Can Epstein–Barr virus-deoxyribonucleic acid load after induction chemotherapy combined with American Joint Committee on Cancer stage determine the chemotherapy intensity of locally advanced nasopharyngeal carcinoma?

Background: Induction chemotherapy (IC) with docetaxel, cisplatin, and fluorouracil (TPF), combined with concurrent chemoradiotherapy (CCRT), has been shown to improve survival in patients with locally advanced nasopharyngeal carcinoma (LA-NPC) . Our previous study demonstrated that adjusting the number of IC cylces based on TNM stage and Epstein-Barr virus DNA (EBV-DNA) load after IC did not compromise efficacy while reducing toxicity. However, due to the small sample size, there is a need for further confirmation of the long-term outcomes . Methods: This retrospective analysis evaluated the clinical data and survival outcomes of patients with stage III–IVaLA-NPC treated with TPF IC followed by CCRT. Patients in the conventional treatment group received three standard cycles of TPF IC an d CCRT, while those in the experimental group had IC cycles determined by EBV-DNA clearance . If EBV-DNA was undetectable after a certain IC course, subsequent IC was stopped, and CCRT commenced. Propensity score matching (PSM) was performed at a ratio of 1:4 to balance baseline characteristics. Survival outcomes between the two groups were compared. Results: A total of 730 patients were included , and 481 patients were successfully matched into 106 pairs . The median followed-up duration was 116months. The 5-year survival outcomes before and after matching, respectively, were as follows: distant metastasis-free survival (89 .3%vs.87.6%, P=0.52/ 87.9% vs . 87.6%, P=0.886), local recurrence-free survival (90 .3%vs. 81.9%, P=0.015/88 .8% vs . 81.9%, P=0.069),progression-free survival (81 . 1%vs . 68.7%, P=0.003/78.5%vs .68.7%, P=0.033), and overall survival (85 .9% vs . 85.3%, P=0.795 / 84.4%vs.85.3%, P=0.870) . Conclusions: This study addresses an important clinical question about the use of EBV-DNA as a marker for optimizing IC in LA-NPC patients, and presents promising findings that could enhance patient outcomes.The results provides a valuable foundation for future research but requires further confirmation through well-designed prospective trials. Trial registration : This is a retrospective study without registration for prospective clinical trial.