Radiotherapy in Young, High-Risk Patients with Aggressive B-cell Lymphoma: Long-Term Results from the Open-Label, Randomized, Phase 3 R-MegaCHOEP Trial

PURPOSE/OBJECTIVE(S)

The role of consolidative radiotherapy (RT) for young (< 60 years), high-risk patients with aggressive B-cell lymphoma is discussed. The R-MegaCHOEP trial investigated the use of high-dose chemotherapy and rituximab with subsequent autologous stem cell transplantation compared to conventional R-CHOEP immunochemotherapy for patients up to 60 years1,2. Despite no prognostic difference between treatment arms even after 10-year follow-up, excellent long-term results were achieved. The presented work represents a detailed RT-analysis providing long-term data on efficacy and side-effects.

MATERIALS/METHODS

The 10-year follow-up dataset of the R-MegaCHOEP trial with a median follow-up of 81.1 months (range 0.6-175.9 months) was used for this analysis. Indications for consolidative RT were extralymphatic involvement or bulky disease (maximum diameter ≥ 7.5 cm). Additionally, RT could be administered because of insufficient response at end of therapy as evaluated by CT scan.

RESULTS

Overall, 261 patients were analyzed, 120 of whom underwent RT. Patients with RT were predominantly male (65.8 %), had an age-adjusted IPI of 2 (75 %), an elevated LDH (96.7 %) and showed an ECOG-Score of 0-1 (65 %). Bulky disease was present in 103/120 patients in the RT-arm with a bulk size of 7.5-20.0 cm (median: 11 cm) and was located predominantly in the mediastinal (44), paraaortal (17) and mesenteric (13) regions. The most frequently irradiated regions were the mediastinal (50), paraaortic (27) and mesenteric (15) regions. Median RT dose was 36 Gray in median fractions of 1.8 Gray. Toxicities were generally mild to moderate with 24 and 8 grade 3 and 4 toxicities reported during RT. During long-term follow-up, 23 secondary malignancies occurred, with RT being no significant contributing risk factor (p = 0.188). Analysis of the overall study population showed that patients with RT had an improved event-free survival (EFS; 63.9 % vs. 46.0 %; p<0.001) and progression-free survival (PFS; 67.2 % vs. 54.1 %; p = 0.025) but not overall survival (OS; 72.8 % vs. 65.9 %; p = 0.132) in comparison to non-irradiated patients after 10 years. Considering only those patients with RT after a complete remission/unconfirmed complete remission after systemic therapy, a significantly improved EFS (66.4 % vs. 46.0 %; p = 0.006), but not PFS and OS, was shown (PFS: p = 0.054; OS: p = 0.222). For patients with bulky disease, RT resulted in a significantly better outcome (10-year EFS: 64.4 % vs. 34.5 %; p<0.001; 10-year PFS: 68.3 % vs. 47.4 %; p = 0.003; 10-year OS: 71.5 % vs. 59.4 %; p = 0.011), when compared to patients without RT. For patients with extralymphatic involvement, RT improved EFS (10-year EFS: 61.7 % vs. 51.1 %; p = 0.017), but not PFS or OS (PFS: p = 0.068; OS: p = 0.305).

CONCLUSION

RT improved outcome in young, high-risk patients with aggressive B-cell lymphoma and bulky disease.

TRIAL REGISTRATION NUMBER

NCT00129090.

LITERATURE

1 Lancet Oncol 2012;13(12):1250-1259. 2 Lancet Haematol 2021;8(4):e267-e277.

Mature T-/NK-cell lymphomas: Prognostic factors and treatment outcome of patients treated on studies of the German High-Grade Lymphoma Study Group (DSHNHL)

8564

Background: T-cell lymphomas represent a heterogeneous group of malignancies difficult to diagnose and to treat. We evaluated patients (pts) diagnosed according to WHO standards and treated on prospective studies of the DSHNHL. Chemotherapy regimens (CHOP-14 and CHOEP) had significantly improved outcomes of patients with aggressive B-NHL. Methods: Between 1993 and 2006 we treated 329 pts with ALK-positive ALCL (73 pts), ALK-negative ALCL (108 pts), PTCL, NOS (68 pts), AITL (28 pts), NK-/T-cell lymphoma (18 pts), and rare T-cell lymphomas on prospective studies. All pts received CHOP ± etoposide (E) every 2 or 3 weeks; in pts <=60 yrs C, H, and E were escalated to further improve outcomes. Results: The majority of pts with ALK-positive ALCL presented with IPI 0, 1 (62%) or IPI 2 (26%) and had an excellent overall survival (OS) of 89 % and event-free survival (EFS) of 75% at 3 yrs. E significantly improved TTTF for pts <=60 yrs (p=0.007). Pts with other histologies did significantly worse (OS 58%, EFS 44 % at 3 yrs). The IPI discriminated between pts with a favorable (IPI 0, 1: OS 73%), moderate (IPI 2: OS 55%), and poor prognosis (IPI 3: OS 35%; IPI 4, 5: OS 19%) at 3 yrs. OS, EFS were significantly better for ALK-positive ALCL but did not significantly differ for pts in other histological subgroups. Neither shortening of the treatment interval (CHOP-14) nor the addition of E (CHOEP-21 or -14) significantly improved outcome of elderly pts. In younger pts (ALK-positive ALCL were excluded) and good-risk disease (LDH <= N) there was a trend for better EFS after the addition of E to CHOP (EFS 63% vs. 48%, p = 0.065). The MegaCHOEP protocol (Schmitz et al., CANCER 2006) failed to improve treatment results for younger pts with poor-risk disease (EFS at 3 yrs: 25.9%, 95% CI: 10.4–41.4); the prospective study comparing MegaCHOEP with CHOEP-14 was stopped for pts with T-cell lymphoma. Conclusions: CHO(E)P results in excellent OS of pts with ALK-positive ALCL and selected pts with other histologies and low IPI. All other pts did poorly; CHOP-14 or the addition of E failed to significantly improve outcomes. Notably, also the MegaCHOEP protocol characterized by repetitive high-dose therapy and ASCT did not result in significant improvement.

No significant financial relationships to disclose.

Reduced-intensity conditioning prior to allogeneic transplantation of hematopoietic stem cells: the need for T cells early after transplantation to induce a graft-versus-lymphoma effect

In patients with poor-risk relapse of aggressive lymphoma, reduced-intensity conditioning followed by allogeneic PBSCT may have its limitations because of rapid regrowth of the tumor. We tried to address this problem by intermediate-intensity conditioning followed by allogeneic SCT. A total of 21 patients received fludarabine, busulfan and cyclophosphamide prior to allogeneic SCT. In the first 10 patients, GVHD prophylaxis by CD34+ selection of the grafts was employed (group I). The next 11 patients received nonmanipulated grafts and mycophenolat mofetil plus cyclosporinA (group II). In group I, no GVHD was observed. In contrast, patients in group II had a significant risk of acute GVHD (aGVHD) (six patients with grade II-IV acute GVHD). However, in group I, all surviving patients progressed within 9 months. In contrast, eight of nine surviving patients of group II remain in remission after a median observation time of 10.5 months (range 4-22 months). Survival differed significantly between the groups (P=0.004). Multivariate analysis identified intensive GVHD prophylaxis as important risk factor for survival. These results support the existence of a clinically relevant GVL effect in aggressive lymphoma. T-cell depletion (or CD34 selection) of grafts is not recommended in patients with poor-risk aggressive NHL.

Which compartments are involved in Philadelphia-chromosome positive chronic myeloid leukaemia? An answer at the single cell level by combining May-Grünwald-Giemsa staining and fluorescence in situ hybridization techniques

Chronic myeloid leukaemia (CML) is believed to represent a stem cell disorder involving all three cell lineages. The typical chromosomal aberration, the Philadelphia chromosome, is the translocation (9;22)(q34;q11). Several studies with cytogenetics, fluorescence in situ hybridization (FISH), or polymerase chain reaction have investigated the presence of the t(9;22) in different cell compartments. However, questions still remain. In six cases of CML we combined the standard May-Grünwald-Giemsa staining with FISH at the single-cell level and were able to demonstrate that not only all maturation stages of granulopoiesis, erythropoiesis, and megakaryocytes, but also plasma cells, eosinophils, basophils and monocytes carried the Philadelphia chromosome in 53-98% of samples. Using immunological identification of single cells we were able to demonstrate that the t(9;22) is detectable in 34% of CD3-positive T lymphocytes, in 32% of CD19-positive B lymphocytes, and in 82% of CD34-positive precursor cells. The results give new insight into the biology of CML and may have implications for future therapeutic strategies.