Value of ultrasound for postoperative surveillance of Asian patients with history of breast cancer surgery : a single-center study

Abstract

PURPOSE: To assess the diagnostic performance of postoperative ultrasound (US) for the detection of malignant lesions and to evaluate the role of US in postoperative surveillance of patients with breast cancer history.MATERIALS AND METHODS: This retrospective study was approved by the institutional review board at our hospital, and informed consent was waived. We studied a total of 392 patients who underwent surgery for breast cancer between January 2000 and December 2002, including 287 mastectomy patients, 104 breast conservation surgery (BCS) patients, and one patient with both mastectomy and BCS. By December 2010, these patients had undergone a total of 4082 US exams of the remaining breast, chest wall, and regional area for postoperative follow-up, and these ultrasound exams were reviewed. Whether the lesions were final-positive or final-negative was based on cytopathology results, clinical follow-up, and imaging studies, such as breast US or mammogram, during a minimum of 12 months after the procedure. Diagnostic indexes for detecting final-positive lesions were assessed. We also compared the frequency of distant metastases in patients with final-positive lesions and in those without. The 8-year survival rate was assessed.RESULTS: There were 118 positive US in 93 patients (23.7% of 392 patients). At final diagnosis, 28 final-positive lesions (23.7% of 118 lesions; mean time to surgery 1,275 days; 95%CI for mean 1,102 to 1,721days) were detected in 24 patients (26.7% of 90 patients). There were six false-negative cases in five patients. The detection rate for final-positive lesions was 5.6% per patient (24 of 390 patients) and 1.3% per exam (28 of 4082 exams), and the false-negative rate was 1.3% per patient (5 of 390 patients) and 0.14% per exam (6 of 4082 exams). The sensitivity, specificity, PPV, NPV, and accuracy of follow-up US for final-positive lesion after breast cancer surgery among the 2926 US examinations conducted on 287 mastectomy patients were 91.3% (21 of 23), 98.0% (2840 of 2901), 25.0% (21 of 84), 99.9% (2840 of 2842), and 97.8% (2861 of 2926), respectively. For the 1171 follow-up US exams conducted on 104 BCS patients, the sensitivity, specificity, PPV, NPV, and accuracy of follow-up US were 20.0% (1 of 5), 97.4% (1136 of 1166), 3.2% (1 of 31), 99.6% (1136 of 1140), and 97.1% (1137 of 1171), respectively. Among mastectomy patients, patients with final-positive lesions showed a higher incidence of distant metastasis than patients without final-positive lesions (7 of 19 patients (36.8%) versus 25 of 269 patients (9.2%), P=0.0009). Among BCS patients, there was no distant metastasis. Among mastectomy patients, the 8-year survival rate was 100% (3 of 3) in patients with only nonpalpable final-positive lesions and 64.5% (20 of 31) in patients with distant metastasis (P=0.1408).CONCLUSION: Postoperative breast US showed high sensitivity for the detection of malignant lesions in the breast and the regional area, which can be a predictor of distant metastasis in mastectomy patients; however, the role of postoperative breast US in the detection of malignant lesions in BCS patients is unclear.