly with the addition of rituximab, are warranted.

Post-treatment parenthood in Hodgkin's lymphoma survivors

Attempted and achieved post-treatment parenthood, with or without use of assisted reproduction techniques (ARTs), was assessed in Hodgkin's lymphoma survivors treated from 1971–1998, aged below 50 (females) or 65 (males) at diagnosis, aged 18 to 75 at survey. Four treatment groups were constructed: radiotherapy only, low -, medium - and high gonadotoxic chemotherapy (with or without radiotherapy in the three chemotherapy groups). Using Kaplan–Meier estimates, log-rank tests and Cox regression analyses, factors influencing post-treatment parenthood were investigated, with birth of the first child after treatment as the end point. Forty-five per cent (120/269) of males and 50% (91/184) of females reported attempted post-treatment parenthood. Of these, 76 (63%) males and 68 (75%) females had a child without use of ARTs. In addition 10 males and one female achieved post-treatment parenthood with use of ARTs. Treatment group was significantly associated with post-treatment parenthood, with highest probabilities after radiotherapy only and low gonadotoxic chemotherapy. In univariate analyses, age at diagnosis was a significant factor related to post-treatment parenthood in females.

Cytoreduction of lymphoid malignancies and mobilization of blood hematopoietic progenitor cells with high doses of cyclophosphamide and etoposide plus filgrastim

We evaluated the efficiency of high doses of cyclophosphamide (6 g/m2) and etoposide (2 g/m2) plus filgrastim (granulocyte colony-stimulating factor; G-CSF) to mobilize autologous hematopoietic progenitor cells in patients with non-Hodgkin lymphoma, multiple myeloma, and Waldenström macroglobulinemia. We also evaluated the safety of this regimen and the engraftment kinetics after myeloablative chemotherapy. Seventy-nine patients with high-risk or relapsed/primary refractory non-Hodgkin lymphoma, multiple myeloma, or Waldenström macroglobulinemia were treated. The mobilizing regimen was as follows: cyclophosphamide 600 mg/m2 twice daily for 10 doses, etoposide 200 mg/m2 twice daily for 10 doses (continuous; n=57) or 2 g/m2 over 10 hours on day 5 of etoposide (bolus; n=22), and G-CSF 5 microg/kg/d beginning day 14. Fifty-nine percent of patients achieved the primary end point (a CD34 cell dose of 5 million per kilogram with a single leukapheresis). More bolus etoposide patients achieved the primary end point (86%) compared with continuous etoposide patients (47%; P<.0001). The CD34 cell dose collected was greater in bolus etoposide patients (44 million per kilogram) than in continuous etoposide patients (10.9 million per kilogram; P<.0001). Patients took 3 weeks to recover >500/microL neutrophils and >20000/microL platelets after cyclophosphamide and etoposide. The overall response rate was 69% for non-Hodgkin lymphoma patients and 71% for multiple myeloma/Waldenström macroglobulinemia patients. The treatment-related mortality was 2.5%. Sixteen percent of surviving patients experienced grade>or=3 nonhematologic toxicity. Patients receiving bolus etoposide had significantly less grade>or=2 oral mucositis, less use of total parenteral nutrition, and less need for red blood cell and platelet transfusions. Sixty-four patients (81%) underwent autologous hematopoietic progenitor cell transplantation, with prompt engraftment. Four patients (5%) did not undergo autologous hematopoietic progenitor cell transplantation because of toxicity from high-dose cyclophosphamide and etoposide. We conclude that high doses of cyclophosphamide and etoposide combined with G-CSF are an efficient and safe mobilizing regimen for the collection of hematopoietic progenitor cells during aggressive cytoreduction of tumor burden in patients with lymphoid malignancies.

ESHAP plus G-CSF as an effective peripheral blood progenitor cell mobilization regimen in pretreated non-Hodgkin's lymphoma: comparison with high-dose cyclophosphamide plus G-CSF

The ESHAP (etoposide, methylprednisolone, high-dose cytarabine, and cisplatin) regimen has been shown to be effective as an active salvage therapy for lymphoma. Mobilizing stem cells following ESHAP should decrease time to transplantation by making separate mobilizing chemotherapy (MC) unnecessary, while controlling a patient's lymphoma. We therefore assessed the mobilization potential of ESHAP plus G-CSF in 26 patients (ESHAP group) with non-Hodgkin's lymphoma (NHL) and compared these results with those of 24 patients with NHL who received high-dose (4 g/m2l) cyclophosphamide (HDCY) as MC (HDCY group). The age, sex, and radiotherapy to the axial skeleton were well matched between groups, but the number of patients with poor mobilization predictors was higher in the ESHAP group. Significantly higher numbers of CD34+ cells (x 10(6)/kg) (17.1+/-18.8 vs 5.8+/-5.0, P=0.03) and apheresis day 1 CD34+ cells (x 10(6)/kg) (5.5+/-6.6 vs 1.7+/-2.0, P=0.014) were collected from the ESHAP group than from the HDCY group, and the number of patients who achieved an optimal CD34+ cell target of 5 x 10(6)/kg was higher in the ESHAP group (81 vs 50%, P=0.022). Log-rank test revealed that time to target peripheral blood progenitor cell collection (> or =5 x 10(6)/kg) was shorter in the ESHAP group (P=0.007). These results indicate that ESHAP plus G-CSF is an excellent mobilization regimen in patients with relapsed and poor-risk aggressive NHL.

Infused CD34+ cell dose, but not tumour cell content of peripheral blood progenitor cell grafts, predicts clinical outcome in patients with diffuse large B-cell lymphoma and follicular lymphoma grade 3 treated with high-dose therapy

Previously, we have shown that patients with diffuse large B-cell lymphoma (DLBCL) transplanted with contaminated bone marrow (BM) generally have a poor outcome. Whether this is also the case when peripheral blood progenitor cell (PBPC) grafts are used is not known. Forty-three patients with chemosensitive DLBCL or follicular lymphoma grade 3 (FLgr3) were treated with high-dose therapy (HDT) and autologous stem cell support. Nine patients received purged grafts. Quantitative real-time polymerase chain reaction (QRT-PCR) for either the BCL2/IgH translocation or allele specific oligonucleotide (ASO) QRT-PCR for the immunoglobulin heavy chain (IgH) complementarity-determining region 3 were used. Nine of 25 (36%) PBPC grafts contained tumour cells as tested by QRT-PCR, including two grafts purged by CD34(+) cell enrichment combined with B-cell depletion. The level of contamination of the PBPC/CD34(+) cells ranged from 0 to 8.28%. No relationship could be shown between the total number of tumour cells infused and relapse. Patients receiving PCR-positive or PCR-negative PBPC grafts had similar progression-free survival (PFS) (P = 0.49). However, a significant difference was seen in PFS and overall survival (OS) for the patients given >/=6.1 x 10(6) CD34(+) cells/kg compared with those given <6.1 x 10(6) CD34(+) cells/kg (P = 0.01 and P < 0.05 respectively).

Outpatient-based ifosfamide, carboplatin and etoposide (ICE) chemotherapy in transplant-eligible patients with non-Hodgkin's lymphoma and Hodgkin's disease

We have treated 38 transplant-eligible patients with relapsed/refractory non-Hodgkin's lymphoma and Hodgkin's disease using an outpatient-based regimen of ifosfamide, carboplatin and etoposide (ICE) for both salvage and peripheral blood stem cell mobilisation. Patients included relapsed or refractory diffuse large B-cell lymphoma (n = 17), follicular lymphoma (n = II), T-cell lymphoma (n = 2), mantle cell lymphoma (n = 2) and Hodgkin's disease (n = 6). Seven patients with diffuse large B-cell lymphoma and three patients with follicular lymphoma (26%) were considered chemorefractory. Cycles of ICE therapy were administered every 21 days as an outpatient and consisted of ifosfamide 5000 mg/m2 intravenously (i.v.) fractionated into three equally divided doses over 3 days, carboplatin [mg dose = 5 x area under the curve (AUC)] i.v. on day 1 and etoposide 100 mg/m2- i.v. daily for 3 days. Subsequently. granulocyte colony-stimulating factor (G-CSF)5 microg/kg subcutaneously (s.c.) was administered daily from day +5. Of the I I follicular lymphoma patients, 10 also received rituximab with ICE therapy. Median age of patients was 52 years (range 30-65). Patients received a mean of 2.6 cycles (range 1-4) of ICE. There were no toxic deaths and no significant non-haematological toxicities secondary to ICE therapy. Grade IV thrombocytopenia and grade IV neutropenia with at least one cycle of ICE were seen in 47% and 53% of patients, respectively. Median time to peripheral blood stem cell (PBSC) harvest was 14 days (range 10-20). while the median CD34+ cell yield was 5.2 x 10(6) cells/kg(range 2.3 x 10(6)-27.2 x 10(6)). Only one of the ICE-responders failed to mobilise PBSCs. The overall response rate to ICE was 87%. comprising 14 patients (37%) who achieved a complete response (CR) and 19 (50%) who achieved a partial response (PR). A total of 30 patients have undergone autologous stem cell transplantation(SCT) while two follicular lymphoma patients have received a non-myeloablative allogeneic SCT. Follow-up is short: however, the Kaplan-Meier estimate of the proportion of patients alive and event-free at a median follow-up of 11 months is 80% and 59%, respectively. Event-free survival for patients who achieved a CR after ICE and transplantation is 88% versus 45% for those who achieved a PR. These data confirm the efficacy and tolerability of fractionated ICE chemotherapy as both a salvage and mobilisation regimen that can be readily delivered in an outpatient setting.

Is chemotherapy scoring useful to predict progenitor cell mobilisation in patients with non-Hodgkin's lymphoma?

About 10-30% of patients with non-Hodgkin's lymphoma (NHL) intended to receive high-dose therapy are difficult to mobilise. Damage to the stem cell pool caused by previous chemotherapy may be an important factor in predicting progenitor cell mobilisation. We have analysed associations between chemotherapy score and efficiency of progenitor cell mobilisation in 120 consecutive NHL patients mobilised with intermediate-dose cyclophosphamide (4 g/m(2)) plus G-CSF. The original chemotherapy scoring system proposed by Drake et al was applicable in only 27% of our patients and was not predictive for mobilisation outcome. Therefore we made an improved scoring system for previous chemotherapy by adding new drugs. Altogether, 111 patients (93%) could be scored. Our chemotherapy score showed an inverse correlation with the peak blood CD34(+) count measured after the mobilisation (r=-0.214, P=0.024) and with the number of CD34(+) cells collected (r=-0.234, P=0.02). However, in the receiver operating characteristics curve, no threshold value could be detected for chemotherapy score predicting mobilisation failure. Thus, both the original scoring system as well as our more widely applicable scoring system seem to be of limited value in predicting progenitor cell mobilisation in patients with NHL.

CD34(+) cell enrichment depletes atypical CD30(+) cells from PBPC grafts in patients with HD

BACKGROUND

European Group for Blood and Marrow Transplantation (EBMT) registry data indicate that patients with relapsed HD given high-dose therapy (HDT), supported with PBPC might have a poorer outcome compared with those given BM. Since this can be due to the infusion of contaminating tumor cells in the PBPC products, we studied the presence of minimal residual disease and tested whether CD34(+) cell enrichment was able to remove atypical CD30(+) cells from PBPC grafts.

METHODS

Eighteen HD patients eligible for HDT were included in the study. By the use of immunocytochemistry (ICC), mononuclear cells from BM and peripheral blood (PB) before mobilization, PBPC products and selected CD34(+) fractions were stained using anti-CD30 MAb (Ber-H2) and the APAAP (alkaline phosphatase-anti-alkaline phosphatase) method. Cells scored as atypical CD30(+) cells were large- to medium-sized, with membranous, cytoplasmatic and/or Golgi positivity for CD30.

RESULTS

Nine out of 11 BM tested were positive, while 14 of 14 PB and 18 of 18 PBPC contained atypical CD30(+) cells. The total number of atypical CD30(+) cells was significantly higher in PBPC than in the corresponding BM. CD34(+) cell enrichment employing ISOLEX 300I gave a purity and yield of 99.2% (range 97.8-99.7) and 49.6% (range 30.0-78.4), respectively. After HDT a median of 5.8 x 10(6) (range 2.7-20) CD34(+) cells/kg was infused. Neutrophil counts of > 0.5 x 10(9)/L and platelet counts of > 20 x 10(9)/L were achieved at Day 12 (range 10-17) and at Day 10 (range 7-15), respectively. Sixteen of 18 CD34(+) selected products had no detectable atypical CD30(+) cells, while two had a low number. After HDT, the overall survival was 80% and the event-free survival was 69%, with a median follow-up of 24 months (range 1-36).

DISCUSSION

We show that contaminating atypical CD30(+) cells in PBPC can efficiently be removed by CD34(+) cell enrichment, and the use of such grafts following HDT gives fast and sustained engraftment.

Frequency and differentiation capacity of circulating LTC-IC mobilized by G-CSF or GM-CSF following chemotherapy: a comparison with steady-state bone marrow and peripheral blood

OBJECTIVE

The present study was designed to compare directly the frequency of circulating LTC-IC and E-LTC-IC mobilized in peripheral blood (PB) after chemotherapy supported by either G-CSF (PB-G) or GM-CSF (PB-GM) in comparison to steady-state bone marrow (BM) and PB (PB-ST) values in the same patients.

MATERIALS AND METHODS

Long-term cultures (LTC) were performed from 20 patients with malignant lymphoma at saturating cell concentrations to assess bulk progenitor cell production and by limiting dilution assay (LDA) to measure both frequency of LTC-IC and their proliferative and differentiation capacities.

RESULTS

While CFC production in bulk LTC was higher at weeks 3-5 with PB-G than with PB-GM samples, week-5 LTC-IC and week-10 LTC-IC (E-LTC-IC) frequencies were not different using a LDA. However, the number of CFC derived from a single LTC-IC was higher in PB-G patients than in PB-GM patients (p = 0.01). Interestingly, the frequency of LTC-IC per 1 x 10(5) MNC in mobilized PB positively correlated with one-year marrow progenitor cell recovery, in contrast to the number of autografted CD34(+) cells and CFU-GM per kg.

CONCLUSION

Both G-CSF and GM-CSF resulted in similar increases in LTC-IC and E-LTC-IC in PB at comparable levels to those present in BM. However, the differentiation capacity of LTC-IC was higher after mobilization with G-CSF than with GM-CSF, suggesting qualitative differences in LTC-IC mobilized with these growth factors.

Mobilizing potential of ifosfamide/vinorelbine-based chemotherapy in pretreated malignant lymphoma

The mobilizing potential and therapeutic activity of ifosfamide/vinorelbine-containing regimens with G-CSF support were explored in patients with pretreated malignant lymphomas. Ten patients with non-Hodgkin's lymphoma (NHL) received ifosfamide and vinorelbine, and 17 with Hodgkin's disease (HD) received ifosfamide, vinorelbine and gemcitabine (IGEV regimen), as induction chemotherapy before high-dose chemotherapy (HDT) with peripheral blood stem cell (PBSC) support. Most of the patients had been heavily pretreated with various chemotherapy regimens +/- radiotherapy. The target yield was > or =3 x 10(6) CD34+ cells/kg of body weight in order to support the subsequent myeloablative chemotherapy. The optimal PBSC harvest occurred on days 11 and 12, with no difference in CD34+ cell mobilization kinetics between the ifos- famide/vinorelbine and IGEV regimens. The median number of CD34+ cells/kg body weight collected was 10.9 x 10(6) (range 1.76-61.1 x 10(6)). The median total CD34+ cell/microl, CFU-GM and white blood cells (WBC) for all individual collections was 81.5/microl, 10 x 10(4)/kg, and 17 900/microl, respectively. The target yield of CD34+ cells was reached in 24 of 27 patients. Hematological side-effects were acceptable and no treatment-related hospitalizations or toxic deaths occurred. Fifteen patients have so far received high-dose therapy and PBSC reinfusion with rapid engraftment. These results confirm that ifosfamide and vinorelbine-based chemotherapy regimen with G-CSF support can be successfully and safely used to mobilize PBSCs.

Guanidino-containing drugs in cancer chemotherapy: biochemical and clinical pharmacology

The pharmacology and clinical application of three guanidino-containing compounds are reviewed in this commentary with special focus on a new member of this group of drugs, CHS 828 [N-(6-(4-chlorophenoxy)hexyl)-N'-cyano-N"-4-pyridylguanidine]. m-Iodobenzylguanidine (MIBG) and methylglyoxal bis(guanylhydrazone) (MGBG) have been extensively studied, preclinically as well as clinically, and have established use as anticancer agents. MIBG has structural similarities to the neurotransmitter, norepinephrine, and MGBG is a structural analog of the natural polyamine spermidine. CHS 828 is a pyridyl cyanoguanidine newly recognized as having cytotoxic effects when screening antihypertensive compounds. Apart from having the guanidino groups in common, there are many differences between these drugs in both structure and their mechanisms of action. However, they all inhibit mitochondrial function, a seemingly unique feature among chemotherapeutic drugs. In vitro in various cell lines and primary cultures of patient tumor cells and in vivo in various tumor models, CHS 828 has cytotoxic properties unlike any of the standard cytotoxic drugs with which it has been compared. Among these are non-cross-resistance to standard drugs and pronounced activity in tumor models acknowledged to be highly drug-resistant. Similar to MIBG, CHS 828 induces an early increase in extracellular acidification, due to stimulation of the glycolytic flux. Furthermore, ATP levels decrease, and the syntheses of DNA and protein are shut off after approximately 30 hr of exposure, indicating active cell death. CHS 828 is now in early clinical trials, the results of which are eagerly awaited.

Phase II study of a high-dose ifosfamide-based chemotherapy regimen with growth factor rescue in recurrent aggressive NHL. High response rates and limited toxicity, but limited impact on long-term survival

The purpose of the study was to evaluate in patients with recurrent intermediate-grade NHL, the tolerance to and efficacy of an intensive salvage regimen consisting of high doses of ifosfamide, etoposide and mitoxantrone with G-CSF support, followed by autologous stem cell transplantation and to identify prognostic factors for survival in patients with recurrent aggressive lymphoma. Patients with recurrent intermediate-grade NHL under the age of 60 years were eligible. Induction consisted of ifosfamide 10 g/m(2) and etoposide 900 mg/m(2) with G-CSF 5 microg/kg twice a day. Upon recovery, patients underwent stem cell apheresis. Patients achieving complete remission (CR) underwent autologous stem cell transplantation using BEAM conditioning. Those with partial remission (PR) received treatment with ifosfamide 10 g/m(2), mitoxantrone 20 mg/m(2) and G-CSF 5 microg/kg. Those with CR received BEAM, those with PR received cyclophosphamide 4.5 g/m(2), etoposide 1200 mg/m(2) and cisplatin 135 mg/m(2) with stem cell rescue followed by BEAM. Antibiotic prophylaxis was given with all treatment cycles. The results were compared with those obtained in a prior study that used MINE-ESHAP salvage. Forty-four patients with recurrent intermediate-grade NHL were enrolled between March 1994 and September 1996. Median age was 50 years (24-61). Eleven patients had transformed lymphoma and seven had a T cell phenotype. Response rate to the high-dose ifosfamide regimen was 77% +/- 12% after two cycles and the complete response rate was 41% +/- 14%. Myelosuppression was profound but short. Median nadir ANC was 0 and the median duration of ANC <0.5 x 10(9)/l was 6 days (range 3-12). No severe infections occurred; 55% of the patients required blood transfusion and 42% required platelet transfusions. Myelosuppression and transfusion requirements were similar after the first and second cycles. Thirty-five of the 44 patients proceeded to autologous stem cell transplantation and one transplant-related death occurred. With a median follow-up of 52 months, progression-free survival at 2 years is 38% +/- 14% and survival is 52% +/- 15%. Data from these 44 patients were pooled with data on 53 patients who had received salvage treatment with MINE-ESHAP, for a multivariate analysis of prognostic factors. In multivariate analysis, serum LDH was strongly associated with survival. The use of a more intensive salvage regimen, did not result in a significant increase in long-term outcome, despite a high response rate. In conclusion, duration of treatment, response rates, treatment-related mortality and survival compare favorably with previous salvage regimens, but recurrence remains a major problem. Long-term survival in recurrent large cell lymphoma is influenced more by disease characteristics than by the type of salvage regimen used.

High-dose therapy in patients with Hodgkin's disease: the use of selected CD34(+) cells is as safe as unmanipulated peripheral blood progenitor cells

Register data suggest that patients with Hodgkin's disease (HD) given high-dose therapy (HDT) with peripheral blood progenitor cells (PBPC) have a less favourable prognosis as compared to those given bone marrow as stem cell support. Since this can be due to infusion of tumour cells contaminating the PBPC grafts, we initiated a feasibility study in which PBPC grafts from HD patients were purged by CD34(+) cell enrichment. Controversy exists about whether the use of CD34(+) enriched stem cells leads to a delayed haematological and immune reconstitution. We compared these parameters, including risk of infections and clinical outcome after HDT, in patients with HD given either selected CD34(+) cells or unmanipulated PBPC as stem cell support. From October 1994 to May 2000, 40 HD patients with primary refractory disease or relapse were treated with HDT and supported with either selected CD34(+) cells (n = 21) or unmanipulated PBPC (n = 19) as stem cell support. All patients had chemosensitive disease at the time of transplantation. A median of 5.8 (range 2.7-20.0) vs 4.5 (range 2.3-17.6) x 10(6) CD34(+) cells per kilo were reinfused in the CD34(+) group and PBPC group, respectively. No difference was observed between the two groups with regard to time to haematological engraftment, reconstitution of B cells, CD56(+) cells and T cells at 3 and 12 months and infectious episodes after HDT. Two (5%) treatment-related deaths, one in each group, were observed. The overall survival at 4 years was 86% for the CD34(+)group and 74% for the PBPC group with a median follow-up of 37 months (range 1-61) and 46 months (range 4-82), respectively (P = 0.9). The results of this study demonstrate that the use of CD34(+) cells is safe and has no adverse effects either with respect to haematological, immune reconstitution or to infections after HDT.

Should we always choose a nonparametric test when comparing two apparently nonnormal distributions?

When clinical data are subjected to statistical analysis, a common question is how to choose an appropriate significance test. Comparing two independent groups with observations measured on a continuous scale, the question is typically whether to choose the two-sample-t test or the Wilcoxon-Mann-Whitney test (WMW test). Similar results are often obtained, but which conclusion can be drawn if significance tests give highly different P-values? The t test is optimal for normally distributed observations with common variance and robust to deviations from normality if sample sizes are not very small. The WMW test makes no distributional assumptions, but depends heavily on equal shape and variance of the two distributions (homoscedasticity). We have compared the properties of the traditional two-sample t test, a modified t test allowing unequal variance, and the WMW test by stochastic simulation. All show acceptable behaviour when the two distributions have similar variance. When variances differ, the modified t test is superior to the other two.

Selection and use of chemotherapy with hematopoietic growth factors for mobilization of peripheral blood progenitor cells

Peripheral blood progenitor cells (PBPCs) have become the preferred means of stem cell support for high-dose chemotherapy in recent years. The biology of PBPC mobilization is complex and may be influenced by several variables. Signals from both stromal and hemopoietic cells may induce downregulation of adhesion molecules and upregulate the expression of metalloproteinases. Cytokines alone can mobilize PBPCs but a synergistic effect has been shown when they are used in conjunction with chemotherapy. Disease-specific mobilization strategies appear to have the advantage of less toxicity, greater stem cell yield, and enhanced antitumor activity. Studies have demonstrated that the number of peripheral blood CD34+ cells can be used as a predictor for the timing of apheresis and for estimating PBPC yield. Similarly the CD34+ cell dose is the strongest predictor of hematologic recovery after PBPC transplant. Age, prior radiotherapy, marrow involvement, and prior chemotherapy (especially with alkylating agents) are important factors influencing the yield of stem cells.