The role of body mass index in survival outcome for lymphoma patients: US intergroup experience.

BACKGROUND: The role of body mass index (BMI) in survival outcomes is controversial among lymphoma patients. We evaluated the association between BMI at study entry and failure-free survival (FFS) and overall survival (OS) in three phase III clinical trials, among patients with diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and Hodgkin's lymphoma (HL). PATIENTS AND METHODS: A total of 537, 730 and 282 patients with DLBCL, HL and FL were included in the analysis. Baseline patient and clinical characteristics, treatment received and clinical outcomes were compared across BMI categories. RESULTS: Among patients with DLBCL, HL and FL, the median age was 70, 33 and 56; 29%, 29% and 37% were obese and 38%, 27% and 37% were overweight, respectively. Age was significantly different among BMI groups in all three studies. Higher BMI groups tended to have more favorable prognosis factors at study entry among DLBCL and HL patients. BMI was not associated with clinical outcome with P-values of 0.89, 0.30 and 0.40 for FFS, and 0.64, 0.67 and 0.09 for OS, for patients with DLBCL, HL and FL, respectively. The association remains non-significant after adjusting for other clinical factors in the Cox model. A subset analysis of males with DLBCL treated on R-CHOP revealed no differences in FFS (P = 0.48) or OS (P = 0.58). CONCLUSION: BMI was not significantly associated with clinical outcomes among patients with DLBCL, HD or FL, in three prospective phase III clinical trials. The findings contradict some previous reports of similar investigations. Further work is required to understand the observed discrepancies.

Myeloablative therapy with autologous stem cell rescue for patients with Ewing sarcoma.

The aim of this study was to identify risk factors associated with PFS in patients with Ewing sarcoma undergoing ASCT; 116 patients underwent ASCT in 1989-2000 and reported to the Center for International Blood and Marrow Transplant Research. Eighty patients (69%) received ASCT as first-line therapy and 36 (31%), for recurrent disease. Risk factors affecting ASCT were analyzed with use of the Cox regression method. Metastatic disease at diagnosis, recurrence prior to ASCT and performance score <90 were associated with higher rates of disease recurrence/progression. Five-year probabilities of PFS in patients with localized and metastatic disease at diagnosis who received ASCT as first-line therapy were 49% (95% CI 30-69) and 34% (95% CI 22-47) respectively. The 5-year probability of PFS in patients with localized disease at diagnosis, and received ASCT after recurrence was 14% (95% CI 3-30). PFS rates after ASCT are comparable to published rates in patients with similar disease characteristics treated with conventional chemotherapy, surgery and irradiation suggesting a limited role for ASCT in these patients. Therefore, ASCT if considered should be for high-risk patients in the setting of carefully controlled clinical trials.

Allogeneic hematopoietic cell transplantation for metastatic breast cancer.

We reviewed 66 women with poor-risk metastatic breast cancer from 15 centers to describe the efficacy of allogeneic hematopoietic cell transplantation (HCT). Median follow-up for survivors was 40 months (range, 3-64). A total of 39 patients (59%) received myeloablative and 27 (41%) reduced-intensity conditioning (RIC) regimens. More patients in the RIC group had poor pretransplant performance status (63 vs 26%, P=0.002). RIC group developed less chronic GVHD (8 vs 36% at 1 year, P=0.003). Treatment-related mortality rates were lower with RIC (7 vs 29% at 100 days, P=0.03). A total of 9 of 33 patients (27%) who underwent immune manipulation for persistent or progressive disease had disease control, suggesting a graft-vs-tumor (GVT) effect. Progression-free survival (PFS) at 1 year was 23% with myeloablative conditioning and 8% with RIC (P=0.09). Women who developed acute GVHD after an RIC regimen had lower risks of relapse or progression than those who did not (relative risk, 3.05: P=0.03), consistent with a GVT effect, but this did not affect PFS. These findings support the need for preclinical and clinical studies that facilitate targeted adoptive immunotherapy for breast cancer to explore the benefit of a GVT effect in breast cancer.

Ex vivo expansion of umbilical cord blood stem cells for transplantation: growing knowledge from the hematopoietic niche.

Umbilical cord blood transplantation (UCBT) in adults is limited by the small number of primitive hematopoietic stem cells (HSC) in each graft, resulting in delayed engraftment post transplant, and both short- and long-term infectious complications. Initial efforts to expand UCB progenitors ex vivo have resulted in expansion of mature rather than immature HSC, confounded by the inability to accurately and reliably measure long-term reconstituting cells. Ex vivo expansion of UCB HSC has failed to improve engraftment because of resulting defects that promote apoptosis, disrupt marrow homing and initiate cell cycling. Here we discuss the future of ex vivo expansion, which we suggest will include the isolation of immature hematopoietic progenitors on the basis of function rather than surface phenotype and will employ both cytokines and stroma to maintain and expand the stem cell niche. We suggest that ex vivo expansion could be enhanced by manipulating newly discovered signaling pathways (Notch, Wnt, bone morphogenetic protein 4 and Tie2/angiopoietin-1) and intracellular mediators (phosphatase and tensin homolog and glycogen synthase kinase-3) in a manner that promotes HSC expansion with less differentiation. Improved methods for ex vivo expansion will make UCBT available to more patients, decrease engraftment times and allow more rapid immune reconstitution post transplant.

Retrospective utility of bronchoscopy after hematopoietic stem cell transplant.

Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is thought to be the procedure of choice to evaluate pulmonary infiltrates in hematopoietic stem cell transplant (HSCT) recipients. We retrospectively reviewed 91 bronchoscopies performed on 190 in-patient HSCT recipients admitted or treated for pneumonia from January 1994 to December 2004. These yielded a diagnosis 49% of the time with an overall survival of 35 days post-bronchoscopy. We were unable to detect any survival benefit from an addition to the treatment regimen after a positive result from analysis of the BAL fluid or transbronchial biopsy. The most common bacteria isolated was Pseudomonas that was often resistant to the patient's current antibiotics, suggesting that in lieu of this diagnostic procedure, changes to better cover resistant Gram-negative bacteria are reasonable. Although transbronchial biopsies provided an additional diagnosis in one out of 21 biopsies performed, six of the seven complications in our series were directly related to the transbronchial biopsy. With approximately a 50% yield from a bronchoscopy, additional treatment given after only 20% of all bronchoscopies, and no detectable survival benefit with a bronchoscopy that yielded a diagnosis, the utility of a bronchoscopy in this patient population is questioned by these data.

Patients' understanding of disease status and treatment plan at initial hematopoietic stem cell transplantation consultation.

Patients referred for hematopoietic stem cell transplantation (HSCT) often have knowledge deficits about their disease and overestimate their prognosis making it difficult initially to discuss potentially life-threatening transplant options. To determine patients' understanding of their disease and the adequacy of a 3-h consultation at our center, we developed a survey that measured perceived knowledge deficits of disease, prognosis, and emotional status before and after their initial consultation. Ninety nine consecutive eligible patients completed the survey. Although 76.7% claimed adequate information about their disease pre-HCST visit, 51.5 and 41.4% respectively lacked knowledge about their 1-year prognosis with and without any therapy. After the visit, 66.7% of the patients had obtained enough information to make an informed decision regarding HSCT versus 23.2% pre-visit, and a significant reduction in the need for further information was reported by 53.5% of patients (P<0.001). Patients were not overwhelmed or confused by the visit and there was a small but significant decrease in negative affect. Measures to increase patients understanding of their disease and its prognosis pre-HSCT consultation visit are warranted; however, a 3-h consultation visit provides the majority of patients with sufficient information to make an informed decision about the risk/benefit ratio of HSCT.

Reliability and validity of a patient self-administered daily questionnaire to assess impact of oral mucositis (OM) on pain and daily functioning in patients undergoing autologous hematopoietic stem cell transplantation (HSCT).

Oral mucositis (OM) is a frequent complication of myeloablative therapy and HSCT. We evaluated the feasibility, reliability, and validity of a new patient self-reported daily questionnaire on OM and its impact on daily functions. This OM Daily Questionnaire (OMDQ), containing 10 items, was developed for use in palifermin clinical trials. In a phase 3 study, 212 patients received palifermin or placebo for three consecutive days before conditioning and three consecutive days after HSCT. Compliance rates were consistently >80% for most patients. Mouth and throat soreness (MTS) and MTS-Activity Limitations (MTS-AL) (swallowing, drinking, eating, talking, and sleeping) scores on consecutive days were highly correlated (days 7,8 = 0.70-0.86; test-retest reliability). Correlations among items measuring the same construct ranged between 0.5 and 0.8 (internal consistency reliability). The WHO Oral Toxicity scale was the clinical comparator to assess the criterion, discriminative, and evaluative validities of MTS-related questions. Most correlation coefficients between the WHO and MTS ranged between 0.45 and 0.55. Patients with more severe WHO OM grades had higher MTS mean scores. Changes in MTS scores were similar, but patients detected changes 1-3 days earlier than clinicians. In conclusion, the OMDQ is a feasible, reliable, valid, and responsive patient-reported measure of OM severity.

A phase I trial of high-dose diaziquone and autologous bone marrow transplantation: an Illinois Cancer Council study.

Diaziquone (AZQ), a synthetic quinone with demonstrated activity against acute nonlymphocytic leukemia (ANLL), primary CNS tumors, and non-Hodgkin's lymphoma (NHL), is virtually devoid of nonhematopoietic toxicity at conventional doses. As a prelude to its inclusion into bone marrow transplant (BMT) preparative regimens, a phase I study of high-dose AZQ with autologous BMT (ABMT) was performed. Patients with refractory solid tumors and lymphomas were treated with a single 24-hour infusion of AZQ at 50 to 355 mg/m2 in dose escalations of 20%. Fifty-six patients received 69 courses. Those receiving greater than 60 mg/m2 had nadir granulocyte and platelet counts less than 500/microL and 20,000/microL, respectively. Nausea, vomiting, stomatitis, and diarrhea were mild, transient, and not dose-related. Transient minimal elevations of liver function tests were seen in five patients and were also not dose-related. The maximally tolerated dose (MTD) of high-dose AZQ was found to be 245 mg/m2, with nephrotoxicity being dose-limiting. Significant azotemia was seen in four of 12 patients treated at 295 and 355 mg/m2, including fatal anuric renal failure in three of these patients. Reversible proteinuria also occurred in 24 of 26 courses above 150 mg/m2, including nephrotic range proteinuria in eight courses, all at doses of 205 to 355 mg/m2. The proteinuria was also associated with multiple proximal tubular defects including generalized aminoaciduria and proximal renal tubular acidosis. There were six early deaths including two of early renal failure (295 and 355 mg/m2), two of sepsis (205 and 245 mg/m2), one of a pulmonary embolus (85 mg/m2), and one of progressive disease (60 mg/m2). Of 50 patients who were assessable for response, there were seven responses including two of 10 with primary CNS tumors, one of 12 with malignant melanoma, one of five with non-small-cell lung carcinoma, two of two with breast carcinoma, and one of one with ovarian carcinoma. Because of its activity in ANLL and NHL and its unique toxicity spectrum, high-dose AZQ may improve the efficacy of current BMT preparative regimens without significantly increasing their nonhematopoietic toxicity.

High-dose chemotherapy with autologous transplantation for persistent/relapsed ovarian cancer: a multivariate analysis of survival for 100 consecutively treated patients.

PURPOSE: To examine the prognostic factors associated with prolonged progression-free survival (PFS) and overall survival (OS) in 100 consecutively treated women undergoing autologous stem-cell transplant for advanced ovarian cancer. PATIENTS AND METHODS: From October 1989 to February 1996, we transplanted 100 patients with ovarian cancer following chemotherapy with high-dose carboplatin, mitoxantrone, and cyclophosphamide with or without cyclosporine (n = 70); melphalan and mitoxantrone with or without paclitaxel (n = 25); or other regimens (n = 5). Their median age was 48 years (range, 23 to 65), 70% had papillary serous histology, 72% had grade III tumors, 66% were platinum-resistant, and 61% had > or = 1 cm bulk. The median number of prior regimens was two (range, one to six). Univariate and multivariate analyses were performed to examine age (< v > or = mean), stage, initial bulk, histology, grade, response to initial therapy, number of prior regimens, time from diagnosis to transplant, transplant regimen, platinum sensitivity, and bulk (< v > or = 1 cm) at transplant. RESULTS: The median PFS and OS times for the 100 patients were 7 and 13 months. A stepwise Cox proportional hazards model identified tumor bulk (P = .0001), and cisplatin sensitivity (P = .0249) as the best predictors of PFS. Age (P = .0017), bulk at transplant (P = .0175), and platinum sensitivity (P = .0330) provided the best prediction of OS. The median PFS and OS times for the 20 patients with platinum-sensitive, < or = 1-cm disease were 19 and 30 months. No differences in OS were seen when chemotherapy or surgery was used to achieve a minimal disease state. CONCLUSION: Before consideration of high-dose therapy for recurrent/persistent advanced ovarian cancer, patients should undergo debulking surgery or chemotherapy to achieve a minimal disease state. Patients with platinum-resistant, bulky disease should not be transplanted. The optimal patients for this therapy may be those with minimal disease responsive to initial chemotherapy.

High-dose melphalan with autotransplantation for refractory multiple myeloma: results of a Southwest Oncology Group phase II trial.

PURPOSE: To evaluate high-dose melphalan followed by autologous stem-cell transplantation in patients with refractory multiple myeloma. PATIENTS AND METHODS: Multiple myeloma patients with alkylating agent or vincristine/doxorubicin/dexamethasone-refractory disease were eligible for the phase II multi-institutional Southwest Oncology Group trial S8993. Patients up to age 70 years were enrolled between April 15, 1991, and May 1, 1996. Patients without prior stem-cell collection were primed with high-dose cyclophosphamide (HD-CTX; 6 g/m(2)) and granulocyte-macrophage colony-stimulating factor. After stem-cell procurement, patients received melphalan 200 mg/m(2) with autologous transplantation. Upon recovery from melphalan, patients were to receive interferon alfa-2b until relapse. RESULTS: Seventy-two patients were enrolled onto S8993; five were ineligible and one received no therapy. Of the 66 assessable patients, 56 patients underwent the transplant procedure; 54 were assessable for response and 56 for toxicity. The response to HD-CTX (n = 37) included three complete remissions (CRs; 8%) and five partial remissions (PR; 14%); response to melphalan (n = 54) included 16 CRs (30%) and 19 PRs (35%), for an overall CR and >/= PR (n = 66; intent-to-treat) of 27% and 58%, respectively. Toxicities included six treatment-related deaths: two during HD-CTX and four during transplantation. The median progression-free survival (PFS) and overall survival (OS) durations on an intent-to-treat basis from transplant registration was 11 months and 19 months (95% confidence interval, 14 to 29 months), respectively. The 3-year actuarial PFS and OS rates were 25% and 31%, respectively. CONCLUSION: High-dose therapy with melphalan 200 mg/m(2) is feasible with high response rates (58% overall) and an OS of 19 months in patients with refractory multiple myeloma.

Phase I clinical and pharmacokinetic study of high-dose mitoxantrone combined with carboplatin, cyclophosphamide, and autologous bone marrow rescue: high response rate for refractory ovarian carcinoma.

PURPOSE: To develop an active high-dose chemotherapy regimen for the treatment of ovarian carcinoma. Due to the rapid development a drug resistance, conventional chemotherapy cures only 20% of patients with advanced disease. However, in vitro data demonstrate a steep dose-response curve to a variety of agents, most notably mitoxantrone. PATIENTS AND METHODS: A phase I study of escalated bolus mitoxantrone (10 to 25 mg/m2 x 3) and cyclophosphamide (30 to 50 mg/kg x 3) with a 5-day infusion of carboplatin (1,500 mg/m2) and an autologous bone marrow transplant (ABMT) was performed. Mitoxantrone pharmacokinetics were performed to document levels required to kill platinum-resistant ovarian carcinoma in vitro. RESULTS: We treated 25 patients; the maximum-tolerated total doses (MTD) were 75 mg/m2 for mitoxantrone, 120 mg/kg for cyclophosphamide, and 1,500 mg/m2 for carboplatin. The dose-limiting toxicity was gastrointestinal, with severe diarrhea, ileus, and resulting sepsis. Transient partial deafness was seen in four patients, and acute renal failure (ARF) occurred in one patient at the first dose level, but was eliminated in subsequent patients with aggressive hydration. There were four early deaths due to ARF (n = 1), Legionella pneumonia (n = 1), and sepsis (n = 2). Peak mitoxantrone levels at the MTD were 623 to 2,810 ng/mL, and the area under the curve (AUC) values of the concentration versus time measurements were 560 to 1,700 ng/mL/h. Of 20 assessable patients, 65% responded, with a 45% complete remission (CR) rate. All six of the assessable patients with ovarian cancer responded: CR in five (83%) and partial remission (PR) in one (17%); the CRs have lasted 7 to 30+ months. Responses were also seen in testicular and breast carcinoma. CONCLUSION: This regimen was well tolerated at the MTD and appears promising for relapsed/refractory ovarian carcinoma, with mitoxantrone levels achieved that are active in vitro against platinum-resistant ovarian carcinoma cells.

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.

Granulocyte-macrophage colony-stimulating factor/interleukin-3 fusion protein versus granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for non-Hodgkin's lymphoma: results of a randomized double-blind trial.

PURPOSE: A phase III trial to compare PIXY321 with granulocyte-macrophage colony-stimulating factor (GM-CSF) following high-dose therapy and autologous bone marrow transplant (ABMT) was conducted to evaluate the time to hematopoietic recovery. PATIENTS AND METHODS: One hundred seventy-seven patients with non-Hodgkin's lymphoma (NHL) receiving ABMT were randomized to receive either PIXY321 750 micrograms/m2/d divided into two subcutaneous (SC) doses or GM-CSF 250 micrograms/m2/d as a 2-hour intravenous (IV) infusion starting on day 0 post-ABMT for a maximum of 28 days. RESULTS: The median time to reach an absolute neutrophil count (ANC) > or = 500/microL in the PIXY321 group was 17 days versus 19 days in the GM-CSF group (P = .07) and the median time to reach platelet transfusion independence in the PIXY321 group was 25 days versus 23 days in the GM-CSF group (P = .30). The toxicity profiles of the two agents appeared to be equivalent with the exception of more patients in the PIXY321 group with a rash (64%) compared with the GM-CSF group (48%) (P = .028). A logistic regression model identified the use of a non-total-body irradiation (TBI) regimen and/or receipt of unpurged marrow and a body-surface area greater than 2.0 m2 as predictive of faster neutrophil engraftment, and those three factors, as well as the receipt of < or = two prior chemotherapy regimens as predictive for rapid platelet engraftment. CONCLUSION: There was a trend toward a slight improvement in neutrophil engraftment post-ABMT with the PIXY321 administered by an SC route compared with GM-CSF administered by an IV route. However, no differences could be identified between the two agents with respect to the time to platelet transfusion independence. Patient, regimen, and graft characteristics were most predictive of the engraftment tempo.

Second allografts for relapsed hematologic malignancies: feasibility of using a different donor.

A second allogeneic hematopoietic stem cell transplant (HSCT) for relapsed hematologic malignancies is an option in select patients after an initial allograft has failed. If the original donor is not available, a different donor may have to be considered. We report our experience of performing a second allogeneic HSCT using a different donor in patients with relapsed leukemia and lymphoma. In a 5-year period, six patients underwent a second allograft with myeloablative conditioning using a different donor. Four of these were retransplanted using a matched-unrelated donor. Four of the patients (67%) remain progression-free at a median follow-up of 32 months (range 3-72). There were no cases of transplant-related mortality. We conclude that a second allogeneic HSCT using a different donor is a viable option for selected patients relapsing after an allograft if the original donor is not available.

High-dose chemotherapy combined with escalating doses of cyclosporin A and an autologous bone marrow transplant for the treatment of drug-resistant solid tumors: a phase I clinical trial.

High response rates are seen in patients undergoing dose-intensive chemotherapy and autologous marrow transplantation due to the ability of the therapy to overcome inherent or acquired drug resistance. However, relapse rates are also high because this drug resistance reversal is incomplete. Because both P-glycoprotein- and platinum-induced resistance appear to be clinically important and can be reversed in vitro with a short exposure of cyclosporin A (CSA) at 2000 and 5000 ng/ml, respectively, we undertook a trial of high-dose chemotherapy with carboplatin (1500mg/m2), mitoxantrone (75 mg/m2), and cyclophosphamide (120 mg/kg) over a 5-day period combined with escalating doses of CSA. Thirty-seven patients with primarily breast cancer (61% doxorubicin resistant) and ovarian cancer (85% platinum resistant) were treated with CSA given as a bolus 18 h prior to chemotherapy, followed by a 5-day infusion at doses of 5.0-28.2 mg/kg/day and the chemotherapy. The maximum tolerated dose of CSA was a bolus of 5.5 mg/kg and an infusion of 15. 9 mg/kg/day, which gave a mean serum CSA level of 1544 ng/ml. The dose-limiting toxicity was severe mucositis and enteritis, leading to infectious complications. Nephrotoxicity was seen in 42% and, while usually mild and reversible, was fatal in two patients with pretreatment creatinine clearances h80 ml/min. Grade III-IV isolated hyperbilirubinemia was seen in 39%, but appeared to be of no clinical significance. The overall response rate for the 26 patients with measurable/evaluable disease was 73% and 63% for those with doxorubicin- or platinum-resistant disease. The median overall survival and progression-free survival for the group were 18.1 and 8. 0 months. The overall survival for the nine patients with doxorubicin-resistant breast cancer was 19.3 months. Although we did not achieve CSA levels needed to reverse platinum resistance in vivo, levels approaching those needed to reverse P-glycoprotein resistance were reached at the maximum tolerated dose. The strategy of combining dose intensity with drug resistance reversal deserves further study, especially with the advent of potentially less toxic agents available to reverse P-glycoprotein-mediated resistance.

In vitro chemoseparation of leukemic cells from murine bone marrow using VP16-213: importance of stem cell assays.

The use of chemopurified autologous bone marrow (BM) is being explored as a transplant source for patients with leukemia who do not have a HLA-matched donor. Because stem cell assays have not previously been found to predict engraftment after transplantation, the optimal drug(s) and drug concentrations have not been determined. To determine the effectiveness of the podophyllotoxin derivative, VP16, and the value of stem cell assays in chemopurification studies, a murine model using the C57B1/6 mouse and its syngeneic leukemia EL-4 was developed. Kill of committed (CFU-C) and pluripotent (CFU-S) hematopoietic stem cells and tumor (tCFU) stem cells after a 1-h exposure to VP16 was first determined. A marked kill differential of tCFU compared to that of the CFU-C/S populations was found, with no tCFU surviving at VP16 concentrations greater than 30 micrograms/ml. No kill differential of CFU-C versus CFU-S was seen at VP16 doses greater than 10 micrograms/ml. All mice transplanted with a mixture of 25 X 10(6) BM cells and 1 X 10(7) EL-4 cells treated in vitro with 40 micrograms/ml of VP16 died of their tumors. However by reducing the tumor burden to 1 X 10(6) EL-4 and 5 X 10(6) EL-4, nine of ten and four of six of the mice, respectively, survived 90+ days tumor free. On the basis of survival data, it was found that engraftment of VP16-treated BM was directly proportional to the product of the degree of CFU-S inhibition and BM cell inoculum, i.e., the number of viable CFU-S transplanted. The maximum VP16 concentration that led to predictable engraftment at BM doses less than 25 X 10(6) cells was 55 micrograms/ml. Thus, 15 mice were transplanted with 1 X 10(7) BM cells and 1 X 10(7) EL-4 cells, incubated with 55 micrograms/ml of VP16; 13 out of 15 survived tumor free for 90+ days. When VP16 was used as a BM chemopurification agent, up to 50% of contaminating tumor cells were eliminated from BM suspensions without affecting engraftment after transplantation. Because stem cell inhibition predicted engraftment, drug concentrations that maximized tumor cell kill could be chosen.

Treatment options for recurrent lymphomas.

The prognosis of patients with aggressive non-Hodgkin's lymphomas who fail to achieve a complete remission or who relapse following initial chemotherapy has improved dramatically in recent years. Bone marrow transplantation now provides a curative option and is the current treatment of choice. Conventional chemotherapeutic regimens are not capable of salvaging these patients; however, most patients should be treated with chemotherapy to induce a temporary remission prior to the transplantation procedure. Numerous studies are currently attempting to improve preparative chemotherapy and/or radiation therapy. Since conventional chemotherapy provides short-term palliation only, patients who are not candidates for transplantation should be entered into investigational protocols.

Cytotoxic synergy of cisplatin with concurrent hydroxyurea and cytarabine: summary of an in vitro model and initial clinical pilot experience.

Cytarabine and hydroxyurea in combination are known to inhibit the DNA excision repair system. Given this system is responsible for repair of cisplatin-DNA adducts, we hypothesized that combining cytarabine, hydroxyurea, and cisplatin in an appropriate schedule might inhibit adduct repair, increase the number of DNA lesions, and produce synergistic cell kill. In vitro experiments using clinically achievable doses and schedules of these antimetabolites demonstrated cytotoxic synergy with the three-drug combination, but little or no such synergy with either antimetabolite plus cisplatin. The inclusion of hydroxyurea was necessary to achieve maximum synergy. Increased levels and persistence of cisplatin-induced DNA interstrand cross-links were observed, suggesting repair inhibition may have occurred. The dose of cisplatin required to inhibit colony formation by 90% was reduced approximately one third, even after normalization for the cytotoxic component(s) of hydroxyurea, cytarabine, and hydroxyurea plus cytarabine. Using one of the two optimal in vitro schedules for the three-drug combination, we performed a clinical pilot study in two patient cohorts (with and without prior systemic therapy). Administration of the program was feasible, and resulted in dose-limiting thrombocytopenia only in the cohort with prior chemotherapy. Azotemia was treatment-limiting in responding patients. Responses were observed in patients with a variety of solid tumors, including several patients who had previously failed cisplatin therapy. Modifications of this program are discussed, which have, to date, significantly decreased the toxicity concerns raised by the first trial. Phase II trials are planned in patients with a variety of cisplatin-responsive and nonresponsive neoplasms.

Management strategies for the hard-to-mobilize patient.

Delayed hematopoietic engraftment, particularly of platelets, is seen in 5-35% of patients undergoing high-dose chemotherapy with autologous stem cell transplantation. Studies indicate that delayed engraftment is related to low CD34+ cell dose, and that risk factors for poor mobilization of CD34+ cells relate primarily to the type and extent of prior therapy. Data indicating an appropriate strategy to ensure that 'hard-to-mobilize' patients will achieve adequate CD34+ cell numbers are limited. It is clear, however, that marrow harvesting (performed frequently by a number of centers), is of limited value. Remobilization, best accomplished with a regimen of high-dose chemotherapy and cytokines, is of benefit in selected patients, but has substantial costs and morbidity. Instead of ad hoc treatment of patients who have a poor first mobilization, high-risk groups should be identified prospectively, and strategies should be developed to ensure adequate mobilization in all high-risk patients. The first randomized trial utilizing this approach has recently been reported. In this trial, stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) alone was compared to mobilization with G-CSF combined with stem cell factor (SCF) in heavily pretreated patients with Hodgkin's and non-Hodgkin's lymphoma. The combination of G-CSF and SCF led to collection of a higher total CD34+ cell dose compared to G-CSF alone. Further, more patients in the combination group were able to mobilize an optimal CD34+ cell dose (ie 5 x 10(6)/kg). Additional trials are needed to determine long-term outcomes and the economic impact of achieving optimal stem cell mobilization in these patients, who would otherwise not be candidates for high-dose chemotherapy.

Analysis of remobilization success in patients undergoing autologous stem cell transplants who fail an initial mobilization: risk factors, cytokine use and cost.

Inadequate stem cell mobilization is seen in approximately 25% of patients undergoing autotransplantation for hematologic malignancies. Remobilization strategies include chemotherapy/cytokine combinations or high-dose cytokines alone or in combination. From 1/1997 to 7/2002, we remobilized 86 patients who failed an initial mobilization (median total CD34=0.72 x 10(6)/kg) in sequential cohorts using high-dose G-CSF (32 microg/kg/day) or G-CSF(10 microg/kg/day)+GM-CSF (5 microg/kg/day). No difference in CD34/kg yields were seen (G-CSF alone: 2.2 x 10(6) and G-CSF+GM-CSF 1.6 x 10(6)) in the median 3 aphereses performed (P=0.333). Of the 86, 23 (27%) failed the second mobilization; 14 were remobilized again (yield=1.5 x 10(6) CD34/kg; three aphereses). Of the 86, 93% went to transplant: three progressed, and three had inadequate stem cells. Significant risk factors for a failed remobilization were: number of stem-cell-damaging regimens (P=0.015), time between last chemotherapy and first mobilization (P=0.028), and higher WBC at initiation of first mobilization (P=0.04). High-dose G-CSF (32 microg/kg/day) was more costly @ USD $9,016, vs $5,907 for the G-CSF+GM-CSF combination (P<0.001). Most patients failing an initial mobilization benefit from a cytokine only remobilization. Lower cost G-CSF+GM-CSF is as effective as high-dose G-CSF.