Purpose: To determine the contribution of surveillance mammography to the early detection of metachronous contralateral breast cancer (MCBC) and to assess its impact on the survival of breast cancer patients with relation to compliance.
Method: Breast cancer patients (5589) were identified using files from the regional cancer registry of the Comprehensive Cancer Centre North Netherlands (CCCN Groningen, The Netherlands). The programme sensitivity and the impact on prognosis of follow-up mammography with relation to compliance were evaluated in 114 patients who developed MCBC during hospital follow-up.
Results: The cumulative MCBC incidence rate at year 10 was 3.4% (95% CI: 2.8-4.0%). The programme sensitivity of surveillance mammography was 59.6% (95% CI: 50.6-68.7). In patients who complied with annual mammography, sensitivity was increased to 70.8% (95% CI: 61.7-80.0). Patients with MCBCs detected by routine mammography have better survival rates than patients with MCBCs detected by other means (HR: 3.18; 95% CI: 1.59-6.34). Though there was a trend towards improved survival in patients being compliant with regular clinical follow-up (HR: 1.69; 95% CI: 0.72-3.96), this was not the case for patients being compliant with annual mammography (HR:1.02; 95% CI:0.50-2.09).
Conclusion: Mammography is a valuable tool for the early detection of MCBC during hospital follow-up of breast cancer patients and is probably beneficial to survival. The utilisation of follow-up surveillance in breast cancer patients and its potential impact on survival deserve further investigation.