Giannini, Caterina

Abstract cIMPACT‐NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy) was established to evaluate and make practical recommendations on recent advances in the field of CNS tumor classification, particularly in light of the rapid progress in molecular insights into these neoplasms. For Round 2 of its deliberations, cIMPACT‐NOW Working Committee 3 was reconstituted and convened in Utrecht, The Netherlands, for a meeting designed to review putative new CNS tumor types in advance of any future World Health Organization meeting on CNS tumor classification. In preparatory activities for the meeting and at the actual meeting, a list of possible entities was assembled and each type and subtype debated. Working Committee 3 recommended that a substantial number of newly recognized types and subtypes should be considered for inclusion in future CNS tumor classifications. In addition, the group endorsed a number of principles—relating to classification categories, approaches to classification, nomenclature, and grading—that the group hopes will also inform the future classification of CNS neoplasms.

Abstract Purpose: Despite therapeutic advancements, biological markers that predict the natural history of primary central nervous system lymphoma (PCNSL) are lacking and age and performance status are the only consistently identified independent prognostic variables. BCL6 rearrangements and deletion of the tumor suppressor gene R-PTP-κ (PTPRK) at 6q22 are thought to be common genetic abnormalities in PCNSL but their prognostic significance is unknown. The aim of this study is to determine the prevalence and survival impact of del(6)(q22), BCL6, immunoglobulin heavy chain (IGH), and MYC gene rearrangements and prevalence of Epstein-Barr virus (EBV) infection in PCNSL affecting immunocompetent patients. Patients and methods: Seventy-six specimens from 76 HIV-negative, immunocompetent patients with PCNSL newly diagnosed and treated at Mayo Clinic between 1985 and 2006 were studied. Interphase fluorescence in-situ hybridization (FISH) was performed using two-color break apart probes (BAP) for BCL6 and MYC, a two-color dual-fusion probe for IGH-BCL6, and a two-color probe for del(6)(q22) on thin sections of paraffin-embedded tumor samples. Two-color IGH BAP FISH probes were also used to confirm IGH rearrangements in cases showing extra IGH signals without fusion using the IGH-BCL6 probe. In situ hybridization was performed using probes that recognize EBV-encoded RNA (EBER) on paraffin-embedded tumor samples. Survival data were analyzed for patients diagnosed after 1997 (n=53), corresponding to the change to high dose methotrexate as the standard of care. Survival was calculated from the date of tissue diagnosis to date of death or last contact. Survival curves were estimated using the Kaplan-Meier method. The log-rank test was used to compare survival across groups. Two-tailed p-values <0.05 were considered statistically significant. Clinical information for the 1985–2006 and 1997–2006 groups was comparable, including median age (67 years (y) vs 68 y), age range (26–87 y for both groups), percentage of deaths (67 vs 64) and median follow up for survivors (588 d vs 395 d). Results: Thirty-four (45%) cases showed del(6)(q22), 6 of which alsocontained a BCL6 rearrangement. Seventeen (22%) cases had a BCL6 rearrangement. Translocations involving IGH and an unknown partner gene (n=2) and MYC and an unknown partner gene (n=2) were also identified. All cases were EBER negative. Of the 53 patients diagnosed after 1997, 23 lacked del(6)(q22) or BCL6 rearrangement and had a median overall survival (MS) of 731 days (d). The 17 patients with an isolated del(6)(q22) had a MS of 90 d and the 13 patients with a BCL6 rearrangement had a MS of 442 d (p=0.0016). Conclusions: Del(6)(q22) and BCL6 rearrangements are common in PCNSL (45% and 22% of cases, respectively) and are associated with decreased survival, particularly del(6)(q22) seemingly independent of patient age and treatment time trends. IGH translocations were less frequent than in systemic diffuse large B-cell lymphoma (13% vs 51%), suggesting a distinct pathogenesis. MYC translocations and EBV infection are rare in PCNSL affecting immunocompetent patients.

PCNSL molecular pathogenesis in immunocompetent patients is largely unknown. Small studies suggest a role for immunoglobulin heavy chain (IGH) gene translocations. We studied the incidence of IGH, BCL6, and MYC gene rearrangements in 44 PCNSL affecting immunocompetent patients, diagnosed and treated at Mayo Clinic (1992–2006). All cases were DLBL according to the WHO classification, confined to the CNS. Interphase fluorescence in‐situ hybridization (FISH) was performed using a two‐color IGH‐BCL6 dual‐fusion probe and a two‐color MYC breakapart (BAP) probe on paraffin‐embedded tumor samples. Two‐color BCL6 or IGH BAP FISH probes were also used in cases showing extra FISH signals other than IGH‐BCL6 fusion. Sufficient tumor cells for FISH analysis using the IGH‐BCL6 and MYC probes were available in 43 and 39 cases, respectively. IGH‐BCL6 fusion was present in 6 (14%) cases, one also with a separated MYC signal. Three (7%) cases showed 3 intact BCL6 signals using both the IGH‐BCL6 and BCL6 BAP probes, indicating trisomy 3. One (2%) showed 3 intact IGH signals using both the IGH‐BCL6 and IGH BAP probes, indicating trisomy 14. Remaining 33 (77%) cases lacked abnormalities involving IGH, BCL6 or MYC. IGH‐BCL6 fusion was present in 14% of cases, 1 of which also had a translocation involving MYC and an unknown partner gene. All other cases lacked translocations involving IGH, BCL6, and MYC. The frequency of IGH‐BCL6 translocations in PCNSL is less than that seen in systemic DLBCL. Other translocations involving IGH that are not uncommon in systemic DLBCL, such as IGH‐BCL2 and IGH‐MYC, are rare to absent in PCNSL, suggesting a distinct pathogenesis for PCNSL compared to systemic DLBCL.

Abstract Background Consensus in timing of radiotherapy is yet to be established in esthesioneuroblastoma (ENB). Objective This study was aimed to investigate if planned adjuvant radiotherapy improves tumor control after complete margin negative resection of low Hyams' grade (1 or 2) ENB. Methods A retrospective review of patients with pathologically confirmed negative margin resection of Kadish's stage B or C and Hyams' grade 1 and 2 ENBs was conducted. Seventeen patients meeting the criteria were divided into the following two groups for cohort study: (1) those who underwent planned immediate postoperative adjuvant radiotherapy (IR group) and (2) those who did not (delayed radiotherapy [DR] group). Results The IR group included nine patients (Kadish's stage B in one and stage C in eight; Hyams' grade 1 in two and grade 2 in seven). Mean follow-up was 140.8 months. Seven patients (78%) had disease progression (DP) at a median of 88 months (four with cervical lymph node metastasis [CLNM], one with distant metastasis, and two with both local recurrence and CLNM). One patient experienced frontal lobe abscess. The DR group included eight patients (Kadish's stage B in six and stage C in two; all Hyams' grade 2). Mean follow-up was 123.3 months. Four (50%) patients who developed DP (all local recurrence) were salvaged with surgery and adjuvant radiotherapy at a median of 37.5 months. There was no statistically significant difference in DP rate (p = 0.23), time to DP (p = 0.26), or the local tumor control rate (p = 0.23). Conclusion In our limited cohort, immediate postoperative radiotherapy did not demonstrate superiority in tumor control, although risk of radiotherapy toxicity appears low.

PCNSLs in elderly persons are usually not mediated by Epstein Barr Virus (EBV), unlike PCNSLs in patients with AIDS or organ transplantation; hence IHC or ISH studies for EBV are not routinely performed. We have encountered patients 65 years or older who had autoimmune polyneuropathy (on CellCept for 3 years), polymyositis (oral prednisone alone for >15 years), rheumatoid arthritis (methotrexate >10 years), myasthenia gravis (azathioprine >10 years), or “senile immunosuppression” who developed multifocal, necrotic, EBV+ PCNSLs. Reducing or withdrawing immunosuppressive medications lead to recovery and regression of the PCNSL in some patients, but not all. The striking feature of this series is the variety of underlying diseases‐‐ and accompanying medications‐‐ that can be associated with EBV‐mediated PCNSLs in the elderly patient. Increased testing of PCNSLs for EBV by IHC or ISH may be warranted in any elderly person on any immunosuppressive medication.

2025 Background: Although adjuvant radiation has demonstrated a clear survival benefit in anaplastic astrocytomas (AA), the role of concurrent temozolomide (TMZ) remains controversial. Methods: All adult patients diagnosed with AA from 2001 to 2011 and treated with standard doses of adjuvant radiation were identified retrospectively using the neuro-oncology database at the Mayo Clinic (Rochester, MN). Clinical data was extracted from the electronic medical record. IDH mutation status was also determined by obtaining either IDH1R132H immunostain on existing unstained slides or paraffin block sections, or by sequencing. Cumulative survival probabilities were estimated using the Kaplan-Meier method. Univariable and multivariable Cox proportional hazards regression models were fit to compare patients who did/did not receive TMZ. Results: 218 patients were identified that met inclusion criteria. 34 patients were excluded due to missing data on adjuvant chemotherapy. 146 patients had received adjuvant TMZ while 38 had not. Of these, IDH mutation status was determined on 124 patients who received TMZ and 33 of those who had not. The median duration of follow up was 36.4 months. On univariable analysis, adjuvant TMZ demonstrated a trend towards improved median survival from 35.2 to 53.1 months (p=0.06). As an independent variable, patients with IDH mutations had longer median survivals (111.7 months) when compared to IDH wild-type patients (23.3 months) (p<0.001). On multivariable analysis, five-year-survival was significantly impacted by receipt of adjuvant TMZ (HR = 0.56, p=0.03) and IDH mutation status remained a significant prognostic factor (HR = 0.19, p < 0.001) (see Table). Conclusions: IDH mutation strongly predicts a favorable outcome in patients with AA. Secondarily, concurrent TMZ is also associated with improved survival in patients with AA who are receiving adjuvant radiotherapy. [Table: see text]

2031 Background: The mammalian target of rapamycin (mTOR) functions within the PI3K/Akt pathway as a critical modulator of cell survival. Preclinical studies in GBM indicate that the combination of mTOR inhibitors, such as everolimus (RAD001), with either radiation therapy (RT) or temozolomide (TMZ) provide increased tumor cell killing. Methods: Newly diagnosed GBM pts were eligible for the study. RAD001 was dosed orally at 70 mg/week weekly, starting 1 week prior to RT/TMZ, and continued throughout RT/TMZ, adjuvant TMZ and then until progression. This was a single arm phase II design powered to detect a true overall survival at 12 months (OS12) of 73% (vs 58% in historical controls). Secondary endpoints were toxicity, response rate, and time to progression (TTP). A subgroup of patients with measurable residual disease were eligible for the PET imaging component of the study, consisting of an 18FLT-PET/CT scan performed before and after the initial two doses of RAD001 but before the first dose of RT or TMZ. Results: 103 patients were accrued to phase II of which 100 were evaluable. The median age was 60.5 years (23-81), median ECOG PS was 1, 46 patients had GTR, 33 STR, and the remainder had biopsy at diagnosis. Treatment tolerance was acceptable: 17% patient had at least one grade 3 hematologic toxicity; 14% had at least one grade 4 hematologic toxicity, 42% had at least one grade 3 non-heme toxicity, while 12% had at least one grade 4 non-heme toxicity. No increased incidence of infectious complications was observed and there were no treatment related deaths. Median PFS was 5.3 months (1.3-21.4), with 22 patients progression free. Mature OS data will be available at the meeting. MGMT methylation status analysis is ongoing. Of the pts who had evaluable FLT-PET data, three of eight (37.5%) had a drop in SUVmax >25% after two treatments of RAD001. Conclusions: RAD001 with standard of care chemoradiation had moderate toxicity. Serial 18FLT-PET was feasible for evaluating drug-induced changes in tumor proliferation following RAD001. Final outcome data and association of MGMT status with outcome will be reported at the meeting.

2046 Background: Vorinostat (VOR) is a histone deacetylase inhibitor that represents a rational targeted agent in GBM treatment. Given its single-agent activity in recurrent disease (Galanis,et al, 2009) and radiosensitizing properties, this phase I/II trial was designed to test the addition of VOR to standard chemoradiation in newly diagnosed GBM patients (pts): the phase I portion of the trial is the focus of this report. Methods: A standard cohorts of three design was used to assess the safety of VOR in combination with RT and concomitant TMZ and establish the phase II dose of the combination. VOR was given orally days 1 - 5 every wk beginning with the first dose of RT (total dose 60 Gy) and (75mg/m²/day). Following a 4 - 6 week rest, pts received up to 12 cycles of standard adjuvant TMZ in combination with VOR on days 1-7 and 15 – 21 of each cycle; dose was based on NABTT trial 04-03 (Lee, et al, 2012). Results: The phase I component is complete with 15 pts, 12 pts at dose level 0 (VOR 300 mg/day days 1 - 5, weekly x 6 wks), and 3 pts at dose level 1 (VOR 400 mg/day, days 1 – 5 weekly x 6 wks) in combination with RT/TMZ. Dose limiting toxicity (DLT) in dose level 1 included grade 3 fatigue in 2 pts, grade 3 wound dehiscence in 1 pt, and grade 4 neutropenia and thrombocytopenia in 1 pt. In dose level 0, 1/6 pts had DLT (gr 3 dyspnea). An MTD expansion cohort of 6 additional patients was added to dose level 0; one patient experienced grade 4 thrombocytopenia and grade 3 fatigue, and 1 patient experienced grade 3 febrile neutropenia. In the 12 pts treated in the phase II dose, most common toxicities were hematologic, including lymphopenia (gr 3/4 in 66.7%), thrombocytopenia (gr 3 in 16.7%, gr 4 in 16.7%) and neutropenia (gr 3 in 16.7%, gr 4 in 8.3%). Grade 3 fatigue was observed in 8.3% of the pts. Conclusions: MTD for VOR in combination with TMZ/RT in newly diagnosed GBM patients is 300 mg/d, days 1 - 5 weekly during RT. Toxicity was primarily hematologic. This dose was used in the recently completed phase II trial of the combination (110 pts). RNA expression profiling in patient samples is in process to assess vorinostat responsive signatures observed in preclinical models. Clinical trial information: NCT00731731.

2014 Background: PFS6 is low (2.3%) and med OS brief (4 mos) for recurrent GBM pts who progress after prior RT/TMZ and bevacizumab (Bev), and then receive non-Bev containing regimens (Reardon et al, Br J Canc 2012). Following VEGFi exposure, tumor cell resistance potentially may result from activation of Ras/Raf/MEK/ERK (MAPK) and PI3K/Akt/mTOR signaling pathways. Temsirolimus (mTOR inhibitor) and sorafenib (Raf, PDGFR, VEGFR inhibitor) have previously shown limited single agent activity in GBM. Methods: Recurrent GBM pts who showed radiographic progression despite prior surgery, RT + temozolomide, and VEGFi (initially or at recurrence) received sorafenib 200 mg PO bid and temsirolimus 20 mg IV weekly (the NCCTG N0572 phase I MTD) until progression. All pts had received < 2 prior chemo regimens. A two-stage design was used, with 90% power to detect an increase in PFS6 from 8% to 23%, requiring 41 evaluable pts. The primary endpoint was PFS6; secondary endpoints included OS, TTP, and ORR. Toxicity (TOX) was assessed using CTC ver 3.0. Results: 44 evaluable pts were accrued. Four of the first 40 (10%) reached PFS6, but this did not meet the pre-study threshold for success. Median TTP was 1.8 mos. (40 events, 95% CI: 1.5 – 2.3); median OS was 5 mos. (36 events, 95% CI: 6.6 – 3.1), and no objective responses were reported. Eight pts are alive; 4 have not progressed (median F/U 3.1 mos.; max, 12.2 mos.). Grade 3+ non-heme AE were observed in 51% (23/45; fatigue-5, hypophosphatemia-7, hypercholesterolemia-5, hypertriglyceridemia-5). One grade 4 hematologic AE (thrombocytopenia) occurred. 13.3% (6/45 pts) went off due to TOX, and 71.1% (32/45) due to disease progression. Conclusions: Sorafenib plus temsirolimus was tolerable, but the primary endpoint threshold for success (PFS6) was not met in post-VEGFi recurrent GBM patients. Nevertheless, PFS6 (10%) and OS (5 mos.) compared favorably to contemporary series of Bev-refractory, recurrent GBM pts who are subsequently treated with a non-Bev containing regimen. Supported by NCI CA-25224. Clinical trial information: NCT00329719.

2032 Background: Dasatinib is a potent oral ATP competitive multi-targeted kinase inhibitor of multiple members of the Src kinase family, known to be involved in gliomagenesis and invasion. N0877 is a phase I/randomized phase II trial evaluating the combination of dasatinib, radiation (RT) and temozolomide (TMZ) in newly diagnosed GBM. The phase I portion has been completed and is the focus of this report. Methods: A cohorts-of-3 design was used to assess the safety of dasatinib in combination with RT and concomitant TMZ, and establish the phase II dose of the combination. Dasatinib was given orally for 42 days, beginning with the first day of RT (total dose 60 Gy) and first dose of TMZ (75 mg/m2/d). A 24 - 42 day rest (cycle 2) followed the RT/TMZ/dasatinib. Patients (pts) were observed for DLT to the end of cycle 2. Patients then received 6 cycles (28 day cycles) of dasatinib (once daily) and TMZ (days 1-5). At the completion of 6 cycles of TMZ + dasatinib, pts stay on dasatinib only (28 day cycles) until progressive disease. Results: Phase I component is complete with 13 patients (3 at dose level 0, 3 at dose level 0-A, 7 at dose level 1). One patient in dose level 1 had to be replaced due to the development of unrelated medical issues. One DLT (grade 4 pancytopenia) was observed in 1 patient at dose level 0 (50mg bid) and one DLT (grade 3 rash) was observed in 1 patient at dose level 1 (150mg qd). MTD of dasatinib was determined to be 150mg daily. Most common adverse events throughout the entire study period were hematologic with the most common toxicity being lymphopenia (grade 3 in 69% of patients, grade 4 in 8%). Other toxicities attributed to treatment and occurring in > 10% of patients included anemia (31%), neutropenia (15%), and fatigue(15%). Best response was stable disease in 10 patients, progressive disease in 1 patient, and not evaluable in 2. Conclusions: MTD for dasatinib in combination with TMZ and RT in newly diagnosed GBM patients is 150mg daily. Toxicity was primarily hematologic with minimal non-hematologic events. This dose is currently being used in the ongoing placebo-controlled, randomized phase II trial.