High dose chemotherapy with autologous stem cell transplant for patients with transformed B-cell non-Hodgkin lymphoma in the rituximab era

Evaluation and Management of Disease Transformation in Waldenström Macroglobulinemia

Histologic transformation (HT) to diffuse large B-cell lymphoma occurs rarely in Waldenström macroglobulinemia, with higher incidence in MYD88 wild-type patients. HT is suspected clinically when rapidly enlarging lymph nodes, elevated lactate dehydrogenase levels, or extranodal disease occur. Histologic assessment is required for diagnosis. HT carries a worse prognosis compared with nontransformed Waldenström macroglobulinemia. A validated prognostic score based on three adverse risk factors stratifies three risk groups. The most common frontline treatment is chemoimmunotherapy, such as R-CHOP. Central nervous system prophylaxis should be considered if feasible and consolidation with autologous transplant should be discussed in fit patients responding to chemoimmunotherapy.

Transformed Waldenström Macroglobulinemia: Update on Diagnosis, Prognosis and Treatment

Histological transformation (HT) to an aggressive lymphoma results from a rare evolution of Waldenström macroglobulinemia (WM). A higher incidence of transformation events has been reported in MYD88 wild-type WM patients. HT in WM can be histologically heterogeneous, although the diffuse large B-cell lymphoma of activated B-cell subtype is the predominant pathologic entity. The pathophysiology of HT is largely unknown. The clinical suspicion of HT is based on physical deterioration and the rapid enlargement of the lymph nodes in WM patients. Most transformed WM patients present with elevated serum lactate dehydrogenase (LDH) and extranodal disease. A histologic confirmation regarding the transformation to a higher-grade lymphoma is mandatory for the diagnosis of HT, and the choice of the biopsy site may be dictated by the findings of the 18fluorodeoxyglucose-positron emission tomography/computed tomography. The prognosis of HT in WM is unfavorable, with a significantly inferior outcome compared to WM patients without HT. A validated prognostic score based on 3 adverse risk factors (elevated LDH, platelet count < 100 × 109/L and any previous treatment for WM) stratifies patients into 3 risk groups. The most common initial treatment used is a chemo-immunotherapy (CIT), such as R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). The response duration is short and central nervous system relapses are frequent. Whether autologous stem cell transplantation could benefit fit patients responding to CIT remains to be studied.

Autologous stem cell transplantation for untreated transformed indolent B-cell lymphoma in first remission: an international, multi-centre propensity-score-matched study

High-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) are used as consolidation in first remission (CR1) in some centres for untreated, transformed indolent B-cell lymphoma (Tr-iNHL) but the evidence base is weak. A total of 319 patients with untreated Tr-iNHL meeting prespecified transplant eligibility criteria [age <75, LVEF ≥45%, no severe lung disease, CR by positron emission tomography or computed tomography ≥3 months after at least standard cyclophosphamide, doxorubicin, vincristine and prednisolone with rituximab (R-CHOP) intensity front-line chemotherapy] were retrospectively identified. Non-diffuse large B-cell lymphoma transformations were excluded. About 283 (89%) patients had follicular lymphoma, 30 (9%) marginal-zone lymphoma and six (2%) other subtypes. Forty-nine patients underwent HDC/ASCT in CR1, and a 1:2 propensity-score-matched cohort of 98 patients based on age, stage and high-grade B-cell lymphoma with MYC, BCL2 and/or BCL6 rearrangements (HGBL-DH) was generated. After a median follow-up of 3·7 (range 0·1-18·3) years, ASCT was associated with significantly superior progression-free survival [hazard ratio (HR) 0·51, 0·27-0·98; P = 0·043] with a trend towards inferior overall survival (OS; HR 2·36;0·87-6·42; P = 0·1) due to more deaths from progressive disease (8% vs. 4%). Forty (41%) patients experienced relapse in the non-ASCT cohort - 15 underwent HDC/ASCT with seven (47%) ongoing complete remission (CR); 10 chimeric antigen receptor-modified T-cell (CAR-T) therapy with 6 (60%) ongoing CR; 3 allogeneic SCT with 2 (67%) ongoing CR. Although ASCT in CR1 improves initial duration of disease control in untreated Tr-iNHL, the impact on OS is less clear with effective salvage therapies in this era of CAR-T.

Similar prognosis of transformed and de novo diffuse large B-cell lymphomas in patients treated with immunochemotherapy

BACKGROUND

The prognosis of diffuse large B-cell lymphomas (DLBCL) transformed from indolent lymphoma (TL) has been considered poorer than that of de novo DLBCL. However, it seems to have improved since the introduction of rituximab.

PATIENTS AND METHODS

We compared the characteristics (including the cell-of-origin), and the prognosis of 29 patients with TL and 101 with de novo DLBCL treated with immunochemotherapy.

RESULTS

Patients with TL and de novo DLBCL had similar characteristics. All TL cases evolving from follicular lymphoma were germinal-center B-cell-like, while those TL from marginal zone lymphoma or chronic lymphocytic leukemia were non-germinal-center B-cell-like. The complete response rate was similar in TL and de novo DLBCL (62 vs. 66%, P=.825). The 5-year overall and progression-free survival probabilities (95% CI) were 59% (40-78) and 41% (22-60) for TL and 63% (53-73) and 60% (50-70) for de novo DLBCL, respectively (P=.732 for overall survival and P=.169 for progression-free survival).

CONCLUSION

In this study, the prognosis of TL and de novo DLBCL treated with immunochemotherapy was similar. The role of intensification with stem cell transplantation in the management of TL may be questionable in the rituximab era.

Outcomes of transformed follicular lymphoma in the modern era: a report from the National LymphoCare Study (NLCS)

We assessed the incidence, prognostic features, and outcomes associated with transformation of follicular lymphoma (FL) among 2652 evaluable patients prospectively enrolled in the National LymphoCare Study. At a median follow-up of 6.8 years, 379/2652 (14.3%) patients transformed following the initial FL diagnosis, including 147 pathologically confirmed and 232 clinically suspected cases. Eastern Cancer Oncology Group performance status >1, extranodal sites >1, elevated lactate dehydrogenase, and B symptoms at diagnosis were associated with transformation risk. Relative to observation, patients initiating treatment at diagnosis had a reduced risk of transformation (hazard ratio [HR], 0.58; 95% confidence interval [CI], 0.46-0.75). The risk of transformation was similar in patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone compared with rituximab, cyclophosphamide, vincristine, and prednisone (adjusted HR, 0.94; 95% CI, 0.62-1.42). Maintenance rituximab was associated with reduced transformation risk (HR, 0.67; 95% CI, 0.46-0.97). Five-year survival from diagnosis was significantly worse for patients with vs without transformation (75%, 95% CI, 70-79 vs 85%, 95% CI, 83-86). The median overall survival post-transformation was 5 years. Forty-seven patients with evidence of transformation at the time of diagnosis shared similar prognostic factors and survival rates to those without transformation. Improved outcomes for transformation in the modern era are suggested by this observational study. This trial is registered at www.clinicaltrials.gov as #NCT00097565.