Transformed follicular lymphoma in the rituximab era: A report from the Spanish Lymphoma Oncology Group

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma (NHL) subtype. The histological transformation (HT) of FL is an event considered frequent in the natural history of this tumor. We studied the transformation rates, predictive factors, and treatment characteristics that may impact in the survival of patients with FL and HT. A total of 1074 patients diagnosed with FL were prospectively enrolled from 1990 to 2016 in a Spanish registry. Sixty-four HTs were recorded based on clinical criteria (55%) or histological confirmation (45%). The cumulative incidence rate of transformation at 5 years is 7.3%. The 5-year overall survival (OS) without HT was 85% (95% confidence interval [CI], 70%-90%) vs 66% (95% CI, 51%-76%; P = 0.0012) with HT. Factors associated with HT were elevated lactate dehydrogenase (LDH) (odds ratio [OR] 1.83), intermediate-high Follicular lymphoma international prognostic index (FLIPI) (OR 2.16-OR 3.21), B symptoms (OR 2.46), or Eastern Cooperative Oncology Group (ECOG) 1 (OR 2.35). Treatment options related to HT were "watch and wait" or no rituximab or anthracyclines initially. A 5-year OS for patients treated with chemotherapy before HT was 55% (95% CI, 38%-69%) versus 81% (95% CI, 53%-93%; P = 0.009) for those who had not received it. The HT rate has decreased after the introduction of rituximab, as has been previously described. The timing of this treatment had an impact on the survival of these patients.

Advanced-stage follicular lymphoma in the rituximab era: when should patients receive anthracycline-based chemotherapy?

Follicular lymphoma (FL), the most common subtype of indolent lymphoma, is usually diagnosed at an advanced stage (III-IV), although patients are often asymptomatic. Traditionally, a palliative approach to management has been taken, cycling through watchful waiting, radiotherapy, oral alkylating agents and, eventually, combination chemotherapy, as deemed necessary. However, accumulating evidence suggests that in patients requiring treatment, early initiation of an anthracycline-based regimen may achieve better response rates and progression-free survival compared with reserving such options until late in the course of disease. Delivery of myelosuppressive chemotherapy has been facilitated by the availability of granulocyte colony-stimulating factors. Incorporation of the anti-CD20 monoclonal antibody rituximab into upfront chemotherapy regimens further improves outcomes. With a trend towards early use of rituximab chemotherapy combinations, median survival appears to have increased in patients with FL. A number of issues remain to be addressed by ongoing research. These include identification of the most effective rituximab chemotherapy regimen, the impact of treatment on responsiveness to future treatment, the need for rituximab maintenance therapy and the place of newer treatments. Clearly, there are arguments in favour of considering early aggressive rituximab and chemotherapy regimens in patients with FL requiring treatment, and it is hoped that new prognostic tools will help us to more accurately identify which patients are most likely to benefit.

Phase II trial of short-course CHOP-R followed by 90Y-ibritumomab tiuxetan and extended rituximab in previously untreated follicular lymphoma

PURPOSE

Radioimmunotherapy has been approved for relapsed follicular lymphoma (FL), including rituximab-refractory FL. This study was designed to determine the CR rate with short-course chemoimmunotherapy with cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (CHOP-R) followed by 90-Y ibritumomab tiuxetan (RIT) with extended rituximab as first-line treatment.

EXPERIMENTAL DESIGN

Between March 2004 and February 2007, 60 patients with stage II to IV symptomatic or bulky FL from a single institution supported by a large community network entered this phase II trial. Patients received CHOP-R for three treatment cycles before RIT followed by four additional weekly treatments with rituximab. Response was determined using fusion [(18) F] fluorodeoxyglucose-positron emission tomography (PET)-computed tomography (CT) imaging.

RESULTS

Of the 60 patients entering this trial, 55 patients completed all protocol therapy. The median follow up was 19.7 months (range, 0.26-35.9 months). For intent-to-treat analysis, the complete response (CR) rate after CHOP-R, as assessed by CT and PET imaging, was 40% and 46%, respectively. After RIT, the CR rate improved, as assessed by CT and PET imaging, to 82% and 89%, respectively. Ten patients have progressed, including eight from best response of CR. Seven of 18 patients who were PET positive after CHOP-R progressed compared with 3 of 37 patients who were PET negative (P=0.010).

CONCLUSIONS

In patients with previously untreated, symptomatic or bulky FL, short-course chemoimmunotherapy and consolidation RIT and extended rituximab resulted in a high CR rate. Failure to achieve an early PET CR after CHOP-R indicated high risk of relapse.

Risk and Clinical Implications of Transformation of Follicular Lymphoma to Diffuse Large B-Cell Lymphoma

Purpose

To study the clinical significance of transformation to diffuse large B-cell lymphoma (DLBCL) in patients with follicular lymphoma (FL).

Patients and Methods

From 1972 to 1999, 325 patients were diagnosed with FL at St Bartholomew's Hospital (London, United Kingdom). With a median follow-up of 15 years, progression occurred in 186 patients and biopsy-proven transformation in 88 of the 325. The overall repeat biopsy rate was 70%.

Results

The risk of histologic transformation (HT) by 10 years was 28%, HT not yet having been observed after 16.2 years. The risk was higher in patients with advanced stage (P = .02), high-risk Follicular Lymphoma International Prognostic Index (FLIPI; P = .01), and International Prognostic Index (IPI; P = .04) scores at diagnosis. Expectant management (as opposed to treatment being initiated at diagnosis) also predicted for a higher risk of HT (P = .008). Older age (P = .005), low hemoglobin level (P = .03), high lactate dehydrogenase (P < .0001), and high-risk FLIPI (P = .01) or IPI (P = .003) score at the time of first recurrence were associated with the diagnosis of HT in a biopsy performed at that time. The median survival from transformation was 1.2 years. Patients with HT had a shorter overall survival (P < .0001) and a shorter survival from progression (P < .0001) than did those in whom it was not diagnosed.

Conclusion

Advanced stage and high-risk FLIPI and IPI scores at diagnosis correlate with an increased risk of HT. This event strongly influences the outcome of patients with FL by shortening their survival. There may be a subgroup of patients in whom HT does not occur.