Factors Affecting Survival in Cervical Cancer Stage IIIB Treated with Radiation Therapy

Abstract

Introduction: To evaluate the factors affecting overall survival (OS) and local control (LC) rates in patients with uterine cervical cancer FIGO stage IIIB treated with radiation therapy (RT).

Materials and Methods: A retrospective study was conducted on 229 patients diagnosed with FIGO stage IIIB cervical cancer who received external beam RT (EBRT) followed by high-dose rate intracavitary brachytherapy (HDR-ICBT) at the Division of Radiation Oncology, Srinagarind Hospital, Khon Kaen University, Thailand, between January 1, 2009, and December 31, 2011. Key prognostic factors, including age, pre-treatment hemoglobin level, tumor size, histology, pelvic side wall involvement, concurrent chemoradiation (CCRT), equivalent dose in 2 Gy (EQD2) at point A, parametrial boost, and overall treatment time (OTT), were analyzed. Survival and local control rates were estimated using the Kaplan-Meier method; hazard ratios (HR) were calculated via Cox proportional hazards regression. Toxicities were recorded per CTCAE v4.03 and RTOG/EORTC criteria.

Results: A total of 229 patients were analyzed.The median age was 55 years (range 33-79). The 5-year OS rate was 41.9% and the 5-year LC rate was 71.4%. Multivariate analysis identified pre-treatment hemoglobin <10 vs. ≥10 g/dL (HR=1.565, p=0.017), tumor size <5 vs. ≥5 cm (HR=0.621, p=0.008), squamous cell carcinoma (SCCA) histology vs. non-SCCA (HR=0.62, p=0.035), unilateral vs. bilateral pelvic side wall involvement (HR=0.691, p=0.049), and RT alone vs. CCRT (HR=1.852, p=0.001) as significant prognostic factors for OS. For LC, significant factors included age ≥50 years, higher hemoglobin, squamous histology, and smaller tumor size. Grade 3-4 gastrointestinal toxicities were most common; no grade 4 hematologic toxicity was seen.

Conclusion: Pre-treatment hemoglobin level, tumor size, pelvic side wall involvement, histology, and CCRT were significant predictors of survival in FIGO stage IIIB cervical cancer treated with EBRT plus HDR-ICBT. Optimizing these factors may improve outcomes.