Chan ATC, et al. - Experts conducted a prospective, multicenter, randomized controlled trial to identify patients with nasopharyngeal cancer (NPC) at a higher risk of relapse for adjuvant chemotherapy using plasma Epstein-Barr virus (EBV) DNA. Adjuvant chemotherapy with cisplatin and gemcitabine did not improve RFS in patients having NPC with detectable post-RT plasma EBV DNA. In future clinical trials of adjuvant therapy in NPC, post-RT plasma EBV DNA level should be incorporated as the selection factor.

Methods

• Authors screened the eligible patients with histologically confirmed NPC of Union for International Cancer Control stage IIB to IVB, adequate organ function, and no locoregional disease or distant metastasis by plasma EBV DNA at 6 to 8 weeks after radiotherapy (RT).
• Standard surveillance was carried out in patients with undetectable plasma EBV DNA.
• They randomly assigned the patients with detectable plasma EBV DNA to either adjuvant chemotherapy with cisplatin and gemcitabine for six cycles (arm 1) or observation (arm 2).
• They stratified the patients for primary treatment (RT vs CRT) and stage (II/III vs IV).
• Relapse-free survival (RFS) was included as the primary end point.

Results

• As per data, 789 patients underwent EBV DNA screening.
• Findings suggested that in 573 (72.6%), plasma EBV DNA was undetectable and it was detectable in 216 (27.4%); 104 (13.2%) with detectable EBV DNA were randomly assigned to arms 1 (n = 52) and 2 (n = 52).
• After a median follow-up of 6.6 years, results demonstrated no significant difference in 5-year RFS rate between arms 1 and 2 (49.3% v 54.7%; P=.75; hazard ratio for relapse or death, 1.09; 95% CI, 0.63 to 1.89).
• They noted a significant association of the level of post-RT plasma EBV DNA with the hazards of locoregional failure, distant metastasis, and death.