Concurrent chemoradiotherapy for locoregionally advanced nasopharyngeal carcinoma: is Intergroup Study 0099 feasible in Japanese patients?

Background: Since the publication of the significant results of the Intergroup Study 0099 (IGS) in 1998, radical radiation therapy (RT) with concurrent and adjuvant chemotherapy has become the standard care for patients with locoregionally advanced nasopharyngeal carcinoma (NPC) in the United States. An update in 2001 further strengthened the findings of the interim analysis, however, no prospective randomized trials other than this study have confirmed the feasibility of this strategy. Methods: We attempted to adopt the same combined modality treatment for three consecutive Japanese patients with locoregionally advanced NPC to evaluate its toxicity and efficacy. They were planned to receive radical RT concurrently with cisplatin every 3 weeks, and to receive adjuvant chemotherapy thereafter. Results: The hematological toxicities were mild and well tolerated in all three patients; however, they all experienced severe (grade 3 and/or 4) skin reactions, pharyngitis and dysphagia, which led to the discontinuation of the planned chemotherapy. They were able to complete RT without treatment breaks, and all three patients achieved complete response at the end of treatment. However, two experienced recurrences after 8 and 10 months, respectively, and died of their disease. Conclusions: Due to these severe acute adverse events, poor compliance and unsatisfactory outcomes, we have concluded that physicians should be careful in applying the concurrent chemoradiotherapy protocol employed by the IGS for locoregionally advanced Japanese NPC patients.