Effect of health disparities on overall survival of patients with glioblastoma.

BACKGROUND: Examine the potential effects of health disparities in survival of glioblastoma (GB) patients. METHODS: We conducted a retrospective chart review of newly diagnosed GB patients from 2000 to 2015 at a free standing dedicated cancer center (MD Anderson Cancer Center-MDACC) and a safety net county hospital (Ben Taub General Hospital-BT) located in Houston, Texas. We obtained demographics, insurance status, extent of resection, treatments, and other known prognostic variables (Karnofsky Score-KPS) to evaluate their role on overall GB survival (OS). RESULTS: We identified 1073 GB patients consisting of 177 from BT and 896 from MDACC. We found significant differences by ethnicity, insurance status, KPS at diagnosis, extent of resection, and percentage of patients receiving standard of care (SOC) between the two centers. OS was 1.64 years for MDACC patients and 1.24 years for BT patients (p < 0.0176). Only 81 (45.8%) BT patients received SOC compared to 577 (64%) of MDACC patients (p < 0.0001). However, there was no significant difference in OS for patients who received SOC, 1.84 years for MDACC patients and 1.99 years for BT patients (p < 0.4787). Of the 96 BT patients who did not receive SOC, 29 (30%) had KPS less than 70 at time of diagnosis and 77 (80%) lacked insurance. CONCLUSIONS: GB patients treated at a safety net county hospital had similar OS compared to a free standing comprehensive cancer center when receiving SOC. County hospital patients had poorer KPS at diagnosis and were often lacking health insurance affecting their ability to receive SOC.

Randomized phase II adjuvant factorial study of dose-dense temozolomide alone and in combination with isotretinoin, celecoxib, and/or thalidomide for glioblastoma.

BACKGROUND: Chemoradiation, followed by adjuvant temozolomide, is the standard treatment for newly diagnosed glioblastoma. Adding other active agents may enhance treatment efficacy. METHODS: The primary objective of this factorial phase II study was to determine if one of 3 potential chemotherapy agents added to dose-dense temozolomide (ddTMZ) improves progression-free survival (PFS) for patients with newly diagnosed glioblastoma. A prior phase I trial established the safety of combining ddTMZ with isotretinoin, celecoxib, and/or thalidomide. Adults with good performance status and no evidence of progression post chemoradiation were randomized into 8 arms: ddTMZ alone (7 days on/7 days off) or doublet, triplet, and quadruplet combinations with isotretinoin, celecoxib, and thalidomide. RESULTS: The study enrolled 155 participants with a median age of 53 years (range, 18-84 y). None of the agents demonstrated improved PFS when compared with arms not containing that specific agent. There was no difference in PFS for triplet compared with doublet regimens, although a trend for improved overall survival (OS) was seen (20.1 vs 17.0 months, P = .15). Compared with ddTMZ, the ddTMZ + isotretinoin doublet had worse PFS (10.5 vs 6.5 months, P = .043) and OS (21.2 vs 11.7 months, P = .037). Trends were also seen for worse outcomes with isotretinoin-containing regimens, but there was no impact with celecoxib or thalidomide combinations. Treatment was well tolerated with expected high rates of lymphopenia. CONCLUSIONS: The results do not establish a benefit for these combinations but indicate that adding isotretinoin to ddTMZ may be detrimental. This study demonstrated the feasibility and utility of the factorial design in efficiently testing drug combinations in newly diagnosed glioblastoma. CLINICALTRIALSGOV IDENTIFIER: NCT00112502.

Isotretinoin maintenance therapy for glioblastoma: a retrospective review.

OBJECTIVES: The current standard treatment of glioblastoma includes maximal safe surgical resection, radiation, and temozolomide. Although isotretinoin has been used for maintenance therapy to delay tumor recurrence, this approach has not been proven to be effective. The objectives of the study are to compare the overall survival, progression-free survival and tolerability of isotretinoin maintenance therapy in patients who received isotretinoin maintenance therapy to patients who did not receive this treatment. METHODS: This study is a retrospective review of adult patients with glioblastoma treated at MD Anderson Cancer Center from 2004 to 2009. Patients who underwent surgical resection, radiation with concurrent temozolomide, and adjuvant treatment with temozolomide were included in the control group, and compared to similarly treated patients who received isotretinoin maintenance following adjuvant temozolomide. RESULTS: Eighteen patients who received isotretinoin maintenance therapy and 70 control patients were included in the analysis. Progression-free survival was 25.3 months with maintenance therapy versus 8.3 months for those not receiving maintenance (p = 0.04). There was no difference in the 2-year or 3-year overall survival estimates (p = 0.11). The common toxicities of isotretinoin included dermatologic-, metabolic-, and psychiatric-related adverse effects. CONCLUSIONS: Isotretinoin maintenance therapy was associated with increased progression-free survival, but did not increase the overall survival in this retrospective review. The potential benefit of maintenance therapy should be weighed against toxicities and negative impact on quality of life in this patient population.

A phase I factorial design study of dose-dense temozolomide alone and in combination with thalidomide, isotretinoin, and/or celecoxib as postchemoradiation adjuvant therapy for newly diagnosed glioblastoma.

External beam radiation therapy (XRT) with concomitant temozolomide and 6 cycles of adjuvant temozolomide (5/28-day schedule) improves survival in patients with newly diagnosed glioblastoma compared with XRT alone. Studies suggest that dose-dense temozolomide schedules and addition of cytostatic agents may further improve efficacy. This factorial design phase I/II protocol tested dose-dense temozolomide alone and combined with cytostatic agents. Patients with newly diagnosed glioblastoma received fractionated XRT to 60 Gy concomitant with temozolomide (75 mg/m²)/day for 42 days). In the phase I portion, patients with stable disease or radiologic response 1 month after chemoradiation were randomized to adjuvant temozolomide alone (150 mg/m²/day, 7/14-day schedule) or with doublet combinations of thalidomide (400 mg/day), isotretinoin (100 mg/m²/day), and/or celecoxib (400 mg twice daily), or all 3 agents. Toxicity was assessed after 4 weeks. Among 54 patients enrolled (median age, 52 years; median Karnofsky performance status, 90), adjuvant treatment was not administered to 12 (22%), primarily because of disease progression (n = 10). All combinations were well tolerated. Grade 3/4 lymphopenia developed in 63% of patients, but no related infections occurred. One patient treated with temozolomide plus isotretinoin plus thalidomide had dose-limiting grade 3 fatigue and rash, and 1 patient receiving all 4 agents had dose-limiting grade 4 neutropenia. Venous thrombosis occurred in 7 patients, 4 of whom received thalidomide. From study entry, median survival was 20 months and the 2-year survival rate was 40%. Multiple cytostatic agents can be safely combined with dose-dense temozolomide. The factorial-based phase II portion of this study is currently ongoing.

Chronic electrical stimulation does not prevent spiral ganglion cell degeneration in deafened guinea pigs.

Several studies have demonstrated that treatment with intracochlear chronic electrical stimulation (CES) protects spiral ganglion cells (SGCs) from degeneration in deafened animals. Other studies could not confirm this effect of CES. The present study examined whether CES in a mode as presented in cochlear implant users (amplitude modulated, high pulse rate) affects survival, morphology and functionality of SGCs in deafened guinea pigs. Eleven guinea pigs were implanted in the right cochlea with an electrode array to monitor the electrically evoked auditory brainstem responses (eABRs). The guinea pigs were deafened four weeks later. Two days after deafening, monopolar CES was started in five animals through three electrodes in the basal cochlear turn. CES lasted 4 hours per day, five days per week, for six weeks. SGC packing densities, perikaryal area, cell circularity, amplitudes of suprathreshold eABRs and eABR thresholds were not affected by CES. SGCs of all implanted cochleae were larger and more circular than SGCs in unimplanted cochleae, but this did not depend on CES treatment. Interestingly, an increase in eABR latencies observed after deafening, occurred faster in CES-treated than in untreated animals. In conclusion, amplitude-modulated chronic electrical stimulation with a high pulse rate does not affect survival, morphology and functionality of spiral ganglion cells with the exception of eABR latencies.

Review of microdialysis in brain tumors, from concept to application: first annual Carolyn Frye-Halloran symposium.

In individuals with brain tumors, pharmacodynamic and pharmacokinetic studies of therapeutic agents have historically used analyses of drug concentrations in serum or cerebrospinal fluid, which unfortunately do not necessarily reflect concentrations within the tumor and adjacent brain. This review article introduces to neurological and medical oncologists, as well as pharmacologists, the application of microdialysis in monitoring drug metabolism and delivery within the fluid of the interstitial space of brain tumor and its surroundings. Microdialysis samples soluble molecules from the extracellular fluid via a semipermeable membrane at the tip of a probe. In the past decade, it has been used predominantly in neurointensive care in the setting of brain trauma, vasospasm, epilepsy,and intracerebral hemorrhage. At the first Carolyn Frye-Halloran Symposium held at Massachusetts General Hospital in March 2002, the concept of microdialysis was extended to specifically address its possible use in treating brain tumor patients. In doing so we provide a rationale for the use of this technology by a National Cancer Institute consortium, New Approaches to Brain Tumor Therapy, to measure levels of drugs in brain tissue as part of phase 1 trials.