The purpose of this study is to compare concurrent chemoradiotherapy (CCRT) alone with induction chemotherapy (gemcitabine+cisplatin) plus CCRT in patients with low-risk locoregionally advanced nasopharyngeal carcinoma(NPC).

Patients with low risk NPC( Stage III-IVa, except T4N2/AnyTN3, AJCC 8th and EBV DNA <4000 copies/ml) are randomly assigned to receive CCRT alone or induction chemotherapy plus CCRT. Patients in both groups receive cisplatin 100 mg/m² every 3 weeks for 3 cycles, concurrently with intensity-modulated radiotherapy (IMRT). IMRT is given as 2.12 Gy per fraction with five daily fractions per week to a total dose of 70 Gy. The induction chemotherapy plus CCRT group receive gemcitabine (1000 mg/m² d1,8) and cisplatin (80mg/m² d1) every 3 weeks for three cycles before CCRT. Our primary endpoint is progress-free survival. Secondary end points include overall survival (OS), Locoregional progression, Distant progression and toxic effects. All efficacy analyses are conducted in the intention-to-treat population, and the safety population include only patients who receive their randomly assigned treatment.

Inclusion Criteria:

1. Age 18-70 years old.
2. Patients with newly histologically confirmed non-keratinizing (according to WHO histologically type).
3. Tumor staged as III-IVa except T4N2/AnyTN3 (according to the 8th AJCC edition) and pretreatment plasm EB Virus DNA<4000copies/ml.
4. ECOG Performance status less or equal to 1.
5. Male and no pregnant female.
6. Adequate marrow: leucocyte count ≥ 4000/μL, hemoglobin ≥ 90g/L and platelet count ≥ 100000/μL.
7. Normal liver function test: Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST) < 1.5×upper limit of normal (ULN) concomitant with alkaline phosphatase (ALP) < 2.5×ULN, and bilirubin < ULN.
8. Adequate renal function: creatinine clearance ≥ 60 ml/min.
9. Patients must be informed of the investigational nature of this study and give written informed consent.

Exclusion Criteria:

1. Patients have evidence of relapse or distant metastasis.
2. WHO Type keratinizing squamous cell carcinoma or basaloid squamous cell carcinoma.
3. Treatment with palliative intent.
4. History of previous RT (except for non-melanomatous skin cancers outside intended RT treatment volume).
5. Prior chemotherapy or surgery (except diagnostic) to primary tumor or nodes.
6. Pregnancy or lactation (consider pregnancy test in women of child-bearing age and emphasize effective contraception during the treatment period).
7. Prior malignancy except adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer.
8. Any severe intercurrent disease, which may bring unacceptable risk or affect the compliance of the trial, for example, unstable cardiac disease requiring treatment, renal disease, chronic hepatitis, diabetes with poor control (fasting plasma glucose > 1.5×ULN), and emotional disturbance.