Comparing treatment outcomes of stage IIIB cervical cancer patients between those with and without lower third of vaginal invasion

OBJECTIVE To evaluate treatment outcomes between stage IIIB cervical cancer with and without lower third of vaginal invasion (LTI) in terms of response to treatment and overall survival (OS). METHODS Matching one patient with LTI for 2 patients without LTI who had completed treatment between 1995 and 2012 were conducted by using treatment modalities (radiation therapy [RT] alone vs. concurrent chemoradiation therapy [CCRT]) and tumor histology (squamous cell carcinoma [SCC] vs. adenocarcinoma [ADC]). Treatment outcomes including complete response (CR) rate of RT/CCRT, patterns of treatment failure and survival outcomes were analyzed. RESULTS Of 216 stage IIIB cervical cancer patients, 114 of them had no LTI and 72 had LTI. Most of the patients (83.8%) had tumor histology as SCC. The CR rates between stage IIIB without LTI and with LTI were 93.8% and 81.9% (p=0.009), and corresponding with disease progression at pelvis accounted for 18.2% and 34.4% (p=0.017), respectively. Distant metastasis was comparable between 2 groups of patients, 28.9% in patients without LTI and 29.5% in patients with LTI (p=0.988). The 2-year and 5-year OS of stage IIIB without LTI were 66.5% and 46.8% compared to stage IIIB with LTI which were 43.1% and 28.9% (p=0.004), respectively. For multivariable analysis, stage IIIB with LTI was only the influential factor on OS with hazard ratio (HR) of 1.63 (p=0.012). CONCLUSION Stage IIIB cervical cancer patients with LTI have poorer treatment outcomes including response to treatment and survival outcomes than patients in the same stage without LTI.