Salvage chemotherapy with procarbazine and fotemustine combination in the treatment of temozolomide treated recurrent glioblastoma patients

The purpose of this study was to evaluate safety and efficacy of Procarbazine (PCB) and fotemustine (FTM) combination in the treatment of pre-temozolomide treated, recurrent GBM patients. The primary end-point was progression free survival at 6 months (PFS-6). Secondary end-points were overall survival, response rates (CR + PR) and toxicity. About 54 patients (41 men and 13 women) aged 26–68 years (median age, 53.5 years) with recurrent GBM were treated. PCB was administered as an oral dosage of 450 mg on days 1–2 and a total dose of 300 mg on day 3. FTM was administered on day 3, 3 h after the last PCB intake at a dose of 110 mg/mq/BSA. The treatment was repeated every 5 weeks. Treatment was continued for a maximum of six cycles or until disease progression. After two cycles of chemotherapy: 6 patients (11.2%) experienced a neuroradiographic partial response (PR), 29 patients (53.7%) had stable disease (SD), and 19 patients (35.1%) had progressive disease (PD). For the whole group of patients, the median PFS was 19.3 weeks (95% CI, 14.1–24.4 weeks), and PFS-6 was 26.7% (95% CI, 10.6–42.8%). Overall MST from the beginning of PCB + FTM chemotherapy was 28.7 weeks (95% CI, 24.8–32.7 weeks). At 6 and 12 months, 64.4% (95% CI, 51.5–77.3%) and 23.6% (95% CI, 10.1–37.1%) of patients were alive. The median survival time calculated from the first diagnosis was 20.8 months (95% CI, 16.7–24.8). We concluded that the PCB + FTM combination as done in the current trial for patients with recurrent GBM after treatment with TMZ showed some benefit with regards to increased survival and that a Phase III trial is warranted. Two errata are available for this article; the first one at , the second one at . An erratum to this article can be found at     

Combined chemotherapy with temozolomide and fotemustine in recurrent glioblastoma patients

Journal of Neuro-Oncology -     

Twice-daily dosing of temozolomide in combination with fotemustine for the treatment of patients with refractory glioblastoma

Alkylating agents, such as temozolomide (TMZ) and fotemustine (FTM) are widely used in recurrent glioblastoma (GBM) regimes. Several strategies have been proposed to prevent resistance to these agents, by combining or sequencing them. We report the results of a pilot study of patients with refractory GBM receiving a regime of twice-daily dosing of temozolomide administered on day 1, (with an initial oral dose of 200 mg/m(2) and a second oral dose of 75 mg/m(2) 12 h later), followed by fotemustine in a single i.v. infusion at 75 mg/m(2) on day 2, repeated every four weeks. Enrolment was stopped at 15 patients due to lack of effectiveness of this schedule for patients with GBM. Toxicity was mild, with no grade 4 side effects reported. Results indicate that our temozolomide -FTM combined schedule is not effective, although well tolerated, in non responsive patients with GBM. Further strategies are required to improve the outcome of these patients.     

Health-related quality of life in patients treated with temozolomide versus procarbazine for recurrent glioblastoma multiforme.

PURPOSE: To determine whether chemotherapy with temozolomide (TMZ) versus procarbazine (PCB) for recurrent glioblastoma multiforme (GBM) was associated with improvement in health-related quality of life (HRQOL). PATIENTS AND METHODS: HRQOL was assessed at baseline and during treatment using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and a Brain Cancer Module (BCM20) in two clinical trials that enrolled a total of 366 patients. Two hundred eighty-eight patients provided HRQOL data that could be used for analysis; 109 patients received TMZ in a phase II study, whereas 89 patients received TMZ and 90 received PCB in a randomized phase III study. Changes from baseline in the scores of seven preselected HRQOL domains (role and social functioning, global quality of life [QOL], visual disorders, motor dysfunction, communication deficit, and drowsiness) were calculated for all groups. Statistical significance, effect sizes, and proportions of patients with improved HRQOL scores (changes of > or = 10 points) were calculated. RESULTS: Before disease progression, patients treated with TMZ were found to have an improvement in most of the preselected HRQOL domain scores compared with their baseline (pretreatment) scores. Those who were progression-free on TMZ at 6 months had improvement in all the preselected HRQOL domains. Conversely, patients treated with PCB reported deterioration in HRQOL that was independent of whether or not the disease had progressed by 6 months. Patients with disease progression, regardless of treatment, experienced a sharp decline in all domains at the time of progression. CONCLUSION: Treatment with TMZ was associated with improvement in HRQOL scores compared with treatment with PCB. The deterioration reported by PCB-treated patients was likely because of toxicity. Delaying disease progression by treatment with TMZ is beneficial to the HRQOL status of patients with recurrent GBM.     

Efficacy and safety of second-line fotemustine in elderly patients with recurrent glioblastoma

Fotemustine (FTM) is a common treatment option for glioblastoma patients refractory to temozolomide (TMZ). Although elderly patients represent a large component of glioblastoma population, the feasibility and the efficacy of second-line FTM are not available in those patients.We retrospectively analyzed the records of glioblastoma patients older than 65 years, receiving FTM at a dose of 70–100 mg/m² of FTM every week for 3 consecutive weeks (induction phase) and then every 3 weeks (70–100 mg/m²), as second-line treatment.Between January 2004 and December 2011, 65 glioblastoma patients (median age, 70 years; range, 65–79 years) were eligible for this analysis. Sixty-five patients received a total of 364 FTM cycles, with a median of 4 cycles for each patient. After induction, we observed 1 complete response (1.5 %), 12 partial responses (18.5 %), 18 stable diseases (27.7 %), and 34 patients’ progressions (47.7 %). Disease control rate was 43.1 %. Median survival from the beginning of FTM therapy was 7.1 months, while the median progression-free survival was 4.2 months, and the 6-months progression free survival rate was 35.4 %. The most relevant grade 3–4 toxicity events were thrombocytopenia (15.3 %) and neutropenia (9.2 %). In the univariate and multivariate analysis, time from radiotherapy to FTM, number of TMZ and FTM cycles and disease control resulted independent prognostic factors.This study showed that FTM is a valuable therapeutic option for elderly glioblastoma patients, with a safe toxicity profile.     

Salvage chemotherapy with cyclophosphamide for recurrent, temozolomide-refractory glioblastoma multiforme

BACKGROUND: The primary objective of the current prospective Phase II study of cyclophosphamide (CYC) in adult patients with recurrent, temozolomide-refractory glioblastoma multiforme was to evaluate 6-month progression-free survival (PFS). METHODS: Forty patients (28 men and 12 women) ages 28-67 years (median age, 51.5 years), with recurrent glioblastoma multiforme were treated. All patients had been treated previously with surgery and involved-field radiotherapy (median dose, 60 grays [Gy]; range, 59-61 Gy). In addition, all patients were treated adjuvantly with either nitrosourea-based chemotherapy (21 patients: procarbazine, lomustine, and vincristine in 13 patients; carmustine in 8 patients) or temozolomide (19 patients). Twenty-one patients who were treated previously with a nitrosourea were treated with temozolomide at the time of first recurrence. Twenty-one patients were treated with CYC at the time of second recurrence, and 19 patients were treated with CYC at the time of first recurrence. CYC was administered intravenously on 2 consecutive days (750 mg/m2 per day) every 4 weeks (operationally defined as a single cycle). Neurologic and neuroradiographic evaluations were performed every 8 weeks. RESULTS: All patients were evaluable. In total, 170 cycles of CYC (median, 2 cycles; range, 2-12 cycles) were administered. CYC-related toxicity included alopecia in all patients (100%), anemia in 6 patients (3.5%), thrombocytopenia in 7 patients (4.1%), and neutropenia in 9 patients (5.3%). Four patients required transfusions (two required red blood cell transfusion, and two required platelet transfusion). One patient developed neutropenic fever without bacteriologic confirmation. No treatment-related deaths occurred. Seven patients (17.5%; 95% confidence interval [95% CI], 8-33%) exhibited a neuroradiographic partial response, 11 patients (27.5%; 95% CI, 15-44%) had stable disease, and 22 patients (55%) had progressive disease after a single cycle of CYC. The time to tumor progression ranged from 2 months to 18 months (median, 2 months). Survival ranged from 3 months to 24 months (median, 4 months). In patients with either a neuroradiographic response or stable disease (n = 18 [45%]), the median time to tumor progression was 6 months (range, 4-18 months; 95% CI, 6-8 months), and the median survival was 10 months (range, 5-24 months; 95% CI, 8-10 months). The 6-month PFS rate was 20%. CONCLUSIONS: CYC exhibited modest efficacy with acceptable toxicity in the current cohort of adult patients with recurrent glioblastoma multiforme, all of whom had previously experienced treatment failure after temozolomide chemotherapy.     

A pilot study of metronomic temozolomide treatment in patients with recurrent temozolomide-refractory glioblastoma

Frequent regular administration of chemotherapeutic agents at low doses, known as 'metronomic chemotherapy', can increase the anti-angiogenic activity of the drugs, as has been confirmed by several other experimental tumor models. The aim of this pilot study was to evaluate the efficacy and safety of metronomic temozolomide (TMZ) treatment in twelve consecutive patients with recurrent TMZ-refractory glioblastoma. The patients were administered by metronomic treatment schedule (continuous low-dose chemotherapy) with TMZ at a daily dose of 40 mg/m(2). The median overall survival (OS) and progression-free survival (PFS) from the start of metronomic treatment were 11.0 months (95% CI, 5.2-10.5 months) and 6.0 months (95% CI, 0-12.3 months), respectively. During the follow-up period, complete response (CR) was not achieved in any patient, partial response (PR) in 2, and stable disease (SD) in 5 patients. Estimated PFS (CR+PR+SD) was 58.3% at 3 months. Grade III/IV toxicity according to the National Cancer Institute Common Toxicity Criteria (NCI CTC) was not found. These results suggest that the change of chemotherapeutic schedule from conventional to metronomic treatment overcomes the chemo-resistance in patients with recurrent TMZ-refractory glio-blastoma without any major toxicity.     

Fractionated stereotactic reirradiation and concurrent temozolomide in patients with recurrent glioblastoma

The aim of this paper is to evaluate the efficacy of fractionated stereotactic radiotherapy (FSRT) and concomitant temozolomide (TMZ) as a salvage treatment option in patients with recurrent glioblastoma (GBM). Between May 2006 and December 2009, 36 patients with recurrent GBM received FSRT plus concomitant TMZ at University of Rome La Sapienza, Sant’ Andrea Hospital. All patients had Karnofsky performance score ≥60 and were previously treated with standard conformal radiotherapy (RT) (60 Gy) with concomitant and adjuvant TMZ for 6–12 cycles. The median time interval between primary RT and reirradiation was 14 months. At the time of recurrence, all patients received FSRT plus concomitant daily TMZ at the dose of 75 mg/m², given 7 days per week from the first day of RT. Radiation dose was 37.5 Gy delivered in 15 fractions over 3 weeks. Median overall survival after FSRT was 9.7 months, and the 6- and 12-month survival rates were 84 and 33%, respectively. The median progression-free survival (PFS) was 5 months, and 6- and 12-month PFS rates were 42 and 8%, respectively. In univariate analysis, KPS (P = 0.04), the interval between primary RT and reirradiation (P = 0.02), and O6-methylguanine-DNA-methyltransferase (MGMT) methylation status at the time of diagnosis (P = 0.009) had an effect on survival; however, in multivariate analysis, only MGMT methylation was statistically significant (P = 0.03). In general, FSRT was well tolerated and the treatment was completed in all patients. Neurological deterioration due to radiation-induced necrosis occurred in three patients (8%). FSRT plus concomitant TMZ is a feasible treatment option associated with survival benefits and low risk of complications in selected patients with recurrent GBM. The potential advantages of combined chemoradiation schedules in patients with recurrent GBM need to be explored in future studies.     

Prognostic significance of O6-methylguanine-DNA methyltransferase protein expression in patients with recurrent glioblastoma treated with temozolomide

BACKGROUND: Temozolomide (TMZ) is active against newly diagnosed glioblastoma (GBM), and O(6)-methylguanine-DNA methyltransferase (MGMT) is implicated in resistance to TMZ and nitrosoureas. We evaluated the efficacy and safety of the standard 5-day TMZ regimen in patients with recurrent GBM after initial therapy including nitrosourea-based chemotherapy, in conjunction with an analysis of the prognostic value of MGMT protein expression regarding response to TMZ and survival. METHODS: From September 2003 to January 2007, 30 patients having recurrent GBM received 150-200 mg/m(2)/day of TMZ for five consecutive days every 28 days. Tumor tissue from 19 patients was analysed for MGMT protein expression using western blotting, and 17 of them were assessable for a response. RESULTS: The overall response rate was 23.5% (one complete response and three partial responses). Six patients had stable disease (35.3%). Median progression-free survival (PFS) time was 2.2 months, and median overall survival (OS) time was 9.9 months from the initiation of TMZ therapy. Patients with low MGMT protein expression had a significantly improved PFS (P = 0.016) and OS (P = 0.019) compared to those with high expression. Both low MGMT expression (P = 0.040) and re-resection at relapse (P = 0.014) persisted as significant independent favorable prognostic factors for OS. The most common grade 3 and 4 hematological toxicity was lymphopenia (22.2%). CONCLUSIONS: The standard 5-day TMZ regimen resulted in moderate antitumor activity with an acceptable safety profile in patients with nitrosourea-pretreated recurrent GBM, and protein expression of MGMT is an important prognostic factor for patients treated with TMZ even after recurrence.     

Phase 2 study of temozolomide and Caelyx in patients with recurrent glioblastoma multiforme

Temozolomide has established activity in the treatment of recurrent glioblastoma multiforme (GBM). Caelyx (liposomal doxorubicin) has established activity in a broad range of tumors but has not been extensively evaluated in the treatment of GBM. Phase 1 data suggest that temozolomide and Caelyx can be combined safely at full dose. In this phase 2 study, combination temozolomide (200 mg/m(2) orally, days 1-5) and Caelyx (40 mg/m(2) i.v., day 1) was given every 4 weeks to a cohort of 22 patients with recurrent GBM, who received a total of 109 cycles (median 3.5 cycles). The median age of the patients was 55 years (range, 31-80 years), and 17 were male. All patients had received radiotherapy, but only 2 had received prior chemotherapy. One patient (5%) had a complete response, 3 patients (14%) had a partial response, and 11 patients (50%) had stable disease. The median time to progression for the cohort was 3.2 months (range, 1-13 months). Median overall survival was 8.2 months (range, 1-16+ months). Seven patients (32%) were progression free at 6 months. Hematological toxicity included grade 3/4 neutropenia in 4 patients (18%) and grade 3/4 thrombocytopenia in 4 patients (18%). Grade 3 non-hematologic toxicity included rash in 3 patients (14%), nausea and vomiting in 1 patient (4%), hypersensitivity reaction to Caelyx in 3 patients (14%), and palmar-plantar toxicity in 1 patient (4%). We conclude that the combination of temozolomide and Caelyx is well tolerated, results in a modest objective response rate, but has encouraging disease stabilization in the treatment of recurrent GBM.     

A phase II study of temozolomide vs. procarbazine in patients with glioblastoma multiforme at first relapse

A randomized, multicentre, open-label, phase II study compared temozolomide (TMZ), an oral second-generation alkylating agent, and procarbazine (PCB) in 225 patients with glioblastoma multiforme at first relapse. Primary objectives were to determine progression-free survival (PFS) at 6 months and safety for TMZ and PCB in adult patients who failed conventional treatment. Secondary objectives were to assess overall survival and health-related quality of life (HRQL). TMZ was given orally at 200 mg/m(2)/day or 150 mg/m(2)/day (prior chemotherapy) for 5 days, repeated every 28 days. PCB was given orally at 150 mg/m(2)/day or 125 mg/m(2)/day (prior chemotherapy) for 28 days, repeated every 56 days. HRQL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30 [+3]) and the Brain Cancer Module 20 (BCM20). The 6-month PFS rate for patients who received TMZ was 21%, which met the protocol objective. The 6-month PFS rate for those who received PCB was 8% (P = 0.008, for the comparison). Overall PFS significantly improved with TMZ, with a median PFS of 12.4 weeks in the TMZ group and 8.32 weeks in the PCB group (P = 0.0063). The 6-month overall survival rate for TMZ patients was 60% vs. 44% for PCB patients (P = 0.019). Freedom from disease progression was associated with maintenance of HRQL, regardless of treatment received. TMZ had an acceptable safety profile; most adverse events were mild or moderate in severity.     

Salvage ifosfamide-doxorubicin chemotherapy in patients with recurrent nasopharyngeal carcinoma pretreated with cisplatin-based chemotherapy

This study evaluated the efficacy and toxicity of ifosfamide and doxorubicin chemotherapy regimen in Turkish patients with recurrent or metastatic nasopharyngeal carcinoma (NPC) previously treated with platinum-based chemotherapy. Twenty-one patients with recurrent or metastatic NPC previously treated with platinum-based chemotherapy as adjuvant or palliative treatments who received ifosfamide 2500 mg/m² d 1–3, mesna 2500 mg/m² d 1–3, doxorubicin 60 mg/m² d 1, repeated every 21 d was retrospectively analyzed. Patients received a median number of three cycles of ifosfamide-doxorubicin (range: 1–6). Seven patients (33.3%) achieved partial response and no patient achieved complete response. Six (28.5%) had stable disease, whereas three (18.75%) had progressive disease. The median time to progression was 7.0 mo. Ifosfamide-doxorubicin regimen is an effective salvage regimen in patients with recurrent and metastatic NPC.     

Hypofractionated radiotherapy followed by adjuvant chemotherapy with temozolomide in elderly patients with glioblastoma

Objectives The optimal treatment for elderly patients (age >70 years) with glioblastoma (GBM) remains controversial. We conducted a prospective trial in 43 consecutive elderly patients with GBM treated with hypofractionated radiotherapy (RT) followed by adjuvant temozolomide. Patients and methods Forty-three patients 70 years of age or older with a newly diagnosed GBM and a Karnofsky performance status (KPS) ≥ 60 were treated with hypofractionated RT (6 fractions of 5 Gy each for a total of 30 Gy over 2 weeks) followed by up to 12 cycles of adjuvant temozolomide (150–200 mg/m² for 5 days during each 28 day cycle). The HRQOL was assessed with the EORTC Quality of Life Questionnaire C30. The primary endpoint was overall survival (OS). Secondary endpoints included progression free survival (PFS), toxicity and quality of life. Results The median OS was 9.3 months and the median PFS was 6.3 months. The 6 and 12 month survival rates were 86% and 35%, respectively. The 6 and 12 month PFS rates were 55% and 12%, respectively. In multivariate analysis KPS was the only significant independent predictive factor of survival (P = 0.008). Neurological deterioration occurred during or after RT in 16% of patients and was resolved in most cases with the use of steroids. Grade 3–4 hematologic toxicity occurred in 28% of patients during the adjuvant chemotherapy treatment with temozolomide. The treatment had no negative effect on HRQOL, however, fatigue (P = 0.02) and constipation (P = 0.01) scales worsened over time. Conclusions Hypofractionated RT followed by temozolomide may provide survival benefit maintaining a good quality of life in elderly patients with GBM. It may represent a reasonable therapeutic approach especially in patients with less favourably prognostic factors.     

Salvage therapy with whole-abdominal irradiation in patients with advanced carcinoma of the ovary previously treated by combination chemotherapy

Whole-abdominal irradiation was delivered to 22 patients with epithelial carcinoma of the ovary who had persistent disease after chemotherapy. Seventeen patients were treated with an open whole-abdominal field and 5 with the moving-field technique. Eleven of the 22 also received a pelvic boost. Two of nine patients with microscopic disease at second look are alive and disease-free at 34 and 52 months, respectively. There were no salvages among the patient with macroscopic disease. Major complications included bowel obstruction in three patients and radiation enteritis in one patient. Whole-abdominal irradiation is not an effective salvage regimen after multiagent chemotherapy.     

Bevacizumab and daily temozolomide for recurrent glioblastoma

BACKGROUND:

The authors performed a phase 2 trial of combined protracted daily temozolomide and biweekly bevacizumab for patients with recurrent glioblastoma who had previously received radiation therapy and temozolomide.

METHODS:

There was no limit on the number of previous disease progressions or previous regimens allowed. Thirty‐two adult patients were enrolled. Patients received temozolomide 50 mg/m² daily and bevacizumab 10 mg/kg intravenously every 14 days. Patients underwent physical examination and brain magnetic resonance imaging every 8 weeks.

RESULTS:

The authors observed a 6‐month progression‐free survival (PFS) rate of 18.8% (95% confidence interval [CI], 7.6%‐33.7%) and a median PFS of 15.8 weeks. The median overall survival (OS) was 37 weeks, the 6‐month OS rate was 62.5% (95% CI, 43.5%‐76.7%), and the 12‐month OS rate was 31.3% (95% CI, 16.4%‐47.3%). Nine patients (28%) had a radiographic response, and 7 patients (22%) had disease progression within the first 8 weeks of treatment. Patterns of progression were available for 21 patients. The authors observed that 52% of patients (n = 11) progressed locally, 38% (n = 8) progressed with a diffuse pattern, and 10% (n = 2) progressed at a distant site. Two patients discontinued therapy secondary to toxicity (prolonged thrombocytopenia and grade 4 pancreatitis). One patient experienced grade 5 pneumonia.

CONCLUSIONS:

The current study demonstrated that a regimen of combined daily temozolomide and biweekly bevacizumab had some activity and was well tolerated. However, the results obtained in this study were inferior to those observed in studies of bevacizumab monotherapy and of combined irinotecan and bevacizumab therapy. The current patient population was more heterogeneous and was pretreated more heavily than patients in previous studies. Cancer 2012;. © 2011 American Cancer Society.     

Continuous low-dose temozolomide and celecoxib in recurrent glioblastoma

Even after gross tumor resection and combined radiochemotherapy, glioblastomas recur within a few months. Salvage therapy often consists of rechallenging with temozolomide in a dose-intensified schedule. Previously, low-dose metronomic temozolomide in combination with cyclo-oxigenase 2 inhibitors has had a beneficial effect as first-line treatment for glioblastoma. We report our experience with this procedure in recurrent glioblastomas after standard treatment. From June 2007 to April 2009, 28 patients with recurrent glioblastoma received continuous low-dose temozolomide of 10 mg/m² twice daily and 200 mg celecoxib. Before therapy the recurrent tumor was resected in 19 of 28 patients. Microvessel density (MVD) was determined by immunohistochemistry in 19 patients, and MGMT promoter methylation status, using the pyrosequencing method, was determined in 17 patients. In 14/28 patients, positron emission tomography with [F-18]-fluoroethyl)-l-tyrosine (FET-PET) was performed. Tumor progression was defined by the Macdonald criteria on MRI every 8–12 weeks or by clinical deterioration. The median time to progression was 4.2 months. Progression-free survival (PFS) after 6 months was 43%. Except for a lymphopenia in one patient, there was no grade 3 or 4 toxicity. PFS did not correlate with MVD or MGMT status. A high FET uptake correlated with tumor control after 6 months under therapy (P = 0.041, t-test). Low-dose continuous temozolomide in combination with celecoxib seems to have activity in recurrent glioblastoma without relevant toxicity. High FET uptake correlated with a better outcome under metronomic therapy.     

Neurocognitive function in patients with recurrent glioblastoma treated with bevacizumab

Neurocognitive decline is a frequent adverse effect of glioblastoma. Antitumor therapies that are efficacious, as measured by traditional endpoints such as objective response (OR) and progression-free survival (PFS), and have beneficial effects on neurocognitive function (NCF) are of clinical benefit to these patients. We evaluated neurocognitive changes across time in 167 patients with recurrent glioblastoma treated with bevacizumab-based therapy in BRAIN, a phase II, randomized, multicenter trial. All patients underwent MRI and neurocognitive testing at baseline and every 6 weeks thereafter. Memory, visuomotor scanning speed, and executive function were evaluated using the Hopkins Verbal Learning Test-Revised, the Trail Making Test, and the Controlled Oral Word Association test, respectively. NCF relative to baseline for patients with an OR, PFS >6 months, or disease progression was evaluated at time of OR, 24 weeks, and time of progression, respectively. For patients with an OR or PFS >6 months, median standardized test scores were examined from baseline to week 24. Most patients with an OR or PFS >6 months had poorer NCF performance compared to the general population at baseline and had improved or stable NCF at the time of response or at the 24-week assessment, respectively; most patients with progressive disease had neurocognitive decline at the time of progression. For patients with an OR or PFS >6 months, median standardized test scores were largely stable across the first 24 weeks on study. Neurocognitive testing was an objective, valid, and feasible method of monitoring NCF in patients with recurrent glioblastoma.