Treatment of non-Hodgkin lymphoma

Carbonic Anhydrase IX Inhibitors as Candidates for Combination Therapy of Solid Tumors

Combination therapy is becoming imperative for the treatment of many cancers, as it provides a higher chance of avoiding drug resistance and tumor recurrence. Among the resistance-conferring factors, the tumor microenvironment plays a major role, and therefore, represents a viable target for adjuvant therapeutic agents. Thus, hypoxia and extracellular acidosis are known to select for the most aggressive and resilient phenotypes and build poorly responsive regions of the tumor mass. Carbonic anhydrase (CA, EC 4.2.1.1) IX isoform is a surficial zinc metalloenzyme that is proven to play a central role in regulating intra and extracellular pH, as well as modulating invasion and metastasis processes. With its strong association and distribution in various tumor tissues and well-known druggability, this protein holds great promise as a target to pharmacologically interfere with the tumor microenvironment by using drug combination regimens. In the present review, we summarized recent publications revealing the potential of CA IX inhibitors to intensify cancer chemotherapy and overcome drug resistance in preclinical settings.

NMR-based metabolomic analysis of the molecular pathogenesis of therapy-related myelodysplasia/acute myeloid leukemia

Hematopoietic stem cell transplantation is the oldest and most successful form of stem cell therapy. High dose therapy (HDT) followed by hematopoietic stem cell transplantation allows physicians to administer increased amounts of chemotherapy and/or radiation while minimizing negative side effects such as damage to blood-producing bone marrow cells. Although HDT is successful in treating a wide range of cancers, it leads to lethal therapy-related myelodysplasia syndrome or acute myeloid leukemia (t-MDS/AML) in 5--10% of patients undergoing autologous hematopoietic cell transplantation for Hodgkin lymphoma and non-Hodgkin lymphoma. In this study, we carried out metabolomic analysis of peripheral blood stem cell samples collected in a cohort of patients before hematopoietic cell transplantation to gain insights into the molecular and cellular pathogenesis of t-MDS. Nonparametric tests and multivariate analyses were used to compare the metabolite concentrations in samples from patients that developed t-MDS within 5 years of transplantation and the patients that did not. The results suggest that the development of t-MDS is associated with dysfunctions in cellular metabolic pathways. The top canonical pathways suggested by the metabolomic analysis include alanine and aspartate metabolism, glyoxylate and dicarboxylate metabolism, phenylalanine metabolism, citrate acid cycle, and aminoacyl-t-RNA biosynthesis. Dysfunctions in these pathways indicate mitochondrial dysfunction that would result in decreased ability to detoxify reactive oxygen species generated by chemo and radiation therapy, therefore leading to cancer-causing mutations. These observations suggest predisposing factors for the development of t-MDS.

Combinations of mTORC1 inhibitor RAD001 with gemcitabine and paclitaxel for treating non-Hodgkin lymphoma

Single-agent mammalian target of rapamycin complex 1 (mTORC1) inhibitors have recently been reported as effective salvage treatment in non-Hodgkin lymphoma (NHL). The combined effect of mTORC1 inhibitor, RAD001, with chemotherapeutic agents used for relapsed or refractory NHL was examined. Synergistic interactions were observed for RAD001 plus gemcitabine or paclitaxel in six NHL cell lines; enhanced gemcitabine- and paclitaxel-induced caspase-dependent apoptosis associated with down-regulation of mTOR signaling was detected. Synergistic interactions were also observed with RAD001 plus gemcitabine and paclitaxel. In conclusion, synergistic cytotoxicity was observed with RAD001 plus gemcitabine and paclitaxel in NHL cells. Combination therapy with these three drugs should be examined in patients with refractory or relapsed NHL.

Surgical approach of primary splenic lymphoma: report of a case and review of the literature

A 80-year-old woman was hospitalized due to anemia and fever. Computed tomography depicted a solitary concentric, sharply marginated lesion of the spleen. Laparotomy identified a creamy-white soft tumor. Histopathological examination confirmed the diagnosis of non-Hodgkin B-cells anaplastic lymphoma. Extended range of pathological manifestations explains the variety of radiological appearances and difficulty in accurate diagnostic process of primary splenic lymphoma.

Palliative care in orthopaedic surgical oncology

Hundreds of thousands of Americans are affected every year by skeletal complications of oncologic disease. Recent developments in medical oncology, radiation oncology and radiology, particularly with respect to the use of bisphosphonate medication and radiofrequency techniques, have served to greatly lessen the morbidity associated with metastatic skeletal disease. Similarly, there has been significant advancement in the field of orthopaedic oncology in the areas of internal fixation, endoprosthetic implant design, and minimally invasive kyphoplasty technology. Given the palliative intent of intervention in this patient population, the goal of treatment of skeletal metastases must be optimization of limb function and ultimately, quality of life.

Results of a clinical phase I dose-escalation study of cytarabine in combination with fixed-dose vinorelbine, paclitaxel, etoposide and cisplatin for the treatment of relapsed/refractory lymphoma

Management of relapsed lymphoma depends upon the variables of chemosensitive disease and successful stem cell mobilization. The microtubule specific agents, paclitaxel and vinorelbine, have efficacy in relapsed lymphoma and can enhance stem cell mobilization. We performed a phase I dose-escalation study of cytarabine combined with fixed doses of vinorelbine, paclitaxel, etoposide and cisplatin (VTEPA) for patients with relapsed/refractory lymphoma. The regimen consisted of paclitaxel 175 mg/m2 and vinorelbine 30 mg/m2 on day 1; cisplatin 20 mg/m2 and etoposide 100 mg/m2 over 4 h on days 2 - 5. Cytarabine 2 g m/m2 over 4 h, in successive cohorts on 1, 2, or 3 consecutive days: cohort A day 5; cohort B days 4 - 5; and cohort C days 3 - 5. Sixteen patients (Hodgkin's disease, n = 6; non-Hodgkin's lymphoma, n = 10) were enrolled. Fourteen of 16 patients (88%) had refractory and seven patients (44%) had primary refractory disease. Major toxicities included hematologic toxicity, mucositis and infectious complications. Infectious complications (10/16 patients) included neutropenic fever, sepsis and fungal pneumonia. Dose-limiting toxicity was achieved in cohort C, which received three doses of cytarabine. There were 33% partial responses, 27% stable disease and 40% progressive disease following a single cycle of VTEPA. Two of 16 patients suffered treatment-related mortality. Five patients went on to receive autologous (n = 4) or allogeneic transplant (n = 1), and five out of seven patients in this heavily pretreated group who received VTEPA for mobilization of an autologous graft were successfully collected. The recommended dose of cytarabine for further evaluation in a phase II study is 2 g m/m2 for 2 consecutive days in combination with VTEPA. Treatment of subjects with relapsed/refractory lymphoma using VTEPA as second- or third-line salvage therapy produced remissions in some patients and permitted collection of grafts and subsequent autologous transplantation, supporting a planned phase II trial.

Treatment options for primary splenic low-grade non-Hodgkin's lymphomas

The purpose of this comparative study was to evaluate the response of primary splenic low-grade non-Hodgkin's lymphomas (NHL) to chemotherapy, splenectomy, and chemotherapy combined with splenectomy in order to elaborate the optimum treatment modality. A total of 104 patients (age range: 15-82 years) with primary low-grade B-cell NHL of the spleen were comprised by our study. Stage IV disease was determined in 102 (98.1%) cases. Regarding the treatment modality, splenectomy was performed in 14 patients, early splenectomy and single-agent chemotherapy in 15, early splenectomy and combined chemotherapy in 19, single-agent chemotherapy in 23, and combined chemotherapy in 33. In the above-mentioned order, complete remission rate was following: none, 40.0, 31.6, 21.8, and 18.2%. Partial remissions were achieved in 85.7, 46.7, 57.9, 30.4, and 69.7% of cases, respectively. The median remission duration turned out to be longer (74.5 months) in the group of patients with complete remissions attained by means of splenectomy and combined chemotherapy. Local relapses in the spleen developed in 19 (72.7%) patients treated with combined chemotherapy and in 9 (90.0%), who had undergone single-agent chemotherapy. The 5-year overall survival was 54.4% after splenectomy, 39.4% after single-agent chemotherapy, and 37.1% after combined chemotherapy, being significantly higher (P <0.05) after splenectomy and single-agent chemotherapy (67.2%), and splenectomy followed by combined chemotherapy (64.7%). Early splenectomy combined with chemotherapy is the optimum treatment option for primary low-grade NHL of the spleen because of the superiority in complete remission rate, remission duration, and in overall survival rate. Splenectomy leads to somatic compensation of patients, makes impossible local relapsing in the spleen, prevents continuous dissemination from the primary tumor site, and mostly corrects cytopenias, creating better conditions for chemotherapy.

Cellular and molecular signal transduction pathways modulated by rituximab (rituxan, anti-CD20 mAb) in non-Hodgkin's lymphoma: implications in chemosensitization and therapeutic intervention

The clinical application of rituximab (chimeric mouse anti-human CD20 mAb, Rituxan, IDEC-C2B8), alone and/or combined with chemotherapy, has significantly ameliorated the treatment outcome of patients with relapsed and refractory low-grade or follicular non-Hodgkin's lymphoma (NHL). The exact in vivo mechanisms of action of rituximab are not fully understood, although antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and apoptosis have been suggested. We have proposed that modifications of the cellular signaling pathways by rituximab may be crucial for its clinical response. The B-cell restricted cell surface phosphoprotein CD20 is involved in many cellular signaling events including proliferation, activation, differentiation, and apoptosis upon crosslinking. Monomeric rituximab chemosensitizes drug-resistant NHL cells via selective downregulation of antiapoptotic factors through the type II mitochondrial apoptotic pathway. Several signaling pathways are affected by rituximab which are implicated in the underlying molecular mechanisms of chemosensitization. ARL (acquired immunodeficiency syndrome (AIDS)-related lymphoma) and non-ARL cell lines have been examined as in vitro model systems. In ARL, rituximab diminishes the activity of the p38MAPK signaling pathway resulting in inhibition of the interleukin (IL)-10/IL-10R autocrine/paracrine cytokine autoregulatory loop leading to the inhibition of constitutive STAT-3 activity and subsequent downregulation of Bcl-2 expression leading to chemosensitization. Rituximab upregulates Raf-1 kinase inhibitor protein (RKIP) expression in non-ARL cells. Through physical association with Raf-1 and nuclear factor kappaB (NF-kappa B)-inducing kinase (NIK), RKIP negatively regulates two major survival pathways, namely, the extracellular signal-regulated kinase1/2 (ERK1/2) and the NF-kappa B pathways, respectively. Downmodulation of the ERK1/2 and NF-kappa B pathways inhibits the transcriptional activity of AP-1 and NF-kappa B transcription factors, respectively, both of which lead to the downregulation of Bcl-(xL) (Bcl-2 related gene (long alternatively spliced variant of Bcl-x gene)) transcription and expression and sensitization to drug-induced apoptosis. Bcl-(xL)-overexpressing cells corroborated the pivotal role of Bcl-(xL) in chemosensitization. The specificity of rituximab-mediated signaling and functional effects were corroborated by the use of specific pharmacological inhibitors. Many patients do not respond and/or relapse and the mechanisms of unresponsiveness are unknown. Rituximab-resistant B-NHL clones were generated to investigate the acquired resistance to rituximab-mediated signaling, and chemosensitization. Resistant clones display different phenotypic, genetic and functional properties compared to wild-type cells. This review summarizes the data highlighting a novel role of rituximab as a signal-inducing antibody and as a chemosensitizing agent through negative regulation of major survival pathways. Studies presented herein also reveal several intracellular targets modified by rituximab, which can be exploited for therapeutic and prognostic purposes in the treatment of patients with rituximab- and drug-refractory NHL.

Effect of a novel somatostatin analogue combined with cytotoxic drugs on human tumour xenografts and metastasis of B16 melanoma

A novel somatostatin analogue, TT-232 (which inhibits the proliferation of various cell cultures and transplantable mouse tumours), was examined regarding its effect on human melanoma and lymphoma xenografts as a single treatment or in combination with DTIC (dacarbazine) and etoposide. TT-232 inhibited the growth of HT-18 melanoma xenografts, a dose of 5 mg kg(-1) being the most effective. Combination of 1 mg kg(-1) TT-232 with 30 or 60 mg kg(-1) DTIC (administered daily) resulted in a stronger inhibitory effect compared to TT-232 or DTIC as a single modality. Antimetastatic effect of TT-232 treatment combined with DTIC was studied using the B16 mouse melanoma muscle - lung metastasis model. The number of lung metastases of B16 melanoma could be decreased by the daily administration of 1 mg kg(-1) TT-232 or 60 mg kg(-1), but not of 30 mg kg(-1) DTIC. TT-232, combined with 30 or 60 mg kg(-1) DTIC decreased the lung metastasis number significantly lower than the control. Nearly 50% growth inhibition of HT-58 lymphoma was achieved by daily treatment with 1 mg kg(-1) TT-232. 5 mg kg(-1) etoposide, administered daily, resulted in a similar effect. The combination of 1 mg kg(-1) TT-232 and 5 mg kg(-1) etoposide was significantly more effective than TT-232 or etoposide as a single treatment. The very strong tumour growth inhibitory effect of 10 mg kg(-1) etoposide could even be increased by combination with TT-232. These experimental data suggest that TT-232 may be an effective new tool in the combination chemotherapy of malignant tumours like melanoma and lymphoma.

Rituximab-mediated sensitization of B-non-Hodgkin's lymphoma (NHL) to cytotoxicity induced by paclitaxel, gemcitabine, and vinorelbine

Non-Hodgkin's lymphoma (NHL) responds initially to chemotherapy, however, the disease often relapses and acquires a chemoresistant phenotype. Third line treatment options such as paclitaxel, gemcitabine, and vinorelbine have been tried in patients with refractory or relapsed NHL with antilymphoma activity. Currently, rituximab (anti-CD20) has been approved for treatment of indolent NHL, with significant activity in a wide spectrum of B-cell malignancies, though a percentage of patients do not respond to rituximab treatment. Previous findings from our laboratory have demonstrated that rituximab can sensitize drug-resistant NHL B-lymphoma in vitro to some chemotherapeutic drugs. Hence, in this study, we examined the effect of combination treatment of rituximab and the drugs paclitaxel, gemcitabine, and vinorelbine on various NHL cell lines. Our findings indicate that pretreatment of NHL tumor cells with rituximab sensitizes drug-resistant NHL tumor cells to drug-mediated cytotoxicity. These findings suggest the potential clinical application of combination treatments of rituximab and paclitaxel, gemcitabine or vinorelbine in the treatment of drug/rituximab refractory non-Hodgkin's lymphoma.

Bendamustine is effective in relapsed or refractory aggressive non-Hodgkin's lymphoma

BACKGROUND

Bendamustine, an alkylating agent with a nitrogen mustard group and a purine-like benzimidazol group, has been shown to be effective in several solid tumors and indolent non-Hodgkin's lymphomas, but has not yet been studied for efficacy in aggressive lymphomas.

PATIENTS AND METHODS

We conducted a phase II study in patients with relapsed or refractory high-grade non-Hodgkin's lymphomas, using bendamustine at a dose of 120 mg/m(2) on days 1 and 2, every 3 weeks for up to six cycles. Twenty-one patients were enrolled; 18 were evaluable for response and toxicity, 10 of whom were refractory to previous chemotherapy.

RESULTS

With three patients achieving a complete response (at 6, >or=8 and >or=22 months) and five a partial response (three at 2 months, one at 3 months and one at 10 months), the total response rate of the evaluable patients was 44% (eight out of 18; 38% of all patients). Two complete and two partial responders were refractory to prior treatment. In 10 patients, treatment had to be stopped after one to three cycles due to progressive disease or hematological toxicity (n = 2). Non-hematological side effects were mild. Eight (13%) WHO grade 3 and no grade 4 events were observed in 60 evaluable treatment cycles. Hematologic toxicity was moderate (grade 3 and 4): anemia in five cycles (8%), leukopenia in seven (12%) and thrombocytopenia in eight (13%).

CONCLUSIONS

Bendamustine as a single agent is effective against aggressive lymphoma, even in cases of refractory disease. Further studies are warranted to determine the significance of bendamustine in the treatment of aggressive lymphomas.

Current treatment of follicular non-Hodgkin's lymphoma

56200 new cases of NHL are expected to be diagnosed in the United States (US) per year. For reasons that are not fully understood, the number of new cases per year has nearly doubled in the past three decades. Most patients with follicular lymphoma are over 50 years of age and present with widespread disease at diagnosis. Nodal involvement is very common, often accompanied by splenic and bone marrow disease. Despite the advanced stage, the median survival ranges from 8 to 12 years. The vast majority of patients with advanced stage follicular lymphoma are not cured using the current therapeutic options. The rate of relapse is fairly consistent over time, even in patients who have achieved complete responses (CRs) to treatment. Therapeutic options in follicular NHL include watchful waiting, oral alkylating agents, purine nucleoside analogues, combination chemotherapy, interferon and monoclonal antibodies. Radiolabelled monoclonal antibodies, autologous or allogeneic bone marrow or peripheral stem cell transplantation are under current clinical evaluation. The approval of rituximab, an unconjugated chimeric antibody against the CD20 antigen for the treatment of relapsed follicular B-cell NHL marked a milestone in the development of antibody treatment. In addition, newer approaches like radioimmunoconjugates with myeloablative activity induced response rates of 80-100% in heavily pretreated patients. Various clinical trials combining monoclonal antibodies with conventional therapies are currently ongoing to determine whether these new biological agents will alter the natural history of follicular lymphoma.

Pregnancy in a Patient with Non-Hodgkin Lymphoma

The overall incidence of lymphoma during pregnancy has not been established accurately. Hodgkin's disease is the fourth most frequently diagnosed cancer in pregnancy (1 in 1000 to 1 in 6000 pregnancies). In contrast, the incidence of non-Hodgkin lymphoma during pregnancy is rare, with fewer than one hundred cases reported(2). A case of small intestinal lymphoma in association with pregnancy is presented, with emphasis on the major clinical issues involved in the approach to the management of such cases.