Efficacy and safety of prophylactic high-dose MTX in high-risk DLBCL: a treatment intent-based analysis

Rechallenge With High-Dose Methotrexate After Treatment With Glucarpidase in Adult Patients With Lymphoma

PURPOSE

Limited evidence exists regarding methotrexate (MTX) resumption after patients with lymphoma receive glucarpidase for toxic MTX levels and acute kidney injury (AKI).

METHODS

This retrospective review included adults with lymphoma treated with glucarpidase after MTX at Mayo Clinic between January 31, 2020, and October 10, 2022. Descriptive statistics summarize patient characteristics and clinical outcomes.

RESULTS

Of 11 patients treated with glucarpidase after MTX, seven (64%) were rechallenged with MTX. Indications for MTX rechallenge included confirmed CNS disease (n = 6, 86%) and intravascular lymphoma (n = 1, 14%). Compared with the nonrechallenged subgroup, before receiving MTX that required glucarpidase rescue, the rechallenged patients had lower median pretreatment serum creatinine (Scr; 0.7 v 1.2 mg/dL), and none had AKI with previous MTX doses, n = 0 (0%) versus n = 2 (50%). During the MTX dose requiring glucarpidase rescue, the rechallenged group had lower median peak Scr (1.26 v 3.32 mg/dL) and lower incidence of AKI stage III (n = 1 [14%] v n = 3 [75%]), and none of the rechallenged patients required renal replacement therapy (RRT; n = 0 [0%] v n = 1 [25%]). At the first rechallenge after glucarpidase administration, the median MTX dose reduction was 56% (range, 46%-75%), and the lowest used dose when prescribed according to each treatment protocol schedule was 1.5 g/m2. Two (29%) patients experienced AKI (n = 1 stage I, n = 1 stage II) after MTX rechallenge. Zero patients required RRT, and zero required another glucarpidase administration. Six (86%) patients completed all recommended MTX doses.

CONCLUSION

In selected adults with lymphoma who required glucarpidase for toxic MTX levels after administration of high-dose MTX, resumption of MTX therapy at lower doses is safe. Patients selected for MTX resumption had experienced less severe AKI during the previous cycle compared with those not selected for MTX resumption.

IELSG30 phase 2 trial: intravenous and intrathecal CNS prophylaxis in primary testicular diffuse large B-cell lymphoma

ABSTRACT

Primary testicular diffuse large B-cell lymphoma (PTL) is characterized by high risk of contralateral testis and central nervous system (CNS) relapse. Chemoimmunotherapy with intrathecal (IT) CNS prophylaxis and contralateral testis irradiation eliminates contralateral recurrences and reduces CNS relapses. The IELSG30 phase 2 study investigated feasibility and activity of an intensified IT and IV CNS prophylaxis. Patients with stage I/II PTL who had not received treatment received 2 cycles of IV high-dose methotrexate (MTX) (1.5 g/m2) after 6 cycles of the R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, every 21 days). IT liposomal cytarabine was administered on day 0 of cycles 2 to 5 of 21-day R-CHOP regimen. Contralateral testis radiotherapy (25-30 Gy) was recommended. Fifty-four patients (median age: 66 years) with stage I (n = 32) or II (n = 22) disease were treated with R-CHOP, 53 received at least 3 doses of IT cytarabine, 48 received at least 1 dose of IV MTX, and 50 received prophylactic radiotherapy. No unexpected toxicity occurred. At a median follow-up of 6 years, there was no CNS relapse; 7 patients progressed, and 8 died, with 5-year progression-free and overall survival rates of 91% (95% confidence interval [CI], 79-96) and 92% (95% CI, 81-97), respectively. Extranodal recurrence was documented in 6 patients (in 2 without nodal involvement). In 4 cases, the relapse occurred >6 years after treatment. Causes of death were lymphoma (n = 4), second primary malignancy (n = 1), cerebral vasculopathy (n = 1), unknown (n = 2). Intensive prophylaxis was feasible and effective in preventing CNS relapses. Late relapses, mainly at extranodal sites, represented the most relevant pattern of failure. This trial was registered at www.clinicaltrials.gov as #NCT00945724.

Comparison of standardized prophylactic high-dose and intrathecal methotrexate for DLBCL with a high risk of CNS relapse

The efficacy of high-dose methotrexate (HD-MTX) for central nervous system (CNS) relapse prophylaxis in patients with high-risk diffuse large B-cell lymphoma (DLBCL) is controversial. We compared the prophylactic effects of HD-MTX and intrathecal methotrexate (IT-MTX) on CNS relapse in high-risk DLBCL, in a multicenter retrospective study. A total of 132 patients with DLBCL at high risk of CNS relapse who received frontline chemotherapy and IT-MTX from 2003 to 2013 (n = 34) or HD-MTX from 2014 to 2020 (n = 98) were included. After a median follow-up of 52 months (range: 9-174), 11 patients had isolated CNS relapse: six (6.1%) in the HD-MTX group and five (14.7%) in the IT-MTX group. The median time until CNS relapse was 38 months (range: 11-122), and the cumulative incidence of CNS relapse at 3 years was 3.9% in the HD-MTX group and 6.1% in the IT-MTX group (P = 0.93). Similar results were obtained after adjusting for background factors using propensity score-matched analysis (4.5% HD-MTX vs. 7.6% IT-MTX, P = 0.84). The CNS relapse rate in HD-MTX-treated patients was equivalent to that in IT-MTX patients, demonstrating that HD-MTX was not superior to IT-MTX in preventing CNS relapse.

Recent updates on central nervous system prophylaxis in patients with high-risk diffuse large B-cell lymphoma

The use of central nervous system (CNS) prophylaxis for patients with diffuse large B-cell lymphoma (DLBCL) remains controversial. Although uncommon, CNS relapses are invariably fatal in this otherwise curable disease. Accurate identification of patients at risk and the optimal approach to CNS prophylaxis therefore remains an area of unmet need. The existing literature, largely retrospective in nature, provides mixed conclusions regarding the efficacy of CNS prophylaxis. The utility of CNS prophylaxis has itself been challenged. In this review, we dissect the issues which render the value of CNS prophylaxis uncertain. We first compare international clinical guidelines for CNS prophylaxis. We then interrogate the factors that should be used to identify high-risk patients accurately. We also explore how clinical patterns of CNS relapse have changed in the pre-rituximab and rituximab era. We then discuss the efficacy of CNS-directed approaches, intensification of systemic treatment and other novel approaches in CNS prophylaxis. Improved diagnostics for early detection of CNS relapses and newer therapeutics for CNS prophylaxis are areas of active investigation. In an area where prospective, randomized studies are impracticable and lacking, guidance for the use of CNS prophylaxis will depend on rigorous statistical review of retrospective data.

Development and validation of a model to predict acute kidney injury following high-dose methotrexate in patients with lymphoma

STUDY OBJECTIVE

To develop and validate a model for predicting acute kidney injury (AKI) after high-dose methotrexate (HDMTX) exposure.

DESIGN

Retrospective analysis.

SETTING

Multisite integrated health system throughout Minnesota and Wisconsin.

PATIENTS

Adult patients with lymphoma who received HDMTX as a 4-h infusion.

MEASUREMENTS AND MAIN RESULTS

LASSO methodology was used to identify factors available at the outset of therapy that predicted incident AKI within 7 days following HDMTX. The model was then validated in an independent cohort. The incidence of AKI within 7 days following HDMTX was 21.6% (95% confidence interval (CI) 18.4%-24.8%) in the derivation cohort (435 unique patients who received a total of 1642 doses of HDMTX) and 15.6% (95% CI 5.3%-24.8%) in the validation cohort (55 unique patients who received a total of 247 doses of HDMTX). Factors significantly associated with AKI after HDMTX in the multivariable model included age ≥ 55 years, male sex, and lower HDMTX dose number. Other factors that were not found to be significantly associated with AKI on multivariable analysis, but were included in the final model, were body surface area, Charlson Comorbidity Index, and estimated glomerular filtration rate. The c-statistic of the model was 0.72 (95% CI 0.69-0.75) in the derivation cohort and 0.72 (95% CI 0.60-0.84) in the validation cohort.

CONCLUSION

This model utilizing identified sociodemographic and clinical factors is predictive of AKI following HDMTX administration in adult patients with lymphoma.

Central nervous system prophylaxis in diffuse large B-cell lymphoma: What does the evidence tell us?

Secondary involvement of the central nervous system (CNS) by diffuse large b-cell lymphoma (DLBCL) is a rare yet often catastrophic event for DLBCL patients. As standard first-line therapy for DLBCL with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) does not cross the blood-brain barrier, one approach to lessen the risk of CNS relapse has been to include additional agents, primarily methotrexate, directed at the CNS with standard R-CHOP although the timing, dose, and mode of administration differs widely across treating physicians. This practice derives from decades of non-randomized, often retrospective data with inconsistent outcomes. The current available tools and risk models are imprecise in their ability to predict which patients are truly at risk of secondary CNS relapse and more recent, large-scale real-world analyses call into question these longstanding practices. In a field lacking any prospective, randomized studies, this review synthesizes the available data investigating the utility of CNS prophylaxis in patients with DLBCL receiving 1st line therapy.

Central Nervous System Progression/Relapse in Mature T- and NK-Cell Lymphomas

Non-Hodgkin lymphomas (NHL) are cancers of mature B-, T-, and NK-cells which display marked biological heterogeneity between different subtypes. Mature T- and NK-cell neoplasms are an often-aggressive subgroup of NHL and make up approximately 15% of all NHL. Long-term follow up studies have demonstrated that patients with relapsed/refractory disease have dismal outcomes; in particular, secondary central nervous system (CNS) involvement is associated with higher mortality, though it remains controversial whether this independently confers worse outcomes or if it simply reflects more aggressive systemic disease. Possible risk factors predictive of CNS involvement, such as an elevated lactate dehydrogenase and more than two sites of extranodal involvement, may suggest the latter, though several studies have suggested that discrete sites of anatomic involvement or tumor histology may be independent risk factors as well. Ultimately, small retrospective case series form the basis of our understanding of this rare but devastating event but have not yet demonstrated a consistent benefit of CNS-directed prophylaxis in preventing this outcome. Nonetheless, ongoing efforts are working to establish the epidemiology of CNS progression/relapse in mature T- and NK-cell lymphomas with the goal of identifying clinicopathologic risk factors, which may potentially help discern which patients may benefit from CNS-directed prophylactic therapy or more aggressive systemic therapy.

An Aged/Autoimmune B-cell Program Defines the Early Transformation of Extranodal Lymphomas

A third of patients with diffuse large B-cell lymphoma (DLBCL) present with extranodal dissemination, which is associated with inferior clinical outcomes. MYD88L265P is a hallmark extranodal DLBCL mutation that supports lymphoma proliferation. Yet extranodal lymphomagenesis and the role of MYD88L265P in transformation remain mostly unknown. Here, we show that B cells expressing Myd88L252P (MYD88L265P murine equivalent) activate, proliferate, and differentiate with minimal T-cell costimulation. Additionally, Myd88L252P skewed B cells toward memory fate. Unexpectedly, the transcriptional and phenotypic profiles of B cells expressing Myd88L252P, or other extranodal lymphoma founder mutations, resembled those of CD11c+T-BET+ aged/autoimmune memory B cells (AiBC). AiBC-like cells progressively accumulated in animals prone to develop lymphomas, and ablation of T-BET, the AiBC master regulator, stripped mouse and human mutant B cells of their competitive fitness. By identifying a phenotypically defined prospective lymphoma precursor population and its dependencies, our findings pave the way for the early detection of premalignant states and targeted prophylactic interventions in high-risk patients.

SIGNIFICANCE

Extranodal lymphomas feature a very poor prognosis. The identification of phenotypically distinguishable prospective precursor cells represents a milestone in the pursuit of earlier diagnosis, patient stratification, and prophylactic interventions. Conceptually, we found that extranodal lymphomas and autoimmune disorders harness overlapping pathogenic trajectories, suggesting these B-cell disorders develop and evolve within a spectrum. See related commentary by Leveille et al. (Blood Cancer Discov 2023;4:8-11). This article is highlighted in the In This Issue feature, p. 1.

Ultralight Porous Cu Nanowire Aerogels as Stable Hosts for High Li-Content Metal Anodes

Using porous copper (Cu) as the host is one of the most effective approaches to stabilize Li metal anodes. However, the most widely used porous Cu hosts usually account for the excessive mass proportion of composite anodes, which seriously decreases the energy density of Li metal batteries. Herein, an ultralight porous Cu nanowire aerogel (UP-Cu) is reported as the Li metal anode host to accommodate a high mass loading of Li content of 77 wt %. Specifically, the Li/UP-Cu electrode displays a satisfactory gravimetric capacity of 2715 mAh g^-1, which is higher than that of the most reported Li metal composite anodes. The UP-Cu host achieves a high Coulombic efficiency of ∼98.9% after 250 cycles in the half cell and exceptional electrochemical stability under high-current-density and deep-plating-stripping conditions in the symmetrical cell. The Li/UP-Cu|LiFePO₄ battery displays a specific capacity of 102 mAh g^-1 at 5 C for 5000 cycles. The Li/UP-Cu|LiFePO₄ pouch cell achieves a significantly high capacity of 146.3 mAh g^-1 with a high capacity retention of 95.83% for 360 cycles. This work provides a lightweight porous host to stabilize Li-metal anodes and maintain their high mass-specific capacity.

Diffuse Large B-Cell Lymphoma (DLBCL): Early Patient Management and Emerging Treatment Options

Diffuse large B-cell lymphoma (DLBCL) represents a curable disease with a 60-70% chance of cure with current R-CHOP chemoimmunotherapy. However, 30-40% of patients are refractory or relapsing. Many attempts failed to improve the outcome of DLBCL patients, including the intensification of R-CHOP regimen, consolidation, or maintenance therapy since the introduction of R-CHOP in 2000. Better understanding of both molecular biology of lymphoma cells and the tumor microenvironment raised the hope for future improvement of DLBCL patients' survival. Novel molecular findings have initiated clinical trials exploring targeted therapy based on driver genetic alterations with an intent to improve survival of high-risk subsets of patients. But the preliminary results remain ambiguous. The approach "agnostic" to specific molecular alterations of lymphoma cell includes antibody-drug conjugates (especially polatuzumab vedotin), immunotherapy comprising different antibodies with immunomodulatory effect (tafasitamab, lenalidomide), and T-cell engaging therapy (bispecific antibodies, early use of CAR T-cell). This approach could increase the cure rates and change the current therapeutic paradigm. However, better prognostic stratification, smarter designs of clinical trials, modification of endpoints including the use of ctDNA are needed. This review covers the complexity of DLBCL management.

Limited efficacy of high-dose methotrexate to prevent the central nervous system relapse in patients with IVLBCL

To evaluate the efficacy of high-dose methotrexate (HD-MTX, ≥1 g/m²) for the prevention of central nervous system (CNS) recurrence in patients with intravascular large B-cell lymphoma (IVLBCL), we reviewed 51 patients with pathologically diagnosed untreated IVLBCL. In total, there were five cases of CNS relapse (9.8%), and the 12-month CNS relapse rate was 9.2%. No statistical difference in CNS relapse rate (p = 0.86) was observed between patients with and without HD-MTX (n = 20 and 31, respectively). Furthermore, the composite endpoint defined as either CNS and/or neurolymphomatosis relapse was not significant in terms of the administration of HD-MTX (p = 0.25). No significant predictor of CNS relapse was found. In conclusion, patients with IVLBCL are at high risk of CNS recurrence; however, HD-MTX administration may not be effective for CNS recurrence prophylaxis. Key pointsThe administration of HD-MTX for patients with untreated IVLBCL may not be effective for preventing CNS relapse.

Clinical prognostic risk analysis and progression factor exploration of primary breast lymphoma

PURPOSE

: A primary breast lymphomais a rare form of extranodal lymphoma type. We aimed to analyze prognosticriskfactors and explore relapse factors in primary breast diffuse large B cell lymphoma (PB-DLBCL).

METHODS

: From November 2003 to September 2020, sixty-three patients from two medical centers newly diagnosed with PB-DLBCL patients were analyzed retrospectively.

RESULTS

: The median age was 52, and >50% of patients were post-menopausal. The international prognostics index (IPI) (0-1) was mainlyin the low-risk group (84%), and there were four patients with stage IV (6%) who had bilateral breast involvement. With a median follow-up time of 4.92 years (3.17-8.00), five-year overall survival (OS) and progression-free survival (PFS) were 78.9% and 67.1%, respectively. Univariate and multivariate analyses showed that elevated erythrocyte sedimentation rate (ESR) and B symptoms were independent adverse prognostic risk factors for OS, whereas bilateral breast involvement was unfavorable for PFS. Disease recurrence and relapse occurred in 40% (25/63) patients, mainly in the breast, followed by the central nervous system (CNS) and skin/soft tissue.

CONCLUSION

: This is the first study to explore the prognostic risk factors and relapse factorsof PB-DLBCL in a relatively large Chinese PBL cohort. Local breast and CNS recurrence after standard R-CHOP treatment were the main issues we are facing now.

SOHO State of the Art Updates and Next Questions: Prophylaxis and Management of Secondary CNS Lymphoma

Secondary CNS lymphoma (SCNSL) is a rare but frequently fatal complication of systemic lymphoma. There is no standard treatment for SCNSL, and patients who develop SCNSL at diagnosis or after frontline therapy often receive highly intensive chemotherapy regimens that are inactive against primary chemorefractory disease and too toxic for older, frail patients to tolerate. Because the prognosis of SCNSL is so poor, management has historically emphasized prevention, but the current methods of CNS prophylaxis are not universally effective. To improve both the prevention and management of SCNSL, better characterization of the molecular determinants of CNS invasion is needed. Novel treatments that are currently being studied in SCNSL include targeted pathway inhibitors and cellular therapy, but SCNSL patients are often excluded from clinical trials of promising new therapies.

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.

Timing of high dose methotrexate CNS prophylaxis in DLBCL: a multicenter international analysis of 1,384 patients

Prophylactic high-dose methotrexate (HD-MTX) is often used for diffuse large B-cell lymphoma (DLBCL) patients at high risk of central nervous system (CNS) relapse, despite limited evidence demonstrating efficacy or the optimal delivery method. We conducted a retrospective, international analysis of 1,384 patients receiving HD-MTX CNS prophylaxis either intercalated (i-HD-MTX) (n=749) or at the end (n=635) of R-CHOP/R-CHOP-like therapy (EOT). There were 78 CNS relapses (3-year rate 5.7%), with no difference between i-HD-MTX and EOT; 5.7% vs 5.8%, p=0.98, 3-year difference: 0.04% (-2.0% to 3.1%). Conclusions were unchanged on adjusting for baseline prognostic factors or on 6-month landmark analysis (n=1,253). In patients with high CNS international prognostic index (n=600), 3-year CNS relapse rate was 9.1% with no difference between i-HD-MTX and EOT. On multivariable analysis, increasing age and renal/adrenal involvement were the only independent risk factors for CNS relapse. Concurrent intrathecal prophylaxis was not associated with reduction in CNS relapse. R-CHOP delays of ≥7 days were significantly increased with i-HD-MTX versus EOT, with 308/1573 (19.6%) i-HD-MTX treatments resulting in delay to subsequent R-CHOP (median 8 days). Increased risk of delay occurred in older patients when delivery was later than day 10 in the R-CHOP cycle. In summary, we found no evidence that EOT delivery increases CNS relapse risk versus i-HD-MTX. Findings in high-risk subgroups were unchanged. Rates of CNS relapse in this HD-MTX-treated cohort were similar to comparable cohorts receiving infrequent CNS prophylaxis. If HD-MTX is still considered for certain high-risk patients, delivery could be deferred until R-CHOP completion.

Feasibility of High-dose Methotrexate Administered on Day 1 of (R)CHOP in aggressive non-Hodgkin Lymphomas

HDMTX administration on day 1 of (R)CHOP is feasible and compares favorably with reports of HDMTX administration midcycle.

Delaying prophylactic HDMTX beyond cycle 1 of (R)CHOP might lower the risks of neutropenic fever and acute kidney injury.

The optimal timing for administering high-dose methotrexate (HDMTX) when combined with (R)CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone, with/without rituximab) is unclear. Recent data showed that the administration of prophylactic HDMTX before day 10 of R- CHOP may lead to fewer treatment delays. Herein, we report our experience with HDMTX administered on day 1 of (R)CHOP in patients with aggressive non-Hodgkin lymphoma (NHL). We identified 140 patients treated with ≥1 cycle of HDMTX combined with (R)CHOP for prophylaxis against (n = 84) or treatment of (n = 56) central nervous system (CNS) involvement. Overall, (R)CHOP treatment delays ≥7 days (4% of cycles, 13% of patients), doxorubicin, and/or cyclophosphamide dose reductions (1% of cycles, 6% of patients) or (R)CHOP discontinuations due to toxicity (4% of patients) were uncommon. Neutropenic fever (NF) occurred in 7% of cycles and 24% of patients and was more common during HDMTX-containing cycles. Acute kidney injury (AKI) occurred in 19% of cycles but was mostly grade ≤2. Grade ≥3 hepatotoxicity and mucositis were uncommon (each 2% of cycles). In the prophylaxis cohort, the rates of NF and grade ≥2 AKI were lower in patients who initiated HDMTX with cycle 2 or later (11% vs 30%, P = .03 and 16% vs 39%, P = .03, respectively). Our data show that HDMTX administration on day 1 of (R)CHOP may improve the deliverability of (R)CHOP and the overall safety of the regimen compared with historical data of HDMTX administration on day 10 or later of R-CHOP. Delaying prophylactic HDMTX beyond cycle 1 of (R)CHOP may reduce the risk of NF and AKI.

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

CNS prophylaxis is commonly used in Diffuse Large B-Cell Lymphoma (DLBCL) patients with risk features for CNS relapse. This systematic review and meta-analysis compares CNS relapse rates with and without CNS prophylaxis, for patients at intermediate to high CNS relapse risk. Studies reporting CNS relapse risk category and CNS outcomes with and without CNS prophylaxis for antiCD20-CHOP treated DLBCL patients were included. 10 studies with 3770 patients at intermediate to high CNS relapse risk were analyzed. No significant difference in the pooled Absolute Risk Difference (ARD 0.01, 95 % CI -0.01 to 0.02, P = 0.61) or Risk (RR 1.22, 95 % CI 0.81-1.83, P = 0.34) was noted in patients with and without CNS prophylaxis. There were also no differences within pre-specified subgroups of IV Methotrexate or IT chemotherapy. However, the quality of evidence supporting these observations was low. A meta-analysis of individual patient data will help evaluate the benefit of CNS prophylaxis strategies.

High-dose methotrexate is effective for prevention of isolated CNS relapse in diffuse large B cell lymphoma

The role of central nervous system (CNS) prophylaxis with high-dose methotrexate (HDMTX) in DLBCL is controversial. In this retrospective study, we evaluated the efficacy of prophylactic HDMTX on isolated CNS relapse, concomitant CNS and systemic relapse, systemic relapse, and survival outcomes in 226 patients with newly diagnosed DLBCL and high-risk CNS International Prognostic Index (CNS-IPI) score treated with RCHOP. The three-year risk of isolated CNS relapse was significantly lower in patients who received HDMTX, at 3.1% compared to 14.6% (P = 0.032) in those who did not. However, neither concomitant CNS-systemic relapse rates, systemic relapse rates, nor three-year PFS and OS were significantly different between treatment groups in multivariable analysis. Among propensity score-matched patients (N = 102), HDMTX was also associated with significantly lower isolated CNS relapse rates (HR 0.06, 95% CI 0.004–0.946, P = 0.046). HDMTX was well tolerated with manageable toxicities when given at a dose of 3 g/m² by day 3 of RCHOP chemotherapy. Using propensity score matching and multivariable regression to yield treatment groups with well-balanced covariates, we showed that prophylactic HDMTX improved isolated CNS relapse rates but did not decrease concomitant CNS-systemic relapse rates, systemic relapse rates, or improve survival outcomes.