Japanese Journal of Clinical Oncology Advance Access originally published online on August 2, 2007
Japanese Journal of Clinical Oncology 2007 37(8):559-567; doi:10.1093/jjco/hym072
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© 2007 Foundation for Promotion of Cancer Research
Influence of Delayed Tumor Clearance on Reliability of Complete Response Rate in Chemoradiotherapy for Head and Neck Cancer
1 Radiation Oncology Division
2 Gastrointestinal Medical Oncology Division
3 Head and Neck Surgery Division
4 Diagnostic Radiology Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
For reprints and all correspondence: Mitsuhiko Kawashima, 6-5-1, Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan. E-mail: mkawashi{at}east.ncc.go.jp
Received March 12, 2005; accepted March 23, 2007
Objective: The relationship was studied between the timing of assessment of complete response and ultimate cure rate in the chemoradiotherapy of advanced head and neck cancer.
Methods: A retrospective review was conducted regarding tumor responses at 4 weeks, 3 months, and 6 months after concomitant chemoradiotherapy using cisplatin and 5-FU for 70 patients with stage III/IV squamous cell carcinoma of the oropharynx, hypopharynx and supraglottic larynx. Predictive values of tumor responses at these three time points for survival and tumor control at 2 years were tested using the chi-square test.
Results: Twelve (17%) patients achieved complete response (CR) at 4 weeks. Because of late regression or early recurrence, the CR rate changed to 18/70 (26%) and 24/70 (34%) at 3 and 6 months, respectively. CR or not at 6 months was significantly correlated with all survival endpoints (P < 0.001), but not those at 4 weeks and 3 months (P > 0.100). Kaplan–Meier estimate of overall survival at 5 years was 63% (95% CI 43–84%) for 24 CR patients at 6 months.
Conclusion: CR rate at 6 months was a better surrogate endpoint than that at 4 weeks or 3 months in this series of patients.
Key Words: head and neck cancer chemoradiotherapy response rate surrogate end point
"*" Present address: Jichi Medical University, Tochigi, Japan.
dagger; This study was presented at the 47th Annual Meeting of the American Society for Therapeutic Radiology and Oncology, Denver, CO, 16–20 October 2005.