New approaches to the treatment of follicular lymphoma

Identification of cytogenetic subgroups and karyotypic pathways of clonal evolution in follicular lymphomas

Follicular lymphoma (FL) is characterized by the activation of BCL2 through t(14;18)(q32;q21). Additional acquired mutations are necessary to generate a fully malignant clonal proliferation. Many of these secondary genetic alterations are visible in the clonal karyotype; however, the sequence by which they arise and their influence on clinical behavior have not been determined. The ability to address these issues has been hampered by the lack of computational methods to manipulate complex chromosomal data in a sufficiently large cohort of cases. In the present investigation, we analyzed secondary karyotypic alterations in 336 cases of FL with t(14;18) to identify the most common regions of recurrent chromosomal gain or loss. This revealed 29 recurrent changes present in more than 5% of the tumors. Each tumor karyotype was then assessed for the presence or absence of each of these 29 specific changes. By statistical means, we show that the chromosomal changes arise in an apparent temporal order, with distinct early and late changes. We identify, by principal-components analysis, four possible cytogenetic pathways that characterize the early stages of clonal evolution, which converge to a common route at later stages. We show that FLs with t(14;18) may be classified into cytogenetic subgroups determined by the presence or absence of 6q-, +7, or der(18)t(14;18). Correlation with clinical outcomes in a subset of cases with clinical data revealed del(17p) and +12 to be correlated with an adverse clinical outcome. The clinical implications of these pathways of clonal evolution need to be examined on a prospective basis in a large cohort of FLs.

Multicolour fluorescence in situ hybridization analysis of t(14;18)-positive follicular lymphoma and correlation with gene expression data and clinical outcome

In order fully to identify secondary chromosomal alterations, such as duplications, additions and marker chromosomes that remained unresolved by G banding, 60 cases of t(14;18)-positive follicular lymphoma (FL) were analysed by multicolour karyotyping techniques [multicolour fluorescence in situ hybridization (MFISH)/multicolour banding for chromosome 1 (MBAND1)]. A total of 165 additional structural chromosomal aberrations were delineated. An increased frequency of chromosomal gains involving X, 1q, 2, 3q27-q29, 5, 6p11-p21, 7, 8, 11, 12, 14q32, 17q, 18 and 21 and deletions of 1p36, 3q28-q29, 6q, 10q22-q24 and 17p11-p13 was revealed by the MFISH/MBAND1 analysis. Balanced translocations other than t(14;18) were uncommon, whereas unbalanced translocations were numerous. Deletion of 1p36 and duplication of 1p33-p35, 1p12-p21 and 1q21-q41 were regularly involved in chromosome 1 alterations, seen in 53% of the cases. A strong correlation was demonstrated between gains of individual chromosomal bands and increased gene expression, including 1q22/MNDA, 6p21/CDKN1A, 12q13-q14/SAS, 17q23/ZNF161, 18q21/BCL2 and Xq13/IL2RG. Unfavourable overall survival was associated with del(1)(p36) and dup(18q). These data support the notion that translocation events are primarily responsible for FL disease initiation, whereas the unbalanced chromosomal gains and losses that mirror the gene expression patterns characterize clonal evolution and disease progression, and thus provide further insights into the biology of FL.

High response rates and lasting remissions after low-dose involved field radiotherapy in indolent lymphomas

PURPOSE

To study the response rates and duration of response after low-dose (4 Gy) involved field radiotherapy (LD-IF-RT) in patients with recurrent indolent lymphoma.

PATIENTS AND METHODS

A total of 109 assessable patients (304 symptomatic sites) were irradiated (53 males and 56 females; median age, 62 years; range, 35 to 93), including 98 patients with follicular lymphoma (43 grade 1 and 55 grade 2), nine extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue-type and two patients with lymphoplasmacytoid lymphoma. Bulky disease (> or =5 cm) was present in 52% of all patients. A median of two prior regimens (range, 0 to 11) preceded LD-IF-RT. The median time since diagnosis was 41 months (range, 2 to 358 months). Time to (local) progression was calculated according to the Kaplan-Meier method. Differences in response rates between treatments within the same patient were compared using the McNemar test.

RESULTS

The overall response rate was 92%; complete response was reached in 67 patients (61%), partial response in 34 patients (31%), stable disease in six patients (6%), and progressive disease in two patients (2%). The median time to progression was 14 months. The median time to local progression was 25 months. The 67 patients with complete response showed a median time to progression of 25 months and a median time to local progression of 42 months. None of the factors studied (age, sex, follicular lymphoma grade, radiotherapy regimen, number of previous regimens and previous history, number of positive sites or largest lymphoma diameter) were found to be related to response rate.

CONCLUSION

LD-IF-RT is a valuable asset in the management of patients with follicular lymphoma and should be considered in patients with recurrent disease.

Successful treatment of gastrointestinal follicular lymphoma with rituxan and combination chemotherapy

The clinical course of follicular lymphoma (FL) is well known. Although it is a chemosensitive disease, thereby allowing substantial palliation, recurrence is the rule; only a small subset who presents with limited stage disease is cured. Multiple attempts have been made over the past two decades to improve the survival of patients with FL, and a large number of phase III trials have been reported. These have included a variety of different therapeutic interventions, such as combination chemotherapy, recombinant interferons, new cytotoxic drugs, and immunologic agents. Most studies have not demonstrated that the use of a particular therapy convincingly prolongs survival. Follicular lymphoma cells express CD20 and are associated in most cases with the t(14:18) chromosomal translocation. Rituximab is a chimeric monoclonal antibody directed against the B-cell CD20 antigen, which has been utilized for the therapy of B-cell non-Hodgkin's lymphoma. Rituximab was shown to be active in FL, and studies of its effectiveness in combination with cytotoxic chemotherapy to increase the response rate are forthcoming.

Analysis of secondary chromosomal alterations in 165 cases of follicular lymphoma with t(14;18)

Follicular lymphoma is characterized by the t(14;18) in up to 85% of cases. Almost all cases display evidence of secondary chromosomal alterations at initial diagnosis. The influence of recurrent secondary changes on disease progression has not been fully determined. The purpose of this study was to define the full spectrum of recurrent karyotypic events present at diagnosis in a large cohort of cases and to evaluate the sequence of cytogenetic evolution in relation to morphologic progression. A total of 165 cases of follicular lymphoma with t(14;18) were ascertained for which complete clinical information, histopathology, immunophenotype, and karyotype were available. One hundred sixty cases showed secondary alterations with an average of 7.9 additional changes per case. Recurrent alterations seen at the 10% or greater level included +X, +1q21-q44, +7, +12q, +18q, del(1)(p36), del(6q), del(10)(q22-q24), the development of polyploidy and sidelines, and the presence of extra marker chromosomes and chromosomal additions. Changes that correlated with morphologic progression included del(1)(p36), del(6q), del(10)(q22-q24), +7, the total number of abnormalities, the number of markers and additions, and the presence of polyploidy. The most frequent second event arising after the t(14;18) was duplication of the der(18)t(14;18). This study demonstrates that the number and type of secondary chromosomal alterations in follicular lymphoma is highly variable between cases, but that a relatively small number of changes are seen repeatedly in different combinations. A consistent pattern of cytogenetic evolution could not be identified. Potentially significant gene duplications or amplifications may be disguised within marker chromosomes and additions. Additional cytogenetic investigation is required to decipher the karyotypic complexity associated with the progression of follicular lymphoma.

Follicular lymphomas--a review of treatment modalities

Follicular lymphoma is the most common low-grade non Hodgkin's lymphoma and represent an homogeneous entity as defined by pathological, molecular and clinical data. This indolent disease is characterised by a slow growth pattern with possible spontaneous regression, is often disseminated but remains incurable with available treatments when disseminated. For localised stages, involved field radiotherapy remains the standard choice but other approaches remain to be investigated. In advanced disease, chemotherapy has been demonstrated to produce high response rates but recent trials with new treatment strategies including interferon and monoclonal antibodies may improve the current situation. In this article, we will review treatment of follicular lymphomas, specially emphasising published phase III trials.

Salvage extended-field irradiation in follicular non-Hodgkin's lymphoma after failure of chemotherapy

PURPOSE

To evaluate the efficacy of total abdominopelvic (TAI) and total body irradiation (TBI) in heavily pretreated follicular non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

From 1983 to 1998, 34 patients received TAI (n = 22) or TBI (n = 12). All had Stage III or IV, Class B, C, D NHL in the working formulation and failed after receiving 1-5 regimens of chemotherapy. TAI was given at 20 Gy over a 3-week period. TBI was delivered in two successive half-body irradiations of 15 Gy over a 2-week period with a 4-week interval between each.

RESULTS

Mean follow-up from TAI or TBI was 120 months (range, 6-180). Seventy-six percent of patients achieved complete response and 24% partial response. Median survival was 62 months, 5-year and 10-year overall survival was 59% and 41%, and disease-free survival was 56% and 30%, respectively. Grade III or IV toxicity was gastrointestinal in 38% of patients and hematologic in 30%. No toxic death or delayed complications were observed.

CONCLUSION

Extended-field irradiation is feasible and efficient after failure of chemotherapy in follicular NHL.

Mantle cell lymphoma in the Chinese: clinicopathological features and treatment outcome

We report the clinical, molecular, and immunohistological findings of 20 Chinese patients with mantle cell lymphoma diagnosed over a 10-year period. The disease affected mainly elderly patients (median age, 65.5 years) with a male predominance (M/F, 3/1). Eighty percent presented with advanced stage III/IV disease but only 25% had B symptoms. Eighty-five percent had extranodal disease at presentation. Complete remission (CR) and partial remission (PR) were achieved in 45% and 40% of the patients, respectively. There was no difference in the CR rate for patients treated with anthracycline-containing or nonanthracycline-containing regimens (43% and 50%, P = 0.67). Disease progression or relapse was observed after a median of 26 months in patients who initially responded to treatment. Extranodal relapse occurred in the central nervous system (n = 1), bone marrow (n = 1), pleura (n = 2), orbit (n = 2), and the gastrointestinal tract (n = 3). The median overall survival (OS) was 52 months but there were no long-term survivors. This was not different from the median OS of 53 months of patients with diffuse large cell (DLC) lymphoma treated in the same center over the same period (log rank, P = 0.76). Of the 12 patients who were tested for bcl-1 rearrangement by polymerase chain reaction (PCR), five (42%) were positive for rearrangement in the major translocation cluster (MTC) region. The median OS rates were 45 months and 63 months for PCR positive and negative patients, respectively (P = 0.97). In conclusion, MCL is a disease mainly of the elderly in the Chinese with a male predominance and most had advanced-stage disease and extranodal involvement at presentation. Clinicopathologic features and treatment outcome were similar to Caucasian patients, in that the disease combined the aggressive nature of DLC lymphoma and the incurability of low-grade lymphoma.

Long-term results of total abdominopelvic irradiation in non-Hodgkin's lymphomas after failure of chemotherapy

PURPOSE

To evaluate the therapeutic efficacy of moderate-dose total abdominopelvic irradiation (TAI) in a retrospective series of pretreated non-Hodgkin's lymphomas (NHL).

METHODS AND MATERIALS

From 1977 to 1994, 45 patients received TAI after failure of chemotherapy (CT). According to the Working Formulation, 10 patients were diagnosed with class A (group I), 19 with class B, C, or D (follicular) (group II), and 16 with class E or more severe (group III) NHL. Irradiation consisted of two daily fractions of 0.80 Gy each for a total dose of 20 Gy.

RESULTS

Mean follow-up after TAI was 102 months (range 8-156). For the entire group, the complete response (CR) rate was 66%, the partial response (PR) rate 29%, 10-year overall survival (OS) 35%, 10-year disease-free survival (DFS) 29%, and median survival 32 months. When results between subgroups were compared, CR was 70% in group I, 84% in group II, and 44% in group III; and survival was statistically higher in group II than in groups I and III: 10-year OS 52% vs. 10% (p < 0.01) and 31% (p < 0.05), respectively, 10-year DFS 37% vs. 10% (p < 0.03) and 19% (p < 0.05), respectively. Grade III or IV complications were gastrointestinal in 27% of patients and hematologic in 25%.

CONCLUSION

Large-field irradiation in moderate doses could provide an alternative to bone marrow transplantation in refractory NHL, especially in cases showing a follicular growth pattern.

Autologous stem cell transplants in lymphomas

Hodgkin's disease and non-Hodgkin's lymphomas can be treated and, in a large number of cases, cured by first-line chemotherapy or radiotherapy. Unlike many other malignancies, relapse is not uniformly fatal but the treatment is usually markedly myelotoxic with the high doses of chemotherapy used in relapse. Haematopoietic reconstitution with either autologous marrow or peripheral stem cells postchemotherapy has made high-dose chemotherapy relatively safe with mortality rates as low as 2% in some centres. The clinical indications for high-dose therapy in lymphoma management for patients with relapsed and bad prognosis disease are reviewed. The advantages of autologous bone marrow and peripheral stem cell transplants are compared and current peripheral stem cell mobilization and harvesting practice is discussed.

Current status and future perspectives in the treatment of low-grade non-Hodgkin's lymphomas

Low-grade non-Hodgkin lymphomas (NHL) comprise a heterogeneous group of disorders both in terms of their cellular and histological composition as well as in terms of their clinical course. The most usually applied classification systems, the Working Formulation and the Kiel classification as well as the recently proposed Revised European American Lymphoma classification, discriminate between low-, intermediate- and high-grade subtypes. In general, low-grade NHL are characterized by a low to moderate proliferative activity and a long clinical course with median survival times ranging from approximately 3 years for centrocytic (CC) or mantle-cell lymphomas (MCL) to 5-8 years for centroblastic-centrocytic (CB-CC) or follicular lymphomas (FL). Recent cytogenetic and molecular biologic analyses indicate that these differences may result from distinct genetic abnormalities such as the translocation t(14;18), which is frequently observed in FL-NHL and is associated with a bcl-2 overexpression and inhibition of apoptosis, or the deregulation of PRAD1 in MCL-NHL induced by the translocation t(11;14). Therapy of low-grade lymphomas depends mainly on the extent of the disease. In the early stages I and II, at which approximately 15 to 20% of low-grade NHL are diagnosed, radiotherapy may be applied with curative intention. The treatment of patients with more advanced stages III and IV is controversial. The currently available information justifies a conservative approach of observing the natural course of the disease until therapeutic intervention is required due to the occurrence of B-symptoms, hematopoietic insufficiency or lymphoma progression.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Use of Interferon Alpha-2, Chlorambucil and Prednisone in Previously Treated Patients with Low-Grade Non-Hodgkin's Lymphomas. Results of a Phase II Study

Aims and Background

To investigate therapeutic activity and safety of alpha-interferon (alpha-IFN) in combination with chlorambucil (CLB) and prednisone (PDN), we treated 9 low-grade non-Hodgkin lymphoma patients with clinical evidence of relapsed (5 cases) or resistant (4 cases) disease with such an association.

Methods

In all instances, treatment consisted of alpha-2a IFN administered by subcutaneous route thrice weekly for 3 weeks, CLB, 5 mg/day for 21 days, and PDN, 30 mg three times a week for 3 weeks. Cycles were repeated every 28 days.

Results

A well-documented clinical response was observed in 6 (4 CRs+2 PRs) of 9 patients. Interestingly, 3 of 4 CRs were achieved in patients with histologically proven bone marrow involvement. Median duration of response was 18.5 months (range, 4-29 months). Myelosuppression was a common side effect. Two patients experienced grade 3 hematologic toxicity which did not preclude continuation of therapy.

Conclusions

As new purine analogues are not currently available, the combination of alpha-IFN, CLB, and PDN may represent, in our opinion, a valid therapy for patients not eligible for aggressive therapy such as autologous bone marrow transplantation.