Session Item

To determine the effect of primary tumor volume on clinical outcomes of nasopharyngeal carcinoma treated with definitive chemoradiation in the present staging framework. 

Between February 2006 and December 2012, 40 patients with non metastatic nasopharyngeal carcinoma treated with definitive chemoradiation at our institution were reviewed after approval from institutional ethics review committee. The primary tumor volume was calculated from planning computed tomography scans retrospectively.  Demographic characteristics, stage of the disease and treatment parameters were recorded from medical charts. The clinical outcomes that was assessed include loco-regional failure free survival (LFFS), disease free survival (DFS) and distant metastasis free survival (DMFS)  and correlated with primary tumor volume. The Kruskal-Wallis and Mann-Whitney test were used for comparison among variables. The Kaplan Meier and hazard model were used for outcome analysis

At a median follow up 38 months (IQR: 5-103 months), 5 (12.5%) patients developed locoregional failure and 12 (30%) patients were failed at distant sites. The median primary tumor volume of the entire cohort was 84.7cm3 (23-255.3cm3). Although a wide variation in tumor volume was observed within the same as well as different T stage however there was a gradual increase in tumor volume with advancing T stage (p< 0.001), similar finding was also observed in N classification without statistically significance (p=0.467). The 5-year Locoregional failure free survival (LFFS), disease free survival (DSF) and distant metastasis free survival (DMFS) was 87.2%, 74.6% and 64.5% respectively. In order to better estimate the impact of tumor volume on clinical outcomes, tumor volumes were divided into three equal groups < 66cm3, 66-95cm3 and > 95cm3. On analysis N stage showed good relationship with distant metastasis free survival (DMFS) (p < 0.05),  T stage on local control (p 0.09), but primary tumor volume was found to have significant correlation with all defined clinical outcomes i.e. LFFS, DFS & DMFS (p < 0.05).

Primary tumor volume was found to have significant correlation with clinical outcome i.e., locoregional as well distant metastasis in nasopharyngeal carcinoma.