Considerable controversy exists regarding the frequency and intensity of surveillance following treatment for breast cancer. This paper is a systematic, structured literature review that evaluates the practice of routine surveillance mammography and its impact on disease outcomes. Patients who undergo breast conserving therapy (BCT) show a prolonged time course to recurrent disease. Ipsilateral recurrence develops in 1% to 2% of patients per year, while contralateral breast cancer (CBC) occurs in 0.4% to 0.8% of patients per year. Recurrences at or near the original tumour site appear earlier than recurrences elsewhere in the breast. In contrast to early recurrence, later recurrence is associated with improved survival. Both early time to recurrence and the location of recurrence have been reported to significantly affect overall survival when taking into consideration the mode of detection.
While annual surveillance mammography is recommended by professional groups and required in the protocols of randomized controlled trials, there is variation in practice among breast cancer specialists in terms of the frequency of follow-up mammograms. Currently there are no randomized controlled trials demonstrating that early detection of local recurrence (LR) and/or CBC improves survival in women with breast cancer. Retrospective studies to date show no significant difference in the median time to detection of ipsilateral recurrence, 5 and 10 year actuarial LR rates, or overall survival between mammography and clinical examination. However, LR detected by mammography may be more frequently associated with smaller tumour size, lower stage and older patient age. CBC may be more frequently detected by mammography than are ipsilateral tumours. No direct evidence currently exists to suggest that mammography decreases mortality by detecting ipsilateral recurrence; however, indirect evidence suggests that clinical examination or mammography, or both, are beneficial in detecting CBC.