Failure Patterns of Recurrence and Metastasis After Intensity-Modulated Radiotherapy in Patients With Nasopharyngeal Carcinoma: Results of a Multicentric Clinical Study.

Sixia Chen,Pingting Zhou,Tingting Zhao,Min Kang,Kang Liu,Dong Yang,Ying Bin,Zhendong Yang,Ying Lu,Meng Xu,Bin Yu,Xueyin Liao,Rensheng Wang

doi:10.3389/fonc.2021.693199

Abstract

PurposeThis study aimed to explore factors associated with recurrence and metastasis after intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC) and provide evidence for NPC treatment.MethodsWe retrospectively analysed the treatment dose and survival outcomes of 645 patients with nasopharyngeal carcinoma without distant metastases treated with IMRT for the first time at three treatment centres in the Guangxi Zhuang Autonomous Region, China, between January 2009 and December 2012.ResultsThere were 9.3% of patients (60/645) had recurrence and 17.5% (113/645) had distant metastasis 5 years after treatment. The 1-year, 3-year and 5-year local recurrence rates were 0.9%, 6.5% and 9.0% respectively. And the 1-year, 3-year and 5-year distant metastasis rates were 3.4%, 10% and 17.2%, respectively. In the 60 patients with recurrence, the in-field, marginal-field, and out-field recurrence rates were 93.3% (56/60), 5.0% (3/60) and 1.7% (1/60), respectively. Recurrence failures occurring within the first three years after treatment accounted for 81.7% (49/60). In the 113 patients with metastasis, the size of the cervical lymph node, the presence of lower cervical lymph node metastasis, the residual cervical lymph node size and the time of residual cervical lymph node complete response (CR) were independent prognostic factors for DMFS (P <0.05).ConclusionMost recurrences occured in the first three years after IMRT. In-field recurrence was the most common pattern for loco-regional failure of NPC treatment. The risk of distant metastasis was positively correlated with higher N stage, lower neck nodal metastasis, larger size of cervical lymph nodes, and longer time to response for residual NPC in cervical adenopathy.

Highlights

Nasopharyngeal carcinoma (NPC) is a common malignant tumor, with higher incidence in southeastern China than that in other regions of China
According to the 2021 National Comprehensive Cancer Network (NCCN) guidelines for nasopharyngeal carcinoma,concurrent chemoradiotherapy (CCRT) is the standard treatment for patients that are stage IIIVb and Cisplatin (CDDP)-based chemotherapy is the regimen most commonly used in recent years
We reviewed a large cohort of patients to explore the factors related to NPC recurrence and distant metastasis after intensity-modulated radiotherapy (IMRT), which could provide evidence for NPC treatment

Summary

Introduction

Nasopharyngeal carcinoma (NPC) is a common malignant tumor, with higher incidence in southeastern China than that in other regions of China. Comprehensive treatment with IMRT as the primary treatment approach significantly improves the prognosis of patients with a local control rate over 90%, and overall survival rate over 80% [2,3,4,5,6]. Radiotherapy alone has excellent performance in the treatment of early nasopharyngeal carcinoma, radiotherapy is a local treatment and has limited effect on distant metastasis. Radiotherapy combined with chemotherapy can reduce the distant metastasis rate and improve the long-term survival rate of nasopharyngeal carcinoma. According to the 2021 National Comprehensive Cancer Network (NCCN) guidelines for nasopharyngeal carcinoma,concurrent chemoradiotherapy (CCRT) is the standard treatment for patients that are stage IIIVb and Cisplatin (CDDP)-based chemotherapy is the regimen most commonly used in recent years

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