18F-fluorodeoxyglucose positron emission tomography in patients with recurrent ovarian cancer: in comparison with vascularity, Ki-67, p53, and histologic grade.

The aim of this study was to assess the correlation between 18F-fluorodeoxyglucose positron emission tomography (FDG PET) positivity of tumor recurrence and vascularity, Ki-67, p53, and histologic grade in patients with ovarian cancer. Nineteen patients with recurrent ovarian cancer underwent FDG PET before second-look surgery. Archival paraffin-embedded tissue materials were used to assess histologic grade including architectural pattern, mitotic activity, and nuclear pleomorphism; intratumor microvessel density (MVD); Ki-67; and p53. Univariate analysis was used to evaluate the correlation between FDG PET positivity and each biomarker. Stepwise logistic regression analysis was used to determine the best parameter to explain FDG PET positivity. MVD revealed significant positive correlation with FDG PET positivity (p=0.0341). There was no significant correlation between FDG PET positivity and Ki-67 or p53 (p=0.4040, p=0.6027). Mitotic activity yielded statistically significant positive correlations with FDG PET positivity (p=0.0448) although histologic grade revealed no positive correlation (p=1). Stepwise logistic regression analysis revealed MVD to be the strongest parameter for FDG PET positivity (OR=0.696, 95% CI 0.487-0.993, p=0.0458). In conclusion, FDG PET positivity revealed positive correlation with MVD and mitotic activity. MVD was the strongest parameter in predicting positive tumor recurrence on FDG PET.