Influence of delayed tumor clearance on reliability of complete response rate in chemoradiotherapy for head and neck cancer.
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.


CONCLUSIONS
CR rate at 6 months was a better surrogate endpoint than that at 4 weeks or 3 months in this series of patients.
Radiation Oncology Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. mkawashi@east.ncc.go.jp
Mitsuhiko
M
Kawashima
Hirofumi
H
Fujii
Ryuichi
R
Hayashi
Makoto
M
Tahara
Katsuhiro
K
Nasu
Satoko
S
Arahira
Takashi
T
Ogino
D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000628:therapy*; D002945:Cisplatin / Q000627:therapeutic use; D003131:Combined Modality Therapy; D005472:Fluorouracil / Q000627:therapeutic use; D006258:Head and Neck Neoplasms / Q000628:therapy*; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000628:therapy; D007822:Laryngeal Neoplasms / Q000628:therapy; D009959:Oropharyngeal Neoplasms / Q000628:therapy; D012189:Retrospective Studies; D013997:Time Factors
D000970:Antineoplastic Agents; D002945:Cisplatin; D005472:Fluorouracil