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.

SPARC-positive macrophages are the superior prognostic factor in the microenvironment of diffuse large B-cell lymphoma and independent of MYC rearrangement and double-/triple-hit status

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with respect to outcome. Features of the tumor microenvironment (TME) are associated with prognosis when assessed by gene expression profiling. However, it is uncertain whether assessment of the microenvironment can add prognostic information to the most relevant and clinically well-established molecular subgroups when analyzed by immunohistochemistry (IHC).

PATIENTS AND METHODS

We carried out a histopathologic analysis of biomarkers related to TME in a very large cohort (n = 455) of DLBCL treated in prospective trials and correlated with clinicopathologic and molecular data, including chromosomal rearrangements and gene expression profiles for cell-of-origin and TME.

RESULTS

The content of PD1+, FoxP3+ and CD8+, as well as vessel density, was not associated with outcome. However, we found a low content of CD68+ macrophages to be associated with inferior progression-free survival (PFS) and overall survival (OS; P = 0.023 and 0.040, respectively) at both univariable and multivariable analyses, adjusted for the factors of the International Prognostic Index (IPI), MYC break and BCL2/MYC and BCL6/MYC double-hit status. The subgroup of PDL1+ macrophages was not associated with survival. Instead, secreted protein acidic and cysteine rich (SPARC)-positive macrophages were identified as the subtype of macrophages most associated with survival. SPARC-positive macrophages and stromal cells directly correlated with favorable PFS and OS (both, P[log rank] <0.001, P[trend] < 0.001). The association of SPARC with prognosis was independent of the factors of the IPI, MYC double-/triple-hit status, Bcl2/c-myc double expression, cell-of-origin subtype and a recently published gene expression signature [lymphoma-associated macrophage interaction signature (LAMIS)].

CONCLUSIONS

SPARC expression in the TME detected by a single IHC staining with fair-to-good interobserver reproducibility is a powerful prognostic parameter. Thus SPARC expression is a strong candidate for risk assessment in DLBCL in daily practice.

Optimization of rituximab for the treatment of DLBCL (I): dose-dense rituximab in the DENSE-R-CHOP-14 trial of the DSHNHL

BACKGROUND

To improve outcome of elderly patients with diffuse large B-cell lymphoma, dose-dense rituximab was evaluated in the prospective DENSE-R-CHOP-14 trial.

PATIENTS AND METHODS

Rituximab (375 mg/m(2)) was given on days 0, 1, 4, 8, 15, 22, 29, 43, 57, 71, 85, and 99 together with six CHOP-14 cycles. Results were to be compared with patients who had received the same chemotherapy in combination with eight 2-week applications of rituximab in RICOVER-60.

RESULTS

One hundred twenty-four patients are assessable. Dose-dense rituximab resulted in considerably higher serum levels during the first 50 days of treatment, but rituximab exposure time was not prolonged. Grade 3 and 4 infections were exceptionally high in the first 20 patients without anti-infective prophylaxis, but decreased after introduction of prophylaxis with aciclovir and cotrimoxazole in the remaining 104 patients (from 13% to 6% per cycle and from 35% to 18% per patient; P = 0.007 and P = 0.125, respectively). Patients with international prognostic index = 3-5 had higher complete response/complete response unconfirmed rates (82% versus 68%; P = 0.033) than in the respective RICOVER-60 population, but this did not translate into better long-term outcome, even though male hazard was decreased (event-free survival: from 1.5 to 1.1; progression-free survival: from 1.7 to 1.1; overall survival: from 1.4 to 1.0).

CONCLUSIONS

Dose-dense rituximab achieved higher rituximab serum levels, but was not more effective than eight 2-week applications in the historical control population, even though minor improvements in poor-prognosis and male patients cannot be excluded. The increased, though manageable toxicity, precludes its use in routine practice. Our results strongly support anti-infective prophylaxis with aciclovir and cotrimoxazole for all patients receiving R-CHOP.