Does the use of diagnostic PET/CT cause stage migration in patients with primary advanced ovarian cancer?

OBJECTIVE

To investigate if the use of diagnostic FDG-PET/CT leads to stage migration in patients with advanced ovarian cancer and to evaluate the prognostic significance of FDG-PET/CT.

METHODS

From September 2004 to August 2007, 201 patients with a Risk of Malignancy Index (RMI) >150 based on serum CA-125, ultrasound examinations and menopausal state, underwent PET/CT within 2 weeks prior to standard surgery/debulking of a pelvic tumor. On 15 August, 2009 overall survival and prognostic variables were analysed in 66 ovarian cancer patients (64 stage III and 2 stage IV).

RESULTS

Median follow-up was 30.2 months; median age was 62.5 years (range 35-85 years); 97% (64/66) had a performance status <or=2; 38% (25/66) underwent complete debulking (no macroscopic residual tumor); 51% (39/66) was diagnosed with PET/CT stage III and 41% (27/66) was diagnosed with PET/CT stage IV. Survival was significantly longer for patients with PET/CT stage III than for patients with PET/CT stage IV (P=0.03). Using univariate analysis, PET/CT stage III (P=0.03), complete debulking (no macroscopic residual tumor) (P=0.002), and GOG performance status <or=2 (P=0.04) were statistically significant prognostic variables. Using multivariate Cox regression analysis, complete debulking was the only statistically significant independent prognostic variable (P=0.02).

CONCLUSION

In primary advanced ovarian cancer the use of diagnostic FDG-PET/CT leads to stage migration. Adequate staging is the foundation for ovarian cancer treatment and advanced imaging for optimal evaluation of metastases should be promoted in clinical trials. The strongest determinant of patient outcome is residual abdominal tumor after primary surgery.