ESTRO 2024 - Abstract Book

S1302

Clinical - Head & neck

ESTRO 2024

3. Rathod S, Gupta T, Ghosh-Laskar S, Murthy V, Budrukkar A, Agarwal J. Quality-of-life (QOL) outcomes in patients with head and neck squamous cell carcinoma (HNSCC) treated with intensity-modulated radiation therapy (IMRT) compared to three-dimensional conformal radiotherapy (3D-CRT): evidence from a prospective randomized study. Oral Oncol. 2013;49(6):634-642.

1510

Mini-Oral

CNG (Collaborative Nasopharyngeal Carcinoma Group) stage: Improved prognostic stratification of NPC

Shuiqing He, Ya Liu, Zilu Huang, Chen Chen, Yunfei Xia

sun yat-sen university cancer center, radiation oncology, GuangZhou, China

Purpose/Objective:

Significant advancements have been achieved in the survival rates of patients with nasopharyngeal carcinoma (NPC) in the intensity-modulated radiotherapy (IMRT) era. According to a phase III clinical study conducted by Li et al1. focusing on Stage IVA and IVB NPC patients (AJCC 7th), the 3-year overall survival rate reached 94.7%. The phase III clinical trial by Tang et al2. confirms that patients with low-risk Stage II and T3N0 have the potential to achieve a 3 year failure free survival rate of 98.6%. Differentiated thyroid papillary carcinoma (PTS) is primarily staged based on its prognosis. Due to the high 10-year survival rate exceeding 90% even in the presence of distant metastasis, metastatic differentiated PTS is classified as Stage II in clinical practice3. Considering the improved overall survival of NPC, Gao et al4. proposed stage migration recommendations and the CNG (Collaborative Nasopharyngeal Carcinoma Group) stage in 2017. Based on the 7th AJCC staging, all patients were classified into three stages: CNG Stage I: I, IIA, and Stage III-nonT3N2; CNG Stage II: Stage III-T3N2, IVA, IVB; CNG Stage III: IVC (initial diagnosis metastasis). However, this study did not incorporate pretreatment plasma EBV DNA, an indicator related to tumor burden and biological behavior. We hypothesis CNG Stage could provide better survival rates differentiation for NPC patients, taking into account the advancements in treatment and improved survival outcomes.

Material/Methods:

A total of 1930 patients received IMRT-based treatment between 2018 and 2019 was included. Based on the 7th AJCC stage, all patients were restaged: CNG Stage I: I, II, and Stage III-nonT3N2; CNG Stage II: Stage III-T3N2, IVA, IVB; CNG Stage III: IVC. The ability of CNG stage to differentiate prognosis compared to the 7th and 8th AICC stage in the overall population, as well as in patients with EBV DNA > 0 and EBV DNA > 1000 copies/ml, was analyzed. Additionally, the distribution of EBV DNA levels in each stage of the 7th/8th/CNG stage was compared. Kaplan-Meier method and log-rank test was performed.

Results:

The 5-year overall survival (OS) rate of patients with CNG Stage I, II and III was 93.7%, 86.5% and 75.8%, the survival curves of different stage groups were well-separated (all p<0.05). There was little difference in OS for patients with a