Long-Term Outcomes of Cervical Cancer Patients With Complete Metabolic Response After Definitive Chemoradiotherapy

Abstract

The utility of metabolic positron-emission tomography (PET) parameters in patients with cervical cancer who had complete metabolic response (CMR) after chemoradiotherapy (ChRT) is unclear. We investigated the importance of metabolic parameters measured with 18F-FDG-PET/CT for predicting progression-free survival (PFS) and overall survival (OS).The clinical data of 152 patients with biopsy-proven cervical cancer treated with definitive ChRT at our institution between November 2006 and August 2012 were retrospectively evaluated. The clinical data and PET parameters including standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of 122 patients having CMR in post-treatment 18F-FDG-PET/CT delivered a median of 3.9 months after ChRT completion were analyzed. The PET parameters were measured for primary tumors (p) and metastatic lymph nodes (ln) separately.With a median follow-up of 8.4 years, 55 patients (45%) presented with disease a median of 19.7 months after ChRT. The cut-off values determined with receiver operating curve analysis for survival were 15.8, 48.7 cm³, 552.3, 8.7, 7.0 cm³, and 24.6 and for disease recurrence were 19.9, 49.8 cm³, 597.4, 9.1, 7.3 cm³, and 25.2 for SUVp, MTVp, TLGp, SUVln, MTVln, and TLGln, respectively. All metabolic PET parameters were significant prognostic factors for OS and PFS in univariate analysis. FIGO stage was predictive of both OS and PFS, while pelvic and/or para-aortic lymph node metastasis were predictive of OS only. In multivariate analysis, FIGO stage ≥IIB [HR = 2.53 (95% CI, 1.02-7.34), P = 0.04], MTVp ≥49.8 cm³ [HR = 4.13 (95% CI, 2.51-6.78), P < 0.001] and TLGp ≥597.4 [HR = 2.21 (95% CI, 1.06-4.61), P = 0.03] were predictive of worse OS. Advanced stage [HR = 4.11 (95% CI, 0.98-7.22) P = 0.05], presence of lymph node metastasis [HR = 1.48 (1.09-2.39), P = 0.04], higher TLGp [HR = 2.31 (95% CI, 1.14-4.68), P = 0.02] and larger MTVln [HR = 2.24 (1.05-4.74), P = 0.04] were significant factors for poor PFS rates.Advanced stage and higher TLGp values were significant predictors for poor survival and higher progression rates. Additional prognostic factors for worse OS were larger MTVp and lymph node metastasis and for disease progression, MTVln. We also found that most disease recurrences presented as distant metastasis, which suggests a need for effective systemic treatment.C. Onal: None. O. Guler: None. M. Reyhan: None. A. Yapar: None.