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

Aim: 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 F-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.

Patients And Methods: 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.

Results: 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 SUV 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.

Conclusion: 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.