Jon Glass

Abstract Bruton tyrosine kinase (BTK) links the B-cell antigen receptor (BCR) and Toll-like receptors with NF-κB. The role of BTK in primary central nervous system (CNS) lymphoma (PCNSL) is unknown. We performed a phase I clinical trial with ibrutinib, the first-in-class BTK inhibitor, for patients with relapsed or refractory CNS lymphoma. Clinical responses to ibrutinib occurred in 10 of 13 (77%) patients with PCNSL, including five complete responses. The only PCNSL with complete ibrutinib resistance harbored a mutation within the coiled-coil domain of CARD11, a known ibrutinib resistance mechanism. Incomplete tumor responses were associated with mutations in the B-cell antigen receptor–associated protein CD79B. CD79B-mutant PCNSLs showed enrichment of mammalian target of rapamycin (mTOR)-related gene sets and increased staining with PI3K/mTOR activation markers. Inhibition of the PI3K isoforms p110α/p110δ or mTOR synergized with ibrutinib to induce cell death in CD79B-mutant PCNSL cells. Significance: Ibrutinib has substantial activity in patients with relapsed or refractory B-cell lymphoma of the CNS. Response rates in PCNSL were considerably higher than reported for diffuse large B-cell lymphoma outside the CNS, suggesting a divergent molecular pathogenesis. Combined inhibition of BTK and PI3K/mTOR may augment the ibrutinib response in CD79B-mutant human PCNSLs. Cancer Discov; 7(9); 1018–29. ©2017 AACR. See related commentary by Lakshmanan and Byrd, p. 940. This article is highlighted in the In This Issue feature, p. 920

PURPOSE: Salvage options for recurrent high-grade gliomas (HGGs) are limited by cumulative toxicity and limited efficacy despite advances in chemotherapeutic and radiotherapeutic techniques. Previous studies have reported encouraging survival results and favorable toxicity with fractionated stereotactic radiotherapy, and small studies have shown similar benefit using a shortened course of hypofractionated stereotactic radiation therapy (H-SRT). We sought to determine the efficacy and toxicity profile of H-SRT alone or in addition to repeat craniotomy or concomitant chemotherapy. PATIENTS AND METHODS: Between 1994 and 2008, 147 patients with recurrent HGG were treated with H-SRT (median dose, 35 Gy in 3.5-Gy fractions). Cox regression models were used to analyze survival outcomes. Variables included age, surgery before H-SRT, time to first recurrence, reirradiation dose, inclusion of chemotherapy with H-SRT, and gross tumor volume (GTV). RESULTS: Younger age (P = .001), smaller GTV (P = .025), and shorter time between diagnosis and recurrence (P = .034) were associated with improvement in survival from H-SRT. Doses of radiation > or = 35 Gy approached significance (P = .07). There was no significant benefit of surgical resection or chemotherapy in this population when analysis was controlled for other prognostic factors. CONCLUSION: H-SRT was well tolerated and resulted in a median survival time of 11 months after H-SRT, independent of re-operation or concomitant chemotherapy. Patients who experienced recurrence within 6 months after initial treatment had an excellent response and should not be disqualified from H-SRT. This is the largest series to examine the efficacy and tolerability of H-SRT in recurrent HGG.

The treatment of primary central nervous system lymphoma with chemotherapy prior to whole-brain radiation therapy (WBRT) has improved outcome considerably in this previously fatal disease. Complete or partial responses to intravenous methotrexate (3.5 gm/sq m with leucovorin rescue every 3 weeks for two to four cycles) were seen in 12 of 13 patients originally treated. A total of 25 patients (including the original 13) have now been treated with one to six cycles of methotrexate every 10 to 21 days prior to WBRT. Twenty-two had partial or complete responses, with a median duration of response of 32 months. Median survival time was 33 months (42.5 months in those responding to therapy). Nine patients are alive and without evidence of disease 9 to 122 months following therapy. Acute and long-term toxicities were minimal. Systemic methotrexate administration prior to WBRT is well tolerated and produces long-term survival.

BACKGROUND: Intravascular lymphomatosis (IL) is a systemic neoplasm that often involves the nervous system, inducing progressive neurologic deficits in the setting of undiagnosed or quiescent extranodal non-Hodgkin lymphoma. METHODS: The clinical and pathologic files of the Massachusetts General Hospital and New York University Medical Center and the English language literature were reviewed to identify all reports of intravascular lymphomatosis (angioendotheliomatosis) or other examples of a diffuse proliferation of neoplastic cells filling capillaries, arterioles, and venules. RESULTS: The authors report seven patients with IL and note 114 patients reported in the literature. Almost two-thirds (63%) of patients had neurologic manifestations, without abnormalities on bone marrow biopsy, chest and abdominal tomographic examinations for adenopathy, and cerebrospinal fluid (CSF) analysis. All patients had one or more of four syndromes, each reflecting a vascular occlusive process: progressive, multifocal cerebrovascular events; paraparesis, pain, and incontinence; a subacute encephalopathy; and peripheral or cranial neuropathies. CONCLUSIONS: The unexplained presence of any one or more of these neurologic syndromes should alert the physician to the possible presence of this disease.