Women aged 50 or older, who are three years post-breast cancer diagnosis and cancer-free, show non-inferior results when given less than annual mammography compared to annual screening, a new study has revealed.
Less frequent breast cancer screenings were found to be equally effective in terms of breast cancer-specific survival, recurrence-free interval and overall survival. These findings suggest that leaving more time between mammograms could be a suitable option for this group of women.
The research was undertaken as part of Mammo-50 – a phase three randomised trial running across 114 NHS hospitals in the UK. Between 2014 and 2018, some 5,000 women who had undergone curative surgery were randomly assigned to a cohort of either annual mammography (n=2,618) or less frequent mammography (n=2,617), with a median follow-up of 5.7 years.
The co-primary outcomes were breast cancer-specific survival, with a 3% absolute non-inferiority margin, and cost-effectiveness. The results of the latter will be published separately. Additional outcomes analysed included recurrence-free interval, overall survival and referrals back to the hospital system.
Nearly three-quarters of the women (n= 3,858, 73.6%) were aged 60 years or older. The majority had undergone breast conservation surgery (80.3%), 87.4% had invasive disease, 2.1% had cancer that spread to the lymph nodes, and 82.7% had oestrogen receptor-positive tumours.
During the study and follow-up period, 343 women died. This included 116 who died of breast cancer, 61 from the annual mammography group and 55 in the less frequent mammography group.
The researchers found the five-year breast cancer-specific survival was 98.1% in the annual mammography group and 98.3% in the less frequent mammography group, providing evidence that less frequent mammograms did not negatively affect breast cancer rates.
After five years, 94.1% of the annual mammography group and 94.5% of the less frequent mammography group remained cancer-free. Survival from any cause was 94.7% for the annual mammography group and 94.5% for the less frequent mammography group.
The researchers suggested that less frequent mammograms for breast cancer-specific survival, recurrence-free interval and overall survival should be recommended for patients aged 50 years or older.
Reference
Dunn, J et al. Annual versus less frequent mammographic surveillance in people with breast cancer aged 50 years and older in the UK (Mammo-50): a multicentre, randomised, phase 3, non-inferiority trial. The Lancet 2025; Feb 01: DOI: 10.1016/S0140-6736(24)02715-6.
