Investigation of long-term survival outcomes and failure patterns of patients with nasopharyngeal carcinoma receiving intensity-modulated radiotherapy: a retrospective analysis.

Wei Zhao,Song Qu,Xia Liang,Ling Li,Hao Lei,Xiaodong Zhu

doi:10.18632/oncotarget.13564

Abstract

Intensity-modulated radiotherapy (IMRT) has replaced the conventional radiotherapy (2D-RT) and improved clinical efficacy in Nasopharyngeal Carcinoma (NPC) patients. In the present study, we retrospectively analyzed the clinical characteristics of patients with NPC treated with IMRT to assess the long-term survival outcomes and failure patterns. Of the 527 patients, One hundred and twenty-one patients experienced treatment failure, 86 patients developed distant metastases, and 12 patients developed a second primary tumor. The local and regional recurrence rates were 31.4% and 14.0%, respectively. The 5-year overall survival (OS), progression-free survival (PFS), local recurrence-free survival (LRFS), regional relapse-free survival (RRFS), and distant metastatic relapse-free survival (DMFS) rates were 80.9%, 75.6%, 91.7%, 96.2%, and 83.0%, respectively. The 5-year LRFS rates of Stage T1-4 patients were 100.0%, 93.1%, 92.0%, and 85.8%, respectively. The 5-year DMFS rates of Stage N0-3 patients were 95.0%, 86.1%, 79.5%, and 67.2%, respectively. Multivariate analysis showed age and T-stage were independent predictors of OS, T-stage was an independent predictor of LRFS, and age and N-stage were independent predictors of PFS and DMFS.In summary, the improved treatment results with IMRT are primarily due to the achievement of a higher local tumor control rate and OS in NPC patients. However, distant metastasis was the most commonly observed failure pattern after treatment. These results provide deep insights about the value of IMRT in the treatment and prognosis of NPC patients.

Highlights

Nasopharyngeal Carcinoma (NPC) is the most common malignant head and neck tumor in Asian patients, in southern China
Sun et al retrospectively analyzed 868 patients with NPC treated with Intensity-modulated radiotherapy (IMRT), wherein approximately 69.4% patients had phase III-IVa disease, and found that the 5-year Disease Specific Survival (DSS), local recurrence-free survival (LRFS), regional relapse-free survival (RRFS), distant metastatic relapse-free survival (DMFS), and progression-free survival (PFS) rates were 84.7%, 91.8%, 96.4%, 91.8%, and 77.0%, respectively [3]
Compared with the results of a study on non-IMRT treatment options in our hospital [4], which are similar to those of studies in other research centers [2, 5, 6], the present study indicated that IMRT significantly improved the patient's overall survival (OS), LRFS, and PFS

Summary

Introduction

NPC is the most common malignant head and neck tumor in Asian patients, in southern China. Considering the high sensitivity of radiotherapy, IMRT has exhibited improved clinical efficacy in NPC patients, and has widely replaced the conventional radiotherapy, including two-dimensional radiation therapy technology and three-dimensional conformal radiotherapy technology. From 1996 to 2000, the 5-year OS of 2,687 patients who underwent conventional two-dimensional radiotherapy was 75% [1]. The 5-year diseasespecific survival rate (2005–2010) of 444 patients treated with IMRT was approximately 85% [2]. To our knowledge, studies with a large sample, long-term follow-up, and various disease stages among patients with NPC are rare. We retrospectively analyzed the clinical characteristics of patients with biopsy-proven, non-metastatic NPC treated with IMRT from January 2007 to December 2011 in our hospital to assess the long-term survival outcomes and failure patterns

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Conclusion