Mammographic follow-up of patients after treatment for breast cancer: is 5 years enough?

Introduction

Velindre Cancer Centre (VCC), Cardiff provides radiotherapy and oncology services to the population of 1.5 million across southeast Wales. Historically at Velindre, breast cancer patients are followed up for at least 10 years, with annual mammography underpinning the service. The optimal length for continued annual surveillance has been debated and reduction to 5 years follow-up suggested. Therefore, a retrospective audit of breast cancers diagnosed on follow-up mammograms was undertaken to support the proposed reduced length of mammographic follow-up.

Methods

Using the RIS and HIS electronic databases, follow-up mammograms over a 3-year period from 1 June 2006 to 31 May 2009 were collected and their report codes checked. All mammogram reports are coded using the Breast Imaging Reporting and Data System (BI-RADS). All mammograms coded 3 and above were identified. Subsequent radiological and histological reports were reviewed to identify confirmed malignancies.

Results

In this 3-year period, there were 6,294 follow-up mammogram examinations at VCC. Ninety-seven reports were coded 3 or above (1.5%). Fifty-six new malignancies were confirmed. Of these, 44 (79%) occurred more than 5 years from original diagnosis.

Conclusions

The results do not support reducing the length of follow-up to 5 years. Further analysis of original pathology will be undertaken to attempt to risk-stratify patients and thus allow tailored follow-up regimes to be developed.