Prior malignancy impact on survival outcomes of glioblastoma multiforme; population-based study

Abstract

Background: Glioblastoma multiforme (GBM) patients with a prior malignancy are usually excluded from clinical trials on GBM based on the assumption that this history will affect their survival outcomes. This practice may affect clinical trial accrual and limit the gathering of knowledge essential to the formulation of therapeutic options for this patient population. However, not much is known about the real impact of these prior malignancies on the survival of patients with subsequent GBM. We aimed to investigate the degree of such an impact.

Patients and methods: We used the Surveillance, Epidemiology, and End Results (SEER) Program to analyze data of GBM patients diagnosed between 1973 and 2014. We calculated the overall and GBM-specific survival of these patients using the unadjusted Kaplan-Meier test and the multivariable covariate-adjusted Cox models.

Results: Of 51,158 GBM patients, 3,076 had a prior malignancy. The unadjusted Kaplan-Meier test showed worse overall and GBM-specific survivals for patients who had a prior history of cancer. However, after adjusting for age at diagnosis of GBM, sex, race, marital status, and conduction of surgery, multivariable covariate-adjusted Cox models showed that having a prior malignancy did not significantly affect neither overall survival (HR = 1.025, 95%CI = .986 - 1.066, p = .213) nor GBM-specific survival (HR = 1.005, 95%CI = .963 - 1.049, p = .810).

Conclusions: Our findings suggest that the broad practice of excluding patients with a prior history of cancer should be reconsidered as it may adversely affect accrual, trial completion rates, and generalizability of the results.

Key Words:

• Glioblastoma
• Clinical trial
• Neoplasms
• Second Primary
• SEER Program

Acknowledgments

We would like to thank Dr. Mohamed-Ismail Rakha or revising the final version of the manuscript.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Role of authors

All authors participated in designing the concept of the paper. AMS and MA conducted the analysis of the data and had the access to the database. All authors have contributed to data interpretation and writing the paper. All authors have revised and agreed to the content of the paper. ASA supervised all steps of the study scientifically and had the responsibility to make the final decision as to its readiness for submission for publication. AMS managed and coordinated research planning and execution. AMS and MA contributed equally to this manuscript.

Additional information

Funding

Ahmad S. Alfaar is supported by grant 57147166 from The German Academic Exchange Service (DAAD).