INTENSIFIED (INTRAVENOUS AND INTRATHECAL) CNS PROPHYLAXIS IN PRIMARY TESTICULAR DIFFUSE LARGE B‐CELL LYMPHOMA: 5‐YEAR RESULTS OF THE IELSG30 TRIAL

Epidemiological features and a survival nomogram for primary lymphoma of the male genital tract

Primary lymphoma of the male genital tract (PLMGT) is rare, and data on its epidemiology and prognosis are lacking. Our study aimed to estimate the incidence and develop a predictive nomogram for PLMGT. We pooled the incidence and survival data of PLMGT over the last 20 years from the Surveillance, Epidemiology, and End Results (SEER) database. Incidence rates were calculated by year of diagnosis, age, race, and histology. Independent prognostic factors selected by Cox regression analysis were used to develop a nomogram for predicting overall survival (OS). Our study enrolled 1312 patients with PLMGT. The overall incidence rate of PLMGT was 0.437/1,000,000 during 2000-2019. OS was associated with age, marital status, histological subtype, Ann Arbor stage, and therapeutic strategy, which were used to construct nomograms to predict 1-, 3-, and 5-year OS rates. Receiver operating characteristic curves, calibration plots, and decision curve analysis showed good performance of the nomogram. Based on the total score of each patient from the nomogram, the patients were clustered into three risk groups, and the risk stratification model was more successful in predicting clinical outcomes than the traditional Ann Arbor staging system. The incidence rate of PLMGT has remained relatively stable over the past two decades. For the OS of patients with PLMGT, we established a novel predictive nomogram involving all independent risk factors obtained from the SEER database and developed a corresponding risk classification system that showed better predictive performance than the Ann Arbor staging system.

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.

Model for Predicting Central Nervous System Relapse in Diffuse Large B-Cell Lymphoma and Discussion of Prophylaxis Measures

OBJECTIVE

Relapse of the central nervous system (CNS) is a rare but fatal complication in diffuse large B-cell lymphoma (DLBCL). The purpose of this study is to learn how to identify high-risk patients and take effective preventive measures.

METHODS

We retrospectively analyzed 1,290 adult patients with DLBCL at Peking University Cancer Hospital and Shanxi Bethune Hospital between 2010 and 2020.

RESULTS

There were 55 patients with CNS relapse who had a median follow-up of 5 years. The risk of CNS relapse was 1.58% in the low-risk group, 5.66% in the moderate-risk group, and 11.67% in the high-risk group based on CNS International Prognostic Index (CNS-IPI). We found that CNS-IPI and testicular involvement were risk factors for CNS relapse, with OR 1.913 (95% CI: 1.036∼3.531; P = 0.038) versus. OR 3.526 (95% CI: 1.335∼9.313; P = 0.011), respectively. Intrathecal MTX and/or cytarabine prophylaxis was used in 166 patients (13.94%), intravenous (IV) high-dose methotrexate (HD-MTX) prophylaxis in 8 patients (0.67%), and intrathecal plus intravenous prophylaxis in 15 patients (1.26%). There was no significant difference in CNS relapse risk between IT, HD-MTX, and no prophylaxis recipients (12.7% vs. 0% vs. 23.6%, respectively, P = 0.170). The risk of CNS relapse was similar whether or not patients accepted prophylaxis (5-year risk 4.1% vs. 2.2%, P = 0.140).

CONCLUSIONS

Central nervous system (CNS) relapse is associated with high risk CNS-IPI and testicular involvement. Therefore, it is necessary to pursue novel prophylactic strategies for CNS relapse.

Controversies in central nervous system prophylaxis of high-risk diffuse large B-cell lymphoma

PURPOSE OF REVIEW

Central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL) is an uncommon but devastating complication with an overall survival of less than 6 months. This article will review the recent updates on CNS prophylaxis including new potential advances in the identification of high-risk patients.

RECENT FINDINGS

The identification of patients at a high risk of CNS relapse is based on clinical and biological features has improved over recent years; however, the of different CNS prophylaxis strategies including intrathecal chemotherapy and high-dose methotrexate have been recently questioned in several large retrospective studies. The analysis of cell-free circulating tumor DNA (ctDNA) in the cerebrospinal fluid has been shown to identify patients with a high risk of CNS involvement and work is ongoing to identify how this can be used as a prognostic biomarker.

SUMMARY

Recent clinical retrospective data have questioned the effectiveness of intrathecal and high-dose methotrexate in the prevention of CNS relapse in high-risk DLBCL patients. The role of more sensitive methods to detect CNS involvement and the benefit of novel therapies in CNS relapse prevention are currently under evaluation.

Real-World Data Analysis of Survival Outcomes and Central Nervous System Relapses in Testicular Diffuse Large B Cell Lymphoma

Background

Primary testicular lymphoma is a rare type of non-Hodgkin lymphoma, mostly of the diffuse large B cell lymphoma (DLBCL). Although a consensus on standard treatment has been established, unresolved issues remain, such as recurrence in the central nervous system (CNS).

Methods

We retrospectively analyzed the clinical characteristics and survival outcomes of 65 testicular DLBCL patients according to clinical settings and treatment modalities.

Results

The median age of the patients in our study was 65 years, and two-thirds of them had disease limited to one testis. There was no right or left lateralization of testicular involvement. Over a median follow-up of 53.9 months (95% confidence interval 34.0-73.7 months), patients with stage I disease and a low international prognostic index score showed better survival outcomes than those in other categories. Orchiectomy, six cycles of chemotherapy, and radiation therapy (RT) to the contralateral testis demonstrated survival benefits, whereas CNS prophylaxis therapy did not reduce CNS recurrence. During the follow-up period, the survival curves showed continuous decline, mostly due to disease progression. CNS recurrence was observed in 15% of patients, and parenchymal involvement was dominant. However, no factors were associated with CNS recurrence in our analyses. Although our molecular analyses were performed in a small number of patients, MYD88, CD79B, and PIM1 mutations were frequent.

Conclusion

In our study, treatment with orchiectomy, six cycles of immunochemotherapy, and contralateral RT was effective. However, because CNS prophylaxis is an essential part of testicular DLBCL management, better treatment strategies than intrathecal therapy are required.

Management of primary and secondary CNS lymphoma

Central nervous system (CNS) lymphoma has traditionally had very poor outcomes however advances in management have seen dramatic improvements and long-term survival of patients. In primary CNS lymphoma there are now randomised trial data to inform practice, however secondary CNS lymphoma has a lack of randomised trial data and CNS prophylaxis remains a contentious area. We describe treatment strategies in these aggressive disorders. Dynamic assessment of patient fitness and frailty is key throughout treatment alongside delivery of CNS-bioavailable therapy and enrolment in clinical trials. Intensive high-dose methotrexate-containing induction followed by autologous stem cell transplantation is preferred for patients who are fit. Less intensive chemoimmunotherapy, whole brain radiotherapy and novel therapies may be reserved for patients unfit or chemoresistant. It is essential to better define patients at increased risk of CNS relapse, as well as effective prophylactic strategies to prevent it. Future prospective studies incorporating novel agents are key.

Prevention and management of secondary central nervous system lymphoma

Secondary central nervous system (CNS) lymphoma (SCNSL) is defined by the involvement of the CNS, either at the time of initial diagnosis of systemic lymphoma or in the setting of relapse, and can be either isolated or with synchronous systemic disease. The risk of CNS involvement in patients with diffuse large B-cell lymphoma is approximately 5%; however, certain clinical and biological features have been associated with a risk of up to 15%. There has been growing interest in improving the definition of patients at increased risk of CNS relapse, as well as identifying effective prophylactic strategies to prevent it. SCNSL often occurs within months of the initial diagnosis of lymphoma, suggesting the presence of occult disease at diagnosis in many cases. The differing presentations of SCNSL create the therapeutic challenge of controlling both the systemic disease and the CNS disease, which uniquely requires agents that penetrate the blood-brain barrier. Outcomes are generally poor with a median overall survival of approximately 6 months in retrospective series, particularly in those patients presenting with SCNSL after prior therapy. Prospective studies of intensive chemotherapy regimens containing high-dose methotrexate, followed by hematopoietic stem cell transplantation have shown the most favorable outcomes, especially for patients receiving thiotepa-based conditioning regimens. However, a proportion of patients will not respond to induction therapies or will subsequently relapse, indicating the need for more effective treatment strategies. In this review we focus on the identification of high-risk patients, prophylactic strategies and recent treatment approaches for SCNSL. The incorporation of novel agents in immunochemotherapy deserves further study in prospective trials.

CNS prophylaxis in aggressive B-cell lymphoma

The prevention of central nervous system (CNS) relapse in diffuse large B-cell lymphoma (DLBCL) continues to be one of the most contentious areas of lymphoma management. Outcomes for patients with secondary CNS lymphoma (SCNSL) have historically been very poor. However, in recent years improved responses have been reported with intensive immunochemotherapy approaches, and there is a growing interest in potential novel/cellular therapies. Traditional methods for selecting patients for CNS prophylaxis, including the CNS International Prognostic Index, are hampered by a lack of specificity, and there is accumulating evidence to question the efficacy of widely employed prophylactic interventions, including intrathecal and high-dose methotrexate (HD-MTX). Given the potential toxicity of HD-MTX in particular and the ongoing need to prioritize systemic disease control in high-risk patients, there is an urgent need to develop more robust methods for identifying patients at highest risk of CNS relapse, as well as investigating prophylactic interventions with greater efficacy. Here we review new evidence in this field from the last 5 years, focusing on the potential use of molecular diagnostics to improve the identification of high-risk patients, recent large data sets questioning the efficacy of HD-MTX, and the current approach to management of patients with SCNSL. We provide a suggested algorithm for approaching this very challenging clinical scenario.

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.