Abstract
BACKGROUND
Tumor treating fields (TTFields) are low-intensity alternating electric fields delivered at intermediate frequencies to disrupt cancer cell division and inhibit tumor growth, with significantly longer mean lifetime survival of 1.8 additional years in glioblastoma (GBM). International, national and local clinical practice guidelines have implications for clinical, personal and policy decision-making. Furthermore, they may impact on patients’ decisions to choose treatment at a given institution or even lead to commencement of legal proceedings for withholding therapies recommended by international guidelines. We performed an in-depth landscape analysis of clinical practice guidelines for GBM in Europe and North America to explore variation in treatment recommendations with a specific focus on TTFields.
MATERIAL AND METHODS
A systematic search was conducted of web sites of international guideline developers, relevant cancer agencies and the MEDLINE and Web of Science literature databases. The following information was extracted from each document meeting the inclusion criteria: whether TTFields is discussed and/or recommended in the guideline, the indications for and role of TTFields in the care protocol, the strength of the recommendation and any constraints placed on the situations where this therapy can or may be offered, including on cost grounds, where applicable. Dates of production and validity periods of the guidelines were also noted. In addition, standard operating procedures (SOPs) from several accredited comprehensive cancer centres in Germany, covering GBM care are compared, with a series of clinical vignettes presented.
RESULTS
The guidelines produced by the National Comprehensive Cancer Network (USA), National Institute for Health and Care Excellence (UK), German Society for Neurology, German Society for Haematology and Medical Oncology, European Association for Neuro-Oncology and European Society for Medical Oncology were critically compared. Wide variation in recommendations relating to the TTFields therapy was observed. Many guidelines had not been updated to reflect the results of the EF-14 study.
CONCLUSION
Discrepancy in the adoption of TTFields across clinical practice guidelines and SOPs has potential implications for care practices. This ultimately affects patient outcomes, safety and quality of care. Ideally, guidelines should be updated dynamically when new evidence indicates a need for a substantive change in the guideline based on a priori criteria. An ongoing revision process for guidelines, perhaps with shorter validity periods or a more flexible approach, may facilitate more expedient adoption of novel therapies in clinical practice guidelines and in practice. Meanwhile, therapies significantly improving OS and PFS should be recommended to patients and this should be documented.
Critical appraisal of the Minimal Clinical Recommendations (MCR) of the European Society for Medical Oncology (ESMO): challenges for a European framework for the development of clinical practice guidelines
