Evaluation of the ESMO-magnitude of clinical benefit scale version 2.0 for the definitive treatment of HPV positive oropharynx cancer with radiation therapy.

BACKGROUND

The European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated tool for assessing the clinical benefit of systemic cancer therapies. However, application of the scale to radiotherapy (RT) remains limited. As part of an ongoing initiative to adapt the scale for RT, we applied Form 1a of ESMO-MCBS v2.0 to studies cited in the American Society for Radiation Oncology (ASTRO) guideline for Human Papillomavirus (HPV)-positive oropharyngeal cancer (OPC) to assess feasibility and identify shortcomings.

METHODS

We screened 73 studies cited in the ASTRO OPC guideline. Eligible studies included randomized controlled trials and meta-analyses. Two radiation oncologists scored studies using ESMO-MCBS v2.0 Form 1a; consensus grading was reached through group review. Scoring outcomes and reasons for non-scoreability were analyzed to identify systematic limitations.

RESULTS

Of 73 studies, 33 met eligibility with a total of 37 comparisons noted. Eleven comparisons were scorable. Six scored Grade A (notably for survival benefit from chemoradiation or altered fractionation), and five scored Grade B (toxicity or cost reduction). Twenty-six comparisons were non-scoreable. Four demonstrated benefit in locoregional survival. Six post-hoc subgroup analyses yielded clinically impactful findings. The remaining 16 comparisons showed no evidence of benefit. These results highlight key ESMO-MCBS limitations: lack of credit for improved local control, non-inferiority designs improving convenience/toxicity, and practice-changing post-hoc subgroup analyses.

CONCLUSION

While ESMO-MCBS v2.0 performed reasonably in OPC RT trials, several limitations restrict its utility in radiotherapy. This study identifies actionable gaps that should be addressed in developing a validated RT-specific version.