The effectiveness of mammography surveillance after treatment of primary breast cancer: A single centre retrospective cohort study

Introduction: There is a little evidence that routine follow-up of patients treated for early breast cancer (BC) to detect ibsilateral breast tumour recurrence (IBTR), or contralateral breast cancer (CBC), is either effective or offers any mortality benefits. We report our experience of following patients with early BC for recurrences and new primaries in order to determine the role of mammogram surveillance. Methods: Single centre, retrospective primary observational study was designed. Patients who had BC during year 2001–2006 were included and followed for a minimum of ten years. Patients were divided based on the modalities of detecting BC in to screen detected group and clinically detected one i.e. symptomatic BC. These two groups were compared. Results: Total number of patients considered for analysis was 2530 (screen detected BC - 703 patients and symptomatic BC - 1827 patients). The rate of recurrence including regional and distant metastasis in screen detected BC group was 8% (57/703) and 2% (43/1827) in symptomatic one. However, the prevalence of IBTR/CBC in the whole cohort was 2% (62/2530). Mammography surveillance identified 60% (37/62) of patients who had IBTRs/CBCs. Mammography surveillance detected 85% (29/34) of all IBTRs/CBCs in the screen detected BC group. In contrast, it picked up only 29% (8/28) in the other group (Chi squared 20.5 p < 0.005). Conclusions: Mammography surveillance is efficient for the screen detected BC group but not for the symptomatic one. Hence, it is worth suggesting different follow-up strategies for both groups. Further studies are therefore recommended