Session Item

No consensus has been reached on the risk factor of distant metastasis and the benefit of induction chemotherapy in advanced stage nasopharyngeal carcinoma (NPC). We aimed to investigate the clinical outcome and prognostic factors of different T classification in the initially clinical N3M0 NPC patients. 

This study included clinical N3M0 NPC patients from January, 2012 to December, 2020 in a single institute. All T- and N- classification were reviewed by pretreatment MRI according to the 8th AJCC staging system. In order to focus on the effect of the location in cervical lymphadenopathy, patients without lymph node metastasis below the caudal border of cricoid cartilage were excluded. All patients received curative radiotherapy with 69.96-74.0 Gy. Any combination of systemic treatment was allowed, including induction, concurrent and adjuvant chemotherapy. The endpoints of 2-yr DMFFS (distant metastasis failure-free survival) and 2-yr DSS (disease specific survival) were compared among different T classification. The secondary endpoint was to evaluate possible prognostic factors in these patients.

Fifty-two patients were included in the study. The median follow-up time was 4.3 years with 10 distant metastasis events recorded. There were 13 patients in T1 classification, 11 in T2 classification, 19 in T3 classification and 9 in T4 classification. Comparing the patients in T1 classification with T2-4 classification, the patients in T1 classification have a trend of lower 2-yr DMFFS (69.2% v.s. 89.7%, p=0.073) and 2-yr DSS (76.9% v.s. 94.9%, p=0.067). The hazard ratio of 2-yr DMFFS and 2-yr DSS was 3.296 (95% CI [0.823-13.202]) and 4.578 (95% CI [0.765-27.401]), respectively.

Our preliminary results suggested a trend that the patients with T1N3 NPC have higher risk of distant metastasis and lower 2-yr survival rate. Higher intensity of induction chemotherapy may lead to a better control of distant metastasis rate and survival. Pretreatment PET/CT was also considered in these patients for detecting early metastasis. Further studies with a larger population and specific prognostic factors are needed.