Prognosis of glioblastoma patients improves significantly over time interrogating historical controls

BACKGROUND

Glioblastoma (GBM) is the most common devastating primary brain cancer in adults. In our clinical practice, median overall survival (mOS) of GBM patients seems increasing over time.

METHODS

To address this observation, we have retrospectively analyzed the prognosis of 722 newly diagnosed GBM patients, aged below 70, in good clinical conditions (i.e. Karnofsky Performance Status -KPS- above 70%) and treated in our department according to the standard of care (SOC) between 2005 and 2018. Patients were divided into two groups according to the year of diagnosis (group 1: from 2005 to 2012; group 2: from 2013 to 2018).

RESULTS

Characteristics of patients and tumors of both groups were very similar regarding confounding factors (age, KPS, MGMT promoter methylation status and treatments). Follow-up time was fixed at 24 months to ensure comparable survival times between both groups. Group 1 patients had a mOS of 19 months ([17.3-21.3]) while mOS of group 2 patients was not reached. The recent period of diagnosis was significantly associated with a longer mOS in univariate analysis (HR=0.64, 95% CI [0.51 - 0.81]), p < 0.001). Multivariate Cox analysis showed that the period of diagnosis remained significantly prognostic after adjustment on confounding factors (adjusted Hazard Ratio (aHR) 0.49, 95% CI [0.36-0.67], p < 0.001).

CONCLUSION

This increase of mOS over time in newly diagnosed GBM patients could be explained by better management of potentially associated non-neurological diseases, optimization of validated SOC, better management of treatments side effects, supportive care and participation in clinical trials.

Epileptic seizures in patients with primary central nervous system lymphoma: A systematic review

BACKGROUND

Primary central nervous system lymphoma (PCNSL) accounts for less than 5% of primary brain tumors. Epileptic seizures are a common manifestation of brain tumors; however, literature on the prevalence, characteristics, and oncological implications of seizures in patients with PCNSL is limited, and the management of antiepileptic drugs (AEDs) is unclear. This review aimed to summarize the existing knowledge on seizures in PCNSL, their potential association with surgery, oncological treatment, survival rates, and management of AEDs.

METHODS

A systematic review was performed according to the PRISMA recommendations and included articles published between 1953 and 2023 describing seizures in patients with PCNSL.

RESULTS

The search identified 282 studies, of which 21 were included. Up to 33% of patients with PCNSL developed seizures, mostly at the initial presentation. Little information was found on changes in seizure incidence through the course of the disease, and no details were found on seizure frequency, the percentage of treatment-resistant patients, or the evolution of seizures at remission. Younger age, cortical location, and immunodeficiency have been identified as potential risk factors for seizures, but evidence is very limited. The growing use of vigorous treatments including intensive chemotherapy with autologous stem cell transplantation and immunotherapy with CAR-T cells is associated with a higher incidence of seizures. The association between seizure development and patient mortality in PCNSL remains unknown. There are no data on AED prophylaxis or the use of specific AEDs in PCNSL.

CONCLUSIONS

Further studies are needed to investigate seizures in larger cohorts of PCNSL, to clarify their prevalence, better characterize them, identify risk factors, analyze survival rates, and make recommendations on AED management. We recommend following general practice guidelines for seizures symptomatic of brain tumors and not to prescribe AED prophylaxis in PCNSL.

Recent advances in the diagnosis and the treatment of primary CNS lymphoma

This review focuses on the recent progress in the management of primary central nervous system lymphoma (PCNSL). Multiomic analyses allowed to better understand the tumorigenesis of PCNSL and to establish a molecular classification with prognostic value that will optimize patient management and guide future targeted approaches. Cooperative clinical trials have demonstrated the feasibility and efficacy, in selected fit patients, of high-dose chemotherapy with autologous stem cell transplantation as post-induction consolidation, that will progressively replace whole brain radiotherapy associated with a much higher risk of delayed neurotoxicity. Several novel treatments have shown efficacy and overall good tolerance in PCNSL patients, such as Bruton's tyrosine kinase (BTK) inhibitors, imids, immune checkpoint inhibitors and chimeric antigen receptor T-cells (CAR-T). This opens promising therapeutic perspectives to improve the current standard treatment, especially for elderly and unfit patients who represent a growing population.

Systemic relapses of primary CNS lymphomas (PCNSL): a LOC network study

Primary central nervous system lymphomas (PCNSLs) classically remain confined within the CNS throughout their evolution for unknown reasons. Our objective was to analyse the rare extracerebral relapses of PCNSL in a nationwide population-based study. We retrospectively selected PCNSL patients who experienced extracerebral relapse during their follow-up from the French LOC database. Of the 1968 PCNSL included in the database from 2011, 30 (1.5%, median age 71 years, median KPS 70) presented an extracerebral relapse, either pure (n = 20) or mixed (both extracerebral and in the CNS) (n = 10), with a histological confirmation in 20 cases. The median delay between initial diagnosis and systemic relapse was 15.5 months [2-121 months]. We found visceral (n = 23, 77%), including testis in 5 (28%) men and breast in 3 (27%) women, lymph node (n = 12, 40%), and peripheral nervous system (PNS) (n = 7, 23%) involvement. Twenty-seven patients were treated with chemotherapy, either with only systemic targets (n = 7) or mixed systemic and CNS targets (n = 20), 4 were consolidated by HCT-ASCT. After systemic relapse, the median progression-free survival and overall survival (OS) were 7 and 12 months, respectively. KPS > 70 and pure systemic relapses were significantly associated with higher OS. Extracerebral PCNSL relapses are rare, mainly extranodal, and frequently involve the testis, breast, and PNS. The prognosis was worse in mixed relapses. Early relapses raise the question of misdiagnosed occult extracerebral lymphoma at diagnostic workup that should systematically include a PET-CT. Paired tumour analysis at diagnosis/relapse would provide a better understanding of the underlying molecular mechanisms.

CSF biomarkers in primary CNS lymphoma

PCNSL is a non-Hodgkin lymphoma (NHL) affecting brain, spinal cord, eyes and leptomeninges. In the past two decades, its prognosis significantly improved due to therapeutic advances but it remains a highly aggressive tumor and early diagnosis is necessary for optimal management. Diagnosis relies on the identification of lymphoma cells in brain tissue obtained by stereotactic biopsy. Alternatively, lymphoma cells may be found in CSF through lumbar puncture (LP) or by a vitrectomy. For several reasons, the diagnosis of PCNSL may be challenging. Misleading radiological presentations are frequent. Dramatic response to steroids may bias histological analysis and deep brain location or frail health status can contraindicate brain biopsy. In the follow-up of patients who have been previously treated, differential diagnosis between tumor relapse and post-treatment may be also difficult. Therefore, the development of complementary reliable diagnostic tools is needed. This review will summarize several diagnostic or prognostic CSF biomarkers which have been proposed in PCNSL, their interests and limits.

Molecular and clinical diversity in primary central nervous system lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare and distinct entity within diffuse large B-cell lymphoma presenting with variable response rates probably to underlying molecular heterogeneity.

PATIENTS AND METHODS

To identify and characterize PCNSL heterogeneity and facilitate clinical translation, we carried out a comprehensive multi-omic analysis [whole-exome sequencing, RNA sequencing (RNA-seq), methylation sequencing, and clinical features] in a discovery cohort of 147 fresh-frozen (FF) immunocompetent PCNSLs and a validation cohort of formalin-fixed, paraffin-embedded (FFPE) 93 PCNSLs with RNA-seq and clinico-radiological data.

RESULTS

Consensus clustering of multi-omic data uncovered concordant classification of four robust, non-overlapping, prognostically significant clusters (CS). The CS1 and CS2 groups presented an immune-cold hypermethylated profile but a distinct clinical behavior. The 'immune-hot' CS4 group, enriched with mutations increasing the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and nuclear factor-κB activity, had the most favorable clinical outcome, while the heterogeneous-immune CS3 group had the worse prognosis probably due to its association with meningeal infiltration and enriched HIST1H1E mutations. CS1 was characterized by high Polycomb repressive complex 2 activity and CDKN2A/B loss leading to higher proliferation activity. Integrated analysis on proposed targets suggests potential use of immune checkpoint inhibitors/JAK1 inhibitors for CS4, cyclin D-Cdk4,6 plus phosphoinositide 3-kinase (PI3K) inhibitors for CS1, lenalidomide/demethylating drugs for CS2, and enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) inhibitors for CS3. We developed an algorithm to identify the PCNSL subtypes using RNA-seq data from either FFPE or FF tissue.

CONCLUSIONS

The integration of genome-wide data from multi-omic data revealed four molecular patterns in PCNSL with a distinctive prognostic impact that provides a basis for future clinical stratification and subtype-based targeted interventions.

P11.09.B Chemotherapy is an efficient treatment in primary CNS MALT lymphoma

Background

Mucosae-associated lymphoid tissue (MALT) lymphomas are a rare and still poorly understood form of primary central nervous system lymphoma (PCNSL). The aim of this study was to better describe these tumors and their management, and to better appreciate their long-term prognosis after treatment.

Material and Methods

Adult immunocompetent patients with primary CNS MALT lymphoma (PCNSML) were retrospectively selected from the database on PCNSL of the Pitié-Salpêtrière Hospital. All cases had double-read for pathology.

Results

Eleven PCNSML representing 1.7% of the 662 PCNSL included in the database were selected, There were 9 women and two men, all immunocompetent. Their median age was 56 years (min 29; max 78). The median time from first symptoms to diagnosis was 13 months and the median KPS at diagnosis was 90. Location was dural in 8 cases, suggestive of meningioma in 7 cases and of subdural hematoma in 1 case, and parenchymal in 3 cases. The disease was unifocal/localized in 4 cases and multifocal/diffuse in 7 cases. In 3 cases, it was the second reading that allowed making the diagnosis. In first-line treatment, all patients received chemotherapy (CT): “systemic” CT, i.e usually used in systemic MALT lymphomas, in 7 cases (n=7) and “CNS” CT, i.e usually used in CNS lesions in 4 cases. CT was preceded by surgery in 4 cases. No patient received radiotherapy in first line. According to the IPCG (International PCNSL Collaborative Group) criteria, the overall response rate was 7/11 (64%). At latest news, 5 patients had a persistent contrast enhancement, stable without any treatment since a median of 57 months, raising the question of complete response despite persisting contrast enhancement. No patient developed neurotoxicity except for one of the 2 patients who subsequently received radiotherapy. The median follow-up was 109 months. The median progression-free survival was 78.0 months (95% CI [43.4;NA[) and the 10-year overall survival rate was 90% (95% CI [0.7;1[).

Conclusion

This series confirms the classical clinical and radiological presentation of PCNSML. Compared to the literature where the treatment was based on radiotherapy in almost two thirds of cases, the therapeutic approach presented here appears unconventional. This is the first series demonstrating that chemotherapy is an efficient treatment in PCNSML, with an excellent long-term outcome and the absence of neurotoxicity, and calling into question the relevance of the IPCG criteria for the evaluation of their therapeutic response.

P14.48 Extracerebral relapses of primary CNS lymphoma (PCNSL): a LOC network retrospective study

BACKGROUND

Classically PCNSL remain confined within the CNS throughout their evolution for reasons still unknown (&gt; 80% cerebral relapses). The aim of this study was to describe the characteristics and outcomes of the rare extracerebral relapses of PCNSL.

MATERIAL AND METHODS

This is a multicenter, retrospective study. We included all immunocompetent patients newly diagnosed with diffuse large B-cell PCNSL registered in the national LOC network database since 2010 and followed prospectively, who presented an extracerebral relapse, pure (extracerebral only site) or associated with concomitant CNS relapse (mixed). All had body scan and/or TEP -CT at diagnosis work up.

RESULTS

Of the 1968 PCNSL included in the database, 29 (1.5%) patients presented a systemic relapse [median age 71 years, median KPS 70% at relapse], either pure (n=19) or mixed (n=10), with a histological confirmation in 19 cases (66%). The median delay between initial diagnosis and systemic relapse was 15 months [2–49 months], with 5 very early relapses (&lt;8 months) and 10 late relapses (&gt;21 months). 27 patients had symptoms, 21 related to the location of relapse and 6 with only general symptoms. The localization was thoracic (n=11), abdominal/pelvic (n=14), head/neck (n=6) and limbs (n=9). We found visceral (n=24, 83%), including testis in 5 (28%) men and breast in 3 (27%) women, lymph node (n=12, 41%) and peripheral nervous system (PNS) (n=8, 28%; 4 plexus and 4 extradural roots) involvement. 27 patients were treated with chemotherapy, either with only systemic target (n=8) (R-CHOP alone) or mixed systemic and CNS target (n=19) (R-CHOP-MTX, R-ICE, GEMOX, RDHAC) and consolidated by high-dose chemotherapy with autologous stem cell transplantation (HCT-ASCT) in 4 cases [median age 55 years, median KPS 80%], with 34% of complete response. After systemic relapse, median progression-free survival was 8 months and overall survival (OS) was 9 months, 15 months for pure systemic and 4.5 months for mixed relapses. KPS&gt;70%, pure systemic relapses and complete response were significantly associated with higher OS in univariate analysis.

CONCLUSION

Extracerebral PCNSL relapses are very rare, mainly extranodal and involve a large spectrum of anatomical sites, the most frequent being testis, breast and PNS. Prognosis was worse in case of mixed relapse than in pure systemic relapse that was similar to non PCNSL lymphomas. Very early relapses raise the question of misdiagnosed occult extracerebral lymphoma at diagnostic work up that should include systematically a FDG PET-CT. More studies are needed to refine their treatment and to specify the role of HCT-ASCT. Paired tumor tissues at diagnosis (CNS)/relapse (extracerebral) analysis would provide a better understanding of underlying molecular mechanisms.

P03.04 Primary CNS lymphoma of the corpus callosum: presentation and neurocognitive prognosis. Study of a monocentric cohort of 27 patients

BACKGROUND

The corpus callosum (CC) is frequently involved in primary central nervous system lymphomas (PCNSL). The aim of our study was to describe the impact of these lesions on neurocognition of patients presenting with PCNSL of the CC (PCNSL-CC) and their post-therapeutic evolution.

MATERIAL AND METHODS

This is a retrospective single-center study. Patients newly diagnosed at Pitié Salpêtrière Hospital from (1999–2018) were included in this study according to the following criteria: age &gt;18, immunocompetent patient, pathological confirmation (Diffuse Large B cell lymphoma) and CC as main location of the tumor on MRI. Clinical, neuroradiological and neuropsychological data of the patients were collected. In addition, prognostic factors for the neurocognitive outcome of the patients were investigated.

RESULTS

27 patients were included (median age: 67 years, median KPS: 70). At the time of diagnosis, 74% of patients had cognitive impairment and 59% of patients had balance disorders. The cognitive functions most frequently affected were memory and executive functions. Tumor lesions in the CC had a median maximum diameter of 5 cm with a so called “butterfly pattern” in 92% of cases. All patients received a high dose methotrexate based polychemotherapy, including one with radiation therapy, and 67% of patients achieved a complete remission (CR). Median PFS and OS were 33.3 months and 177.9 months respectively. With a median follow-up of 48 months (range 6–156), despite CR, there were still abnormal values in 17% of patients on overall efficiency, 17–55% of patients on executive function tests, 45–55% of patients on memory tests. No significant impaired values were found for visuo-spatial and language tests. Splenial location and age ≥ 60 years were significantly associated with worse episodic memory scores throughout the follow-up.

CONCLUSION

PCNSL-CC are associated with frequent cognitive dysfunctions, especially memory impairment, which may recover only partially despite CR, that warrant specific rehabilitation. Older age (≥ 60) and splenial location have worse neurocognition outcome.

P14.54 Primary central nervous system lymphoma of the spinal cord: a LOC network cohort study

BACKGROUND

Primary central nervous system lymphoma (PCNSL) mainly affects the brain (&gt;90% of the cases), Very little data can be found in the literature on PCNSL with spinal cord localization.

MATERIAL AND METHODS

We present a retrospective study based on the French LOC network database. We selected adult immunocompetentpatients, with a histological or cytological diagnosis of PCNSL, and a spinal cord localization at initial diagnosis.

RESULTS

Of the 2043 PCNSLof the LOC database newly diagnosed since 2011, 14 patients (9 men, median age 68, median Karnofsky performance status 50%)met the selection criteria. The median diagnostic delay was 82 days (min 15-max 1080) compared to 35 days in primary cerebral lymphomas. At diagnosis, walking was impossible in 7/14 patients and 5/14 had indwelling urinary catheter. On MRI, 100% had enlargement of the spinal cord with homogeneous contrast enhancement in 13/14 cases. Spinal cord lesions were unique in 9/14 patients and multiples in 5/14 patients. CSF IL10 level was increased in 6/7 patients. Brain lesions were found in 9/14 patients, located in the posterior fossa in 5/9 cases. The diagnosis was made either on a brain biopsy (N=6), a spinal cord biopsy or surgery (N=5) or the cytologic analysis of the CSF (N=3).4/5 patients had neurological sequel after spinal cord biopsy or surgery. All the patients were treated by high-dose methotrexate-based chemotherapy, followed by spinal cord irradiation (N=1) or autograft (N=2). There was an overall response rate of 71% (complete response in 8/14). 8/14 patients relapsed, 5 in the brain, 2 in the spinal cord, and 1 both in the spinal cord and in the brain. 2-year PFS and OS were 45% and 64%, respectively. Among the long-term responders, 50% remained in wheel chair, while only 10% could walk normally.

CONCLUSION

Considering the high risk of a spinal cord biopsy,the rarity of the disease, as well as the numerous differential diagnoses, the diagnosis of spinal cord lymphoma is difficult. Searching for other lymphomatous locations or assaying CSF IL10 may be helpful in this disease where delay in diagnosis is often prolonged et can cause irreversible handicap.

P14.73 Toxicity and outcomes of reduced-dose whole brain radiotherapy as consolidation treatment for patients with CNS lymphoma in real life setting

BACKGROUND

Optimal treatment strategy for newly diagnosed primary PCNSL remains controversial. The high risk of radio-induced late-delayed neurotoxicity in patients who achieve long-term disease control constrains the use of classical consolidation WBRT. So as to reduce side cognitive effects, Morris et al, reported a phase II study, to assess the efficacy and toxicity of consolidation reduced-dose (23.4Gy) WBRT (rdWBRT) for patients with complete response after high dose methotrexate based chemotherapy. The study reported a 2-year PFS rate for these patients of 77%, with no evidence of significant cognitive decline during the follow-up (FU) period. The aim of this retrospective study was to report toxicity and outcomes of rdWBRT, in patients < 60 years old with complete response (CR) after HD-MTX based chemotherapy, in real life setting, without selection bias.

MATERIAL AND METHODS

Patients were selected from the French LOC network database, a nationwide database centralizing since 2011 information from 28 different centers in France, representing the main centers involved in PCNSL management. Patients were retrospectively selected according to the following criteria: 1) Pathological diagnosis of diffuse large B cell PCNSL; 2) age>18 and <60 years; 3) immunocompetent status; 4) First line induction treatment based on high dose MTX (At least MTX>1.5 g/m2); 5) CR according to the IPCG criteria after first-line induction treatment. Patients should have received a rdWBRT (23.4Gy in 13 fractions of 1.8Gy).

RESULTS

Twenty seven patients, were included. The median FU from initial diagnosis was 28.5 months [9.6–50.7]. Median age was 50.2 years [25–60]. Median Karnofsky Performans Status (KPS) was 90% [40–100%]. Seventeen patients had a multi focal disease at diagnosis (meningeal involvement n=6, in ophthalmic involvement n=4). PFS rates were 85% IC95[76–100 %], 65% IC95 [45–85%] and 65% IC95 [45–85%] at 1, 2, and 3 years respectively. The OS rates were 100%, 90,5% IC95 [77–100%] and 85%IC95 [69–100%]. 8 patients relapsed, with a median time from radiotherapy to recurrence of 6.5months [2.4–17]. All recurrences were outside the initially involved site(s), and 62.5% of tumors recurred as multifocal disease. All patients received salvage treatment, including intensive chemotherapy with autologous stem cell transplantation in 4 cases. No acute grade III-IV toxicity related to rdWBRT was reported. Neuropsychological follow up was available for 14 patients with no cognitive impairment at last follow up.

CONCLUSION

This is the largest retrospective study evaluating outcomes of rdWBRT for PCNSL young patients with CR after HD-MTX chemotherapy. Real life setting data from this study are quite reassuring, and rdWBRT could be considered as an efficient and safe consolidation strategy in this population. We need a longer FU to confirm the absence of cognitive deterioration.

Ibrutinib monotherapy for relapse or refractory primary CNS lymphoma and primary vitreoretinal lymphoma: Final analysis of the phase II 'proof-of-concept' iLOC study by the Lymphoma study association (LYSA) and the French oculo-cerebral lymphoma (LOC) network

BACKGROUND

Primary central nervous system lymphomas (PCNSLs) are mainly diffuse large B-cell lymphomas (DLBCLs) of the non-germinal centre B-cell subtype, with unmet medical needs. This study aimed to evaluate the efficacy and toxicity of ibrutinib in DLBCL-PCNSL PATIENTS AND METHODS: This prospective, multicentre, phase II study involved patients with relapse or refractory(R/R) DLBCL-PCNSL or primary vitreoretinal lymphoma. The treatment consisted of ibrutinib (560 mg/day) until disease progression or unacceptable toxicity occurred. The primary outcome was the disease control (DC) rate after two months of treatment (P0 < 10%; P1 > 30%).

RESULTS

Fifty-two patients were recruited. Forty-four patients were evaluable for response. After 2 months of treatment, the DC was 70% in evaluable patients and 62% in the intent-to-treat analysis, including 10 complete responses (19%), 17 partial responses (33%) and 5 stable diseases (10%). With a median follow-up of 25.7 months (range, 0.7-30.5), the median progression-free and overall survivals were 4.8 months (95% confidence interval [CI]; 2.8-12.7) and 19.2 months (95% CI; 7.2-NR), respectively. Thirteen patients received ibrutinib for more than 12 months. Two patients experienced pulmonary aspergillosis with a favourable (n = 1) or fatal outcome (n = 1). Ibrutinib was detectable in the cerebrospinal fluid (CSF). The clinical response to ibrutinib seemed independent of the gene mutations in the BCR pathway.

CONCLUSION

Ibrutinib showed clinical activity in the brain, the CSF and the intraocular compartment and was tolerated in R/R PCNSL. The addition of ibrutinib to standard methotrexate-base induction chemotherapy will be further evaluated in the first-line treatment.

CLINICAL TRIAL NUMBER

NCT02542514.

Lenalidomide in combination with intravenous rituximab (REVRI) in relapsed/refractory primary CNS lymphoma or primary intraocular lymphoma: a multicenter prospective 'proof of concept' phase II study of the French Oculo-Cerebral lymphoma (LOC) Network and the Lymphoma Study Association (LYSA)†

BACKGROUND

Primary central nervous system lymphomas (PCNSLs) are mainly diffuse large B-cell lymphomas (DLBCLs) of the non-germinal center B-cell (non-GCB) subtype. This study aimed to determine the efficacy of rituximab plus lenalidomide (R2) in DLBCL-PCNSL.

PATIENTS AND METHODS

Patients with refractory/relapsed (R/R) DLBCL-PCNSL or primary vitreoretinal lymphoma (PVRL) were included in this prospective phase II study. The induction treatment consisted of eight 28-day cycles of R2 (rituximab 375/m2 i.v. D1; lenalidomide 20 mg/day, D1-21 for cycle 1; and 25 mg/day, D1-21 for the subsequent cycles); in responding patients, the induction treatment was followed by a maintenance phase comprising 12 28-day cycles of lenalidomide alone (10 mg/day, D1-21). The primary end point was the overall response rate (ORR) at the end of induction (P0 = 10%; P1 = 30%).

RESULTS

Fifty patients were included. Forty-five patients (PCNSL, N = 34; PVRL, N = 11) were assessable for response. The ORR at the end of induction was 35.6% (95% CI 21.9-51.2) in assessable patients and 32.0% (95% CI 21.9-51.2) in the intent-to-treat analysis, including 13 complete responses (CR)/unconfirmed CR (uCR; 29%) and 3 partial responses (PR; 7%). The best responses were 18 CR/uCR (40%) and 12 PR (27%) during the induction phase. The maintenance phase was started and completed by 18 and 5 patients, respectively. With a median follow-up of 19.2 months (range 1.5-31), the median progression-free survival (PFS) and overall survival (OS) were 7.8 months (95% CI 3.9-11.3) and 17.7 months (95% CI 12.9 to not reached), respectively. No unexpected toxicity was observed. The peripheral baseline CD4/CD8 ratio impacted PFS [median PFS = 9.5 months (95% CI, 8.1-14.8] for CD4/CD8 ≥ 1.6; median PFS = 2.8 months, [95% CI, 1.1-7.8) for CD4/CD8 < 1.6, P = 0.03).

CONCLUSIONS

The R2 regimen showed significant activity in R/R PCNSL and PVRL patients. These results support assessments of the efficacy of R2 combined with methotrexate-based chemotherapy as a first-line treatment of PCNSL.

CLINICAL TRIALS NUMBER

NCT01956695.

Ongoing and prolonged response in adult low-grade gliomas treated with radiotherapy

The aim of the present study was to evaluate the impact of first-line radiotherapy on low-grade gliomas (LGGs) growth kinetics. The mean tumor diameter (MTD) of 39 LGGs was retrospectively measured on serial magnetic resonance images before (n = 16) and after radiotherapy onset (n = 39). After radiotherapy, a decrease of the MTD was observed in 37 patients. Median duration of the MTD decrease was 1.9 years (range 0-8.1 years). According to RANO criteria, the rates of partial and minor responses were 15 and 28 % at the first evaluation after radiotherapy and 36 and 34 % at the time of maximal MTD decrease. The presence of a 1p19q codeletion and the absence of p53 expression were associated with longer durations of MTD decrease (5.3 vs 1 years, p = 0.02 and 2.4 vs 1.8 years, p = 0.05, respectively) while no association was observed between IDH1-R132H expression and duration of MTD decrease. In most patients, MTD decrease after radiotherapy occurred in two phases: an initial phase of rapid MTD decrease followed by a second phase of slower MTD decrease. Patients with a high rate of MTD decrease during the initial phase (>7 mm/year) had both a shorter duration of response (1.9 vs 5.3 years, p = 0.003) and a shorter overall survival (5.5 vs 11.6 years, p = 0.0004). LGGs commonly display a prolonged and ongoing volume decrease after radiotherapy. However, patients who respond rapidly should be carefully monitored because they are at a higher risk of rapid progression.

[Management of primary central nervous system lymphoma]

Primary CNS lymphoma is the malignant brain tumor whose prognosis has improved the most the two past decades. The majority of the patients achieve a complete remission with treatment and a substantial minority may hope to be cured. The treatment includes high-dose methotrexate polychemotherapy combined or not with whole brain radiotherapy (WBRT). Elderly patients who are exposed to a high risk of treatment induced neurotoxicity need a specific management avoiding or defering WBRT. In young patients, the main questions concerning the treatment are the role of consolidation WBRT and intensive chemotherapy with peripheral blood stem cell rescue in the initial treatment of PCNSL. As recently shown, national and international collaborative efforts make now possible randomized trials for this rare disease, which would contribute to better define the treatment strategy. New insights in PCNSL tumorigenesis would help to better understand the heterogeneity of outcome and to develop efficient targeted therapies.

IDH1 or IDH2 mutations predict longer survival and response to temozolomide in low-grade gliomas

OBJECTIVES

Recent studies have shown that IDH1 and IDH2 mutations occur frequently in gliomas, including low-grade gliomas. However, their impact on the prognosis and chemosensitivity of low-grade gliomas remains unclear.

METHODS

Search for IDH1 and IDH2 mutations, loss of heterozygosity on chromosomes 1p and 19q, MGMT promoter methylation, and p53 expression was performed in a series of 271 low-grade gliomas and correlated with overall survival. A subgroup of 84 patients treated up-front with temozolomide was individualized. Response to temozolomide was evaluated by progression-free survival, as well as by tumor size on successive MRI scans, and then correlated with molecular alterations.

RESULTS

IDH (IDH1 or IDH2) mutations were found in 132/189 patients (70%). IDH mutation and 1p-19q codeletion were associated with prolonged overall survival in univariate (p = 0.002 and p = 0.0001) and multivariate analysis (p = 0.003 and p = 0.004). 1p-19q codeletion, MGMT promoter methylation, and IDH mutation (p = 0.01) were correlated with a higher rate of response to temozolomide. Further analysis of the course of the disease prior to any treatment except for surgery (untreated subgroup) showed that 1p-19q codeletion was associated with prolonged progression-free survival in univariate analysis, whereas IDH mutation was not.

CONCLUSION

IDH mutation appears to be a significant marker of positive prognosis and chemosensitivity in low-grade gliomas, independently of 1p-19q codeletion, whereas its impact on the course of untreated tumors seems to be limited.

Supratentorial low-grade gliomas in older patients

BACKGROUND

Low-grade gliomas (LGG) are thought to be very rare in elderly patients (>60 years) and have not been thoroughly studied.

METHODS

A series of 62 elderly (>or=60 years of age) LGG patients were identified in a department database collecting information on pathologically identified adult supratentorial LGG. The clinical, radiologic, pathologic, and therapeutic data of these patients were analyzed and compared to those of 704 younger LGG patients (<60 years).

RESULTS

Comparisons between older and younger groups showed that elderly patients more often presented with a clinical deficit (p < 0.0001), a lower Karnofsky performance status (p = 0.0002), a larger tumor on MRI (p = 0.03), and a lower rate of tumor resection (p < 0.0001). Chemotherapy was more often used as first line treatment (p = 0.001). Among the patients who died of progressive disease, 55% of the elderly patients had not received radiotherapy compared to 11% in the younger group (p < 0.0001). Survival was shorter in older patients (p < 0.0001), with a 5-year survival rate of 40%. An astrocytic phenotype (p = 0.0097), increasing age (p = 0.0049), and a tumor crossing the midline (p = 0.028) were negative prognostic factors in the older group.

CONCLUSION

We found that 8% of low-grade gliomas (LGG) occur in older patients (>or=60 years of age). The clinical-radiologic picture of LGG in the elderly population differs from younger patients. Although long-term survival occurs, the course is generally more severe because elderly patients accumulate negative prognostic factors and because they are probably undertreated.