Clinicopathological Features of Ductal Carcinoma In Situ from 18F-FDG-PET Findings.

Abstract

The presence of ductal carcinoma in situ (DCIS) can increase the risk of developing an invasive ductal carcinoma (IDC), but it is difficult to predict what will occur if a DCIS is left untreated. We reported the usefulness of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for DCIS, and that the presence of FDG uptake in the tumor could be considered a predictor of invasive potential in patients with DCIS. In this study, we retrospectively evaluated the clinicopathological features of DCIS by using FDG-PET findings, and we evaluated the possibility of using FDG-PET in DCIS cases as a biomarker of which lesions will go on to become invasive. We investigated the cases of 185 consecutive patients with primary breast cancer who were diagnosed as having DCIS or IDC and underwent FDG-PET preoperatively. We divided the cases into two groups on the basis of histology; DCIS vs. IDC (n=171). The DCIS cases were divided into two groups on the basis of FDG uptake in the primary tumor. Fourteen of the 185 patients (7.4%) were revealed to have a DCIS. The analysis revealed that the SUVmax and the number of cases not detected by FDG-PET were significantly different between the DICS and IDC groups. The extent of the primary tumor was not significantly different between the two groups. In six cases (42.9%) of the 14 DCIS cases, no FDG uptake was detected by FDG-PET. The extent of tumor did not significantly differ between the two groups. In addition, all six cases without FDG uptake were of the diffuse-spread type, without mass formation. All eight cases with mass formation had FDG uptake. Our present findings suggest that the FDG-PET uptake reflects tumor burden or tumor density, which should be considered to be associated with the presence of invasion.