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(1/1170) L-[1-11C]-tyrosine PET to evaluate response to hyperthermic isolated limb perfusion for locally advanced soft-tissue sarcoma and skin cancer.

PET with L-[1-11C]-tyrosine (TYR) was investigated in patients undergoing hyperthermic isolated limb perfusion (HILP) with recombinant tumor necrosis factor alpha (rTNF-alpha) and melphalan for locally advanced soft-tissue sarcoma and skin cancer of the lower limb. METHODS: Seventeen patients (5 women, 12 men; age range 24-75 y; mean age 52 y) were studied. TYR PET studies were performed before HILP and 2 and 8 wk afterwards. The protein synthesis rates (PSRs) in nanomoles per milliliter per minute were calculated. After final PET studies, tumors were resected and pathologically examined. Patients with pathologically complete responses (pCR) showed no viable tumors after treatment. Those with pathologically partial responses (pPR) showed various amounts of viable tumors in the resected tumor specimens. RESULTS: Six patients (35%) showed a pCR and 11 patients (65%) showed a pPR. All tumors were depicted as hot spots on PET studies before HILP. The PSR in the pCR group at 2 and 8 wk after perfusion had decreased significantly (P < 0.05) in comparison to the PSR before HILP. A significant difference was found in PSR between the pCR and pPR groups at 2 and at 8 wk (P < 0.05). Median PSR in nonviable tumor tissue was 0.62 and ranged from 0.22 to 0.91. With a threshold PSR of 0.91, sensitivity and specificity of TYR PET were 82% and 100%, respectively. The predictive value of a PSR > 0.91 for having viable tumor after HILP was 100%, whereas the predictive value of a PSR < or = 0.91 for having nonviable tumor tissue after HILP was 75%. The 2 patients in the pPR groups with a PSR < 0.91 showed microscopic islets of tumor cells surrounded by extensive necrosis on pathological examination. CONCLUSION: Based on the calculated PSR after HILP, TYR PET gave a good indication of the pathological outcome. Inflammatory tissue after treatment did not interfere with viable tumor on the images, suggesting that it may be worthwhile to pursue TYR PET in other therapy evaluation settings.  (+info)

(2/1170) In vivo isolated kidney perfusion with tumour necrosis factor alpha (TNF-alpha) in tumour-bearing rats.

Isolated perfusion of the extremities with high-dose tumour necrosis factor alpha (TNF-alpha) plus melphalan leads to dramatic tumour response in patients with irresectable soft tissue sarcoma or multiple melanoma in transit metastases. We developed in vivo isolated organ perfusion models to determine whether similar tumour responses in solid organ tumours can be obtained with this regimen. Here, we describe the technique of isolated kidney perfusion. We studied the feasibility of a perfusion with TNF-alpha and assessed its anti-tumour effects in tumour models differing in tumour vasculature. The maximal tolerated dose (MTD) proved to be only 1 microg TNF-alpha. Higher doses appeared to induce renal failure and a secondary cytokine release with fatal respiratory and septic shock-like symptoms. In vitro, the combination of TNF-alpha and melphalan did not result in a synergistic growth-inhibiting effect on CC 531 colon adenocarcinoma cells, whereas an additive effect was observed on osteosarcoma ROS-1 cells. In vivo isolated kidney perfusion, with TNF-alpha alone or in combination with melphalan, did not result in a significant anti-tumour response in either tumour model in a subrenal capsule assay. We conclude that, because of the susceptibility of the kidney to perfusion with TNF-alpha, the minimal threshold concentration of TNF-alpha to exert its anti-tumour effects was not reached. The applicability of TNF-alpha in isolated kidney perfusion for human tumours seems, therefore, questionable.  (+info)

(3/1170) Cell adhesion mediated drug resistance (CAM-DR): role of integrins and resistance to apoptosis in human myeloma cell lines.

Integrin-mediated adhesion influences cell survival and may prevent programmed cell death. Little is known about how drug-sensitive tumor cell lines survive initial exposures to cytotoxic drugs and eventually select for drug-resistant populations. Factors that allow for cell survival following acute cytotoxic drug exposure may differ from drug resistance mechanisms selected for by chronic drug exposure. We show here that drug-sensitive 8226 human myeloma cells, demonstrated to express both VLA-4 (alpha4beta1) and VLA-5 (alpha5beta1) integrin fibronectin (FN) receptors, are relatively resistant to the apoptotic effects of doxorubicin and melphalan when pre-adhered to FN and compared with cells grown in suspension. This cell adhesion mediated drug resistance, or CAM-DR, was not due to reduced drug accumulation or upregulation of anti-apoptotic Bcl-2 family members. As determined by flow cytometry, myeloma cell lines selected for drug resistance, with either doxorubicin or melphalan, overexpress VLA-4. Functional assays revealed a significant increase in alpha4-mediated cell adhesion in both drug-resistant variants compared with the drug-sensitive parent line. When removed from selection pressure, drug-resistant cell lines reverted to a drug sensitive and alpha4-low phenotype. Whether VLA-4-mediated FN adhesion offers a survival advantage over VLA-5-mediated adhesion remains to be determined. In conclusion, we have demonstrated that FN-mediated adhesion confers a survival advantage for myeloma cells acutely exposed to cytotoxic drugs by inhibiting drug-induced apoptosis. This finding may explain how some cells survive initial drug exposure and eventually express classical mechanisms of drug resistance such as MDR1 overexpression.  (+info)

(4/1170) The minimum CD34 threshold depends on prior chemotherapy in autologous peripheral blood stem cell recipients.

We analysed 57 patients with non-myeloid malignancies who received a non-purged autologous PBSCT. All had similar mobilisation and conditioning regimens. A high prior chemotherapy score and the number of chemotherapy lines used (P = 0.015 and P = 0.01, respectively) were adverse predictors of CD34 cell yields. Lower CD34 values (P = 0.002) were seen in patients treated with potent stem cell toxins (BCNU, melphalan, CCNU and mustine), designated toxicity factor 4 agents (TF4). All patients infused with grafts containing CD34 cell doses between 1.0 and 2.0 x 10(6)/kg (range 1.25-1.90) engrafted by day 51. The only variable associated with slow platelet recovery was exposure to TF4 (P = 0.007). The majority of patients with CD34 >1.0 x 10(6)/kg achieved rapid and sustained engraftment and the only predictive factor of delayed recovery is prior exposure to stem cell toxins. Potential PBSCT candidates should if possible avoid first line and salvage chemotherapy containing TF4 drugs. We therefore advocate a minimum CD34 threshold of >1.0 x 10(6)/kg in patients without extensive prior chemoradiotherapy, and > or = 2.0 x 10(6)/kg in all other patients.  (+info)

(5/1170) Potentiation of anti-cancer drug activity at low intratumoral pH induced by the mitochondrial inhibitor m-iodobenzylguanidine (MIBG) and its analogue benzylguanidine (BG).

Tumour-selective acidification is of potential interest for enhanced therapeutic gain of pH sensitive drugs. In this study, we investigated the feasibility of a tumour-selective reduction of the extracellular and intracellular pH and their effect on the tumour response of selected anti-cancer drugs. In an in vitro L1210 leukaemic cell model, we confirmed enhanced cytotoxicity of chlorambucil at low extracellular pH conditions. In contrast, the alkylating drugs melphalan and cisplatin, and bioreductive agents mitomycin C and its derivative EO9, required low intracellular pH conditions for enhanced activation. Furthermore, a strong and pH-independent synergism was observed between the pH-equilibrating drug nigericin and melphalan, of which the mechanism is unclear. In radiation-induced fibrosarcoma (RIF-1) tumour-bearing mice, the extracellular pH was reduced by the mitochondrial inhibitor m-iodobenzylguanidine (MIBG) or its analogue benzylguanidine (BG) plus glucose. To simultaneously reduce the intracellular pH, MIBG plus glucose were combined with the ionophore nigericin or the Na+/H+ exchanger inhibitor amiloride and the Na+-dependent HCO3-/Cl- exchanger inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS). Biochemical studies confirmed an effective reduction of the extracellular pH to approximately 6.2, and anti-tumour responses to the interventions indicated a simultaneous reduction of the intracellular pH below 6.6 for at least 3 h. Combined reduction of extra- and intracellular tumour pH with melphalan increased the tumour regrowth time to 200% of the pretreatment volume from 5.7 +/- 0.6 days for melphalan alone to 8.1 +/- 0.7 days with pH manipulation (P < 0.05). Mitomycin C related tumour growth delay was enhanced by the combined interventions from 3.8 +/- 0.5 to 5.2 +/- 0.5 days (P < 0.05), but only in tumours of relatively large sizes. The interventions were non-toxic alone or in combination with the anti-cancer drugs and did not affect melphalan biodistribution. In conclusion, we have developed non-toxic interventions for sustained and selective reduction of extra- and intracellular tumour pH which potentiated the tumour responses to selected anti-cancer drugs.  (+info)

(6/1170) Early harvest and late transplantation as an effective therapeutic strategy in multiple myeloma.

Transplantation after high-dose chemotherapy prolongs survival in patients with multiple myeloma compared with standard therapy. It is unclear whether the optimal timing of transplantation is immediately after induction chemotherapy or whether stem cells may be cryopreserved for transplantation at subsequent progression or relapse. In this study, stem cells were collected within 6 months of diagnosis, followed by transplantation only at progression of myeloma. One hundred and eighteen patients with multiple myeloma had stem cells collected and cryopreserved. Eleven had transplants early in the disease after they demonstrated failure to respond to primary therapy. The remaining 107 were eligible for transplants when there was evidence of progressive disease. Of the 118 patients, 67 had transplants, nine died of progressive disease before transplantation, and 42 remain alive in plateau phase. The median survival of the group is 58.5 months; 67 are alive. Serum beta2-microglobulin, bone marrow labeling index (S phase), and hemoglobin level predicted overall survival (P < 0.006, P < 0.001, and P < 0.01, respectively). We conclude that early cryopreservation of blood stem cells followed by transplantation at progression is a feasible approach to therapy in patients with myeloma. The underlying biology of the disease has a greater impact on survival than the timing of transplantation. A prospective randomized trial is required to answer definitively the question of the optimal timing of blood cell transplantation.  (+info)

(7/1170) Progressive multifocal leukoencephalopathy after autologous bone marrow transplantation and alpha-interferon immunotherapy.

A patient with a stage IV mantle cell lymphoma (according to the REAL classification) was treated with high-dose chemotherapy and autologous bone marrow transplantation. One year later while on alpha-interferon immunotherapy she suffered from progressive loss of short-term memory and reported difficulties in recognizing objects. Magnetic resonance imaging (MRI) showed a vast ring-enhancing lesion of the left postcentral parietal area. Serial stereotactic biopsies disclosed progressive multifocal leukoencephalopathy without JC-virus in the cerebrospinal fluid. Therapy with subcutaneous interleukin-2 (IL-2) every other day and intrathecal cytarabine once a week was started. After 4 weeks the patient refused further treatment. Nevertheless her condition improved over the next 8 months and MRI scans showed a marked improvement in the lesions.  (+info)

(8/1170) Idiotype vaccination using dendritic cells after autologous peripheral blood stem cell transplantation for multiple myeloma--a feasibility study.

The idiotype (Id) determinant on the multiple myeloma (MM) protein can be regarded as a tumor-specific marker. Immunotherapy directed at the MM Id may stem the progression of this disease. We report here on the first 12 MM patients treated at our institution with high-dose therapy and peripheral blood stem cell transplantation (PBSCT) followed by Id immunizations. MM patients received PBSCT to eradicate the majority of the disease. PBSCT produced a complete response in 2 patients, a partial response in 9 patients and stable disease in 1 patient. Three to 7 months after high-dose therapy, patients received a series of monthly immunizations that consisted of two intravenous infusions of Id-pulsed autologous dendritic cells (DC) followed by five subcutaneous boosts of Id/keyhole limpet hemocyanin (KLH) administered with adjuvant. Between 1 and 11 x 10(6) DC were obtained by leukapheresis in all patients even after PBSCT. The administration of Id-pulsed DC and Id/KLH vaccines were well tolerated with patients experiencing only minor and transient side effects. Two of 12 patients developed an Id-specific, cellular proliferative immune response and one of three patients studied developed a transient but Id-specific cytotoxic T-cell (CTL) response. Eleven of the 12 patients generated strong KLH-specific cellular proliferative immune responses showing the patients' immunocompetence at the time of vaccination. The two patients who developed a cellular Id-specific immune response remain in complete remission. Of the 12 treated patients, 9 are currently alive after autologous transplantation with a minimum follow-up of 16 months, 2 patients died because of recurrent MM and 1 patient succumbed to acute leukemia. These studies show that patients make strong anti-KLH responses despite recent high-dose therapy and that DC-based Id vaccination is feasible after PBSCT and can induce Id-specific T-cell responses. Further vaccine development is necessary to increase the proportion of patients that make Id-specific immune responses. The clinical benefits of Id vaccination in MM remain to be determined.  (+info)