Abstract
BackgroundThe prognostic values of staging parameters require continual re-assessment amid changes in diagnostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non-metastatic nasopharyngeal carcinoma (NPC) in the intensity-modulated radiotherapy (IMRT) era.MethodsWe reviewed the data from 749 patients with newly diagnosed, biopsy-proven, non-metastatic NPC in our cancer center (South China, an NPC endemic area) between January 2003 and December 2007. All patients underwent magnetic resonance imaging (MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log-rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insignificant explanatory variables.ResultsThe 5-year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5-year survival rates were as follows: local relapse-free survival, 94.6%; nodal relapse-free survival, 97.0%; distant metastasis-free survival, 82.6%; disease-free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only significant prognostic factor for local failure (P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho’s location of the cervical lymph nodes were significant prognostic factors for both distant failure and disease failure (all P < 0.05). Intracranial extension had significant prognostic value for distant failure (P = 0.040).ConclusionsThe key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the significant prognostic parameters for local control have also been altered substantially.
Highlights
The prognostic values of staging parameters require continual re-assessment amid changes in diag‐ nostic and therapeutic methods
In the 1970–1980s, conventional radiotherapy alone resulted in similar outcomes in both the endemic and non-endemic areas, with 5-year overall survival (OS) rates of 48%–52%, a cumulative local failure rate of 20%, a cumulative regional failure rate of 14%, and a cumulative distant metastasis rate of 19% [3, 4]
During the 1990s, rapid technological advances in imaging methods, computerized planning systems, and radiotherapy facilities and the accumulation of radiobiological knowledge that enabled schedule, dose, and fractionation optimization led to better outcomes after radiotherapy, with 5-year OS rates of 65%–74%, a cumulative local failure rate of 12%, a regional failure rate of 5%, and a distant metastasis rate of 16% [5, 6]
Summary
The prognostic values of staging parameters require continual re-assessment amid changes in diag‐ nostic and therapeutic methods. In the 1970–1980s, conventional radiotherapy alone resulted in similar outcomes in both the endemic and non-endemic areas, with 5-year OS rates of 48%–52%, a cumulative local failure rate of 20%, a cumulative regional failure rate of 14%, and a cumulative distant metastasis rate of 19% [3, 4]. During the 1990s, rapid technological advances in imaging methods, computerized planning systems, and radiotherapy facilities and the accumulation of radiobiological knowledge that enabled schedule, dose, and fractionation optimization led to better outcomes after radiotherapy, with 5-year OS rates of 65%–74%, a cumulative local failure rate of 12%, a regional failure rate of 5%, and a distant metastasis rate of 16% [5, 6]. Due to the dosimetric advantages of IMRT combined with the use of magnetic resonance imaging (MRI)-guided tumor volume delineation and concurrent chemotherapy, local control rate in NPC patients has improved significantly [7, 8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
