High-dose Methotrexate and Rituximab Induction Regimen In Immunocompetent Patients With Primary CNS Lymphoma: A Retrospective Single-Center Study of Survival Predictors

Purpose:Primary Central Nervous System Lymphoma (PCNSL) is an aggressive tumor that is confined to the CNS. Although the provision of high-dose methotrexate (HD-MTX) has remarkably improved outcomes in PCNSL patients, the optimal treatment regimens and standard MTX dose have been largely controversial. Herein, we sought to explore the impact of adjuvant Rituximab and different dosages of HD-MTX on survival outcomes of immunocompetent patients with PCNSL.Methods:In this study, we examined patients with PCNSL treated at a single NCI-designated comprehensive cancer center to evaluate their survival outcomes. We conducted a retrospective analysis of 51 immunocompetent patients with PCNSL who received their induction chemotherapy at the University of Alabama at Birmingham (UAB) between 2001 and 2019. Only adult patients with a confirmed diagnosis of PCNSL who had either HD-MTX alone or in combination with Rituximab were included. Patients’ demographics, clinical characteristics, and survival data were collected and analyzed.Results:There is no significant difference in survival among patients who received MTX alone versus MTX plus Rituximab. Furthermore, lower doses of MTX were associated with worse survival outcomes; however, this difference in survival was not significant when adjusted to age.Conclusion:Our experience challenges the role of Rituximab in PCNSL during induction therapy. Our study also highlights the shorter survival in elderly patients with PCNSL which can be related, to some extent, to the relatively lower doses of HD-MTX. There is an unmet need to establish a consensus on the most effective upfront regimen in PCNSL through prospective studies.

Primary Central Nervous System Lymphoma: A Real-World Comparison of Therapy Access and Outcomes by Hospital Setting

Background This study analyzes sociodemographic barriers for primary CNS lymphoma (PCNSL) treatment and outcomes at a public safety-net hospital versus a private tertiary academic institution. We hypothesized that these barriers would lead to access disparities and poorer outcomes in the safety-net population. Methods We reviewed records of PCNSL patients from 2007-2020 (n = 95) at a public safety-net hospital (n = 33) and a private academic center (n = 62) staffed by the same university. Demographics, treatment patterns, and outcomes were analyzed. Results Patients at the safety-net hospital were significantly younger, more commonly Black or Hispanic, and had a higher prevalence of HIV/AIDS. They were significantly less likely to receive induction chemotherapy (67% vs 86%, p = 0.003) or consolidation autologous stem cell transplantation (0% vs. 44%, p = 0.001), but received more whole-brain radiation therapy (35% vs 15%, p = 0.001). Younger age and receiving any consolidation therapy were associated with improved progression-free (PFS, p = 0.001) and overall survival (OS, p = 0.001). Hospital location had no statistical impact on PFS (p = 0.725) or OS (p = 0.226) on an age-adjusted analysis. Conclusions Our study shows significant differences in treatment patterns for PCNSL between a public safety-net hospital and an academic cancer center. A significant survival difference was not demonstrated, which is likely multifactorial, but likely was positively impacted by the shared multidisciplinary care delivery between the institutions. As personalized therapies for PCNSL are being developed, equitable access including clinical trials should be advocated for resource-limited settings.

PRIMARY CNS LYMPHOMA MIMICKING TUBERCULOSIS INFECTION - A CASE REPORT

Primary central nervous system lymphoma (PCNSL) is a rare variety of extra nodal non-Hodgkin lymphoma that reportedly involves leptomeninges, the brain, spinal cord, eyes, or may involve other organs systemically. We present a case of 46-yearold woman with complaints of headache and fever for three weeks, associated with right-sided weakness & altered state of consciousness for one week. The most common presentation of primary central nervous lymphoma is diffuse or multifocal supratentorial masses causing cognitive deterioration and involvement of vitreous, retina, and optic nerve. Most cases ofPCNSL are left undiagnosed due to uncommon

Preliminary Evaluation of Zanubrutinib-Containing Regimens in DLBCL and the Cerebrospinal Fluid Distribution of Zanubrutinib: A 13-Case Series

Zanubrutinib is a second-generation Bruton’s tyrosine kinase inhibitor. Its safety and effectiveness in central nervous system (CNS) lymphoma along with its distribution in the brain and ability to cross the blood–brain barrier (BBB) remain unknown. This retrospective case series involved patients with diffuse large B-cell lymphoma (DLBCL) treated with zanubrutinib-containing regimens from August to December 2020 in PUMCH. The amounts of zanubrutinib in the plasma and brain were assessed by liquid chromatography–tandem mass spectrometry in paired plasma and cerebrospinal fluid (CSF) samples. In total, 13 patients were included: eight primary CNS lymphoma cases and five systemic DLBCL cases with 61.5% (8/13) refractory/relapsed and 84.6% (11/13) showing CNS involvement. The overall response rates were 84.5% in the entire population and 81.8% in the CNS-involved cases. A total of 23 time-matched plasma-CSF sample pairs were collected. The mean peak concentration of zanubrutinib in CSF was 2941.1 pg/ml (range, 466–9032.0 pg/ml). The corrected mean CSF/plasma ratio determined based on 94% protein binding was 42.7% ± 27.7% (range, 8.6%–106.3%). This preliminary study revealed the effectiveness of zanubrutinib-containing regimens in DLBLC, especially CNS-involved cases, for the first time. The excellent BBB penetration of zanubrutinib supports its further investigation for the treatment of CNS lymphoma.

Differentiation of Cerebral Neoplasms with Vessel Size Imaging (VSI)

Purpose Cerebral neoplasms of various histological origins may show comparable appearances on conventional Magnetic Resonance Imaging (MRI). Vessel size imaging (VSI) is an MRI technique that enables noninvasive assessment of microvasculature by providing quantitative estimates of microvessel size and density. In this study, we evaluated the potential of VSI to differentiate between brain tumor types based on their microvascular morphology. Methods Using a clinical 3T MRI scanner, VSI was performed on 25 patients with cerebral neoplasms, 10 with glioblastoma multiforme (GBM), 8 with primary CNS lymphoma (PCNSL) and 7 with cerebral lung cancer metastasis (MLC). Following the postprocessing of VSI maps, mean vessel diameter (vessel size index, vsi) and microvessel density (Q) were compared across tumors, peritumoral areas, and healthy tissues. Results The MLC tumors have larger and less dense microvasculature compared to PCNSLs in terms of vsi and Q (p = 0.0004 and p < 0.0001, respectively). GBM tumors have higher yet non-significantly different vsi values than PCNSLs (p = 0.065) and non-significant differences in Q. No statistically significant differences in vsi or Q were present between GBMs and MLCs. GBM tumor volume was positively correlated with vsi (r = 0.502, p = 0.0017) and negatively correlated with Q (r = −0.531, p = 0.0007). Conclusion Conventional MRI parameters are helpful in differentiating between PCNSLs, GBMs, and MLCs. Additionally incorporating VSI parameters into the diagnostic protocol could help in further differentiating between PCNSLs and metastases and potentially between PCNSLs and GBMs. Future studies in larger patient cohorts are required to establish diagnostic cut-off values for VSI.

NQPC-5 Does high-dose methotrexate-based chemotherapy for relapsed primary CNS lymphoma increase a risk of leukoencephalopathy with prior whole brain radiotherapy?

Backgrounds: Standard care for primary central nervous system lymphoma (PCNSL) comprises high-dose (HD) methotrexate (MTX) -based chemotherapy with or without consolidation whole brain radiotherapy (WBRT). HD-MTX administration following WBRT has been suggested to increase a risk of leukoencephalopathy. However, given that there are no other agents with efficacy similar to or better than MTX, patients with relapsed PCNSL may often be treated with regimens containing HD-MTX if the initial MTX treatment achieved a long-term complete remission. Here, we retrospectively analyzed prevalence and an extent of white mater damages in association with prior WBRT in patients with relapsed PCNSL treated with HD-MTX based therapy. Patients & methods: Among 79 patients with relapsed/refractory PCNSL in a total of 162 patients with newly-diagnosed PCNSL treated in our institution from April, 2000 to February, 2021, 35 patients were identified with evaluable KPS, MMSE, and Fazekas scale data at both baseline and follow-up periods. Of the 35 patients, 22 were treated with chemotherapy at a relapse (10 with prior WBRT, while 12 without WBRT), and were included in this preliminary study. Results: In the WBRT group (male/female: 5/5), median age was 65 years (range, 45–73), initial median KPS was 70 (40–90), and median WBRT dose was 27 Gy (23.4–40). Median progression-free survival (mPFS) was 11.8 months, and median overall survival (mOS) was not reached. In the non-WBRT group (M/F 8/4), median age 75 (62–84), initial mKPS 80 (50–90), mPFS 16.2 m, and mOS not reached. Initial KPS and MMSE score tended to be worse in WBRT group, presumably due to enrichment of patients with poorer performance status and more comorbidities. A decline in the Fazekas score was not associated with MMSE deterioration.Conclusions: The preliminary analysis was not informative enough, and further extensive imaging analysis will be exploited.

ML-7 Liquid biopsy for MYD88 mutation in cerebrospinal fluid in patients with suspected primary CNS lymphoma

Background: Treatment intervention for central nervous system lymphoma (CNSL) requires pathological diagnosis by surgical biopsy. However, there are some cases in which the risk of surgery is high due to age, comorbidities, localization of lesions, etc. We are developing a CNSL diagnostic method based on the detection of MYD88 L265P mutation by digital PCR (dPCR) using CSF-DNA, and a high accuracy with a sensitivity of 92.9% and a specificity of 100% has been reported. Here, we report two cases with suspected brain stem CNSL, whose treatment strategy was determined by integrated clinico-laboratory information including neurological presentations, imaging, and the result of liquid biopsy. Result: Case 1. A 63-year-old woman visited our hospital with a complaint of right hemiplegia, which deteriorated in two months. MR images revealed a contrast-enhancing lesion in the left midbrain-ventral pons, suggesting CNSL. Biopsy was not considered because of its location, while dPCR using CSF-DNA showed a cluster of MYD88 mutation signals. Based on these work-ups, she was treated with high-dose methotrexate-based chemotherapy, resulting in a complete response with marked improvement of symptoms. Case 2. An 83-year-old man was referred for a history of diplopia and ataxic gait lasting for a month. MR images revealed an invasive lesion on his right midbrain-dorsal pons. Biopsy was declined due to the location, and liquid biopsy using CSF-DNA was performed to assist the diagnosis. In the first test, the CSF-DNA yield was too insufficient to determine the mutation signal by dPCR. The second dPCR using sufficient amount of CSF-DNA resulted in the Target/Total value of 0.049% which was lower than the threshold, suggesting the absence of MYD88 mutation. The patient underwent radiation therapy accordingly.Conclusions: CSF MYD88 mutation analysis by dPCR may have clinical utility and requires sufficient amount of CSF-DNA for exclusion of noise signals.

ML-10 Tirabrutinib, a second-generation BTK inhibitor in relapsed and refractory primary CNS lymphoma: A single institute study

BACKGROUND: The prognosis of relapsed and refractory (r/r) primary CNS lymphoma (PCNSL) is poor, and the development of new therapeutic agents is desirable. Comprehensive genetic analysis of PCNSL has shown that MYD88 and CD79B are frequently mutated and are oncogenic drivers, suggesting that Bruton’s tyrosine kinase (BTK), which is located downstream of MYD88 and CD79B, may be a reasonable therapeutic target. Tirabrutinib is a second-generation oral BTK inhibitor recently approved in Japan for the treatment of r/r PCNSL. In this study, we evaluated the efficacy and safety of tiraburtinib treatment of r/r PCNSL at Saitama Medical University. MATERIAL AND METHODS: Eighteen patients with r/r PCNSL to HD-MTX-based regimens were treated with 480 mg tiraburtinib daily under fasting conditions until disease progression. RESULTS: The median age was 63.5 years, and the median KPS was 70. Nine patients (50%) achieved a CR, 2 (11%) had a partial response, 3 (17%) had stable disease, and 4 (22%) had progressive disease. After a median follow-up of 17.3 months, the median progression-free survival was 7.9 months, and the median overall survival was 23.6 months. There were four cases of long-term treatment lasting more than one year. Grade 3 or higher adverse events were observed in 1 case of maculopapular rash, 1 case of cardiac failure, 1 case of neutropenia, and 1 case of lymphopenia. CONCLUSION: Tiraburtinib can be administered relatively safely to patients with relapsed or refractory PCNSL, and a certain degree of efficacy can be expected. Which patients can be treated with tiraburtinib over the long term, when can stop tirabrutinib treatment for patients with long-term CR, and the mechanism of tiraburtinib resistance needs to be determined.