How prevalent is fear of cancer recurrence beyond 5 years: a systematic review of validated assessments across tumour types.

Fear of cancer recurrence (FCR) is an established challenge for cancer survivors. Research however has largely focussed early in treatment, with varying assessments and often single tumour sites. This systematic review set out to determine prevalence of FCR in survivors beyond 5 years across all tumour types. We designed a search strategy to identify publications assessing FCR in survivors beyond 5 years with sample size greater than 50, using validated measures. Applying PRISMA methodology and with defined inclusion and exclusion criteria two authors independently assessed the studies for eligibility. Data extraction recorded number of participants, tumour type, study design, FCR tool, time points for assessment and reported prevalence. Risk of bias was assessed to address quality. Ten papers were included, reporting FCR from 5 years to beyond 20 years. Validated tools employed were FCRI-SF and FOP-Q-SF. Sample sizes ranged from 64 to 5983 participants, with a heterogeneous mix of tumour types and age. Only two studies reported longitudinal measurements. Prevalence of FCR above defined threshold ranged from 13 to 33.9% for those studies with acceptable risk of bias reporting distinct cohorts beyond 5 years. The limited evidence suggests that clinically relevant FCR persists in some survivors at 5 years. Our review demonstrates the challenge of heterogeneous patient populations in FCR research emphasising the need for improved consensus on measurements and more prospective longitudinal research representing a comprehensive variety of tumour types. We address the clinical implications of persistent FCR and the need to implement effective interventions.