Early platelet variation during concomitant chemo-radiotherapy predicts adjuvant temozolomide-induced thrombocytopenia in newly diagnosed glioblastoma patients

Adjuvant chemotherapy after severe myelotoxicity during chemoradiation phase in malignant gliomas. Is it feasibile? Results from AINO study (Italian Association for Neuro-Oncology)

BACKGROUND

Malignant gliomas (MG) are aggressive brain tumours in adults. The standard of care is concurrent radiation plus temozolomide (TMZ) [chemo-radiotherapy (CRT)] followed by TMZ maintenance up to 6 months. TMZ is considered to have a low toxicity profile, but several studies reported occurrence of severe myelosuppression, especially during the concomitant phase. Toxicity may be prolonged, thus treatment should be discontinued.

PURPOSE

To evaluate the risk of recurrente myelotoxicity during adjuvant chemotherapy (CT) in patients who recovered from severe myelotoxicity during CRT.

METHODS

We retrospectively collected data on patients with MG who developed and recovered from severe myelotoxicity during CRT from eight Italian neuro-oncology centers.

RESULTS

We included 87 patients. Histology was Glioblastoma (GBM) in 78 patients (89.7%); 60% of patients were female. After myelotoxicity recovery, 54 (62%) received treatment. The majority of them (82%, n = 44) received adjuvant TMZ and 18% (n = 10) others treatments. Out of 44 patients who received adjuvant TMZ, 34% experienced the re-occurrence of grade 3-4 myelotoxicity which required permanent CT discontinuation in 6 (13%) cases. Patients who received TMZ or other treatments had longer overall (OS) (adjusted HR 0.46, p = 0.008) and progression free survival (PFS) (adjusted HR 0.57, p = 0.034) than those who remained untreated.

CONCLUSION

Our study suggests that after severe myelotoxicity the majority of patients received treatment, particularly with TMZ. Only a fraction of patients experienced toxicity recurrence, suggesting that TMZ is well tolerated and had an impact on PFS and OS.

Deleterious impact of a generic temozolomide formulation compared with brand-name product on the kinetic of platelet concentration and survival in newly diagnosed glioblastoma

Chemo-induced thrombocytopenia is a limiting toxicity among patients receiving temozolomide (TMZ) as first-line treatment for glioblastoma. We aimed to compare early platelet concentration kinetics, hematological safety profile, and impact on survival following the initiation of either the brand-name or a generic TMZ formulation. A retrospective trial was conducted in patients suffering from newly diagnosed glioblastoma. Patients were treated with TMZ at 75 mg/m² per day during six weeks, concomitantly with radiotherapy. Platelet concentration was collected each week. Primary endpoint was to perform a linear mixed-effect model of platelet concentration kinetic over weeks. A total of 147 patients were included as follows: 96 received the brand-name TMZ, and 51 received a generic TMZ formulation. Exposition to the generic was a significant variable that negatively influenced the platelet kinetics in the radiotherapy and concomitant TMZ phase, P = 0.02. Grade ≥3 chemo-induced thrombocytopenia was more frequent in the generic group: 19.6% [95% CI 8.7-30.5%] vs 3.1% [0-6.6%], P = 0.001. Exposition to the generic formulation of TMZ led to increase early treatment discontinuation due to TMZ-induced thrombocytopenia and was a worsening independent prognostic factor on overall survival: adjusted HR 1.83 [1.21-2.8], P = 0.031. These data suggest that exposition to a generic formulation of TMZ vs the brand-name product is associated with higher early platelet decrease leading to clinically relevant impacts on treatment schedule in glioblastoma. Further prospective trials are needed to confirm these results.

Predicting chemotherapy-induced thrombocytopenia in cancer patients with solid tumors or lymphoma

Purpose

Chemotherapy-induced thrombocytopenia is a serious complication in chemotherapy-treated patients. Identification of patients at risk for chemotherapy-induced thrombocytopenia could have clinical value in personalized management of patients and optimized administration of prophylactic thrombopoietic agents. The aim of this study was to develop a predictive model for chemotherapy-induced thrombocytopenia (platelet count < 100,000/µl) in cancer patients undergoing chemotherapy.

Methods

A total of 14 covariates were prospectively assessed as explanatory variables in a cohort of consecutive patients with solid tumors or lymphoma. A multivariable logistic regression model was developed after univariable analysis. A bootstrapping technique was applied for internal validation.

Results

Data from 305 patients during 1732 chemotherapy cycles were considered for analysis. Forty-eight patients (15.73%) developed chemotherapy-induced thrombocytopenia during their treatment course. The multivariable model exhibited three final predictors for chemotherapy-induced thrombocytopenia, including high ferritin (odds ratio, 4.41; bootstrap P = 0.001), estimated glomerular filtration rate <60 ml/min/1.73 m2(odds ratio, 3.08; bootstrap P = 0.005), and body mass index <23 kg/m2(odds ratio, 2.23; bootstrap P = 0.044). The main characteristics of the model include sensitivity 75%, specificity 65.4%, positive likelihood ratio 2.16, and negative likelihood ratio 0.382. Moreover, the model was well calibrated (Hosmer–Lemeshow P = 0.713) and the area under the receiver operating characteristic curve was 0.735 (95% confidence interval, 0.654–0.816; P < 0.001).

Conclusions

We developed a predictive model for chemotherapy-induced thrombocytopenia based on readily available and easily assessable clinical and laboratory factors. This study may provide a valuable insight to guide optimized treatment of cancer patients. Further studies with larger sample size are warranted.