Prognostic Significance of Fluorodeoxyglucose Positron Emission Tomography Maximum Standardized Uptake Value in Stage I Ovarian Clear Cell Carcinoma: A Retrospective Observational Study

Abstract

Background: Ovarian clear cell carcinoma (CCC) is often diagnosed at stage I. However, because of the poor prognosis of recurrent cases, even for stage Ia CCC, treatment strategies such as expansion of fertility-sparing treatment and omission of adjuvant chemotherapy have been carefully discussed in recent years. We previously reported the possibility of the maximum standardized uptake value (SUVmax) as a biomarker of CCC prognosis prediction at all stages. In this study, we confirmed differences in SUVmax within stage I CCC and considered treatment strategies. Methods: We selected all 31 patients with ovarian CCC stage I who underwent fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) before treatment between 2006 and 2013 at our institution. This retrospective study was based on their medical records. Results: Clinical tumor stage was Ia in 13 patients, and Ic in 18 (Ic (b) in 11, and Ic (1) + Ic (2) in seven). There were no differences in serum CA125 level, maximum tumor diameter or mural nodules. Median SUVmax was signifi-* Corresponding author. H. Konishi et al. 137 cantly higher in stage Ic (5.87) than stage Ia (3.08) cases (P = 0.02). Progression-free survival was longer in the low SUVmax group than the high SUVmax group (P = 0.08). Conclusions: SUVmax for primary lesions in CCC was significantly higher in stage Ic than stage Ia. As SUVmax represents a prognostic factor in stage I CCC, these findings may suggest SUVmax as an indicator for the application of fertility-sparing surgery and omission of adjuvant chemotherapy for stage Ia CCC.