An evidence based strategy for follow up after breast conserving treatment for breast cancer

Follow up for breast cancer patients aims at the timely detection of loco-regional recurrences and contralateral breast cancers (LRR). This study investigates the annual risk of LRR after breast conserving treatment (BCT) and the potential value of mammographic surveillance and/or routine clinical examination.

Data on 650 women who underwent BCT were obtained and LRR was divided into parenchymal and non-parenchymal. LRR-free and cumulative LRR-free rates were calculated. In patients where recurrence was diagnosed at a routine clinic visit and had negative mammography ("clinical detection only" group) were also separately examined.

Median follow up was 115 months, range 9-196. Seventy-three patients had parenchymal and 16 nodal recurrence. The median probability of LRR was 1.4% and of parenchymal LRR was 1.32% per year, remaining constant for up to 168 months. The 16 patients in the "clinical detection only" group relapsed mainly during the first 2 years (annual risk 0.77% and 0.80%, respectively).

This study shows that the risk of parenchymal LRR remains constant for at least 14 years and is significant enough to warrant routine long-term follow up mammography. Routine clinical examination contributes significantly to the detection of LRR only for the first 2 years.