The association between BMI and BSA-temozolomide-induced myelosuppression toxicities: a correlative analysis of NRG oncology RTOG 0525.

BACKGROUND: Fearing increased myelotoxicity, many practitioners adjust the body surface area (BSA)-calculated doses in obese patients. Regarding temozolomide (TMZ), a prior study suggested men with a BSA >2 m2 may experience increased toxicity; however, surprisingly, the inverse observation was noted in women, ie, BSA <2 m2 was associated with higher toxicity. To further clarify this issue, data derived from a large clinical trial were analyzed. METHODS: The incidence of grade 3 and 4 myelotoxicity in a newly diagnosed glioblastoma phase 3 trial (RTOG 0525) was statistically correlated with BMI and separately with BSA. All patients received radiation and TMZ followed by adjuvant standard dose TMZ vs dose-dense TMZ; dosing regimen-associated myelotoxicity and BMI/BSA were analyzed separately. Obesity was defined as a BMI ≥30. RESULTS: There was no statistically significant correlation between gender and BSA and the occurrence of myotoxicities. For the standard arm, surprisingly the incidence of grade 3/4 myotoxicities in patients with a BMI <30 was significantly higher than in patients with a BMI ≥30 (12% vs 1%, odds ratio [OR] 12.5, P < .001). There was no significant difference between obese and nonobese patients (BMI "cut-point" of 30) in the dose-dense arm (OR = 0.9, 95% confidence interval: 0.4-1.6). The grade hematological 3/4 toxicity rate was significantly higher in women vs men (14% vs 8%) P = .009 in spite of the lack of association between gender and BSA or BMI. CONCLUSION: TMZ dosing based on actual BSA is recommended with the caveat that woman are likely at higher toxicity risk.

Investigating the Effect of Reirradiation or Systemic Therapy in Patients With Glioblastoma After Tumor Progression: A Secondary Analysis of NRG Oncology/Radiation Therapy Oncology Group Trial 0525.

PURPOSE: To determine the impact on overall survival with different salvage therapies, including no treatment, reirradiation, systemic therapy, or radiation and systemic therapy, in participants of a phase 3 clinical trial evaluating dose-dense versus standard-dose temozolomide for patients with newly diagnosed glioblastoma. METHODS AND MATERIALS: This analysis of patients from Trial RTOG 0525 investigated the effect of reirradiation or systemic treatment after tumor progression. Survival from first progression was compared between patients receiving no therapy, systemic therapy alone, radiation alone, and both modalities. The Cox proportional hazards model was used to compare the mortality hazard, controlling for potential confounders. RESULTS: The analysis included 637 patients who progressed and had information on their management, excluding those who died less than half a month after progression. A total of 267 patients (42%) received neither reirradiation nor systemic treatment at progression, 24 (4%) received radiation alone, 282 (44%) received systemic treatment only, and 64 (10%) received both radiation and systemic therapy. Patients who received no treatment had a median survival of 4.8 months, lower than with radiation treatment alone (8.2 months), systemic therapy alone (10.6 months), and both radiation and systemic therapy (12.2 months). In survival models controlling for potential confounders, those who received radiation alone had modestly better survival (hazard ratio HR 0.74, 95% confidence interval [CI] 0.43-1.28), whereas those who underwent systemic therapy either without (HR 0.42, 95% CI 0.34-0.53) or with radiation therapy (HR 0.44, 95% CI 0.30-0.63) had better survival. There was no significant survival difference between patients who received radiation only and those who received systemic therapy (either with radiation or alone). CONCLUSIONS: Patients who received no salvage treatment had poorer survival than those who received radiation, chemotherapy, or the combination. However, patient selection for no treatment likely reflects poorer expected prognosis. There was no significant survival difference among those receiving radiation therapy, systemic therapy, or both. Ongoing clinical trials will help define the role of reirradiation after glioblastoma progression.

Walking forward: the South Dakota Native American project.

BACKGROUND: The "Walking Forward" program is a scientific collaborative program between Rapid City Regional Hospital, the University of Wisconsin, the Mayo Clinic, and partnerships with the American Indian community in western South Dakota-3 reservations and 1 urban population. The purpose is to increase participation of health disparities populations on National Cancer Institute clinical trials as part of the Cancer Disparities Research Partnership program. Clinical practice suggests that Native American cancer patients present with more advanced stages of cancer and hence have lower cure rates and higher treatment-related morbidities. It is hypothesized that a conventional course of cancer treatment lasting 6 to 8 weeks may be a barrier. METHODS: Innovative clinical trials have been developed to shorten the course of treatment. A molecular predisposition to treatment side effects is also explored. These clinical endeavors will be performed in conjunction with a patient navigator research program. RESULTS AND CONCLUSIONS: Research metrics include analysis of process, clinical trials participation, treatment outcome, and assessment of access to cancer care at an early stage of disease.