365MO - Exploring changes in glioblastoma treatment patterns in Europe and the USA with population-based cancer registry data

Background

Glioblastoma (GBM) is the most common and aggressive primary brain tumour. Since the EORTC 2005 trial (Stupp et al.) standard treatment has been temozolomide in combination with radiotherapy. In Europe and the US many population-based cancer registries (CRs) gather data on treatment, which can be used to assess care patterns at population level. This analysis reports on GBM treatment in Europe and US in the period before and after the change in clinical practice.

Methods

Data from CRs contributing to the European Cancer Information System having submitted treatment information and data from the US National Cancer Institute Surveillance (NCI), Epidemiology and End Results (SEER) were analysed, selecting patients diagnosed in 1999-2013 with GBM as first tumour. The proportion of cases by treatment type was calculated for radiotherapy (RT) and RT plus systemic therapy (RT+ST) and overall survival was compared by period (1999-2003 vs 2009-2013) and area.

Results

34,229 cases from 17 CRs in 11 European Countries – 3 each in Eastern, Northern and Western Europe, 2 in Southern Europe – and 36,925 cases from 18 US CRs were analysed. In Europe 45% of cases received RT and 14% RT+ST in 1999-2003. The percentages were 28% RT, 32% RT+ST in 2004-2008 and 21% RT, 44% RT+ST in 2009-2013. Treatment modality distribution was similar in the four European areas. In the US therapy was RT for 38% and RT+ST for 27% of patients in 1999-2003. The percentages were 13% RT, 55% RT+ST in 2004-2008 and 9% RT, 62% RT+ST in 2009-2013. In Europe two-year overall survival was 10% for RT and 20% for cases with RT+ST in 1999-2003, rising to 25% for RT+ST in 2009-13. In the US it was 7% for RT cases and 13% for those with RT+ST in 1999-2003, rising to 9% for RT and 26% for RT+ST in 2009-2013.

Conclusions

A change in treatment modality for GBM was observed between the considered periods, showing that the switch to RT+ST modality has been more marked in the US. Two-year survival differences between patients treated with RT and those with RT+ST are similar in Europe and the US, showing that likely more European patients would benefit if the RT+ST percentage could rise to the US level. CRs could be a powerful tool to assist clinical research and monitor treatment patterns and effects in the population.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.