Central nervous system (CNS) prophylaxis in antiCD20-CHOP treated DLBCL at intermediate to high risk for CNS relapse: A systematic review and meta-analysis

Efficacy of intravenous high-dose methotrexate in preventing relapse to the central nervous system in R-CHOP(-like)-treated, high-risk, diffuse large B-cell lymphoma patients and its effect on mortality: a systematic review and meta-analysis

Central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL) carries a dismal prognosis and most clinical guidelines recommend CNS prophylaxis to patients deemed at high risk of CNS relapse. However, results from observational studies investigating the effect of CNS prophylaxis have yielded conflicting results. The aims of this study were to evaluate: (i) whether addition of prophylactic intravenous high-dose methotrexate (HD-MTX) reduces the risk of CNS relapse in high-risk DLBCL patients treated with R-CHOP or similar, and (ii) whether HD-MTX prophylaxis confers an overall survival benefit, irrespective of CNS relapse. We performed a systematic search of MEDLINE/PubMed and EMBASE for data on DLBCL patients at high risk of CNS relapse treated with R-CHOP or similar who received HD-MTX as an intervention and a comparator arm of patients who did not receive prophylaxis and/or intrathecal prophylaxis. A risk of bias was estimated using the ROBINS-I tool and the quality of the evidence was assessed by the GRADE approach. Finally, a meta- analysis based on the systematic review was conducted. A total of 1,812 studies were screened. No randomized controlled trials were identified. Seven observational studies comprising 1,661 patients met the inclusion criteria. We found a statistically non-significant relative risk of 0.54 (95% confidence interval: 0.27-1.07) of CNS relapse for patients receiving HD-MTX versus controls. The meta-analysis investigating mortality demonstrated a relative risk of death of 0.70 (95% confidence interval: 0.44-1.11) for patients treated with HD-MTX versus controls. The overall risk of bias was adjudged as "serious" and the quality of the evidence was rated as "low". In conclusion, our data indicate that HD-MTX does not prevent or, at best, only slightly reduces the risk of CNS relapse and confers no survival benefit.

Evolving therapeutic landscape of diffuse large B-cell lymphoma: challenges and aspirations

Diffuse large B-cell lymphoma (DLBCL) represents the commonest subtype of non-Hodgkin lymphoma and encompasses a group of diverse disease entities, each harboring unique molecular and clinico-pathological features. The understanding of the molecular landscape of DLBCL has improved significantly over the past decade, highlighting unique genomic subtypes with implications on targeted therapy. At the same time, several new treatment modalities have been recently approved both in the frontline and relapsed settings, ending a dearth of negative clinical trials that plagued the past decade. Despite that, in the real-world setting, issues like drug accessibility, reimbursement policies, physician and patient preference, as well as questions regarding optimal sequencing of treatment options present difficulties and challenges in day-to-day oncology practice. Here, we review the recent advances in the therapeutic armamentarium of DLBCL and discuss implications on the practice landscape, with a particular emphasis on the context of the healthcare system in Singapore.

The role of central nervous system (CNS) prophylaxis in preventing DLBCL patients from CNS relapse: A network meta-analysis

BACKGROUND

Secondary central nervous system (CNS) relapses are an uncommon yet devastating complication in diffuse large B cell lymphoma (DLBCL). Although several prophylaxis attempts were employed clinically in order to reduce the CNS relapse rate, the optimal management remained uncertain.

METHODS

We employed conventional meta-analysis along with Network meta-analysis to investigate an optimal prophylactic strategy. The primary outcome was CNS relapse rate.

RESULTS

A total of thirty-six studies comprising 5 RCTs, one clinical trial and 30 observational studies were included. Rituximab overall was superior in reducing CNS relapse rate, and the statistical significance exists (RR 0.79(0.68-0.93), p = 0.004). In rituximab era, none of intravenous, intrathecal administration or novel target agents could significantly decrease CNS relapse rate in high CNS risk patients. Intensive chemotherapy regimen containing HD-MTX with HD-Ara-C (SUCRA 93.4 %) was ranked as the first in reducing CNS relapse rate followed by no prophylaxis (SUCRA 57.5 %), HD-MTX (SUCRA 53.1 %), IT (SUCRA 34.5 %) and lenalidomide maintenance (SUCRA 11.5 %). In addition, intercalated HD-MTX had a trend of reducing CNS relapse but without statistical significance (RR 0.86(0.44-1.68), p = 0.67). However, i-HD-MTX was associated with increased grade 3-4 toxicities and prolonged inpatient stay. Early HD-MTX exposure also increased the treatment related death.

CONCLUSION

Our network meta-analysis provides an overview of the relative efficacy of all available CNS prophylaxis strategies in DLBCL. In rituximab era, none of intravenous, intrathecal administration or novel target agents could significantly decrease CNS relapse rate in high CNS risk patients. Further studies with prospective, randomized clinical trials as well as with more focus on novel target agents that could spread blood-brain barriers are suggested.