The challenge of rare cancers

Programme stream(s): Treatment
Programme session type(s): Specialist session

Chair: Richard Adams, University of Cardiff, UK
Speaker: Sheela Rao, Royal Marsden Hospital, UK
Speaker: Matt Sydes, University College London, UK
Speaker: Steve Nicholson, International Rare Cancers Initiative in Penile Cancer, UK


Room: Alsh

Topics covered in this session:
– Stats/methodology.
– InterAACT

The challenges of rare cancer: Time for change
Speaker: Richard Adams
Affiliation: Cardiff University


Are all cancers becoming rare? How will we cope with the increasing compartmentalization of cancers in an era of ever increasing data? We will discuss rare cancers in the context of clinical trials, exploring practical issues of trials design and collaboration on an international scale as well as exploring the successes and how they have been achieved

Designing trials in smaller populations
Speaker: Matthew Sydes
Affiliation: MRC Clinical Trials Unit at UCL


How should we approach trial design when the ideal sample size is considered larger than the number of participants that can be recruited in a reasonable time frame? We present an ordered framework for designing randomised trials, staying with the frequentist approach well accepted and understood in large trials, that includes small alterations to the design parameters. The first step should always be to attempt to extend collaborations, consider broadening eligibility criteria and increase the accrual time or follow-up time. The second set of ordered considerations are the choice of research arm, outcome measures, power and target effect. If the revised design is still not feasible, in the third step we propose moving from two- to one-sided significance tests, changing the type I error rate, using covariate information at the design stage, re-randomising patients and borrowing external information. We discuss benefits from some proposals and warn against others. This framework would allow appropriate evaluation of treatments when large-scale phase III trials are not possible, but where the need for high-quality randomised data is as pressing as it is for common diseases.