Prognostic factors of reirradiation for recurrent head and neck cancer.

We analyzed outcomes and prognostic factors to assess the value of reirradiation for recurrent head and neck cancer. Forty-four patients with recurrent squamous-cell carcinoma had undergone external beam reirradiation with cumulative dosing of more than 80 Gy. Six and 38 cases exhibited recurrent stage III and stage IV cancers, respectively. The complete response rate was 32%. Median relapse-free survival time was 4 months, and the 5-year survival was 6%. The major prognostic factor was anatomical location (p < 0.0001). Favorable sites were the nasopharynx, larynx, or oropharynx; unfavorable sites were the oral cavity, nasal cavity, or hypopharynx. Poorly differentiated cancer, no prior surgery, cumulative dose more than 125 Gy, and overlapping field less than 40 cm2 between the initial and reirradiation fields were also favorable factors. Multivariate analysis revealed that anatomical location and overlapping field were significant (0.001 and 0.019, respectively) in relapse-free survival. On exclusion of anatomical location from the analysis, history of prior surgery, and cumulative dose were significant (p = 0.002 and p = 0.023, respectively). Severe late complications occurred in only 1 of 14 (7%) patients followed up for longer than 1 year. Reirradiation would be indicative for nasopharyngeal, oropharyngeal, or laryngeal cancer with small overlapping field, or cancer receiving a cumulative dose more than 125 Gy without prior surgery.