skip to main content

Rare Cancer Trial Design — SCE Medical Oncology MCQ

Instant feedback + full explanation. One question, done properly.

HardClinical Trials & StatisticsRare Cancer Trial DesignSCE Medical Oncology

A rare-sarcoma trial proposes a single experimental arm compared with registry patients treated ten years earlier, when imaging frequency and supportive care differed. Which design revision best addresses the principal inferential problem while retaining feasibility?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Add a small concurrent randomised control and prespecify use of comparable external data

Explanation lettering: C = shown as A · E = shown as C · A = shown as D · D = shown as E

D is correct. The central threats are temporal confounding, selection, stage migration, outcome ascertainment and unmeasured differences in care; a larger historical sample does not remove them. MHRA guidance prioritises fit-for-purpose data, aligned eligibility and outcomes, and prespecified analysis. A small concurrent randomised control provides an internal check and may be augmented transparently by external data when justified. Blinded radiology helps measurement bias but not treatment-era confounding, and selecting favourable controls creates rather than fixes bias.

Reference: MHRA real-world-data guidance: https://www.gov.uk/government/publications/mhra-guidance-on-the-use-of-real-world-data-in-clinical-studies-to-support-regulatory-decisions