No abstract

Epstein–Barr virus (EBV) was the first oncogenic virus identified in humans. It is primarily associated with multiple lymphoid and epithelial cancers, including nasopharyngeal carcinoma (NPC). However, its association with ferroptosis and its role in cancer therapy resistance have not been fully elucidated. Here, we show that EBV infection reduces the sensitivity of NPC cells to ferroptosis by activating the p62-Keap1-NRF2 signaling pathway in conjunction with upregulation of SLC7A11 and GPX4 expression. Knockdown of endogenous GPX4 or blockade of GPX4 using a specific inhibitor enhanced the chemosensitivity of EBV-infected NPC cells. Functional studies revealed that GPX4 knockdown suppresses the proliferation and colony formation of NPC cells. Mechanistically, GPX4 interacts with the TAK1-TAB1/TAB3 complex, regulates TAK1 kinase activity, and further activates downstream MAPK-JNK and NFκB pathways. High GPX4 expression is correlated with poor clinical outcomes in patients with NPC and other cancer types. Taken together, our findings suggest that EBV infection has important effects on redox homeostasis, revealing a previously unappreciated role for GPX4 in tumor progression. This novel mechanism provides a potential new target for the treatment of EBV-related tumors.

PURPOSE Cumulative doses of 200 mg/m2 for concurrent cisplatin (DDP) were indicated by retrospective studies as sufficient in conferring survival benefit for locoregionally advanced nasopharyngeal carcinoma (LA-NPC). We performed an open-label, phase II, randomized, controlled trial to test the noninferiority of a two-cycle 100 mg/m2 concurrent DDP regimen over three-cycle in patients with low-risk LA-NPC with pretreatment Epstein-Barr virus DNA levels < 4,000 copies/mL. PATIENTS AND METHODS Eligible patients were randomly assigned 1:1 to receive two cycles or three cycles concurrent DDP-based chemoradiotherapy. The primary end point was 3-year progression-free survival (PFS). The secondary end points included overall survival, distant metastasis-free survival, locoregional relapse-free survival, etc. RESULTS Between September 2016 and October 2018, 332 patients were enrolled, with 166 in each arm. After a median follow-up of 37.7 months, the estimated 3-year PFS rates were 88.0% in the two-cycle group and 90.4% in the three-cycle group, with a difference of 2.4% (95% CI, –4.3 to 9.1, Pnoninferiority = .014). No differences were observed between groups in terms of PFS, overall survival, and the cumulative incidences of locoregional relapse and distant metastasis. Patients in the three-cycle group developed significantly more grade 3-4 mucositis (41 [24.8%] v 25 [15.1%]), hyponatremia (26 [15.8%] v 14 [8.4%]), and dermatitis (9 [5.5%] v 2 [1.2%]). The overall all-grade and grade 3-4 toxicity burdens were heavier in three-cycle group (T-scores, 12.33 v 10.57, P < .001 for all grades; 1.76 v 1.44, P = .05 for grade 3-4). Patients in the three-cycle group also showed more all-grade hearing impairment, dry mouth and skin fibrosis, and impaired long-term quality of life. CONCLUSION Intensity-modulated radiotherapy plus two cycles of concurrent 100 mg/m2 DDP could be an alternative treatment option for patients with low-risk LA-NPC.

Background: We compared the efficacy and toxicity of three IC regimens (TPF: taxanes, cisplatin, and 5-fluorouracil; TP: taxanes and cisplatin; and PF: cisplatin and 5-fluorouracil) followed by CCRT in locoregionally advanced NPC. Methods: The retrospective study involved 1354 patients with newly diagnosed stage III-IVA NPC treated with IC and CCRT. The median follow-up time in our cohort was 50 months. Based on EBV DNA level, all the patients with stage IV were divided into low-(pre-EBV DNA < 1500 copies) and high-risk group (pre-EBV DNA ≥ 1500 copies). Progression free survival (PFS), overall survival (OS), locoregional relapse free survival (LRFS), distant metastasis free survival (DMFS) and grade 3-4 toxicities were compared among different IC regimens. The survival rates were compared using log-rank test and a Cox proportional hazards model was used to perform multivariate analyses. Results: A multivariate analysis revealed TPF to be more effective than TP. Among stage III patients, no significant difference in clinical outcome between the different IC regimens was showed, while TPF was associated with significantly better survival conditions in the stage IV patients. A further subgroup analysis revealed that only patients with pre-EBV DNA ≥ 1500 copies could benefit from the application of TPF among stage IV NPC. In terms of acute toxicities, PF was associated with fewer grade 3/4 acute toxicities. Conclusions: In low-risk NPC patients, PF-based IC showed similar efficacy as TPF and TP but was associated with fewer grade 3/4 acute toxicities. In high-risk patients, however, the TPF regimen was superior to PF and TP, although grade 3/4 toxicities were more common with the TPF regimen.

IMPORTANCE Nedaplatin-based concurrent chemoradiotherapy (CCRT) regimen at 2 years was noninferior to cisplatin-based regimen in patients with locoregional, stage II to IVB nasopharyngeal carcinoma (NPC) and was associated with fewer late adverse events, but longer-term outcomes and toxicity are unclear. OBJECTIVE To evaluate the 5-year outcomes and late toxicity profile of nedaplatin-based CCRT in patients with locoregional, stage II to IVB NPC. DESIGN, SETTINGS, AND PARTICIPANTS This 5-year follow-up secondary analysis of an openlabel, noninferiority, multicenter randomized clinical trial enrolled patients with nonkeratinizing stage