Marrow-ablative treatment and autologous stem cell transplantation in follicular NHL

What is the best first-line treatment strategy for patients with indolent lymphomas?

Although advanced follicular lymphoma is considered incurable, patient outcomes have improved over the last decade with the use of anti-CD20 monoclonal antibodies. Multiple treatment options are available and their use depends on clinical presentation (i.e., Ann Arbor stage, tumor burden, symptoms) and patient condition and age. Radiation therapy for patients with limited stage disease remains useful, although its use in the era of anti-CD20 antibodies should be re-evaluated. Single-agent rituximab has been tested in multiple studies with patients with low tumor burden. Short treatment duration provides a response lasting 2 to 3 years, although the benefit of maintenance therapy with rituximab after induction therapy with rituximab remains unproven. When watchful waiting is not an option, a combination of rituximab with chemotherapy is the standard of care: alkylating agents with anthracycline or bendamustine appear to be the most widely used regimens, but alkylating agents alone may still be used in selected patients subgroups. The toxicity of regimens containing fludarabine appears to limit their indication as first-line treatment. In patients responding to one of these combinations, consolidation therapy with rituximab maintenance has been shown to prolong progression-free survival with acceptable toxicity. The benefit of radioimmunotherapy in first-line treatment is still uncertain. With patients surviving for many years, the therapeutic strategy of first-line management should weigh the quality and duration of response against the risk of long-term toxicities.

The use of anthracycline at first-line compared to alkylating agents or nucleoside analogs improves the outcome of salvage treatments after relapse in follicular lymphoma The REFOLL study by the Fondazione Italiana Linfomi

Follicular lymphoma (FL) patients experience multiple remissions and relapses and commonly receive multiple treatment lines. A crucial question is whether anthracyclines should be used at first-line or whether they would be better "reserved" for relapse and whether FL outcome can be optimized by definite sequences of treatments. Randomized trials can be hardly designed to address this question. In this retrospective multi-institutional study, time-to-next-treatment after first relapse was analyzed in 510 patients who had received either alkylating agents- or anthracycline- or nucleoside analogs-based chemotherapy with/without rituximab at first-line and different second-line therapies. After a median of 42 months, median time-to-next-treatment after relapse was 41 months (CI95%:34-47 months). After adjustment for covariates, first-line anthracycline-based chemotherapy with/without rituximab was associated with better time-to-next-treatment after any salvage than alkylating agents-based chemotherapy with/without rituximab or nucleoside analogs-based chemotherapy with/without rituximab (HR:0.74, P = 0.027). The addition of rituximab to first-line chemotherapy had no significant impact (HR:1.22, P = 0.140). Autologs stem cell transplantation performed better than any other salvage treatment (HR:0.53, P < 0.001). First-line anthracycline-based chemotherapy significantly improved time-to-next-treatment even in patients receiving salvage autologs stem cell transplantation (P = 0.041). This study supports the concept that in FL previous treatments significantly impact on the outcome of subsequent therapies. The outcome of second-line treatments, either with salvage chemoimmunotherapy or with autologs stem cell transplantation, was better when an anthracycline-containing regimen was used at first-line.

PET/CT before autologous stem cell transplantation predicts outcome in refractory/relapsed follicular lymphoma

PURPOSE

Salvage of young patients with follicular lymphoma (FL) after R-CHOP includes salvage immunochemotherapy followed by autologous stem cell transplantation (ASCT). Previous studies dealing with relapsed Hodgkin lymphoma have shown the prognostic value of PET/CT prior to ASCT.

METHODS

We retrospectively analysed 59 patients with refractory/relapsed FL after first-line R-CHOP who were chemosensitive (as evaluated by CT) to the salvage treatment and who proceeded to ASCT. The role of PET/CT in this setting to define chemosensitivity is not definitely established. So we focused on the prognostic value of PET/CT performed after salvage treatment, before ASCT.

RESULTS

The estimated 3-year progression-free survival (PFS) and overall survival were 63.1% (50.9-78.3%) and 90.5% (82.8 - 98.8%), respectively, and did not differ significantly according to their Follicular Lymphoma International Prognostic Index at relapse, conditioning regimen, or type of salvage. PFS was significantly lower in PET/CT-positive patients, according to the International Harmonization Project revised response criteria, with a 3-year PFS of 45.5% (26.6 - 77.8%) versus 72.6% (58.5 - 90.0%; p = 0.039). To better refine prognosis, we applied two types of throsholds: a Deauville five-point scale positive threshold of ≥3 (3-year PFS of 74.9%, range 61.0 - 92.1% %, versus 42.8%, range 24.7 - 74.4%; p = 0.02), and a ≥70% ∆SUVmax threshold between presalvage and pre-ASCT PET/CT (3-year PFS of 72.4%, range 57.5 - 91.3% versus 13.3%, 2.2 - 81.7%; p < 10(-3)). The PET/CT findings before ASCT were independently correlated with PFS in our series.

CONCLUSION

PET/CT negativity before ASCT is a desirable and achievable goal in the management of chemosensitive FL relapsing after first-line R-CHOP.

Indications for hematopoietic stem cell transplantation in patients with follicular lymphoma: a consensus project of the EBMT-Lymphoma Working Party

The aim of this project was to define indications for hematopoietic stem cell transplantation in follicular lymphoma in Europe. In the absence of evidence-based data, a RAND-modified Delphi procedure was used by an expert panel. After pre-defining statements, these were individually/anonymously scored by each participant using a 9-point scale. Consensus was reached that: 1) high-dose therapy with autologous stem cell rescue is not an appropriate option to consolidate first remission in patients responding to immuno-chemotherapy outside clinical trials; 2) in patients with first chemo-sensitive relapse, high-dose therapy with autologous stem cell rescue is an appropriate option to consolidate remission, especially in patients with a short response after immuno-chemotherapy or with high-risk FLIPI; 3) high-dose therapy with autologous stem cell rescue is also appropriate in second/subsequent chemo-sensitive relapses; 4) allotransplant (preferably a reduced intensity conditioning-allotransplant) should be considered at relapse after high-dose therapy with autologous stem cell rescue. No consensus was reached on the role of high-dose therapy with autologous stem cell rescue in low-risk first relapse, or on when an allotransplant should be preferred over high-dose therapy with autologous stem cell rescue. In the absence of evidence-based data, the consensus method used was a valuable tool to define indications for hematopoietic stem cell transplant in follicular lymphoma.

Autologous stem cell transplantation for follicular lymphoma is of most benefit early in the disease course and can result in durable remissions, irrespective of prior rituximab exposure

The role of autologous stem cell transplantation (ASCT) and the optimal timing of such transplants in patients with follicular lymphoma (FL) remains contentious. We present a single-centre experience documenting the outcomes of 70 FL patients who underwent BEAM (carmustine, cytarabine, etopside, melphalan)-conditioned ASCT between 1988 and 2009. With a median follow-up of 6·8 years (0·1-19·2), the 7-year overall survival (OS) and progression-free survival (PFS) from the date of ASCT was 76% and 60%, respectively. A significant difference in OS was found when comparing the patients transplanted in first or second remission versus those transplanted in later remissions (P = 0·02) and this significance was maintained when OS was calculated from the date of diagnosis (P = 0·03). There was a plateau on the PFS curves for patients transplanted in either first or second remissions after 9·3 and 6·4 years respectively, suggesting that these groups may never relapse. No differences were seen in OS or PFS in those treated with rituximab prior to transplant versus those who were not. Our data shows that BEAM ASCT can be a highly effective treatment in patients with FL early in the disease course, and that a proportion of patients experience prolonged disease-free survival and may be cured.

Mesenchymal stem cells, cancer challenges and new directions

Therapeutic use of multipotent mesenchymal stromal stem cells (MSC) is a promising venue for a large number of degenerative diseases and cancer. Their availability from many different adult tissues, ease of expansion in culture, the ability to avoid immune rejection and their homing ability, are some of the properties of MSCs that make them a great resource for therapy. However, the challenges and risks for cell-based therapies are multifaceted. The blessing of cell culture expansion also comes with a burden. During in vitro expansion, stem cells experience a long replicative history and therefore, become subjected to damage from intracellular and extracellular influences. As previously shown cells that are manipulated to obtain an expanded replicative potential are prone to spontaneous transformation in culture. These manipulations help bypass the naturally built-in controls of the cell that govern the delicate balance between cell proliferation, senescence and carcinogenesis. Because of this, there is a risk for patients receiving stem cells that are in vitro expanded. Whether these cells are genetically engineered or harbouring xenogenic compounds, they cannot truly be considered "safe" unless the cells are closely monitored. In the present communication, we will focus on the therapeutic potential of the human mesenchymal stem cells (hMSC) with special focus on their use in cancer therapy. We will consider different mechanisms, by which stem cells can maintain telomeres and thereby the cell's ability to be expanded in vitro, and also focus on a new therapeutic venue that utilises hMSCs as delivery vehicles in innovative new cancer treatments.

Current and future management of follicular lymphoma

Follicular lymphoma is usually considered as incurable, but patient's outcome has been steadily improving over the last decade. The introduction of anti-CD20 monoclonal antibodies represented a major step. Treatment of patients should take into account accurate staging results, symptoms related to lymphoma, tumor burden, age and comorbidities. Several options are still available for patients with localized or asymptomatic low risk disease, and randomized studies should be developed for those patients. When a systemic therapy is needed, the combination of rituximab with a few of the available cytotoxic regimens clearly provides the best results. Rituximab maintenance appears to further improve the progression-free interval. Since most patients will likely survive for many years, the quality and duration of response as well as the short- and long-term side effects of the treatments should be carefully weighted during this prolonged therapeutic management.