Optimizing breast cancer follow-up: diagnostic value and costs of additional routine breast ultrasound

A total of 2,546,325 breast cancer survivors are estimated to live in the United States. The organized breast cancer follow-up programs do not generally include breast ultrasound in asymptomatic women. The purpose of our prospective study was to investigate the efficacy of breast ultrasound in detecting previously occult recurrences. A total of 735 eligible patients with a history of breast cancer were recruited. We assessed the same patient population before (routine follow-up program) and after (study follow-up program) the introduction of an additional ultrasound examination. In the routine follow-up program 245 of 735 patients (33.3% [95% confidence-interval (CI): 29.9-36.7]) had an ultrasound due to abnormal local or mammographic findings. 490 of 735 patients (66.7% [95% CI: 63.3-70.1]) were initially considered asymptomatic and received an additional ultrasound exclusively within the study follow-up program. All positive examination results were followed by accelerated core needle biopsy. The routine follow-up program led to a biopsy in 66 of 735 patients (9.0%) revealing a recurrent cancer in 27 cases (3.7%). The study follow-up program with the additional ultrasound led to another 21 biopsies raising the total number of patients who had to undergo a biopsy from 9.0% (95% CI: 6.9-11.1) to 11.8% (95% CI: 9.5-14.2). Finally, we diagnosed a previously occult malignant lesion in an additional six patients following this protocol. Therefore, the rate of detected recurrences rose from 3.7% (95% CI: 2.3-5.0) in the routine follow-up program to 4.5% (95% CI: 3.0-6.0) in the study follow-up program (p = 0.041). Negative side effects were the additional costs (the costs per detected malignancy in the routine follow-up program were $2455.69; the costs for each additionally detected malignancy in the study follow-up program were $7580.30), the higher overall biopsy rate (9.0 vs. 11.8%) and the elevated benign biopsies rate (59.1% vs. 71.4%). Regarding these results, the advantages and disadvantages of additional breast ultrasound must be discussed for every follow-up patient individually even today, as we can detect a significantly higher number of previously occult malignancies.