A role for surgery in the treatment of relapsed Hodgkin lymphoma.

Treatment of Hodgkin lymphoma (HL) has advanced over time, rendering a fatal disease now largely curable. Multiagent chemotherapy regimens, hematopoietic stem cell transplantation, and radiotherapy are the mainstays of care. Surgical intervention is rarely indicated other than for biopsy at diagnosis. However, for patients with recurrent relapsed HL isolated to one anatomical location, refractory to all other therapy, there may be a beneficial role for surgical excision. Herein, we report the surgical management of three relapsed patients with stage IVB HL who were refractory to multiple other therapeutic approaches, who all achieved good event-free survival after operative management.

A phase 1 trial of imatinib, bevacizumab, and metronomic cyclophosphamide in advanced colorectal cancer.

BACKGROUND: This phase 1 clinical trial was conducted to determine the safety, maximum-tolerated dose (MTD), and pharmacokinetics of imatinib, bevacizumab, and metronomic cyclophosphamide in patients with advanced colorectal cancer (CRC). METHODS: Patients with refractory stage IV CRC were treated with bevacizumab 5 mg kg(-1) i.v. every 2 weeks (fixed dose) plus oral cyclophosphamide q.d. and imatinib q.d. or b.i.d. in 28-day cycles with 3+3 dose escalation. Response was assessed every two cycles. Pharmacokinetics of imatinib and cyclophosphamide and circulating tumour, endothelial, and immune cell subsets were measured. RESULTS: Thirty-five patients were enrolled. Maximum-tolerated doses were cyclophosphamide 50 mg q.d., imatinib 400 mg q.d., and bevacizumab 5 mg kg(-1) i.v. every 2 weeks. Dose-limiting toxicities (DLTs) included nausea/vomiting, neutropaenia, hyponatraemia, fistula, and haematuria. The DLT window required expansion to 42 days (1.5 cycles) to capture delayed toxicities. Imatinib exposure increased insignificantly after adding cyclophosphamide. Seven patients (20%) experienced stable disease for >6 months. Circulating tumour, endothelial, or immune cells were not associated with progression-free survival. CONCLUSION: The combination of metronomic cyclophosphamide, imatinib, and bevacizumab is safe and tolerable without significant drug interactions. A subset of patients experienced prolonged stable disease independent of dose level.

Evidence for a familial Wilms' tumour gene (FWT1) on chromosome 17q12-q21.

Wilms' tumour (WT) is one of the most common solid tumours of childhood, occurring in 1 in 10,000 children and accounting for 8% of childhood cancers. It is believed to result from malignant transformation of abnormally persistent renal stem cells (nephrogenic rests) which retain embryonic differentiation potential. Although WT is usually sporadic, approximately one percent occur in families in which susceptibility appears to be inherited as an autosomal dominant trait with incomplete penetrance. Predisposition to other cancers or to the developmental abnormalities associated with sporadic WT is not usually apparent in WT families. The WT1 gene at 11p13 (ref.2), and additional genes on chromosomes 11p15 (ref. 3) and 16q (ref. 4) have been implicated in the development of WT but are not responsible for familial WT. We have carried out a genome linkage search in a large Canadian family with seven confirmed cases of WT. Our results provide strong evidence for the localisation of a familial WT predisposition gene, FWT1, to an 18-centimorgan (cM) interval on chromosome 17q12-q21.

Cyclooxygenase inhibitors modulate the p53/HDM2 pathway and enhance chemotherapy-induced apoptosis in neuroblastoma.

Cyclooxygenase-2 (COX-2) is upregulated in many tumors including neuroblastoma, and its overexpression has been implicated in resistance to p53-dependent apoptosis. Although p53 is rarely mutated in neuroblastoma, the p53 protein is rendered inactive via several mechanisms including sequestration in the cytoplasm. Here, we show that COX inhibitors inhibit the growth of neuroblastoma and when combined with low doses of chemotherapy, exert synergistic effects on neuroblastoma cells. Following COX inhibitor treatment, HDM2, which targets p53 for ubiquitin-mediated degradation, is downregulated, resulting in an attenuation of p53 ubiquitination and an increase in p53 half-life. The level of HDM2 phosphorylation at ser166, which influences both HDM2 and p53 subcellular distribution, is markedly diminished in response to COX inhibitors and is associated with increased p53 nuclear localization. Combining COX inhibitors with low-dose chemotherapy potentiates apoptosis and p53 stability, nuclear localization, and activity. p53 knockdown by siRNA resulted in the rescue of COX-inhibitor-treated cells, indicating that COX inhibitor-induced apoptosis is, at least in part, p53-dependent. Taken together, these results provide the first evidence that COX inhibitors enhance chemosensitivity in neuroblastoma via downregulating HDM2 and augmenting p53 stability and nuclear accumulation.

Continuous low-dose therapy with vinblastine and VEGF receptor-2 antibody induces sustained tumor regression without overt toxicity.

Various conventional chemotherapeutic drugs can block angiogenesis or even kill activated, dividing endothelial cells. Such effects may contribute to the antitumor efficacy of chemotherapy in vivo and may delay or prevent the acquisition of drug-resistance by cancer cells. We have implemented a treatment regimen that augments the potential antivascular effects of chemotherapy, that is devoid of obvious toxic side effects, and that obstructs the development of drug resistance by tumor cells. Xenografts of 2 independent neuroblastoma cell lines were subjected to either continuous treatment with low doses of vinblastine, a monoclonal neutralizing antibody (DC101) targeting the flk-1/KDR (type 2) receptor for VEGF, or both agents together. The rationale for this combination was that any antivascular effects of the low-dose chemotherapy would be selectively enhanced in cells of newly formed vessels when survival signals mediated by VEGF are blocked. Both DC101 and low-dose vinblastine treatment individually resulted in significant but transient xenograft regression, diminished tumor vascularity, and direct inhibition of angiogenesis. Remarkably, the combination therapy resulted in full and sustained regressions of large established tumors, without an ensuing increase in host toxicity or any signs of acquired drug resistance during the course of treatment, which lasted for >6 months. This article may have been published online in advance of the print edition. The date of publication is available from the JCI website, http://www.jci.org.

Safety and pharmacokinetics of temozolomide using a dose-escalation, metronomic schedule in recurrent paediatric brain tumours.

The aims of this study were to determine the maximum tolerated dose (MTD), toxicity and pharmacokinetics of oral temozolomide administered over 42 d in children with recurrent/refractory brain tumours. Cohorts of 3-6 patients were treated for 42 d, followed by a 7-d rest period for a maximum of 6 cycles. Patients were stratified as heavily pre-treated (HPT) and non-heavily pre-treated (NHPT). Starting doses were 50 mg/m2 (HPT) or 75 mg/m2 (NHPT). Out of 28 patients enrolled, 20 were evaluable for toxicity and 19 for pharmacokinetics. Three patients in the NHPT group developed grade 3/4 haematological toxicity, 2 experienced dose-limiting toxicity (thrombocytopenia) at 100 mg/m2, and 9/20 developed grade 3 lymphopenia. MTD in both strata was 85 mg/m2. Responses were observed in 4 patients: 2 complete responses (CR) in medulloblastoma and supratentorial primitive neuroectodermal tumours (PNET), and 2 partial responses (PR) in high-grade glioma, respectively. Overall cumulative exposure was at least 1.5 times higher than in the 5-d administration schedule. In conclusion, the recommended dose of temozolomide is 85 mg/m2 x 42 d. Dose-limiting toxicities are thrombocytopenia and lymphopenia. The observed response rate warrants phase II studies.

The familial Wilms' tumour susceptibility gene, FWT1, may not be a tumour suppressor gene.

A familial Wilms' tumour susceptibility gene, known as FWT1, has recently been localised to chromosome 17q12-q21 by genetic linkage analysis. Four Wilms' tumours from a family showing strong evidence of linkage to FWT1 were examined for allele loss using polymorphic microsatellite markers on chromosome 17q. In three tumours no loss of heterozygosity was observed. In the remaining case, loss of heterozygosity was detected at all markers analysed. However, the alleles lost in this Wilms' tumour were those segregating with the disease in the family. This is in contrast to the usual pattern observed in familial cancer syndromes, where the allele lost in tumours arising in gene carriers is the wild type inherited from the non mutation carrying parent. Taken together with previous data indicating that LOH on chromosome 17q is rare in sporadic Wilms' tumour, the results suggest that FWT1 is not a tumour suppressor gene. Moreover, loss of alleles linked to the disease and the implied absence of the mutated susceptibility gene in one tumour, suggests that a mutation in FWT1 may be necessary for the initiation of some familial Wilms' tumours but subsequently the maintenance of the neoplastic phenotype becomes independent of the FWT1 mutation.

The role of oxidative stress in disease progression in individuals infected by the human immunodeficiency virus.

This review describes the potential role of oxidative stress as a cofactor of disease progression from asymptomatic human immunodeficiency virus (HIV) infection to the acquired immunodeficiency syndrome (AIDS). Oxidative stress is a known activator of HIV replication in vitro through the activation of a factor that binds to a DNA-binding protein, NF-kappa B, which in turn stimulates HIV gene expression by acting on the promoter region of the viral long terminal repeat. Tumor necrosis factor alpha (TNF-alpha), an essential cytokine produced by activated macrophages, is also involved in the activation of HIV infection through similar mechanisms. TNF-mediated cytotoxicity of cells exposed to this substance is related to the generation of intracellular hydroxyl radicals. An indirect argument in favor of the role of oxidative stress in HIV-associated disease progression is the consumption of glutathione (GSH), a major intracellular antioxidant, during HIV infection and progression. GSH is known to play a major role in regulation of T cell immune functions. Oxidative stress may also play an important role in the genesis of cellular DNA damage and, in this context, may be related to HIV-associated malignancies and disease progression. Finally, the role of antioxidants as components of therapeutic strategies to combat HIV disease progression is discussed.

In vitro cytoprotective activity of squalene on a bone marrow versus neuroblastoma model of cisplatin-induced toxicity. implications in cancer chemotherapy.

The development of a non-toxic selective cytoprotective agent that preferentially protects normal tissues from chemotherapy toxicity, without protecting malignant tissues, is a major challenge in cancer chemotherapy research. The available cytoprotective agents are either toxic or lack selective cytoprotective activity. Here, we report the in vitro selective cytoprotective activity of squalene, an isoprenoid molecule with antioxidant properties. Normal human bone marrow (BM) derived colony-forming unit (CFU) growth was increased by squalene in a dose-dependent manner. Squalene (12.5-25 microM) treatment significantly protected the CFUs from cisplatin-induced toxicity; the protective effect was equivalent to reduced glutathione (GSH), a known cytoprotective agent. Squalene also increased the long-term survival of cisplatin-treated 4-week-old CFUs. Cisplatin-induced apoptosis of CFUs as measured by the TUNEL assay was reduced by squalene. To examine the squalene-induced protection of tumours, several neuroblastoma cell lines, including five MYCN-amplified cell lines, were grown in monolayers, as well as in anchorage-independent cultures, in the presence of squalene and cisplatin. Squalene did not protect the neuroblastoma (NBL) cell lines from cisplatin-induced toxicity. In addition, squalene did not protect the NBL cells from carboplatin, cyclophosphamide, etoposide and doxorubicin-induced toxicity. In conclusion, our results suggest that squalene has a selective in vitro cytoprotective effect on BM-derived haematopoietic stem cells that is equipotent to GSH.

In vivo selective modulation of tissue glutathione in a rat mammary carcinoma model.

Glutathione (GSH) is known to play a role in cellular sensitivity to some chemotherapeutic agents and to radiation. Depletion of cellular GSH has been demonstrated to result in enhanced toxicity of these drugs, and this approach is being explored in the clinic as a form of biochemical modulation, using the drug buthionine sulfoximine (BSO). The fact that some drug-resistant cell lines have increased glutathione levels, and that enhancing GSH concentrations in animal tissues protects against a variety of xenobiotic agents, suggest a different potential approach to improving anti-cancer therapy. We have examined the efficacy of the cysteine "pro-drug" L-2-oxothiazolidine-4-carboxylate (OTZ) at enhancing normal tissue versus tumor GSH. Animals were treated with OTZ or BSO, and the concentrations of GSH in normal tissues and tumor were measured. We found that the presence of the tumor itself decreased bone marrow GSH, but that OTZ significantly increased it in this setting. Interestingly, OTZ administration significantly depleted tumor GSH levels to the same level as did BSO. OTZ could offer a selective biochemical modulation of GSH.

Risk factors for long-term outcome of ifosfamide-induced nephrotoxicity in children.

Ifosfamide is widely used in the treatment of pediatric solid tumors. Its main adverse effects are various forms of renal tubular and glomerular damage. The authors sought to determine factors that predict the risk for the development and severity of ifosfamide-induced nephrotoxicity in children and to examine the long-term outcome of this complication. A total of 174 children who had received ifosfamide for various cancers were studied. Nephrotoxicity was assessed by laboratory markers of glomerular and tubular function and a grading score (none, mild, moderate, severe). Patients were assessed 4 to 12 weeks after each ifosfamide course, 3 months after completion of chemotherapy, and 5 years later. Of 174 children, 72 (41.4%) developed tubular dysfunction, whereas only 11 (6.3%) demonstrated glomerular dysfunction; 40 (23.0%) demonstrated mild toxicity, 16 (9.2%) demonstrated moderate toxicity, and 16 (9.2%) developed severe nephrotoxicity. The four severity subgroups (none, mild, moderate, severe) received comparable doses/m2/cycle of ifosfamide and mesna. Children exhibiting severe toxicity were significantly younger compared to those with moderate, mild, or no nephrotoxicity (median age: 2.2, 7.0, 8.2, and 10.5 years, respectively; p < 0.001) and received significantly higher cumulative doses of ifosfamide (49.6 +/- 12.3, 46.0 +/- 13.1, 36.2 +/- 9.7, and 33.8 +/- 7.6 g/m2, respectively; p < 0.001). Cumulative doses of cisplatin were higher among children with severe nephrotoxicity compared to those with moderate, mild, or no toxicity, although this difference did not reach statistical significance. Of all risk factors analyzed by multiple regression analysis, age was the most significant predictor for the grade of nephrotoxicity (p < 0.001), followed by the cumulative dose of ifosfamide (p = 0.005). Seven out of 16 children (44.0%) with severe nephrotoxicity and 4 out of 16 children (25.0%) with moderate nephrotoxicity demonstrated severe chronic tubular toxicity over a follow-up period of 5 years. Since severe ifosfamide-induced renal toxicity tends to be chronic in a substantial number of treated children, it should be balanced carefully against efficacy. Cumulative ifosfamide doses of 45 g/m2 and above should be carefully considered, especially in children younger than age 3.

In vitro selective modulation of cellular glutathione by a humanized native milk protein isolate in normal cells and rat mammary carcinoma model.

We report the in vitro selective inhibitory activity of a humanized whey protein concentrate IMMUNOCAL on growth of mammary carcinoma cells and Jurkat T cells in comparison to normal peripheral blood mononuclear cells. We relate this inhibitory activity to a selective depletion of intracellular glutathione synthesis. The use of humanized whey protein concentrate as a food supplementation may have direct implication in clinical trial with adjuvant chemotherapy.

The use of a whey protein concentrate in the treatment of patients with metastatic carcinoma: a phase I-II clinical study.

Glutathione (GSH) concentration is high in most tumour cells and this may be an important factor in resistance to chemotherapy. Previous in-vitro and animal experiments have shown a differential response of tumour versus normal cells to various cysteine delivery systems. More specifically, an in-vitro assay showed that at concentrations that induce GSH synthesis in normal human cells, a specially prepared whey protein concentrate, Immunocal, caused GSH depletion and inhibition of proliferation in human breast cancer cells. On the basis of this information five patients with metastatic carcinoma of the breast, one of the pancreas and one of the liver were fed 30 grams of this whey protein concentrate daily for six months. In six patients the blood lymphocyte GSH levels were substantially above normal at the outset, reflecting high tumour GSH levels. Two patients (#1, #3) exhibited signs of tumour regression, normalization of haemoglobin and peripheral lymphocyte counts and a sustained drop of lymphocyte GSH levels towards normal. Two patients (#2, #7) showed stabilisation of the tumour, increased haemoglobin levels. In three patients (#4, #5, #6,) the disease progressed with a trend toward higher lymphocyte GSH levels. These results indicate that whey protein concentrate might deplete tumour cells of GSH and render them more vulnerable to chemotherapy.

Encephaloduroarterio-synangiosis in a child with sickle cell anemia and moyamoya disease.

We report a black girl with sickle cell anemia. On prophylactic exchange transfusion protocol, she experienced cerebrovascular accidents at 3 and 3.5 years of age, both associated with transient right hemiparesis. At 7.5 years of age, she presented with a partial motor seizure and a left hemiparesis. A cerebral angiogram demonstrated stenosis at the origins of both middle and anterior cerebral arteries bilaterally with extensive basal collateralization. She underwent uncomplicated bilateral encephaloduroarteriosynangiosis (EDAS) procedures using both superficial temporal arteries. At age 9 years, the patient presented with a severe headache and tunnel vision secondary to a stenosis of both posterior cerebral arteries. She underwent bilateral EDAS procedures using both occipital arteries. No complication was encountered. Postoperative cerebral angiogram demonstrated impressive neovascularity at the sites of all four EDAS procedures. Different treatment options of moyamoya disease are discussed.

The use and effectiveness of temozolomide in children with central nervous system tumours: a survey from the Canadian Paediatric Brain Tumour Consortium.

OBJECTIVE: To describe the use of temozolomide (tmz) in Canadian children treated for brain tumours and to evaluate survival and predictors of survival for children treated with this agent. METHODS: A survey was conducted within the Canadian Paediatric Brain Tumour Consortium (cpbtc), a group of tertiary care centres in pediatric neuro-oncology (n = 16) in Canada that are involved in the treatment of children with central nervous system tumours. RESULTS: In 10 of the 16 participating pediatric oncology centres of the cpbtc, 137 children with brain tumours were treated with tmz between January 2000 and March 2006. Although 33% of the children were enrolled into a clinical trial, 67% were treated outside open studies. Most patients (72%) received tmz treatment on recurrence of their brain tumour (first or subsequent). The most commonly administered regimen was single-agent tmz 150-200 mg/m(2) administered on 5 consecutive days every 28 days. The median duration of tmz treatment was 141 days (range: 4-1102 days). Response data were provided for 127 of the 137 patients, of whom 6 showed a complete response. Sixteen patients experienced a minor or partial response, 53 had stable disease, and 52 had progressive disease. Of 32 patients alive at last follow-up, 19 had a diagnosis of low-grade glioma. CONCLUSIONS: Temozolomide is used in a variety of pediatric brain tumours, often at the time of recurrence. The lack of insight into clear indications for this agent in pediatric brain tumours-used either alone or in combination therapy-may be a result of suboptimal design of phase i and ii studies and a lack of phase iii trials in the pediatric brain tumour population.

Cyclooxygenase inhibitors differentially modulate p73 isoforms in neuroblastoma.

p73 encodes multiple functionally distinct isoforms. Proapoptotic TAp73 isoforms contain a transactivation (TA) domain, and like p53, have tumor suppressor properties and are activated by chemotherapies to induce cell death. In contrast, antiapoptotic DeltaNp73 isoforms lack the TA domain and are dominant-negative inhibitors of p53 and TAp73. DeltaNp73 proteins are overexpressed in a variety of tumors including neuroblastoma. Thus, identification of drugs that upregulate TAp73 and/or downregulate DeltaNp73 represents a potential therapeutic strategy. Here, we report that cyclooxygenase (COX) inhibitors induce apoptosis independent of p53, and differentially modulate endogenous p73 isoforms in neuroblastoma and other tumors. COX inhibitor-mediated apoptosis is associated with the induction of TAp73beta and its target genes. COX inhibitors also downregulate the alternative-spliced DeltaNp73(AS) isoforms, Deltaexon2 and Deltaexon2/3. Furthermore, forced expression of DeltaNp73(AS) results in diminished apoptosis in response to the selective COX-2 inhibitor celecoxib. Celecoxib-mediated downregulation of DeltaNp73(AS) is associated with decreased E2F1 levels and diminished E2F1 activation of the p73 promoter. These results provide the first evidence that COX inhibitors differentially modulate p73 isoforms leading to enhanced apoptosis, and support the potential use of COX inhibitors as novel regulators of p73 to enhance chemosensitivity in tumors with deregulated E2F1 and in those with wild-type (wt) or mutant p53.

Cisplatin treatment increases survival and expansion of a highly tumorigenic side-population fraction by upregulating VEGF/Flt1 autocrine signaling.

The cellular and molecular mechanisms of tumor progression following chemotherapy are largely unknown. Here, we demonstrate that cisplatin (CDDP) treatment upregulates VEGF and Flt1 expression leading to the survival and expansion of a highly tumorigenic fraction of side-population (SP) cells in osteosarcoma (HOS), neuroblastoma (SK-N-BE2) and rhabdomyosarcoma (RH-4) cell lines. In all three lines, we show that CDDP treatment increases levels of VEGF and Flt1 expression, and induces enhanced clonogenic capacity and increased expression of the 'stemness'-associated genes Nanog, Bmi-1 and Oct-4 in the SP fraction. In HOS, these changes are associated with the transformation of a non-tumorigenic osteosarcoma SP fraction to a highly tumorigenic phenotype. Inhibition of Flt1 led to complete reduction of tumorigenicity in the HOS SP fraction, and reduction of clonogenic capacity and expression of stemness genes in the SK-N-BE(2) and RH-4 SP fractions. Treatment with U0126, a specific inhibitor of MAPK/ERK1,2 completely downregulates CDDP-induced VEGF and Flt1 expression and induction/expansion of SP fraction in all three cell lines, indicating that these effects are mediated through MAPK/ERK1,2 signaling. In conclusion, we report a novel mechanism of CDDP-induced tumor progression, whereby the activation of VEGF/Flt1 autocrine signaling leads to the survival and expansion of a highly tumorigenic SP fraction.

Relief of sickle cell priapism by hydralazine. Report of a case.

We report a 16-year-old Tanner IV male with homozygous hemoglobin S who presented with recurrent episodes of priapism unresponsive to standard therapy with hydration, analgesia, and exchange transfusion. He had a complete resolution of his symptoms with hydralazine therapy. We therefore suggest a trial of vasodilator therapy for recurrent sickle cell priapism before attempting surgical therapy.

Whey proteins as a food supplement in HIV-seropositive individuals.

On the basis of numerous animal experiments, a pilot study was undertaken to evaluate the effect of undenatured, biologically active, dietary whey protein in 3 HIV-seropositive individuals over a period of 3 months. Whey protein concentrate was prepared so that the most thermosensitive proteins, such as serum albumin which contains 6 glutamylcysteine groups, would be in undenatured form. Whey protein powder dissolved in a drink of the patient's choice was drunk cold in quantities that were increased progressively from 8.4 to 39.2 g per day. Patients took whey proteins without adverse side effects. In the 3 patients whose body weight had been stable in the preceding 2 months, weight gain increased progressively between 2 and 7 kg, with 2 of the patients reaching ideal body weight. Serum proteins, including albumin, remained unchanged and within normal range, indicating that protein replenishment per se was not likely the cause of increased body weight. The glutathione content of the blood mononuclear cells was, as expected, below normal values in all patients at the beginning of the study. Over the 3-month period, glutathione levels increased in all 3 cases. In conclusion, these preliminary data indicate that, in patients who maintain an adequate total caloric intake, the addition of "bioactive" whey protein concentrate as a significant portion of total protein intake increases body weight and shows elevation of glutathione (GSH) content of mononuclear cells toward normal levels. This pilot study will serve as a basis for a much larger clinical trial.