Use of contrast-enhanced computed tomography in clinical staging of asymptomatic breast cancer patients to detect asymptomatic distant metastases.

The use of computed tomography (CT) with regards to the clinical staging of patients with asymptomatic breast cancer has been on the increase in clinical practice. However, the benefits of routine CT have yet to be fully clarified. This study investigated the value of employing contrast-enhanced CT (CECT) to screen for distant metastases in patients with asymptomatic breast cancer. The clinical records of 483 patients with asymptomatic breast cancer who underwent CECT at a single institution between April 2006 and January 2011 were reviewed retrospectively. The CECT results were classified into normal, true-positive (metastases) or false-positive findings. Abnormal CECT findings, including true- and false-positive results, were detected in 65 patients (13.5%). Of these, 26 patients (5.4%) showed confirmed true metastatic disease, including 18 lung metastases, 11 liver metastases and 13 bone metastases. Upstaging to stage IV due to the results of the CECT scan occurred in 0 of 155 patients at stage I, 5 of 261 patients (1.9%) at stage II and 21 of 67 patients (31.3%) at stage III. The false-positive rates were 7.7, 9.0 and 8.7% in stages I, II and III, respectively. The size of the lung or liver metastasis was significantly larger than the false-positive lesion. Routine CECT did not appear to be useful for detecting distant metastases in completely asymptomatic patients. Conversely, a small number of patients were upstaged from early to stage IV and a predictive factor beyond T and N stage alone appears to be needed in order to predict which asymptomatic patients have distant metastases.