A rare neoplasm of the thyroid gland

Burkitt's lymphoma of the thyroid gland is a rare malignancy. We present a case of a 58-year-old female who developed a rapid enlargement of her thyroid gland. Core biopsy confirmed the diagnosis of Burkitt's lymphoma. The tumour resolved after three cycles of chemotherapy. This case report emphasises the importance of considering lymphoma when dealing with thyroid nodules and goitres, as its management is different from that of other thyroid pathologies and delaying treatment has an impact on prognosis.

[Therapeutics of Burkitt lymphoma in adults - review]

Burkitt lymphoma is a highly aggressive non-Hodgkin's lymphoma. As Burkitt lymphoma cells are very sensitive to chemotherapy, chemotherapy is the major therapeutic schedule for this disease. Rituximab raised the overall survival rate markedly. Bone marrow transplant, surgery and radiotherapy also demonstrated to have a supporting role for patients with Burkitt lymphoma. This review focus on research progress of the therapeutics and major regimens for the disease.

Rituximab sensitizes a Burkitt lymphoma cell line to cell killing by X-irradiation

Clinical trials with rituximab in combination with chemotherapeutic regimens have shown promising results. Data on the effects of rituximab treatment in combination with irradiation are, however, limited and inconsistent. This study aims to investigate the effects of rituximab (R) on cell death induced by X-irradiation in Raji lymphoma cells and to evaluate its mechanisms. We found the cell growth inhibition by irradiation was enhanced by additional rituximab exposure both in cells precultured with rituximab followed by irradiation (R + irradiation) or in cells treated in the reverse sequence (irradiation + R). R + irradiation combination treatment induced more apoptotic cells than irradiation and irradiation + R treatment as early as 12 h after treatment. At 24 h, both combination treatments, R + irradiation and irradiation + R, showed apoptotic cells, which were significantly different from irradiation alone. G2/M cell cycle arrest was observed after irradiation alone and the combination treatment. The combination treatment revealed an elevation in reactive oxygen species (ROS) generation in a radiation dose-dependent manner. In addition, rituximab enhanced the cell growth inhibition and apoptotic cell death induced by the oxidative agent, H(2)O(2). We propose that rituximab mediates a significant in vitro radiosensitizing effect and induces cell cycle changes and apoptosis in Raji cells. ROS probably play an important role in these events.

t(8;14;18): a 3-way chromosome translocation in two patients with Burkitt's lymphoma/leukemia

Burkitt's lymphoma (BL) is a heterogeneous group of highly aggressive mature B-cell malignancies. It is characterized by a high rate of turnover of malignant cells and deregulation of the c-myc gene. It is typically associated with a t(8;14) translocation. Dual translocation of t(8;14) (c-myc) and t(14;18) (bcl-2) was reported to be associated with extremely poor prognosis. This study reports a novel t(8;14;18) triple translocation in two patients with Burkitt's lymphoma.

Absence of prognostic impact of CD13 and/or CD33 antigen expression in adult acute lymphoblastic leukemia. Results of the GIMEMA ALL 0496 trial

BACKGROUND AND OBJECTIVES

The prognostic value of myeloid antigen (MyAg) expression in adult acute lymphoblastic leukemia (ALL) is still controversial. The aim of this study was to correlate the expression of MyAg with clinical, hematologic and biological parameters, and to analyze the impact on response to treatment and prognosis in a large series of adult ALL uniformly characterized and treated.

DESIGN AND METHODS

We analyzed the expression of the MyAg CD13 and/or CD33 in a cohort of 377 adult patients with de novo ALL enrolled and treated in the GIMEMA ALL 0496 protocol.

RESULTS

MyAg expression was documented in 35% of the 377 adult ALL cases analyzed. MyAg were significantly more frequently associated with B-lineage ALL (38%) than with T-ALL (24%) (p=0.02). No difference was found with regard to clinical features at presentation; a difference was found only for white cell count (p=0.03), percentage of peripheral blasts (p=0.004) and platelet count (p=0.004). No difference was observed in the expression of MyAg between patients with normal or abnormal cytogenetics or between those with high-risk (BCR-ABL+, ALL1-AF4+, E2A-PBX1+) or low-risk B-lineage ALL. We failed to observe any difference between MyAg-positive and MyAg-negative cases in terms of achievement of complete remission, disease-free survival and overall survival at 5 years.

INTERPRETATION AND CONCLUSIONS

Our data indicate that ALL MyAg expression in adults with ALL is not associated with adverse presenting clinical and biological features, and that response to treatment and prognosis is comparable in MyAg-positive and MyAg-negative ALL patients with regards to both complete remission rate and overall survival. We suppose that these result are due to more intensive treatment modalities adopted in the GIMEMA ALL 0496 protocol.

Pretreatment with interferon-alpha radiosensitizes Daudi cells modulating gene expression and biomarkers

BACKGROUND

Interferon (IFN) potentiates cytotoxicity by X-ray irradiation. To elucidate the mechanism of this potentiation, the biological markers related to DNA damage and cell survival were studied.

MATERIALS AND METHODS

IFN-alpha-sensitive Daudi and its resistant cells were used. Survival after treatment was assessed by clonogenic assays. DNA breaks were studied by pulse-field gel electrophoresis (PFGE). Production of reactive oxygen metabolites was measured using flow cytometry. Messenger RNA and protein were examined by RT-PCR and immunoblot, respectively.

RESULTS

IFN-alpha treatment for 24 h before irradiation potentiated the sensitivity of Daudi cells to X-rays. This combination induced 50 kb DNA fragmentation and activated caspase-3 in Daudi cells. Pretreatment with IFN-alpha inhibited the production of reactive oxygen species by irradiation. IFN-alpha pretreatment down-regulated most of the double-strand break (DSB) repair-related mRNAs, but did not affect the repair of DSBs studied by PFGE. The induction and phosphorylation of p21(Cip1/WAF1) (p21) was prominently suppressed in cells pretreated with IFN-a.

CONCLUSION

Pretreatment with IFN-alpha potentiates the cytotoxic effects of X-rays. Inhibition of X-ray-induced p21 may cause the augmented sensitivity by IFN-alpha pretreatment.

Pretreatment with rituximab enhances radiosensitivity of non-Hodgkin's lymphoma cells

The present study examines the effects of ionizing radiation in combination with rituximab (RTX), a chimeric human anti-CD20 monoclonal antibody, on proliferation, cell cycle distribution and apoptosis in B-lymphoma RL and Raji cells. Exposure to ionizing radiation (9 Gy) induced cell growth delay and apoptosis in RL cells, whereas Raji cells showed moderate radio-resistance. The simultaneous exposure of lymphoma cells to ionizing radiation and RTX (10 microg/mL) markedly enhanced apoptosis and cell growth delay in RL and Raji cells. Cooperative antiproliferative and apoptotic effects of RTX and radiation were achieved through the inhibition of c-myc and bcl-XL expression. Furthermore, RTX-modulated expression of cell cycle regulating proteins, such as p53, p21/WAF1, p27/KIP1, contributed to the development of radiation-induced cell killing and growth arrest. Each NHL cell line that underwent apoptosis induced by combination treatment revealed enhanced caspase-3 and poly (ADP-ribose) polymerase (PARP) cleavage as compared to only irradiated cells. These findings show that rituximab synergistically enhances radiation-induced apoptosis and cell growth delay through the expression of proteins involved in the programmed cell death and cell cycle regulation pathways.

[Limited mouth opening, xerostomia and extensive caries after nasopharyngeal carcinoma]

This report describes a 19 year old trainee with a history of Nasopharyngeal Carcinoma (NPC), a rare malignancy with distinct epidemiological, histopathological and clinical characteristics. During a screening for dental status, the soldier presented a limited mouth opening (25 mm), xerostomia, and extensive caries. Despite his resistance, he was referred to the TMJ unit in order to examine the reason for the limited mouth opening. During the anamnesis it was revealed that he suffered from NPC and was treated using chemotherapy and radiation therapy 6 month prior to the examination. This case emphasizes the importance of a thorough anamnesis and examination in order to discover such phenomenon, since withholding medical information is a well known phenomenon, especially among recruits and young soldiers. Unusual findings such as limited mouth opening, xerostomia and extensive caries, should be further examined. In this case a specialist's opinion is prompt, and until the definitive answer, treatment should be restricted to palliative dental treatment only, excluding any surgical procedure.

Radiotherapy of CD19 expressing Daudi tumors in nude mice with Yttrium-90-labeled anti-CD19 antibody

Studies were performed to determine the suitability of using two different anti-CD19 monoclonal antibodies to deliver the high energy beta-particle emitting isotope 90Y to B-cell lymphoma grown as flank tumors in athymic nude mice. The antibodies BU12 and HD37, both of the IgG1 subclass, recognize CD19, an internalizing B-lineage-specific membrane glycoprotein and member of the Ig supergene family. The antibodies were readily labeled with 90Y using the highly stable chelate, 1B4M-MX-DTPA. The radioimmunoconjugates selectively bound to the CD19 expressing B cell line Daudi, but not to CD19 negative control cells. Significantly more 90Y anti-CD19 bound to Daudi tumors growing in nude mice than did a control non-binding antibody (p = 0.001). The biodistribution data correlated with an anti-tumor effect. Anti-tumor activity was dose dependent and the best results were observed in mice receiving a single dose of approximately 300 uCi. The anti-CD19 antibody had significantly better anti-tumor activity as compared to a control 90Y-labeled antibody and most mice survived over 119 days with no evidence of tumor (p < 0.003). Histology studies showed no significant injury to the kidney, liver, or small intestine. Because radiolabeled anti-CD19 antibody can be used to deliver radiation selectively to lymphohematopoietic tissue, these data support the use of 90Y anti-CD19 antibodies in treating B-cell malignancies.

Intratumoral injection of 188Re labeled cationic polyethylenimine conjugates: a preliminary report

188Re (Rhenium) is easily obtained from an in-house 188W/188Re generator that is similar to the current 99Mo/99mTc generator, making it very convenient for clinical use. This characteristic makes this radionuclide a promising candidate as a therapeutic agent. Polyethylenimine (PEI) is a cationic polymer and has been used as a gene delivery vector. Positively charged materials interact with cellular blood components, vascular endothelium, and plasma proteins. In this study, the authors investigated whether intratumoral injection of 188Re labeled transferrin (Tf)-PEI conjugates exert the effect of radionuclide therapy against the tumor cells. When the diameters of the Ramos lymphoma (human Burkitt's lymphoma) xenografted tumors reached approximately 1 cm, 3 kinds of 188Re bound compounds (HYNIC-PEI-Tf, HYNIC-PEI, 188Re perrhenate) were injected directly into the tumors. There were increases in the retention of 188Re inside the tumor when PEI was incorporated with 188Re compared to the use of free 188Re. The 188Re HYNIC-Tf-PEI showed the most retention inside the tumor (retention rate=approximately 97%). H&E stain of isolated tumor tissues showed that 188Re labeled HYNIC-PEI-Tf caused extensive tumor necrosis. These results support 188Re HYNIC-PEI-Tf as being a useful radiopharmaceutical agent to treat tumors when delivered by intratumoral injection.

131I-rituximab: relationship between immunoreactivity and specific activity

As part of a search for optimal conditions for radioimmunotherapy of lymphoma, rituximab was labeled with 2 different specific activities of 131I and immunoreactivity was comparatively measured.

METHODS

Labeling was performed with chloramine T using as starting conditions 185 MBq of 131I per 1 mg and per 5 mg of antibody for labelings A and B, respectively. Six comparative labelings were performed over a period of 10 mo with similar efficacy and purified by anion-exchange chromatography. Immunoreactivity was determined immediately after labeling in parallel assays using different concentrations of fresh Raji and Daudi cells. Results were compared at maximal observed specific binding on 10(7) cells and after extrapolation to infinite antigen excess. A statistical analysis was performed to predict the frequency of radiolabeled mono- and polyiodinated antibodies: First, a gaussian distribution predicted the number of iodine atoms per antibody in labelings A and B, respectively; then, the radiolabeling probability was developed according to the Newton binome.

RESULTS

Final radiochemical purity was >98.4% for all labelings. The final mean specific activities were 169.7 MBq/mg and 32.8 MBq/mg, corresponding to 0.87 and 0.17 iodine atoms per antibody in labelings A and B, respectively. Labeling B showed a significantly higher immunoreactivity than did labeling A, the mean relative increase in binding being > or =28% for both Raji cells and Daudi cells. The predictive statistical analysis indicated that 57.3% and 15.4% of radiolabeled antibodies in labelings A and B, respectively, were polyiodinated.

CONCLUSION

The low specific activity of 131I-rituximab allowed preservation of a high immunoreactivity and correlated with the prediction of a low percentage of polyiodinated radiolabeled antibodies.

Burkitt's lymphoma in the base of the tongue: differential diagnosis and management

Burkitt's lymphoma is the most common malignancy in African children but can occur sporadically in every country. It is one of the most aggressive malignancies in the human body, and in the past the prognosis was very poor. However, complex chemotherapy regimens can now cure approximately 50-80% of adult patients with Burkitt's lymphoma or small noncleaved lymphoma, and in pediatric populations the cure rate is even higher. Although the African type has a preference to the head and neck region (whereas the sporadic type to the abdomen), involvement of the base of the tongue is extremely rare as only 1 case has ever been reported in the English literature. The present study describes a patient with Burkitt's lymphoma presenting as a single mass in the base of the tongue without any abdominal or other extra-abdominal involvement. The patient was submitted to chemotherapy (intravenous and intrathecal) and skull radiotherapy. Today, 17 months after the diagnosis, the patient is disease free. Physicians should be aware of the extranodal manifestations of Burkitt's lymphoma and their differential diagnosis in order to achieve early diagnosis and treatment.

Differences in lethality between cancer cells and human lymphocytes caused by LF-electromagnetic fields

The lethal response of cultured cancer cells lines K-562, U-937, DG-75, and HL-60 were measured directly after a 4 h exposure to a pulsating electromagnetic field (PEMF, sinusoidal wave form, 35 mT peak, 50 Hz) [Traitcheva et al. (2003): Bioelectromagnetics 24:148-158] and 24 h later, to determine the post-exposure effect. The results were found to depend on the medium, pH value, conductivity, and temperature. From these experiments, suitable conditions were chosen to compare the vitality between K-562 cells and normal human lymphocytes after PEMF treatment and photodynamic action. Both agents enhance necrosis synergistically for diseased as well as for healthy cells, but the lymphocytes are more resistant. The efficacy of PEMF on the destruction of cancer cells is further increased by heating (hyperthermia) of the suspension up to 44 degrees C or by lowering the pH-value (hyperacidity) to pH 6.4. Similar apoptosis and necrosis can be obtained using moderate magnetic fields (B < or = 15 mT 50/60 Hz), but this requires longer treatment of at least over a week. PEMF application combined with anticancer drugs and photodynamic therapy will be very effective.

Intensive chemotherapy with and without cranial radiation for Burkitt leukemia and lymphoma

BACKGROUND

The objective of the current study was to evaluate the efficacy of intensive chemotherapy with and without cranial radiation for central nervous system (CNS) prophylaxis in adults with Burkitt leukemia or lymphoma.

METHODS

Patients received 18 weeks of therapy. Prophylactic cranial radiation (2400 centigrays) and 12 doses of triple intrathecal chemotherapy were administered to the first cohort of patients. A subsequent cohort received the same therapy, with the exceptions that intrathecal therapy was reduced to six doses and radiotherapy was administered only to high-risk individuals.

RESULTS

The median follow-up durations were 6.8 years in Cohort 1 and 4.1 years in Cohort 2. Three occurrences of transverse myelitis, 2 severe neuropathies, 3 cases of aphasia, and 1 case of blindness were documented in the first cohort of 52 patients (Cohort 1). In the subsequent cohort of 40 patients (Cohort 2), none of these occurrences were observed, and patients experienced less neurologic toxicity overall (61% vs. 26%; P=0.001). Responses were similar, and the 3-year event-free survival rate was 0.52 (95% confidence interval, 0.38-0.65) for Cohort 1 and 0.45 (0.29-0.60) for Cohort 2.

CONCLUSIONS

Intensive, short-duration chemotherapy with less intensive CNS prophylaxis led to control at this sanctuary site with little neurotoxicity and may be curative for adults with Burkitt leukemia or lymphoma.

Anti-CD22 ligand-blocking antibody HB22.7 has independent lymphomacidal properties and augments the efficacy of 90Y-DOTA-peptide-Lym-1 in lymphoma xenografts

CD22 is a membrane glycophosphoprotein found on nearly all healthy B-lymphocytes and most B-cell lymphomas. Recent in vitro studies have identified several anti-CD22 monoclonal antibodies (mAbs) that block the interaction of CD22 with its ligand. One of these mAbs, HB22.7, has been shown to effectively induce apoptosis in several B-cell lymphoma cell lines. Lymphoma xenograft studies with Raji-xenograft mice were used to assess the toxicity and efficacy of HB22.7 alone and with combined modality immunotherapy (CMIT) with yttrium (90)Y-DOTA-peptide-Lym-1 radioimmunotherapy (RIT). The effect of the sequence of these agents on the combined treatment was assessed by administering HB22.7 24 hours before, simultaneously with, or 24 hours after RIT. Within the groups treated with RIT alone or with RIT and HB22.7 (CMIT), the reduction in tumor volume was the greatest when HB22.7 was administered simultaneously with and 24 hours after RIT, and in the RIT treatment groups, this translated into the greatest overall response and survival, respectively. Overall survival rates at the end of the 84-day CMIT trial were 67% and 50% in the groups treated with HB22.7 simultaneously and 24 hours after RIT, respectively. This compared favorably with the untreated and the RIT alone groups, which had survival rates of 38% and 43% at the end of the trial. Surprisingly, when compared with untreated controls and all other treatment groups, the greatest cure and overall survival rates were observed in the group treated with HB22.7 alone, with 47% cured and 76% surviving at the end of the 84-day trial. RIT clearance was not affected by treatment with HB22.7. When compared with RIT alone, there was no significant additional hematologic (white blood cell, red blood cell, or platelet count) toxicity when HB22.7 was added to RIT. Nonhematologic toxicity (assessed as change in body weight) was also unchanged when HB22.7 was added to RIT. Thus the anti-CD22 ligand-blocking antibody HB22.7 has independent lymphomacidal properties and augments the efficacy of (90)Y-DOTA-peptide-Lym-1 in lymphoma xenografts without significant toxicity.

Antiviral agent cidofovir decreases Epstein-Barr virus (EBV) oncoproteins and enhances the radiosensitivity in EBV-related malignancies

The Epstein-Barr virus (EBV) is involved in the carcinogenesis of several human cancers such as nasopharyngeal carcinoma (NPC) and Burkitt lymphoma (BL). Given the consistent role of EBV in transformation and maintenance of malignant phenotype, antiviral strategies provide an attractive approach to target EBV-expressing cells. In that aim, we have tested the Cidofovir, which is an acyclic nucleoside phosphonate analog known to exert an antiproliferative activity in some human virus-related tumors. Here, we show that Cidofovir induces a downregulation of the EBV oncoprotein LMP1 associated with a decrease of the antiapoptotic Bcl-2 and an increase of the proapoptotic Bax protein in Raji (BL) and C15 (NPC) cells. Using BL cell line BL2 B95-8 (BL2 infected with the B95.8 strain of EBV), we addressed the relation between EBV genome expression and modulation of viral oncoproteins by Cidofovir and/or ionizing radiation (IR). Cidofovir was able to significantly reduce LMP1 and EBNA2 mRNA and protein expression. This effect was associated with inhibition of proliferation, stimulation of apoptosis, and decrease of Bcl-2 expression in BL2 B95.8 cells. In addition, Cidofovir enhanced the radiation-induced apoptosis and the radiosensitivity through the proteolytic cleavage of death effectors caspase-9 and -3, which was specifically induced by combined treatment in EBV-positive cells compared to their negative counterparts. Furthermore, the combined treatment in nude mice led to a complete tumor remission without increasing toxicity in two human EBV-related cancer xenografts (Raji and C15). These results provide the basis for a novel anticancer strategy to enhance the therapeutic ratio of IR in EBV-related cancers.

Preclinical studies targeting normal and leukemic hematopoietic cells with Yttrium-90-labeled anti-CD45 antibody in vitro and in vivo in nude mice

A study was undertaken to investigate the suitability of using a high affinity (Kd = 1.1 nM) anti-CD45 monoclonal antibody for delivering the high energy beta-particle emitting isotope (90)Y to lymphohematopoietic target cells in vivo. The antibody, AHN-12, recognized the tyrosine phosphatase CD45 expressed on the surface of normal and malignant hematopoietic cells and studies showed that it reacted with both CD45-expressing normal peripheral blood cells and leukemia cells from patients. The antibody was readily labeled with (90)Y using the highly stable chelate 1B4M-DTPA and the radioimmunoconjugate was designated (90)Y-anti-CD45. The agent selectively bound to CD45(+) B cell line Daudi, but not CD45(-) control cells and significantly (p = 0.007) more bound to Daudi tumors growing in athymic nude mice than did a control non-reactive antibody. Moreover, biodistribution data correlated well to an anti-Daudi effect observed against established tumors in nude mice. The effect was dose dependent and irreversible with the best results in mice receiving a single dose of 137 microCi (90)Y-anti-CD45. These mice displayed a significantly (p < 0.0095) better anti-tumor effect than a control (90)Y-labeled antibody and survived over 135 days with no evidence of tumor. Histology studies showed no significant injury to kidney, liver, or small intestine even at 254 microCi, the highest dose tested. Because radiolabeled anti-CD45 antibody can be used to deliver radiation selectively to lymphohematopoietic tissue, these data indicate that this agent may be used to improve treatment of hematopoietic malignancies, particularly leukemia and lymphoma, when combined with hematopoietic stem cell transplantation in a future clinical trial.

Radioimmunotherapy for model B cell malignancies using 90Y-labeled anti-CD19 and anti-CD20 monoclonal antibodies

In recent years, radioimmunotherapy (RIT) with beta(-) particle emitting radionuclides targeting the CD20 antigen on B cells in the treatment of non-Hodgkin's lymphoma has provided the most compelling human clinical data for the success of RIT. CD19, like CD20, is an antigen expressed on the surface of cells of the B lineage, and CD19 may provide an alternative target for radioimmunotherapy of B cell neoplasms. CD19 has been largely overlooked as a target for conventional 131I RIT, because the antigen rapidly internalizes upon binding of antibody, resulting in catabolism and significant release of 131I. Such modulation may be an advantage to RIT with radiometals such as 90Y, 177Lu, 213Bi and 225Ac. Herein, we have compared beta(-) particle RIT with antibodies targeting either CD19 or CD20. The anti-CD19 and anti-CD20 antibodies, B4 or C2B8, respectively, were appended with the SCN-CHX-A''-DTPA bifunctional chelating agent and labeled with 90Y. In the tumor model used, there were three times as many CD20 target sites on lymphoma cells as compared to CD19 sites (62000 vs 20000 binding sites, respectively). We compared the efficacy of the 90Y-labeled antibodies to reduce lymphoma in a nude mouse xenograft solid tumor model, after measurable lymphoma appeared. Reduction in tumor size began at day 3 in all three 90Y-treated groups, but tumor began to recur in many animals 9 days after the treatments. There was one cure in each specific treatment group. In contrast, the tumor in the two control groups showed no regression. There was a significant prolongation of median survival time from xenograft (P < 0.0001) in all the 90Y-labeled antibody construct-treated groups (32 days for 0.15 mCi 90Y-B4; 26 days for 0.20 mCi 90Y-C2B8, and 23 days for 0.15 mCi 90Y-C2B8) in comparison to the two control groups (11 days for 0.02 mg of C2B8 and 9 days for untreated growth controls). Specificity of the radioimmunotherapy was also shown. In conclusion, 90Y-labeled anti-CD19 antibody has efficacy comparable to 90Y-labeled anti-CD20 antibody in the treatment of mice bearing human lymphoma xenografts. These data suggest that CD19-targeted RIT merits further study.

Apoptosis-related gene and protein expression in human lymphoma xenografts (Raji) after low dose rate radiation using 67Cu-2IT-BAT-Lym-1 radioimmunotherapy

Despite low radiation dose rates, radioimmunotherapy (RIT) has proven particularly effective in the treatment of malignancies, such as lymphoma. Apoptosis has been suggested to be a major mechanism for cell death from continuous low-dose rate radiation from radioimmunotherapy. The goal of this study was to examine Raji lymphoma xenografts for induction of apoptosis and modulation of apoptosis-related gene and protein expression in response to 67Cu-2IT-BAT-Lym-1 RIT. In preclinical and clinical trials, 67Cu-2IT-BAT-Lym-1 has shown an exceptionally long tumor residence time associated with substantial cumulated radiation doses. The Raji model mirrors human lymphomas that have mutant p53 and increased BCL2 expression. Untreated athymic BALB/c nu/nu mice and mice treated with 400 micrograms Lym-1, or 335-500 microCi 67Cu on less than 400 micrograms Lym-1 antibody, were observed for toxicity and response over 84 days. Subgroups of 4-5 mice were sacrificed at 3, 6 and 24 h after therapy so that tumors could be examined for poly(ADP-ribose) polymerase (PARP) and DNA ladder evidence for apoptosis and for BCL2, p53, p21, GADD45, TGF-beta 1 and c-MYC gene and protein expression. Untreated tumors had little evidence of apoptosis and Lym-1 had no effect on apoptosis or gene expression. 67Cu-2IT-BAT-Lym-1 RIT induced an overall response rate of 50% with tolerable toxicity, and 29% of the tumors were cured at cumulated tumor radiation doses of about 1800 cGy. Apoptosis was greatly increased in the RIT treated Raji xenografts as evidenced by cleavage of PARP to the characteristic 85 kD fragment at 3 and 6 h and by the DNA cleavage pattern. BCL2 gene and protein expression were substantially decreased at 3 and 24 h, respectively, after 67Cu-2IT-BAT-Lym-1 RIT despite only modest cumulated radiation doses (56 cGy at 3 h). Evidence for apoptosis preceded tumor regression by 4-6 days. In these therapy-resistant, human lymphoma tumors treated with 67Cu-2IT-BAT-Lym-1, apoptosis was convincingly demonstrated to be a major mechanism for the effectiveness of RIT and occurred by p53-independent mechanisms.

Outcome of relapsed or refractory childhood B-cell acute lymphoblastic leukaemia and B-cell non-Hodgkin's lymphoma treated with the UKCCSG 9003/9002 protocols

Twenty-six children with B-cell acute lymphoblastic leukaemia (B-ALL) or Murphy Stage III or IV B-cell non-Hodgkin's lymphoma (B-NHL) progressed or relapsed after first-line therapy with a short, intensive multiagent chemotherapy regimen [United Kingdom Childhood Cancer Study Group (UKCCSG) 9003] (n = 62) or a slightly less intensive regimen (UKCCSG 9002) (n = 112). Eight patients (4.6%) never achieved complete remission (CR) and 18 (10.3%) relapsed. Second-line therapy resulted in remission for eight patients (30%). All patients initially treated with the 9003 protocol died. Three patients (11.5%) in the 9002 group, including one who never achieved CR in the primary site, are alive after second-line therapy. This study confirms that the prognosis of relapsed or refractory B-ALL/B-NHL is poor and exceptionally so if relapse occurred less than 6 months from diagnosis. High-dose therapy with stem cell rescue was used in only seven patients; its role needs to be studied further.

Burkitt's acute lymphocytic leukemia (L3ALL) in adults

Burkitt's acute lymphocytic leukemia is a rare type of adult ALL, probably difficult to distinguish from disseminated Burkitt's lymphoma involving the bone marrow. This tumor is highly proliferative and tends to involve the CNS at diagnosis or early during the disease course. It shows rapid chemosensitivity, initially leading to the risk of severe acute tumor lysis syndrome. Principles of its treatment, by comparison with the other types of ALL, include: 1. A low-dose chemotherapy prephase to prevent acute tumor lysis syndrome. 2. Multiagent chemotherapy using high-dose cyclophosphamide, an anthracycline, high-dose MTX, high-dose ara-C, and probably VP16. A short and intensive treatment (6 to 8 months) without maintenance is indicated. 3. Early intensive CNS treatment, with multiple triple intrathecal injections, high-dose MTX, and high-dose ara-C, and possibly cranial irradiation. Autologous or allogeneic stem cell transplantation do not seem to be useful in first CR. Using such approaches, recent results suggest that about two thirds of L3ALL in adults can be cured, more than in any other type of adult ALL.

[Acute kidney failure and ascites in Burkitt's lymphoma of the stomach]

A case of 25 old man with acute renal failure as the result of uric acid nephropathy in Burkitt's lymphoma of the stomach and ascites, probably chylous, is presented. After starting chemotherapy a regression of stomach tumor and the chylous effusion was observed. Unfortunately, after a short period of remission the regression was observed with tumor lysis syndrome. The reason of death was bleeding from digesting tract.

131I-Lym-1 in mice implanted with human Burkitt's lymphoma (Raji) tumors: loss of tumor specificity due to radiolysis

Preliminary evaluations of 125I-labeled Lym-1, an anti-lymphoma mouse IgG2a monoclonal antibody, demonstrated favorable tumor uptake in mice bearing human Burkitt's lymphoma (Raji) tumors. In this study, the pharmacokinetics of 125I- and 131I-Lym-1, and the dosimetry, efficacy, and toxicity of 131I-Lym-1 in Raji-tumored mice were evaluated.

METHODS

Lym-1 was radioiodinated by the chloramine-T method and analyzed for monomeric fraction and immunoreactivity (antigen cell binding, relative to unmodified Lym-1). Nude mice bearing Raji tumors (20-500 mm3) received 1.5 MBq (40 microCi) 125I-Lym-1, or 1.5, 7.4, 14.8, or 18.5 MBq (40, 200, 400, or 500 microCi) 131I-Lym-1. Pharmacokinetic data (total body and blood clearance and biodistribution) were used to estimate radiation dosimetry. Mini-thermoluminescent dosimetry (TLD) was also used to measure radiation dosimetry directly for 7 days after injection of 131I-Lym-1. Tumor size, survival, body weight, and blood counts were monitored for 60 days to evaluate therapeutic efficacy and toxicity of 131I-Lym-1.

RESULTS

At the time of injection, the mean quality assurance (QA) values for 125I-Lym-1 were 100% monomer and 100% relative immunoreactivity; the corresponding values for 131I-Lym-1 were 73% and 66%, indicating that radiolysis had occurred during the interval between radiolabeling and injection. 125I-Lym-1 exhibited high and sustained concentration in tumors relative to normal organs, whereas 131I-Lym-1 did not. Assuming identical pharmacokinetic behavior to 125I-Lym-1, 131I-Lym-1 would deliver radiation doses of 3.45, 0.83, 1.03, 0.34, and 0.56 Gy per MBq injected (12.8, 3.1, 3.8, 1.3, and 2.1 rad/microCi), to tumor, liver, lungs, total body, and marrow, respectively. When the actual pharmacokinetic data for 131I-Lym-1 (1.5 MBq) were used to estimate dosimetry, corresponding values of 0.51, 0.72, 0.49, 0.31, and 0.41 Gy/MBq (1.9, 2.7, 1.8, 1.1, and 1.5 rad/microCi) were obtained. Similar values were obtained for mice receiving 7.4 or 14.8 MBq of 131I-Lym-1. Similarly, TLD data indicated little preferential radiation dosimetry to tumor. Response rates (cure + CR + PR) for mice receiving 0, 7.4, 14.8, and 18.5 MBq of 131I-Lym-1 were 8%, 7%, 21%, and 45%, respectively. The LD50/30 dose of 131I-Lym-1 was 12.7 MBq (343 microCi).

CONCLUSIONS

125I-Lym-1 exhibited high and sustained concentration in Raji tumors in mice, indicating excellent therapeutic potential for 131I-Lym-1. However, in vitro QA results for 131I-Lym-1 indicated that radiolysis had occurred, and 131I-Lym-1 demonstrated little accumulation in tumor, or preferential radiation dosimetry to tumor in the same model.

Effects of cancer therapy on dental and maxillofacial development in children: report of case

Malignant lymphoma is one of the most common hematological diseases of children. The prognosis is fairly good with multimodal cancer therapy. We reported a boy with Burkitt's lymphoma in the nasal cavity who received chemotherapy and irradiation of the head and neck area at four years of age. During seven years of follow-up, we studied the developmental effects of cancer therapy, including general growth, maxillofacial bones, and dentition. Compared with boys of matching age, the development of his entire body and maxillofacial bones was delayed. In the irradiated areas, the roots of teeth were short or poorly developed and the root apices showed premature closure. After the patient was in remission from the tumor in his early childhood, the long-term effects of cancer therapy on dental and maxillofacial development are worth our further evaluation and follow-up.

Synergistic cytotoxicity of iodine-131-anti-CD20 monoclonal antibodies and chemotherapy for treatment of B-cell lymphomas

Preliminary clinical trials suggest that iodine-131 ((131)I)-labeled anti-CD20 monoclonal antibodies (MAbs) are effective single agents for the treatment of relapsed non-Hodgkin's B-cell lymphomas. However, despite high initial response rates, most patients treated in this manner will eventually relapse. We hypothesized that regimens combining (131)I-anti-CD20 antibodies with standard chemotherapeutic agents may provide synergistic anti-tumor effects, and may improve the durability of responses in patients with lymphoma. To identify promising agents for clinical testing, we assessed the in vitro cytotoxicity of combinations of (131)I-anti-B1 (anti-CD20) antibody and 8 chemotherapeutic agents using 2 human CD20-expressing lymphoma cell lines and 2 corroborative assays, the thiazolyl tetrazolium bromide (MTT) and the Trypan blue dye exclusion assays. ID(50) isobolographic and dose modification factor (DMF) analyses were used to classify interactions between the (131)I-anti-B1 antibody and the chemotherapeutic agents as supra-additive (synergistic), additive or sub-additive. Cytarabine and fludarabine were markedly supra-additive when combined with the radioimmunoconjugate, with the combination enhancing cytotoxicity 3. 5- to 5.2-fold over the level expected by simple addition of the 2 agents (DMFs 3.5-5.2). Etoposide, doxorubicin and SN-38 were moderately supra-additive (DMFs 2.0-2.8). Cisplatin and 4-hydroxycyclophosphamide exhibited merely additive cytotoxicity (DMFs 1.0-1.1). Thus, combination regimens containing (131)I-labeled anti-CD20 antibodies and nucleoside analogs or topoisomerase inhibitors appear particularly attractive for future clinical trials.

Adult head and neck lymphomas in Papua New Guinea: a retrospective study of 70 cases

BACKGROUND

During a 10-year period (1986-95), 70 adult Papua New Guineans with head and neck lymphomas were seen in the 18 years-and-above age group.

METHODS

The clinical information was obtained from the medical records section of the Port Moresby General Hospital. Relevant treatment modalities and the follow-up data were acquired from the National Cancer Centre, Angau Memorial Hospital, Lae.

RESULTS

Of a total of 227 adult lymphomas recorded in a 10-year period, 70 cases were seen in the head and neck region. Non-Hodgkin's lymphoma constituted 56 cases, which included seven cases of adult Burkitt's-like lymphoma. Fourteen cases of Hodgkin's lymphoma were recorded.

CONCLUSIONS

In Papua New Guinea, malignant lymphomas primarily affecting the head and neck region were seen in 30.8% of all lymphomas. This constitues 2.8% of all malignancies in this region. These lymphomas appear to be more aggressive at this site. Proper tissue diagnosis and combination chemoradiotherapy are the key factors in its management.

[Primary cerebral highly-malignant B-cell lymphoma of the Burkitt type]

HISTORY AND CLINICAL FINDINGS

A 40-year-old man was admitted with acute onset of positional vertigo, nausea and vomiting. Neurological examination revealed a fatigable nystagmus to the upward ear in positional testing, to the right more than to the left, as well as latent paresis and rigidity of the left arm.

INVESTIGATIONS

Magnetic resonance imaging of the brain revealed two space-occupying lesions in the cerebellum and pons. Open biopsy showed a highly malignant B-cell lymphoma of Burkitt type. There was no evidence of acquired or congenital immunodeficiency. As there were no significant abnormalities outside of the CNS, a primary lymphoma in this location was diagnosed.

TREATMENT AND COURSE

Chemotherapy with a combination of drugs including methotrexate achieved only partial remission. Subsequent radiotherapy brought about full remission, which has now lasted for over a year.

CONCLUSIONS

Treatment of first choice of a primary cerebral lymphoma in an immunocompetent patient is chemotherapy with cerebrospinal fluid-permeable cytostatics. Partial remission should be followed by radiotherapy.

Combined modality radioimmunotherapy with Taxol and 90Y-Lym-1 for Raji lymphoma xenografts

Despite effective therapies for non-Hodgkin's lymphoma (NHL), the majority of patients are not cured. Radioimmunotherapy (RIT) has shown good results in preclinical and clinical trials even in patients that are non-responsive to standard chemotherapy. To make RIT more effective, agents such as paclitaxel (Taxol), that can enhance radiation effects, are being tested. Nude mice bearing human Burkitt's lymphoma (Raji) xenografts were treated with: 1) 150 or 200 microCi (5.5 or 7.3 MBq) of 90Y-2IT-BAD-Lym-1 alone, 2) 600 micrograms of Taxol alone, 3) 150 or 200 microCi of 90Y-2IT-BAD-Lym-1 plus 600 micrograms of Taxol given 24 hours after RIT, or 4) no treatment. Tumor size, survival, mouse weight and blood counts were monitored to assess efficacy and toxicity. Survival for mice treated in this 84 day trial was: 71% for 90Y-2IT-BAD-Lym-1 (200 microCi) plus Taxol, 29% for Taxol alone, 6% for 90Y-2IT-BAD-Lym-1 (200 microCi) alone and 14% in the untreated group. Average tumor volume in the 90Y-2IT-BAD-Lym-1 (200 microCi) plus Taxol group was reduced by 89 and 99% compared to the RIT alone and Taxol alone groups, respectively. Mice treated with 150 microCi had less toxicity than those treated with 200 microCi of 90Y-2IT-BAD-Lym-1, however, the higher radiation dose, and Taxol, were required for improved survival. Mouse weights and myelotoxicity in the combined modality (RIT plus Taxol) groups were similar to those receiving the same dose of RIT alone. In the Raji tumored nude mouse model, addition of Taxol to 90Y-2IT-BAD-Lym-1, in doses clinically achievable in humans, provided therapeutic synergy without increased or excessive toxicity.

A preliminary cell kinetics model of thrombocytopenia after radioimmunotherapy

Thrombocytopenia is often the dose-limiting toxicity for radionuclide therapy. Prediction of platelet counts after therapy is important for treatment planning. Simple prediction methods based on linear correlation between radiation dose and blood count nadir have been insufficient because they have not considered time, because of the complicated hierarchical structure of the hematopoietic system in which platelets are not directly injured by low dose rate radiation and because of changing radiation dose rates to marrow with time. This study addresses these problems using a cell kinetics model.

METHODS

The model consists of compartments for progenitor cells, megakaryocytes, platelets and stromal cells. A linear quadratic formula was used for progenitor cell survival. Stromal cells were described by a model based on a maximum likelihood estimate for cellular damage, repair and proliferation. Reported values for murine cellular turnover rates and radiosensitivity of progenitor cells were used in the model calculations. Experimental mice received 4 Gy of external beam radiation for tumor implantation and 12.4-23.3 MBq 67Cu-2-iminothiolane-BAT-Lym-1 (BAT = 6-[p-(bromoacetamido) benzyl]-1,4,8,11-tetra-azacyclotetradecane-N,N',N'',N'''-tetraacet ic acid) 19-30 days later. Blood counts were measured three times each week.

RESULTS

The model predicted the severity of thrombocytopenia, and the time of the nadir corresponded to measured values in mice. For a dose of 14.2 MBq 67Cu-2-iminothiolane-BAT-Lym-1 that induced a platelet nadir of 20% of baseline (Grade II), the model predicted that at least 20 days were needed before a second 14.2-MBq injection if a subsequent nadir of <10% of baseline (Grade IV) was to be avoided.

CONCLUSION

The nadir and duration of thrombocytopenia predicted by the model were similar to those observed in the mice. Predicted information could be useful for planning the dose and timing of fractionated radionuclide therapy. This model provides a stepping stone for future development of a predictive model for patients.

Enhancement of 67Cu-2IT-BAT-LYM-1 therapy in mice with human Burkitt's lymphoma (Raji) using interleukin-2

BACKGROUND

Lymphomas have been shown to be responsive to 131I immunoconjugates in studies conducted in mice and patients. We have observed that copper 67 (67Cu)-labeled Lym-1 remains in lymphomatous tissue longer than 131I-Lym-1 and, consequently, results in higher absorbed radiation doses to tumors. In addition, recombinant interleukin-2 (rIL-2) has been reported to increase tumor uptake of radiolabeled antibody. Therefore, we examined the efficacy of 67Cu-labeled Lym-1 and the ability of rIL-2 to enhance this efficacy in athymic mice implanted with Raji xenografts.

METHODS

6[p-(bromoacetamido) benzyl]-1,4,8,11-tetraazacyclotetradecane-N,N', N'',N'''-tetraacetic acid (BAT) was conjugated to Lym-1 via 2-iminothiolane (2IT) to prepare 2IT-BAT-Lym-1, which was labeled with 67Cu. Mice with Raji xenografts were treated with 335-500 microCi (12.4-18.0 MBq) of 67Cu-2IT-BAT-Lym-1 with or without 48,000-144,000 IU of rIL-2 once or were treated b.i.d. for 5 days beginning simultaneously with 67Cu-2IT-BAT-Lym-1. Mouse weight, blood counts, and mortality were monitored to assess toxicity, and tumor size was measured to assess efficacy. In addition, groups of mice were sacrificed to assess the biodistribution of 67Cu-2IT-BAT-Lym-1 with and without rIL-2.

RESULTS

In mice treated with 335 microCi of 67Cu-2IT-BAT-Lym-1 alone, 28% of tumors were cured. When 48,000 IU of rIL-2 were added, 50% were cured. The overall response-rate was 50% for both regimens. In mice treated with 400 microCi of 67Cu-2IT-BAT-Lym-1 alone, 42% responded, all of which were cured. When 48,000 IU of rIL-2 were added, 77% of tumors responded, and 38% were cured. Larger or multiple doses of rIL-2 did not result in additional therapeutic enhancement. The tumor uptake and radiation dose after 67Cu-2IT-BAT-Lym-1 were about two times greater when a single dose of rIL-2 was added: This may be the basis for enhanced therapeutic efficacy. Mortality was not altered for 335 microCi or 400 microCi doses of 67Cu-2IT-BAT-Lym-1 by rIL-2 nor were other toxicity parameters. Mortality was increased at 500 microCi by the addition of rIL-2.

CONCLUSIONS

67Cu-2IT-BAT-Lym-1 provided a therapeutic and frequently curative dose of radiation to tumored mice at tolerated doses. The therapeutic effectiveness of 67Cu-2IT-BAT-Lym-1 may have been enhanced by rIL-2.

Allogeneic bone marrow transplantation for high-risk acute lymphoblastic leukemia in first remission: long-term results for 42 patients conditioned with an intensified regimen (TBI, high-dose Ara-C and melphalan)

Attempts to improve the efficacy of pretransplant conditioning regimens have been published, the potential of a better antileukemic effect being impaired by more frequent and severe toxicities. The efficacy of an intensified regimen, TAM (TBI, high-dose cytosine arabinoside and melphalan), is evaluated by analyzing long-term follow-up of a homogenous group of 42 high-risk ALL patients allografted in first CR. Age at time of BMT was 25.9 +/- 10.4 years (3-41). Twenty-two patients had more than three adverse prognostic factors. Ten patients had a Ph chromosome. Probability of overall survival was 45 +/- 9%, and for all surviving patients median follow-up time was 66 months. Event-free survival was 40 +/- 8% at 7 years after transplantation and the expected relapse rate reached 31%. Twenty-two deaths occurred, six after a relapse but 16 appeared to be directly due to the BMT procedure. None of the pretransplant characteristics significantly affected outcome after BMT. TAM appeared to be an efficient antileukemic therapy for conditioning high-risk ALL patients before allogeneic transplantation, but was still very toxic. The use of TAM in adult ALL patients in first CR is not recommended and the real role of intensified conditioning regimens remains to be demonstrated.

Resistance to radiation-induced apoptosis in Burkitt's lymphoma cells is associated with defective ceramide signaling

Increased sensitivity to ionizing radiation has been shown to be due to defects in double-strand break repair and mutations in the proteins that detect DNA damage. However, it is now recognized that the cellular radiation response is complex and that radioresistance/radiosensitivity may also be regulated at different levels in the radiation signal transduction pathway. Here, we describe a direct relationship between resistance to radiation-induced apoptosis and defective ceramide signaling. Radiation sensitivity in human tumor cells correlated with the immediate accumulation of the second messenger ceramide. In the BL30A Burkitt's lymphoma line, ceramide increased 4-fold by 10 min postirradiation (10 Gy), and in the moderately sensitive HL-60 leukemia cells, ceramide accumulated 2.5-fold above basal levels. In contrast, in all radioresistant tumor cells examined, including several Burkitt's lymphoma lines (BL30K, BL29, and BL36) and the MO59K glioma cell line, ceramide did not accumulate postirradiation. The ability to abrogate ceramide production by pretreatment with the tumor promoter, 12-O-tetradecanoylphorbol 13-acetate, conferred resistance to radiation-induced apoptosis in the sensitive BL30A cells. An isogenic subline of BL30A, BL30K, was resistant to both C8-ceramide (20 microM) and ionizing radiation-induced apoptosis. Bypassing the block in radiation-induced ceramide production by the addition of exogenous ceramide was not sufficient to induce apoptosis; this suggests the existence of a second ceramide-associated signaling defect in these radioresistant cells that confers resistance to ceramide-induced apoptosis. Thus, these results provide compelling evidence that ceramide is an essential mediator of radiation-induced apoptosis and that defective ceramide signaling confers an apoptosis-resistant phenotype in tumor cells.

Degradation of radioiodinated B cell monoclonal antibodies: inhibition via a FCgamma-receptor-II-mediated mechanism and by drugs

Our aim is to treat patients with B cell malignancies with radioimmunotherapy using monoclonal antibodies (mAb) such as CD19, CD20 and CD22. In this study we investigated the rate of internalization and catabolism of these mAb. After 24 h at 37 degrees C, 20%-25% of initially cell-bound (125)I-CD19 mAb and (125)I-CD22 mAb was degraded in B cells, whereas almost no degredation occurred after binding of (125)I-CD20 mAb. For B cells expressing Fcgamma receptor II (FcgammaRII), isotype-dependent degradation was noted as the CD19 IgGl mAb showed an enhanced degradation rate compared to the switch variant IgG2a. The effect of various pharmaceutical agents that delay the internalization or subsequent degradation of mAb was evaluated. The degradation was inhibited most effectively by a combination of etoposide and vinblastine, resulting in accumulation of radioactivity in the target cell. Also the simultaneous application of CD20 or CD22 with (125)I-CD19 mAb or of CD20 with (125)I-CD22 mAb proved to be a potent inhibitor of the rapid degradation of these mAb, by inhibiting internalization via an FcgammaRII-mediated mechanism. Both methods of reducing the degradation of radioiodinated mAb are expected to prolong irradiation of malignant b cells and consequently result in an enhanced therapeutic effect in vivo.

In vitro and in vivo antileukemic activity of B43-pokeweed antiviral protein against radiation-resistant human B-cell precursor leukemia cells

B-cell precursor (BCP) leukemia is the most common form of childhood cancer and represents one of the most radiation-resistant forms of human malignancy. In this study, we examined the antileukemic efficacy of the B43 (anti-CD19)-pokeweed antiviral protein (B43-PAP) immunotoxin against radiation-resistant BCP leukemia cells. B43-PAP caused apoptosis of radiation-resistant primary BCP leukemia cells, killed greater than 99% of radiation-resistant primary leukemic progenitor cells from BCP leukemia patients, and conferred extended survival to severe combined immunodeficiency (SCID) mice xenografted with radiation-resistant human BCP leukemia. Furthermore, the combination of B43-PAP and total body irradiation (TBI) was more effective than TBI alone in two SCID mouse bone marrow transplantation models of radiation-resistant human BCP leukemia. Thus, B43-PAP may prove useful in the treatment of radiation-resistant BCP leukemia.

Relationships between G1 arrest and stability of the p53 and p21Cip1/Waf1 proteins following gamma-irradiation of human lymphoma cells

We investigated temporal relationships between ionizing radiation-induced G1 arrest and induction of the p53-regulated genes GADD45, CIP1/WAF1, and MDM2 in a series of Burkitt's lymphoma and lymphoblastoid cell lines that differed in p53 gene status. Emphasis was placed on characterization of the EW36 cell line, which despite expressing wild-type p53 genes, is defective in G1 arrest following gamma-irradiation (P. M. O'Connor et al., Cancer Res., 53: 4776-4780, 1993). Induction of CIP1/WAF1, GADD45, and to a lesser extent MDM2 mRNA was observed in all wild-type p53 lines that arrested in G1. Cell lines that contained only mutant p53 genes or were heterozygous for p53 mutations failed to induce appreciable levels of these p53-regulated transcripts and did not arrest in G1. G1 arrest in the wild-type p53 cell line WMN was more prolonged than elevation of CIP1/WAF1, GADD45, or MDM2 transcripts, suggesting that G1 arrest duration must be dependent upon stability of these newly synthesized proteins. In agreement, we found that p21Cip1/Waf1, a potent inhibitor of G1-S phase cyclin-dependent kinases, was maintained at elevated levels throughout the period that WMN cells remained arrested in G1. EW36 cells exhibited normal induction of CIP1/WAF1, GADD45, and MDM2 mRNA following gamma-irradiation, suggesting that the defect in G1 arrest must reside downstream of p53 transactivation. Investigations into the stability of p53 and p21Cip1/Waf1 revealed that EW36 cells failed to maintain elevated levels of these proteins following irradiation. p53 levels decreased within 4 h of irradiation, and p21Cip1/Waf1 levels decreased shortly after the normal decline of CIP1/WAF1 mRNA levels. Degradation of p21Cip1/Waf1 coincided with the escape of EW36 cells from G1 arrest. Our studies suggest that p21Cip1/Waf1 stability may determine G1 arrest duration and that premature degradation of this protein could provide an alternative route to subversion of the G1 checkpoint in cancer cells.

Excessive spinal cord toxicity from intensive central nervous system-directed therapies

BACKGROUND

Intrathecal chemotherapy, radiation therapy, and systemic chemotherapy are used for both prophylaxis and treatment of central nervous system (CNS) disease in hematologic malignancies. Twenty-three cases of myelopathy that occurred in patients who received intensive CNS-directed therapy were evaluated to identify the determinants of this severe CNS toxicity.

METHODS

Nine cases treated by the authors and 14 collected from the literature are discussed. Twelve had Burkitt's leukemia/lymphoma. Patient ages ranged from 3 to 30 years (median, 15 years). The dose intensity of CNS-directed therapies, including intrathecal cytosine arabinoside (ara-C), intrathecal methotrexate (MTX), systemic high dose (HD) MTX, systemic HD ara-C, systemic thiotepa, and CNS radiation, was evaluated by the determination of single drug doses and cumulative total drug or irradiation doses over elapsed treatment durations.

RESULTS

Central nervous system treatment was prophylactic in 10 cases; active CNS disease was being treated in 13 cases. One patient received only intrathecal ara-C before toxicity occurred; other received intrathecal ara-C and varying combinations of intrathecal MTX, HD ara-C, HD MTX, CNS radiation, and systemic thiotepa. Eight patients died of toxicity, of whom 6 had autopsy-proven cord necrosis; 3 were ventilator-dependent; 10 had persistent paraplegia or paraparesis; and 2 recovered completely.

CONCLUSION

Both highly intensive, short CNS treatment sequences and lower intensity, long term cumulative treatments may result in this rare but severe myelopathy. The cause is multifactorial, with systemic chemotherapy, intrathecal chemotherapy, and radiation therapy contributing to toxicity. Multiple intrathecal ara-C and/or MTX doses given at frequent (daily) intervals should be avoided. Concurrent intrathecal ara-C and systemic HD ara-C also appear to be especially toxic. Intrathecal hydrocortisone given with intrathecal ara-C does not protect against myelopathy. Multiple, frequently spaced courses of CNS-directed therapies must be avoided, especially in patients who have received prior CNS radiation.

Therapy of B-cell acute lymphoblastic leukaemia in childhood: the BFM experience

In 1981 the BFM group introduced a new treatment strategy for B-ALL based on two alternating 5-day courses of chemotherapy delivered in short intervals up to a total of eight. The therapy courses were composed of fractionated cyclophosphamide, MTX 0.5 g/m2 (24-h infusion), i.t. MTX therapy, and ara-C/VM26 alternating with doxorubicin. The development of the therapy strategies during the subsequent two studies was characterized by shortening treatment duration from eight to six courses, and intensification of CNS chemotherapy in study ALL-BFM-83, and the introduction of HD-MTX (5 g/m2, 24-h infusion) in study ALL-BFM-86. In study ALL-BFM-81, CNS therapy consisted of ID-MTX in combination with i.t. MTX and RX. CNS-positive patients received complete neuroaxis irradiation. In study ALL-BFM-83, CNS chemotherapy was intensified by adding dexamethasone, while MTX/ara-C were administered intraventricularly. Spinal irradiation for CNS-positive patients was omitted. In study ALL-BFM-86, i.t. MTX/ara-C/prednisolone therapy was introduced in combination with HD-MTX but the intraventricular route of drug administration was no longer used. Radiotherapy was omitted completely. In all, 87 patients were enrolled, 22 (eight CNS positive) in study ALL-BFM-81, 24 (seven CNS positive) in study ALL-BFM-83, and 41 (none CNS positive) in study ALL-BFM-86. The estimated 5-year duration of EFS was 40% in study ALL-BFM-81, 50% in study ALL-BFM-83, and 78% in study ALL-BFM-86 (minimal follow-up 36 months). Nineteen of 24 relapses occurred while on therapy or shortly thereafter. In study ALL-BFM-81, the CNS was the most frequent site of failure. In ALL-BFM-83 there were no isolated CNS relapses but more BM relapses occurred. In ALL-BFM-86 localized manifestations were the predominant site of failure, no isolated BM relapses occurred, and only one CNS relapse was diagnosed. No single parameter exerted a consistent influence on outcome with one exception. The presence of residual disease after the first two courses was correlated with an increased risk of therapy failure. Our conclusions from the three studies are listed below. An intensive, short-pulse therapy delivered within a 4 month period is highly effective in the treatment of B-ALL. Prolonged therapy duration is of no value. In addition to fractionated cyclophosphamide-ifosfamide, a 24-h infusion of HD-MTX5 g/m2 in conjunction with an i.t. therapy is a very important component for prevention of both systemic and CNS relapses.(ABSTRACT TRUNCATED AT 400 WORDS)

[Primary manifestation of Burkitt's lymphoma of the non-African type in the orbits]

BACKGROUND

Primary orbital involvement in non-African Burkitt's lymphoma does not occur frequently but when it occurs children are mostly affected.

PATIENT AND METHOD

A 83-year-old woman with a primary manifestation of non-African Burkitt's lymphoma in the orbit was presented in our out-patient department.

RESULTS

After radiation therapy no recurrence after 6 months.

CONCLUSION

To our knowledge, this is the first reported adult patient with definite primary involvement of the orbit in non-African Burkitt's lymphoma.

Recent advances in B cell acute lymphoblastic leukemia (Burkitt leukemia) therapy in childhood

Acute lymphoblastic leukemia with Burkitt type cells has been described in 1975. Until the mid-1980, with conventional treatments, the prognosis was very poor with very few long-term survivors. Failures were mainly due to central nervous system involvement at diagnosis or relapse. After that period a dramatic improvement has been observed with intensified treatments based on Burkitt's lymphoma therapy regimens. High-dose cyclophosphamide, high-dose methotrexate, high-dose ara-C in compact protocols completed in 6-7 months have been proven useful. 75% of the patients can be cured.

Therapy with unlabeled and 131I-labeled pan-B-cell monoclonal antibodies in nude mice bearing Raji Burkitt's lymphoma xenografts

Clinical trials of radioimmunotherapy (RIT) of lymphoma have produced frequent tumor regressions and remissions, but it has been difficult to determine to what extent these tumor responses have been due to antibody-specific targeted radiation, nontargeted radiation, and/or cytotoxicity mediated by the carrier monoclonal antibody (MoAb). In this report, RIT was studied in athymic nude mice bearing s.c. Raji human Burkitt's lymphoma xenografts using two different pan-B-cell MoAbs, MB-1 (anti-CD37) and anti-B1 (anti-CD20), which differ in isotype (and thus the potential for interaction with host effector mechanisms) and isotype-matched control antibodies either in the unlabeled state or labeled with 131I. When a single i.p. injection of 300 microCi 131I-labeled MB-1 (IgG1) was compared to treatment with unlabeled MB-1 or 300 microCi 131I-labeled MYS control IgG1 MoAb, an antibody-specific targeted radiation effect of RIT was seen. 131I-labeled MB-1 produced a 44 +/- 19% (SEM) reduction in tumor size at 3 weeks posttreatment, while unlabeled MB-1 or 300 microCi 131I-labeled MYS control IgG1 antibody treatment resulted in continued tumor growth over this period of time. In vitro studies demonstrated that MB-1 was incapable of mediating antibody-dependent cellular cytotoxicity using Raji tumor cell targets and human peripheral blood mononuclear cells. Similar to the MB-1 studies, treatment with 300 microCi 131I-labeled anti-B1 produced a 64% reduction in mean tumor size, while 300 microCi of control antibody resulted in a 58% increase in tumor size over the same 3-week period. In contrast to MB-1, however, unlabeled anti-B1 (an IgG2a MoAb which in vitro studies showed to be capable of antibody-dependent cellular cytotoxicity) also had a substantial antitumor effect. Indeed, 300 microCi 131I-labeled anti-B1 and unlabeled anti-B1 treatment (using an equivalent amount of total protein in the treatment dose) produced a similar specific reduction in tumor size. Increasing the radionuclide dose of anti-B1 to 450 microCi in another experiment did not produce a significant difference in tumor regression compared to a 300-microCi dose. These results suggest that the antitumor effects of 131I-labeled anti-B1 treatment were dominated by antibody-mediated cytotoxicity mechanisms, such that an antibody-specific targeted radiation effect could not be distinguished. In contrast, antibody-specific targeting of radiation was the dominant mechanism of tumor killing with 131I-labeled MB-1.(ABSTRACT TRUNCATED AT 400 WORDS)

The evaluation of 186Re-labeled antibodies using N2S4 chelate in vitro and in vivo using tumor-bearing nude mice

We have recently described a method for radiolabeling monoclonal antibodies, with metallic radionuclides using a new chelating agent N2S3. Using this chelate the monoclonal antibodies Lym-1 and B72.3 were labeled with 186Re and their biological integrity was evaluated in vitro and in vivo. 186Re-labeled antibodies using N2S4 methodology were found to be stable in human serum and retained their immunoreactivity. Intravenous administration of 0.5 mCi 186Re-labeled antibodies resulted in partial or complete regression of tumor tissue in mice.

The role of surgery in abdominal Burkitt's lymphoma

The abdomen is the most frequent site of involvement in nonendemic Burkitt's lymphoma (small noncleaved cell). Some authors have proposed a role for extensive surgical resection or "second look" laparotomy in these patients. We retrospectively reviewed our series of 53 patients with Burkitt's lymphoma (1977 to 1990) to assess the role of surgery in their treatment. Patients were 2.5 to 21 years of age (median, 9.5 years) and 44 were males. The primary site of disease was the abdomen (38), head and neck (12), axilla (1), and bone marrow (2). Twenty-four of the 38 patients with abdominal primaries underwent laparotomy. Twelve of these patients presented with acute abdominal symptoms (right lower quadrant pain or intestinal obstruction) and at exploration underwent resection of the primary tumor. Ten of these 12 patients achieved grossly complete excision of tumor (9 had disease limited to the ileocecal area and adjacent mesentery and one had exophytic tumor adherent to the liver, which was excised). Of note, only 1 of these 12 patients had metastatic disease outside of the abdomen. The remaining 12 patients who underwent laparotomy had an incisional biopsy performed. Of the 14 patients who did not have a laparotomy, the diagnosis was made by bone marrow biopsy (6), and/or cytology of pleural fluid or ascites (6), lymph node biopsy (1), testicular biopsy (1), tibial biopsy (1), and percutaneous biopsy (1). Murphy staging for these 38 patients was: stage II (10), stage III (19), stage IV (5), and B cell acute lymphoblastic leukemia (ALL) (4). All patients received cyclophosphamide-containing combination chemotherapy regimens and stage III/IV/B cell ALL patients received central nervous system (CNS) prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

Early diagnosis of leukoencephalopathy of acute lymphocytic leukemia by MRI

Using repeated computed tomographic and magnetic resonance imaging scans, we examined 8 patients with acute lymphocytic leukemia during remission induction therapy between 1988 and 1989. In 3 patients, leukoencephalopathy was diagnosed by T2-weighted magnetic resonance imaging. In 1 patient, leukoencephalopathy was progressive and irreversible brain damage and mental retardation persisted. In the other 2 patients, hyperintense lesions in the periventricular white matter were transient and no neurologic sequelae ensued. Magnetic resonance imaging was more useful than computed tomography in the early diagnosis and management of these acute lymphocytic leukemia patients with leukoencephalopathy.

The role of surgery in American Burkitt's lymphoma in children

The records of 28 children with the pathological diagnosis of American Burkitt's lymphoma were reviewed. Twenty-three of these children (82%) presented with primary abdominal tumors and 5 with disease located in the head and neck. Twelve required an emergency operation for either intestinal obstruction (3), intussusception (5), or appendicitis (4); the others underwent an elective exploration for tissue diagnosis. Ten patients had disease localized to one particular site. Seven of these 10 children underwent complete resection of the tumor including a right colectomy (4), small bowel segmental resection (1), tonsillectomy (1), and appendectomy (1). Eight children had a subtotal resection of the tumor (less than 90% of tumor burden) and the rest underwent incisional biopsies. Following the diagnosis, all patients received chemotherapy; 8 (29%) also were treated concurrently with radiation therapy. Nineteen patients (70%) remain long-term survivors with a mean survival time of 3.6 years. Eight patients died of either recurrent disease (6) or sepsis secondary to their chemotherapy, with a mean survival time of 6 months. Sixteen patients (57%) developed complications during their hospitalization that required surgical consultation or intervention (acute renal failure [9], pleural effusion [2], intestinal obstruction [5], gastric outlet obstruction [1], and wound infection [1]). No subsequent treatment of these complications resulted in mortality or morbidity. The significant positive determinant for survival was the initial absence of either bone marrow or central nervous system involvement (P less than .05). In those children who had complete resection of their tumor, survival time was greater than 3.7 years.(ABSTRACT TRUNCATED AT 250 WORDS)

[Chemotherapy of nonendemic Burkitt's lymphoma]

14 patients (12 men, 2 women, mean age 26.3 [15-47] years) with histologically confirmed Burkitt's lymphoma were subjected between 1984 and 1989 to chemotherapy originally developed for treating lymphomas in children. Treatment consisted of medium doses of methotrexate, cyclophosphamide, teniposide, cytarabine, adriamycin and prednisone, intrathecal administration of methotrexate and if necessary prophylactic or therapeutic irradiation of the cranium. Most of the patients (64%) were in advanced stages of the disease. The rate of complete remissions was 100%. Four patients (29%) had a recurrence. Side effects were leukopenia (WHO grade III and IV) in 71%, grade III anaemia in 43% and grade III-IV thrombopenia in 29% of the patients. Considerable mucositides in 5 of the 14 patients (36%), and in one case a tumour lysis syndrome with transient renal insufficiency were other therapy-induced side effects. These results suggest that this treatment course can be successful also in non-endemic Burkitt's lymphoma in adolescents and adults.

High-dose cytosine arabinoside, total body irradiation and marrow transplantation for advanced malignant lymphoma

Twenty-four patients with advanced malignant lymphoma including Hodgkin's disease (HD, n = 1), intermediate grade non-Hodgkin's lymphoma (IGL, n = 12) and high-grade non-Hodgkin's lymphoma (HGL, n = 11) were prepared for syngeneic (n = 2), allogeneic (n = 11) or autologous (n = 11) marrow transplantation with cytosine arabinoside, 3 g/m2 every 12h for 12 doses (HDAC) and total body irradiation, 200 cGy daily for 6 days (TBI) to determine toxicity and efficacy. Eight patients (33%) died from early regimen related toxicity and all eight had a Karnofsky performance score less than or equal to 80 at the start of treatment. The actuarial probability of disease-free survival was 17% with a 65% probability of relapse at 4 years after transplantation. Four patients are surviving 2-4 years post-transplant, three transplanted for IGL and one for HD. None of the patients transplanted for HGL survived. The result of this phase II study suggests that HDAC followed by TBI and marrow infusion offers no apparent advantage over cyclophosphamide + TBI for patients with relapsed advanced malignant lymphoma. Earlier transplantation currently is the only demonstrated method of achieving better results.

Elimination of clonogenic tumor cells from HL-60, Daudi, and U-937 cell lines by laser photoradiation therapy: implications for autologous bone marrow purging

Laser photoradiation therapy was tested in an in vitro model for its efficacy in the elimination of non-Hodgkin's lymphoma cells. Results show that at 31.2 J/cm2 of laser light in the presence of 20 micrograms/mL of merocyanine 540 (MC540) there was greater than 5 log reduction in Burkitt's lymphoma (Daudi) cells. Similar tumor cell kill was obtained for leukemia (HL-60) cells at a laser light dose of 93.6 J/cm2. However, to obtain the same efficiency of killing for histiocytic lymphoma (U-937) cells, a higher dose of MC540 (25 micrograms/mL) was required. Clonogenic tumor stem cell colony formation was reduced by greater than 5 logs after laser photoradiation therapy. Under identical conditions for each cell line the percent survival for granulocyte-macrophage colony-forming units (CFU-GM, 45.9%, 40%, 17.5%), granulocyte/erythroid/macrophage/megakaryocyte (GEMM, 40.1%, 20.1%, 11.5%), colony-forming units (CFU-C, 16.2%, 9.1%, 1.8%), and erythroid burst-forming units (BFU-E, 33.4%, 17.8%, 3.9%) was significantly higher than the tumor cells. Mixing of gamma ray-irradiated normal marrow cells with tumor cells (1:1 and 10:1 ratio) did not interfere with the elimination of tumor cells. The effect of highly purified recombinant interferon alpha (rIFN) on laser photoradiation therapy of tumor cells was also investigated. In the presence of rIFN (30 to 3,000 U/mL), the viability of leukemic cells was observed to increase from 0% to 1.5% with a concurrent decrease in membrane polarization, suggesting an increase in fluidity of cell membrane in response to rIFN. However, at higher doses of rIFN (6,000 to 12,000 U/mL) this phenomenon was not observed. The viability of lymphoma cells remained unaffected at all doses of rIFN tested. These results may have therapeutic relevance in patients undergoing interferon treatment who require bone marrow transplantation, as the complete elimination of tumor cells by marrow-purging procedures may be hampered by this increased survival in the presence of interferon.