Relationship among glycolytic phenotype, grade, and histological subtype in ovarian carcinoma

Knowing the glycolytic phenotype of cancers is important for the appropriate use of F-18 FDG PET/CT imaging. This study was performed to determine the influence of tumor grade and histology on the glycolytic phenotype of epithelial ovarian cancer patients.

Only histopathologically confirmed epithelial ovarian cancer patients, with no other concurrent malignancies, who had F-18 FDG PET/CT either before or at least 3 months after any therapeutic intervention and had confirmed measurable disease of >1 cm were included. The F-18 FDG PET/CT uptake was determined as maximum standard uptake value (SUVmax) at the pathologically confirmed site of disease or in the most active lesion. SUVmax was correlated to tumor grade and histology.

Of 171 ovarian cancer patients, 42 referred for F-18 FDG PET/CT scans between January 2003 and December 2010 were eligible for inclusion. Histologic diagnosis most frequently revealed the serous subtype (n = 32) and grade III (n = 28) epithelial ovarian cancer. Overall, ovarian carcinomas exhibited a strong glycolytic phenotype (average SUVmax, 7.6 g/mL). The SUVmax averaged 7.76 g/mL, 6.76 g/mL, and 7.95 g/mL for Grade I, II, and III, respectively. There was no statistically significant correlation between tumor SUVmax and the histologic tumor grade (P = 0.74). No statistically significant differences were found between the tumor SUVmax of serous and endometrioid subtypes (P = 0.53). For other histology subtypes, no statistic evaluation was possible due to the low number of cases.

The glycolytic phenotype in epithelial ovarian cancer, expressed as SUVmax, is strong. However, tumor FDG uptake is unrelated to tumor grade and histologic subtype implying that F-18 FDG PET/CT cannot be used to predict tumor aggressiveness or histology.