Prognostic factors for survival after salvage reirradiation of head and neck cancer.

PURPOSE: Patients who develop recurrent or new primary head and neck cancer in a previously irradiated site have poor prognosis. Reirradiation is a treatment option, although it is associated with substantial toxicities. We investigated potential prognostic factors, including comorbidity and pre-existing organ dysfunction, for survival after reirradiation.
METHODS: Institutional electronic records of patients treated with reirradiation between January 1998 and 2008 were reviewed. Comorbidity was assessed by Charlson index and Adult Comorbidity Evaluation-27 (ACE-27) grading. Organ dysfunction was defined as feeding tube dependency, functioning tracheostomy, or soft tissue defect.
RESULTS: There were 103 patients, including 46 patients who underwent salvage surgery before reirradiation. Median progression-free and overall survivals were 12.1 months (95% CI, 9.7 to 16.6) and 19.3 months (95% CI, 13.9 to 29.9), respectively. Significant comorbidity was present in 36% of patients by Charlson index and 24% by ACE-27. Baseline organ dysfunction was present in 37% of patients. Median overall survivals were 5.5 months among those with both organ dysfunction and comorbidity per Charlson index, and 4.9 months per ACE-27, compared with 59.6 and 44.2 months, respectively, among the patients with neither organ dysfunction nor comorbidity (P < .001 and < .001). Other independent prognostic factors were interval from previous radiation, recurrent tumor stage, tumor bulk at reirradiation, and reirradiation dose. A nomogram to predict the probability of death within 24 months after reirradiation was developed (concordance index = 0.75).
CONCLUSION: Comorbidity and pre-existing organ dysfunction are among several important prognostic factors for patients undergoing reirradiation. For those with both comorbidity and organ dysfunction, reirradiation largely serves as a palliative therapy.