1053PD - Refining staging system for nasopharyngeal carcinoma treated with intensity-modulated radiation therapy

Date 09 September 2017
Event ESMO 2017 Congress
Session Head and neck cancer, excluding thyroid
Topics Cancer in Adolescents
Head and Neck Cancers
Imaging, Diagnosis and Staging
Surgery and/or Radiotherapy of Cancer
Presenter Victor Lee
Citation Annals of Oncology (2017) 28 (suppl_5): v372-v394. 10.1093/annonc/mdx374
Authors V.H. Lee1, D.L. Kwong1, T.W. Leung1, C. Choi1, B. O'Sullivan2, K.O. Lam1, V. Lai3, P. Khong3, S. Chan1, C. Ng1, C.C. Tong1, P.Y.P. Ho1, W.L. Chan1, L. Wong1, D.K. Leung1, S. Chan1, A.W. Lee1
  • 1Department Of Clinical Oncology, The University of Hong Kong, 000 - Hong Kong/HK
  • 2Department Of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, M5G2M9 - Toronto/CA
  • 3Department Of Diagnostic Radiology, The University of Hong Kong, 000 - Hong Kong/HK

Abstract

Background

We incorporated baseline plasma EBV DNA into refinement of stage groups for nasopharyngeal carcinoma (NPC) treated with radical intensity-modulated radiation therapy (IMRT).

Methods

Patients with non-metastatic NPC treated with radical IMRT +/- adjunct chemotherapy based on 7th edition of American Joint Committee on Cancer (AJCC) system were recruited prospectively from 2010 to 2016. All patients had baseline and serial post-IMRT plasma EBV DNA (in copies/ml) measured and were staged with MRI and PET-CT. Recursive partitioning analysis (RPA) with repeated internal validations derived new stage groups with incorporation of baseline plasma EBV DNA. Multivariable analyses were used to calculate adjusted hazard ratios (AHRs) to derive a new set of AHR stages. Comparison of performance of survival prediction among these 3 sets of stage groups was done to find the best-performing stage set.

Results

The cohort included 520 patients treated with IMRT +/- adjunct chemotherapy with a median follow-up of 5.0 years. They were re-staged based on 8th edition of AJCC system. 5-year overall survival (OS) and cancer-specific survival (CSS) were as follows: stage I (OS 89.5%; CSS 100%), II (OS 87.8%; CSS 94.7%), III (OS 85.0%; CSS 90.0%) and IVA (OS 74.4%; CSS 79.9%) (p = 0.058 and p = 0.003 respectively). RPA derived NPC into 3 new stages with corresponding OS and CSS: RPA-I (T1-T4N0-N2 & T1-T2N3 & EBV DNA 2000) (OS 80.5%; CSS 84.1%) and RPA-III (T3-T4N3) (OS 58.2%; CSS 67.1%) (both p 

Conclusions

A novel RPA-based TNM stage groups revealed significantly better survival prediction compared with the 8th edition AJCC and AHR stages.

Clinical trial identification

NCT02476669

Legal entity responsible for the study

Department of Clinical Oncology, The University of Hong Kong and Clinical Oncology Center, The University of Hong Kong-Shenzhen Hospital

Funding

SK Yee Medical Foundation

Disclosure

All authors have declared no conflicts of interest.