Analysis of Plasma Epstein-Barr Virus DNA in Nasopharyngeal Cancer After Chemoradiation to Identify High-Risk Patients for Adjuvant Chemotherapy: A Randomized Controlled Trial

The Southwest Oncology Group (SWOG) coordinated an Intergroup study with the participation of Radiation Therapy Oncology Group (RTOG), and Eastern Cooperative Oncology Group (ECOG). This randomized phase III trial compared chemoradiotherapy versus radiotherapy alone in patients with nasopharyngeal cancers. Radiotherapy was administered in both arms: 1.8- to 2.0-Gy/d fractions Monday to Friday for 35 to 39 fractions for a total dose of 70 Gy. The investigational arm received chemotherapy with cisplatin 100 mg/m2 on days 1, 22, and 43 during radiotherapy; postradiotherapy, chemotherapy with cisplatin 80 mg/m2 on day 1 and fluorouracil 1,000 mg/m2/d on days 1 to 4 was administered every 4 weeks for three courses. Patients were stratified by tumor stage, nodal stage, performance status, and histology. Of 193 patients registered, 147 (69 radiotherapy and 78 chemoradiotherapy) were eligible for primary analysis for survival and toxicity. The median progression-free survival (PFS) time was 15 months for eligible patients on the radiotherapy arm and was not reached for the chemo-radiotherapy group. The 3-year PFS rate was 24% versus 69%, respectively (P < .001). The median survival time was 34 months for the radiotherapy group and not reached for the chemo-radiotherapy group, and the 3-year survival rate was 47% versus 78%, respectively (P = .005). One hundred eighty-five patients were included in a secondary analysis for survival. The 3-year survival rate for patients randomized to radiotherapy was 46%, and for the chemoradiotherapy group was 76% (P < .001). We conclude that chemoradiotherapy is superior to radiotherapy alone for patients with advanced nasopharyngeal cancers with respect to PFS and overall survival.

Nasopharyngeal carcinoma of the undifferentiated subtype is endemic to southern China, and patient prognosis has improved significantly over the past three decades because of advances in disease management, diagnostic imaging, radiotherapy technology, and broader application of systemic therapy. Despite the excellent local control with modern radiotherapy, distant failure remains a key challenge. Advances in molecular technology have helped to decipher the molecular pathogenesis of nasopharyngeal carcinoma as well as its etiologic association with the Epstein-Barr virus. This in turn has led to the discovery of novel biomarkers and drug targets, rendering this cancer site a current focus for new drug development. This article reviews and appraises the key literature on the current management of nasopharyngeal carcinoma and future directions in clinical research.

Purpose To establish the safety profile and antitumor activity of the anti-programmed death 1 receptor monoclonal antibody, pembrolizumab, in patients with recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) that expressed programmed death-ligand 1 (PD-L1). Patients and Methods KEYNOTE-028 (NCT02054806) is a nonrandomized, multicohort, phase Ib trial of pembrolizumab in patients with PD-L1-positive advanced solid tumors. Key eligibility criteria for the NPC cohort included unresectable or metastatic disease, failure on prior standard therapy, and PD-L1 expression in 1% or more of tumor cells or tumor-infiltrating lymphocytes. Patients received pembrolizumab 10 mg/kg every 2 weeks up to 2 years or until disease progression or unacceptable toxicity. Primary end point was objective response rate (ORR) per investigator review. Tumor response was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1) every 8 weeks for the first 6 months and every 12 weeks thereafter. Results Twenty-seven patients received pembrolizumab. Median age was 52.0 years (range, 18 to 68 years); 92.6% received prior therapies for RM-NPC; 70.4% had received three or more therapies. Partial response and stable disease were observed in seven and 14 patients, respectively, for an ORR of 25.9% (95% CI, 11.1 to 46.3) over a median follow-up of 20 months. ORR by central review was similar (26.3%). Drug-related adverse events that occurred in 15% or more of patients included rash (25.9%), pruritus (25.9%), pain (22.2%), hypothyroidism (18.5%), and fatigue (18.5%). Grade ≥ 3 drug-related adverse events occurred in eight patients (29.6%), and there was one drug-related death (sepsis). As of the data cutoff (June 20, 2016), two patients remained on pembrolizumab treatment. Conclusion Pembrolizumab demonstrated antitumor activity and a manageable safety profile in patients with RM-NPC.