A high bone marrow plasma cell labeling index in stable plateau-phase multiple myeloma is a marker for early disease progression and death

The plasma cell labeling index (PCLI) is a measure of plasma cell proliferative activity and is an important prognostic factor in newly diagnosed multiple myeloma (MM). Occasionally patients have been observed with stable, plateau phase MM with minimal numbers of residual light-chain-restricted monoclonal plasma cells, but a high PCLI. No data are available on the outcomes for such patients. Data from 57 patients with plateau phase MM and a marrow PCLI of more than 1.0% were compared with 105 matched control patients with MM with a marrow PCLI of less than 1.0%. All patients had less than 10% total plasma cells on marrow aspirate and biopsy. The median time to progression and overall survival were 8 months and 20 months, respectively, in the high PCLI group versus 39 months and 56 months, respectively, in the low PCLI group (P < .0001). These findings suggest that a high PCLI in patients with apparently stable, plateau phase MM is an adverse parameter that may predict a short time to disease progression and death.

Cd4+ T-cell immune response to large B-cell non-Hodgkin's lymphoma predicts patient outcome

PURPOSE

Previous studies in patients with non-Hodgkin's lymphoma (NHL) and other malignancies have suggested that the presence of host infiltrates in the tumors of these patients may predict a better outcome. This study was undertaken to determine the prognostic importance of the presence of T cells in the biopsy specimens of patients with B-cell NHL.

PATIENTS AND METHODS

Seventy-two patients with diffuse large B-cell NHL were prospectively evaluated at a single institution between 1987 and 1994. The percentage of CD3+, CD3+/HLA-DR+, CD4+, CD8+, and natural killer cells was determined by flow cytometry in the pretreatment diagnostic biopsy specimen and correlated with patient outcome.

RESULTS

An increase in the percentage CD4+ T cells in the pretreatment tumor biopsies significantly correlated with patient outcome. The percent of CD4+ T cells was also highly correlated with CD3+/HLA-DR+, CD45RO+, and low L-selectin (CD62L) expression, indicating that the CD4+ T cells are activated memory T-helper cells. Those patients with increased numbers of CD4+ T cells, compared with other patients, had a significantly longer 5-year failure-free survival (72% v 43%, respectively; P =.04), as well as a significantly longer 5-year overall survival (65% v 38%, respectively; P =.05). When evaluated in a multivariate model, the International Prognostic Index and more than 20% infiltrating CD4+ T cells in the pretreatment biopsy were significant independent predictors of relapse-free and overall survival.

CONCLUSION

The presence of increased numbers of activated CD4+ cells in the area of B-cell diffuse large-cell NHL predicts a better prognosis. This finding provides a strong rationale for the investigation of cellular immunotherapy in B-cell NHL.

The use of ibritumomab tiuxetan radioimmunotherapy for patients with relapsed B-cell non-Hodgkin's lymphoma

Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA and IDEC Pharmaceutical Corporation, San Diego, CA) is a monoclonal antibody that targets the CD20 antigen present in most B-cell non-Hodgkin's lymphomas. Previous studies have shown overall response rates (ORR) of approximately 50% in relapsed patients. Ibritumomab is the murine parent anti-CD20 antibody that is linked through a MX-DTPA chelator to yttrium 90 (90Y) to form the radioimmunoconjugate 90Y-ibritumomab tiuxetan (Zevalin; IDEC Pharmaceuticals, San Diego, CA). A phase I study of 90Y-ibritumomab tiuxetan determined that 0.4 mCi/kg was the maximum tolerated dose, and responses were reported in 67% of all patients and in 82% of patients with low-grade non-Hodgkin's lymphoma. A separate trial randomized eligible patients to either rituximab or 90Y-ibritumomab tiuxetan. An interim analysis of the first 90 patients showed an ORR of 80% with 90Y-ibritumomab tiuxetan versus 44% with rituximab (P < .05). A subsequent trial for patients with rituximab-refractory disease showed a 46% ORR. These studies show that 90Y-ibritumomab tiuxetan is an active agent in relapsed non-Hodgkin's lymphoma and appears to have a higher ORR compared with unconjugated rituximab.

Effect of complete response on outcome following autologous stem cell transplantation for myeloma

We studied the effect of complete response (CR) among 126 consecutive patients who underwent stem cell transplantation (SCT) for myeloma. The CR rate with SCT was 33%. Median overall survival (OS) from diagnosis of myeloma was 56 months. OS following SCT was 22 months. Progression-free survival (PFS) was 12 months. OS was not different between patients who achieved CR and those who did not, median survival 25 vs 24 months, P = 0.5. Corresponding median times for PFS were 15 and 11 months, P = 0.2. The plasma cell labeling index (PCLI) was high (> or = 1%) in 36% (high risk group) and was associated with poor OS and PFS (P < 0.001). Achieving CR did not influence OS or PFS in either the high or the low risk group. In contrast, OS and PFS were significantly influenced by high PCLI both in patients who achieved CR and those who did not. OS was poor (< 30 months) in high risk patients regardless of CR status and in low risk patients who did not achieve CR, compared to low risk patients achieving CR (57 months), making them candidates for novel post-transplant treatment options. Outcome following SCT is dependent more on biological variables such as the PCLI than on CR status.

A review of angiogenesis and antiangiogenic therapy with thalidomide in multiple myeloma

Angiogenesis is the formation of new blood vessels and occurs physiologically during embryonal growth, wound healing and during the menstrual cycle. It is essential for the proliferation and metastases of most malignant neoplasms. Recent evidence suggests that angiogenesis is increased in multiple myeloma and has prognostic value in the disease. Angiogenic cytokines such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor are expressed by myeloma cells and appear to play a role in the increased angiogenesis seen in myeloma. In addition, VEGF may serve as a paracrine growth factor for myeloma cells. Based on the increased angiogenesis observed in myeloma, thalidomide has been studied as antiangiogenic therapy. Although its mechanism of action in myeloma is still unclear, thalidomide appears to be active in 25-30% of patients with refractory myeloma. Major toxicities include constipation, sedation, skin rash, fatigue, and peripheral neuropathy. Studies are ongoing to determine its role as initial treatment for myeloma. This paper reviews the available data on angiogenesis in myeloma, and summarizes the role of thalidomide therapy in this disease. The pharmacology and toxicity of thalidomide are also discussed.

A randomized, placebo-controlled study of outpatient premedication for bone marrow biopsy in adults with lymphoma

The outpatient bone marrow biopsy and aspiration (BMBA) procedure performed with local anesthetic is often poorly tolerated in adults. This prospective, randomized, placebo-controlled, double-blind trial was designed to determine whether oral (p.o.) lorazepam and hydromorphone reduces pain and anxiety during BMBA. Eligible patients had lymphoma, had no prior BMBA, and were > or = 18 years old. Since patients had bilateral BMBA, each served as their own control. Patients were stratified by anxiety level using the Spielberger Trait Anxiety Scale and randomized to: A) placebo for the first BMBA and 2 mg lorazepam and 2 mg hydromorphone p.o. for the contralateral BMBA, or B) placebo for both BMBAS. Changes in pain and anxiety experienced between the first and second BMBA were measured by the Visual Analogue Scale (VAS) and the Spielberger State Anxiety Scale at the time of the BMBA and 24 hours later. Twenty-seven patients were enrolled and 25 were evaluable; there were 17 males and eight females. The median age was 57 years (range, 28-79 years). Overall, BMBA was reported as painful in both arms, with a median VAS pain score after the second BMBA of 3.9 (scale, 0-10) for arm A and 5.8 for arm B (P = 0.21). There was no difference in the change in pain, anxiety, or recalled anxiety between treatment arms (all P values > 0.05). The difference in the change in recalled pain was of borderline significance (P = 0.07) and consistent with benzodiazepine-induced anterograde amnesia.

Thalidomide in the treatment of relapsed multiple myeloma

OBJECTIVE

To describe the efficacy of therapy with thalidomide, a drug that has antiangiogenic properties, in patients with relapsed multiple myeloma.

PATIENTS AND METHODS

We studied 16 patients (median age, 64 years) who received thalidomide for relapsed myeloma at the Mayo Clinic in Rochester, Minn, between November 1998 and August 1999. Treatment consisted of thalidomide given orally at a dose of 200 mg/d for 2 weeks, then increased by 200 mg/d every 2 weeks, up to a maximal dose of 800 mg/d.

RESULTS

The stage of myeloma at treatment was Durie-Salmon IIIA in 9 patients (56%) and IIIB in 7 (44%). The median time from myeloma diagnosis to initiation of thalidomide therapy was 32 months. In 4 patients (25%) prior stem cell transplantation had failed, and 14 (88%) had received 2 or more prior chemotherapeutic regimens before institution of thalidomide. All patients were evaluable for response. Four (25%) achieved a partial response to therapy, with a greater than 50% reduction in the serum or urine M protein level. Responses lasted 2, 4+, 8, and 10+ months. Major adverse effects included constipation, sedation, rash, and peripheral neuropathy.

CONCLUSION

Thalidomide is an active agent in the treatment of patients with advanced myeloma.

Prognostic value of bone marrow angiogenesis in multiple myeloma

We studied the prognostic value of angiogenesis grading and microvessel density estimation in newly diagnosed multiple myeloma. Seventy-five patients with newly diagnosed myeloma, treated on Eastern Cooperative Oncology Protocol E9486 and Intergroup study 0141 (S9321) at the Mayo Clinic, were studied. Bone marrow microvessels were examined using immunohistochemical staining for von Willebrand factor. Determination of microvessel density and angiogenesis grading was done in a blinded manner. There was a strong correlation between microvessel density and the plasma cell labeling index, rho 0.42, P < 0.001. Angiogenesis grade was also significantly associated with the plasma cell labeling index. Fifteen % of patients with low-grade angiogenesis had a high labeling index (>1%). In contrast, 47% of patients with intermediate or high-grade angiogenesis had high labeling indices (P = 0.02). Overall survival was significantly different among those with high-, intermediate-, and low-grade angiogenesis, with median times of 2, 4, and 4.4 years, respectively (P = 0.02). Similarly, patients with microvessel density >50/x400 field had poorer survival compared with those with 50 or fewer microvessels/field, median survival 2.6 versus 5.1 years, respectively (P = 0.004). There was a strong association between angiogenesis grade and microvessel density (P < 0.001). We conclude that bone marrow angiogenesis is a predictor of poor survival in newly diagnosed myeloma. Angiogenesis is correlated with the plasma cell labeling index but not the bone marrow plasma cell percentage. A simple visual grading of angiogenesis is an efficient alternative to microvessel density estimation.

A prospective study of CD38/45 flow cytometry and immunofluorescence microscopy to detect blood plasma cells in patients with plasma cell proliferative disorders

Malignant plasma cells can be detected in the blood of patients with multiple myeloma (MM) using flow cytometry (FC), immunofluorescence microscopy (IM), or a variety of molecular techniques. Increased numbers of light chain-restricted blood plasma cells as detected by IM is associated with a diagnosis of overt MM and a decreased overall survival. The IM technique is time consuming; therefore, a prospective study was designed to test whether CD38 CD45 FC could simplify the procedure. Blood samples from 769 patients with plasma cell proliferative disorders were studied prospectively by FC and IM over a one-year period. The FC technique was performed on 1 ml of whole blood after ammonium chloride red blood cell lysis and utilized anti-CD38PE and anti-CD45PerCP. The number of CD38+ 45- events were enumerated and compared to the number of light chain-restricted plasma cells detected by the standard IM technique. In 46% (353/769) of cases > or = 1 CD38+ CD45- events were detected by FC whereas IM was positive for light chain restricted plasma cells in 33%; there was concordance between FC and IM in 73% of cases. In 20% of cases FC was positive and IM was negative; however, in 7% of cases FC was negative yet light chain-restricted plasma cells were detected by IM. FC was positive in 88% (134/153) of cases where the IM technique showed a high number of circulating plasma cells. This study demonstrates that two-color CD38/45 FC identifies most cases with a high IM result and reduces the workload in the clinical laboratory. The prognostic implications of a positive FC screen but a negative IM will require long-term patient follow-up.

Phase I/II 90Y-Zevalin (yttrium-90 ibritumomab tiuxetan, IDEC-Y2B8) radioimmunotherapy dosimetry results in relapsed or refractory non-Hodgkin's lymphoma

Dosimetry studies in patients with non-Hodgkin's lymphoma were performed to estimate the radiation absorbed dose to normal organs and bone marrow from 90Y-Zevalin (yttrium-90 ibritumomab tiuxetan, IDEC-Y2B8) treatment in this phase I/II, multicenter trial. The trial was designed to determine the dose of Rituximab (chimeric anti-CD20, Rituxan, IDEC-C2B8, MabThera), the unlabeled antibody given prior to the radioconjugate to clear peripheral blood B cells and optimize distribution, and to determine the maximum tolerated dose of 90Y-Zevalin [7.4, 11, or 15 MBq/kg (0.2, 0.3, or 0.4 mCi/kg)]. Patients received (111)In-Zevalin (indium-111 ibritumomab tiuxetan, IDEC-In2B8 ) on day 0 followed by a therapeutic dose of 90Y-Zevalin on day 7. Both doses were preceded by an infusion of the chimeric, unlabeled antibody Rituximab. Following administration of (111)In-Zevalin, serial anterior/posterior whole-body scans were acquired. Major-organ radioactivity versus time estimates were calculated using regions of interest. Residence times were computed and entered into the MIRDOSE3 computer software program to calculate estimated radiation absorbed dose to each organ. Initial analyses of estimated radiation absorbed dose were completed at the clinical site. An additional, centralized dosimetry analysis was performed subsequently to provide a consistent analysis of data collected from the seven clinical sites. In all patients with dosimetry data (n=56), normal organ and red marrow radiation absorbed doses were estimated to be well under the protocol-defined upper limit of 20 Gy and 3 Gy, respectively. Median estimated radiation absorbed dose was 3.4 Gy to liver (range 1.2-7.8 Gy), 2.6 Gy to lungs (range 0.72-4.4 Gy), and 0.38 Gy to kidneys (range 0.07-0.61 Gy). Median estimated tumor radiation absorbed dose was 17 Gy (range 5.8-67 Gy). No correlation was noted between hematologic toxicity and the following variables: red marrow radiation absorbed dose, blood T(1/2), blood AUC, plasma T(1/2), and plasma AUC. It is concluded that 90Y-Zevalin administered at nonmyeloablative maximum tolerated doses results in acceptable radiation absorbed doses to normal organs. The only toxicity of note is hematologic and is not correlated to red marrow radiation absorbed dose estimates or T(1/2), reflecting that hematologic toxicity is dependent on bone marrow reserve in this heavily pretreated population.

Delayed stem cell transplantation for the management of relapsed or refractory multiple myeloma

The optimal timing of stem cell transplantation for multiple myeloma is controversial. Late stem cell collection is undesirable because of the inability to mobilize stem cells. We report on 64 recipients of stem cells collected within 1 year after diagnosis, none of whom had transplantation in plateau phase of their disease. Patients seen within 12 months after diagnosis received four cycles of standard vincristine, doxorubicin, and dexamethasone (VAD) chemotherapy and then had stem cells mobilized. Patients were then placed on maintenance vincristine, BCNU, melphalan, cyclophosphamide, and prednisone or melphalan and prednisone chemotherapy for 12 cycles. At the sign of first progression, transplantation occurred. Fourteen patients were refractory to VAD chemotherapy, 20 relapsed on maintenance chemotherapy, and 30 relapsed off chemotherapy. The time to platelet engraftment was not affected by the duration of stem cell cryopreservation or extent of chemotherapy exposure after mobilization. The complete response rate was 34%. The actuarial median survival from initial diagnosis, from transplant day 0, and post-transplant progression-free survival was 51, 20 and 11.4 months, respectively. The patient status at transplantation and percentage of plasma cells circulating in the blood at apheresis influenced post-transplant survival; circulating plasma cells, status at transplantation and plasma cell labeling index influenced progression-free survival. Response duration was shorter in patients relapsing on chemotherapy.

Waldenström's macroglobulinaemia: a prospective study comparing daily with intermittent oral chlorambucil

This prospective study compared continuous and intermittent chlorambucil therapy of untreated Waldenström's macroglobulinaemia. The diagnosis was established by the presence of an IgM monoclonal (M-) protein in the serum, an infiltrate of lymphocytes and plasma cells in the bone marrow, anaemia or other laboratory abnormalities, physical findings or constitutional symptoms. Patients were randomized to receive chlorambucil 0.1 mg/kg/d or chlorambucil 0.3 mg/kg/d orally for 7 d, repeated every 6 weeks. Criteria for response included 50% or more reduction of serum M-protein, increase in haemoglobin level of 2 g/dl without transfusion, >/= 50% decrease of urine M-protein, or a reduction of 2 cm in the size of the liver, spleen or lymph nodes. Forty-six patients were randomized to continuous chlorambucil (n = 24) or to intermittent chlorambucil (n = 22). Nineteen (79%) (95% CI = 58-93) of the 24 patients given continuous therapy had an objective improvement by either reduction of serum M-protein or increase in haemoglobin. Fifteen (68%) (95% CI = 45-86) of the 22 patients given chlorambucil intermittently had an objective response. The size of the liver decreased by >/= 2 cm in 55% of patients, and the size of the spleen decreased >/= 2 cm in 67%. Lymphadenopathy decreased in 71%. Acute leukaemia or refractory anaemia developed in four patients. The median duration of survival was 5.4 years, and there was no difference between the regimens. Chlorambucil is effective for the treatment of Waldenström's macroglobulinaemia. Patients must be treated for at least 6 months before therapy is abandoned because response is slow. Chlorambucil is an effective agent and should be compared with purine analogues or rituxan (Rituximab) in a prospective study.

Induction of apoptosis in malignant B cells by phenylbutyrate or phenylacetate in combination with chemotherapeutic agents

Phenylacetate (PA) and phenylbutyrate (PB) are aromatic fatty acids that are presently undergoing evaluation as potential antineoplastic agents. In vitro, PA and PB cause differentiation or growth inhibition of malignant cells. Clinical trials of these drugs as single agents indicate that they are not myelosuppressive; therefore, combinations with other chemotherapy agents may be possible. The goals of this study were to determine whether PA and PB (a) are cytotoxic to malignant B cells from patients with non-Hodgkin's lymphoma and B-cell chronic lymphocytic leukemia and (b) exhibit additive or synergistic induction of apoptosis when administered to myeloma cell lines in combination with conventional drugs. In the clinical specimens, cytotoxicity was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and percent apoptosis was measured using 7-aminoactinomycin D and flow cytometry. Viability was decreased by > 50% in 7% (1/15) of non-Hodgkin's lymphoma samples treated with 5 mM PA, 27% treated with 1 mM PB, and 60% treated with 2 mM PB. Likewise, viability was decreased by > 50% in 44% (4/9) of chronic lymphocytic leukemia samples treated with 5 mM PA, 67% treated with 1 mM PB, and 100% treated with 2 mM PB. Studies in the myeloma cell lines demonstrated that PB treatment induced activation of caspases 3, 7, and 9 accompanied by cleavage of their substrates and internucleosomal DNA degradation. Combinations of PA or PB with conventional drugs (cytarabine, topotecan, doxorubicin, etoposide, chlorambucil, melphalan, fludarabine, carboplatin, and cisplatin) were examined for synergism (combination index < 1 in median effect analysis) in inducing apoptosis of both the MY5 and 8226 human myeloma cell lines. At concentrations that killed > 50% of cells, most combinations were additive; however, PB was synergistic with cytarabine, etoposide, and topotecan, with the combination index < 1 at each of the 50, 75, and 95% apoptosis levels. These observations indicate that PA and PB can induce apoptosis in malignant B cells and enhance the cytotoxicity of agents used in the treatment of these malignancies.

Testicular lymphoma is associated with a high incidence of extranodal recurrence

BACKGROUND

Testicular lymphoma is a rare extranodal presentation of non-Hodgkin lymphoma. The authors report long term follow-up information regarding a group of patients with testicular lymphoma evaluated at the Mayo Clinic and describe the outcome with special attention to patterns of recurrence.

METHODS

The medical records of patients with testicular lymphoma seen at the Mayo Clinic between January 1970 and March 1993 were reviewed. Patients were included if they had evidence of testicular involvement at the time of diagnosis of lymphoma. Pathology specimens were reviewed for confirmation of diagnosis.

RESULTS

Sixty-two patients with a diagnosis of testicular lymphoma were identified. Their median age was 68 years, and 60 patients underwent orchiectomy as the initial therapeutic and diagnostic procedure. Most of patients (79%) had localized or regional disease at the time of presentation. Other treatment modalities after diagnosis included radiotherapy (37%), combination chemotherapy (37%), and combination chemotherapy and radiotherapy (16%). Although 88% of patients had no residual disease after primary treatment, 80% subsequently experienced disease recurrence. There was no significant difference in the rate of recurrence, including Ann Arbor Stage I disease. Treatment did not appear to affect the recurrence rate. At a median follow-up of 2.7 years, 60% of patients had died of disease. Late recurrences were observed, and there appeared to be no plateau in the disease free survival curve. In half (51%) of the patients with disease recurrence, only extranodal locations were involved. Thirteen patients experienced recurrence in the central nervous system, 11 of whom had parenchymal lesions. In 8 of these 13 patients, the central nervous system was an isolated site of disease recurrence.

CONCLUSIONS

Testicular lymphoma is a unique and aggressive extranodal non-Hodgkin lymphoma. Better treatment strategies are needed to prevent recurrences. The risk of extranodal recurrence is high, especially in the central nervous system.

Phase I/II trial of IDEC-Y2B8 radioimmunotherapy for treatment of relapsed or refractory CD20(+) B-cell non-Hodgkin's lymphoma

PURPOSE

Yttrium-90 ibritumomab tiuxetan (IDEC-Y2B8) is a murine immunoglobulin G1 kappa monoclonal antibody that covalently binds MX-DTPA (tiuxetan), which chelates the radioisotope yttrium-90. The antibody targets CD20, a B-lymphocyte antigen. A multicenter phase I/II trial was conducted to compare two doses of unlabeled rituximab given before radiolabeled antibody, to determine the maximum-tolerated single dose of IDEC-Y2B8 that could be administered without stem-cell support, and to evaluate safety and efficacy.

PATIENTS AND METHODS

Eligible patients had relapsed or refractory (two prior regimens or anthracycline if low-grade disease) CD20(+) B-cell low-grade, intermediate-grade, or mantle-cell non-Hodgkin's lymphoma (NHL). There was no limit on bulky disease, and 59% had at least one mass > or = 5 cm.

RESULTS

The maximum-tolerated dose was 0.4 mCi/kg IDEC-Y2B8 (0.3 mCi/kg for patients with baseline platelet counts 100 to 149,000/microL). The overall response rate for the intent-to-treat population (n = 51) was 67% (26% complete response [CR]; 41% partial response [PR]); for low-grade disease (n = 34), 82% (26% CR; 56% PR); for intermediate-grade disease (n = 14), 43%; and for mantle-cell disease (n = 3), 0%. Responses occurred in patients with bulky disease (> or = 7 cm; 41%) and splenomegaly (50%). Kaplan-Meier estimate of time to disease progression in responders and duration of response is 12.9+ months and 11.7+ months, respectively. Adverse events were primarily hematologic and correlated with baseline extent of marrow involvement with NHL and baseline platelet count. One patient (2%) developed an anti-antibody response (human antichimeric antibody/human antimouse antibody).

CONCLUSION

These phase I/II data demonstrate that IDEC-Y2B8 radioimmunotherapy is a safe and effective alternative for outpatient therapy of patients with relapsed or refractory NHL. A phase III study is ongoing.

Immunophenotypic analysis of peripheral blood and bone marrow in the staging of B-cell malignant lymphoma

This study evaluated the contributing roles of flow cytometric immunophenotyping of blood and bone marrow and immunohistochemical paraffin section staining of bone marrow biopsies in the staging of B-cell malignant lymphoma. Flow immunophenotyping was performed on a marrow specimen in 175 cases; a corresponding blood specimen was also immunophenotyped in 135 of these cases. Morphologic marrow involvement by lymphoma was found in 59 cases; flow immunophenotyping identified 54 cases with a monoclonal B-cell process: morphology-positive/flow-positive (n = 49), morphology-positive/flow-negative (n = 10), morphology-negative/flow-positive (n = 5), and morphology-negative/flow-negative (n = 111). The 10 morphology-positive/flow-negative cases included 5 follicular and 5 large-cell lymphomas with minimal marrow involvement. All 5 morphology-negative/flow-positive cases were from patients with large-cell lymphomas and bulky clinical disease. Because the blood contained the same B-cell clone in 2 of 2 morphology-negative/flow-positive cases studied, blood contamination of marrow may account for these findings. Blood flow cytometric immunophenotyping studies were positive in 32 cases; 30 had marrow involvement by morphology and were from patients with follicular, mantle cell, lymphoplasmacytic, small lymphocytic, or marginal zone lymphomas. From our results, we conclude that (1) bone marrow flow cytometric immunophenotyping is not a cost-effective replacement for good morphologic evaluation in lymphoma staging and that (2) a positive peripheral blood flow cytometric immunophenotyping study when performed in low-grade lymphomas correlates with marrow involvement.

The role of adhesion receptors in the pathogenesis of multiple myeloma

There is now an improved understanding of the types of adhesion receptors present on normal and malignant plasma cells. This knowledge has been helpful in identifying plasma cells and in beginning to understand the pathogenesis of myeloma. Future research is needed to delineate the signaling pathways used by the plasma cell after the adhesion receptor binds to its ligands. This information should help in designing more effective therapy for this fatal disease.

Clinical significance of the translocation (11;14)(q13;q32) in multiple myeloma

The most common chromosomal translocation in multiple myeloma (MM) is t(11;14)(q13;q32). Here, we describe the clinical characteristics of patients with MM who have this translocation. We have identified 24 patients at our institution who had t(11;14)(q13;q32) as determined by standard cytogenetic analysis (CC). Seven patients had the translocation detected at the time of original diagnosis and 17 at the time of relapse. Median survival in all patients after original diagnosis was 43 months; median survival after the translocation was detected was 11.9 months. Four patients had a clinical diagnosis of plasma cell leukemia. Most patients had an elevated beta2-microglobulin (13/20 had >4 microg/ml). The bone marrow (BM) labeling index (LI) of patients, at the time of translocation detection, was elevated in most (median 1.4%, 17/23 patients had BMLI > or = 1%). Of the 24 patients, 19 (79%) died of disease progression and 5 (21%) were alive with disease at last follow-up. Lytic lesions, bone pain, or compression fractures eventually developed in all patients. Patients with MM who have t(11;14)(q13;q32) detected by standard cytogenetics seem to have an aggressive clinical course.

Phase II study of 2-chlorodeoxyadenosine in combination with chlorambucil in previously untreated B-cell chronic lymphocytic leukemia

The objective was to determine the safety and efficacy of adding a maximally tolerated dose of 2-chlorodeoxyadenosine (2-CdA) to standard chlorambucil (CLB) therapy in previously untreated B-cell chronic lymphocytic leukemia (CLL). Thirty patients with CLL (median age, 64 years) received two courses of 2-CdA given intravenously (2 mg/m2 daily for 7 days) added to biweekly administration of CLB at 30 mg/m2 given orally. The diagnosis of CLL, treatment indications, and response criteria were according to the National Cancer Institute established guidelines. Sixteen patients (53%) had advanced-stage disease, and four (13%) had trisomy 12 abnormality. The overall remission rate was 80%, including 20% complete remission (CR), 30% nodular partial remission (nPR), and 30% partial remission (PR). Minimal residual disease was detected phenotypically in two of five patients with CR and in eight of nine with nPR. Overall, CR, nPR, and PR rates were not influenced significantly by the presence of cytogenetic abnormalities or advanced clinical stage. With a median follow-up of 33 months, 58% of patients who had a response had relapse. Median time to progression in all 30 patients was 30 months, and time to progression and progression-free survival were not significantly different for the different response groups, clinical stages, or cytogenetic groups. Severe neutropenia and thrombocytopenia occurred in 33% and 7% of patients, respectively. Only two patients had documented bacterial infections, and four had herpetic infections. Concurrent combination chemotherapy with abbreviated doses of 2-CdA and standard-dose CLB is feasible and safe in previously untreated CLL. Antitumor activity may be superior to that of CLB alone given in conventional doses. Whether a different schedule of combining these two agents would result in improved outcome is being investigated.

Radioimmunotherapy of relapsed non-Hodgkin's lymphoma with zevalin, a 90Y-labeled anti-CD20 monoclonal antibody

Approximately 55,400 new cases of non-Hodgkin's lymphoma (NHL) are diagnosed each year, with the overall prevalence of the disease now estimated to be 243,000. Until recently, treatment alternatives for advanced disease included chemotherapy with or without external beam radiation. Based on the results of several clinical trials, the chimeric monoclonal antibody Rituximab has now been approved by the United States Food and Drug Administration as a treatment for patients with relapsed or refractory, low-grade or follicular, B-cell NHL. Several other monoclonal antibodies in conjugated and unconjugated forms have been evaluated in the treatment of NHL. Ibritumomab, the murine counterpart to Rituximab, radiolabeled with 90Y (Zevalin), is presently being evaluated in clinical trials. The success of radioimmunotherapy is dependent upon the appropriate choice of antibody, isotope, and chelator-linker. The Ibritumomab antibody targets the CD20 antigen. The antibody is covalently bound to the chelator-linker tiuxetan (MX-DTPA), which tightly chelates the isotope 90Y. To date, two Phase I/II Zevalin clinical trials have been completed in patients with low-grade, intermediate-grade, and mantle cell NHL. The overall response rate was 64% in the first trial and 67% in the later trial. Phase II and III trials are ongoing.

Prevention of recurrence and prolonged survival in primary central nervous system lymphoma (PCNSL) patients treated with adjuvant high-dose methylprednisolone

Five patients at risk for primary central nervous system lymphoma (PCNSL) recurrence were treated with high-dose methylprednisolone (HDMP) to prevent 'trafficking' of malignant lymphocytes into the central nervous system (CNS). HDMP was chosen because of its ability to stabilize the 'blood brain barrier (BBB)'. Three men with newly diagnosed PCNSL, ages 62, 76 and 78y, whose survival was projected to be 6.6 months, began treatment after achieving complete response (CR) to initial radiation therapy alone and survived 27, 37 and 59 months after treatment. In none was death from recurrent disease in CNS but one patient did die of systemic non-Hodgkin's lymphoma (NHL) five years after PCNSL diagnosis. A 20 y old man was treated with HDMP after successful combined modality therapy and is alive 75+ months after initial diagnosis without evidence of disease recurrence. A 34 y old man relapsed after combined modality initial treatment and failed to respond to HDMP when treatment was begun after unsuccessful salvage therapy; he died of disease 12 months after initial diagnosis. There were no treatment complications. The promising results in this pilot study from the basis for a North Central Cancer Treatment Group (NCCTG) 96-73-51, a Phase 2 clinical trial of brain radiotherapy and HDMP for PCNSL patients 70y of age and older, a group of patients at high risk for toxicity from intensive combined modality therapy.

Microsatellite instability and 8p allelic imbalance in stage B2 and C colorectal cancers

BACKGROUND

Microsatellite instability (MSI) and allelic imbalance involving chromosome arms 5q, 8p, 17p, and 18q are genetic alterations commonly found in colorectal cancer. We investigated whether the presence or absence of these genetic alterations would allow stratification of patients with Astler-Coller stage B2 or C colorectal cancer into favorable and unfavorable prognostic groups.

METHODS

Tumors from 508 patients were evaluated for MSI and allelic imbalance by use of 11 microsatellite markers located on chromosome arms 5q, 8p, 15q, 17p, and 18q. Genetic alterations involving each of these markers were examined for associations with survival and disease recurrence. All P values are two-sided.

RESULTS

In univariate analyses, high MSI (MSI-H), i.e., MSI at 30% or more of the loci examined, was associated with improved survival (P =.02) and time to recurrence (P =.01). The group of patients whose tumors exhibited allelic imbalance at chromosome 8p had decreased survival (P =.02) and time to recurrence (P =.004). No statistically significant associations with survival or time to recurrence were observed for markers on chromosome arms 5q, 15q, 17p, or 18q. In multivariate analyses, MSI-H was an independent predictor of improved survival (hazard ratio [HR] = 0.51; 95% confidence interval [CI] = 0.31-0.82; P =.006) and time to recurrence (HR = 0.42; 95% CI = 0.24-0.74; P =.003), and 8p allelic imbalance was an independent predictor of decreased survival (HR = 1.89; 95% CI = 1.25-2.83; P =. 002) and time to recurrence (HR = 2.07; 95% CI = 1.32-3.25; P =.002).

CONCLUSIONS

Patients whose tumors exhibited MSI-H had a favorable prognosis, whereas those with 8p allelic imbalance had a poor prognosis; both alterations served as independent prognostic factors. To our knowledge, this is the first report of an association between 8p allelic imbalance and survival in patients with colorectal cancer.

Evaluation of the proliferative index as a prognostic factor in diffuse large cell lymphoma: correlation with the International Index

The reasons for differences in outcome between groups of patients with diffuse large cell lymphoma (DLCL) defined by clinical prognostic factors are largely unknown. Measures of cell proliferation may offer a biological explanation for these differences. This study tested the hypothesis that these survival differences between the groups defined by established prognostic factors were due to the proliferative index. The bromodeoxyuridine labeling index (LI), a measure of the S-phase fraction, was prospectively determined on fresh tumor specimens obtained at initial diagnosis in 80 patients with DLCL seen between 1986-1993 at a single institution. Patients were grouped using prognostic factors that were significant in a univariate analysis as well as the International Index (IPI). The LI in each of these groups was compared to determine whether the differences in outcome between the groups could be explained by differences in the LI. The median LI for all patients was 5.1% (range: 0.1-25%). When the predictive effect of the LI on response and survival was analyzed, the LI did not correlate with complete response or disease-free survival (DFS). There was a trend, however, for patients with a lower LI to have a poorer overall survival (p=0.06). When the patients were analyzed using the International Index (IPI), the mean LI for patients in the low-risk, low-intermediate, high-intermediate and high risk groups was 7.1%, 10.0%, 6.4% and 6.6% respectively (p=0.41). When analyzed separately, there was no significant difference in the LI for any of the patient groups defined by significant prognostic factors. The only difference in the LI was that the median LI in patients with T-cell DLCL was significantly lower than the LI in patients with B-cell DLCL (p=0.001) and these patients had an inferior complete response rate (p=0.001), disease-free survival (p=0.003) and overall survival (p=0.015). In this study, the LI, a measure of lymphoma cell proliferation, was not a significant prognostic factor for response, disease-free survival or overall survival. Furthermore, the LI did not explain the differences in outcome between patient groups defined by the IPI. However, a lower LI seen in patients with T-cell DLCL may account for their poorer response to therapy and inferior survival when compared to patients with B-cell DLCL.