Annual versus less frequent mammographic surveillance in people with breast cancer aged 50 years and older in the UK (Mammo-50): cost-effectiveness and budget impact analysis.

[BACKGROUND] There is limited evidence on the optimal frequency of mammogram surveillance. At 5-year follow-up, the Mammo-50 trial found that, in patients aged 50+ and 3 years post diagnosis, less frequent mammograms were non-inferior to annual mammograms for breast-cancer-specific-survival, recurrence-free interval and overall survival.

[METHODS] A within-trial cost-effectiveness analysis compared annual versus less frequent mammogram surveillance over 5 years from healthcare and societal perspectives. Hospital Episodes Statistics captured hospital-based resource use. Health-related quality of life and other cost data were obtained via questionnaires at surveillance mammograms. A budget impact analysis estimated NHS savings.

[RESULTS] Less frequent surveillance led to cost savings of -£543.88 (-£1116; £26) and a small reduction in quality-adjusted life years (QALYs) of -0.02 (-0.095; 0.06) per patient. The incremental net monetary benefit at a £20,000/QALY threshold was £187 (-£1574; £2027). Including societal costs increased savings to £1543 per person (-£2416; -£669), and cost-effectiveness. Projected NHS savings were £185.87 million over 6 years.

[CONCLUSION] Less frequent mammogram surveillance is cost-effective. Uncertainty remains due to variability in costs and quality of life estimates, and missing data in the less frequent arm due to study design. Given the trial's non-inferiority findings, this strategy is recommended from healthcare and societal perspectives.