Effect of co-morbidity burden on survival following salvage re-irradiation for patients with recurrent or second primary squamous cell carcinoma of the head and neck.

6051 Background: Salvage re-irradiation (ReRT) is a treatment option for squamous cell carcinoma of the head and neck (SCHN) that recurs in a previously irradiated area. ReRT, though toxic, can produce long-term survival, even when tumor is unresectable or poor prognostic feature is present after salvage surgery. The degree to which patient co-morbidities serve as a predictor of survival following re-RT has not been studied to date.,Patients (pts) with SCHN who underwent ReRT with an overlapping target to previous RT during 1998-2007 at our institution were eligible. Co-morbidity burden was assessed by Charlson Index (CI), measuring frequency of co- morbid diseases as score 2-27, and Adult Comorbidity Evaluation-27 (ACE-27), measuring frequency & severity of co-morbid diseases as score 0-3.,69 total pts, including 25 who had salvage surgery, had a median age of 62 yrs. Most common site was oropharynx (48%). Median time since previous RT was 35 mos. Of 41 pts with measurable disease, median tumor bulk was 3 cms. ReRT was delivered at a median of 60 Gy. IMRT/3-D RT was used in 51%; Concurrent chemotherapy, in 78%. Median survival (MS) was 18.3 mos (95% CI 14-30); PFS 13.4 mos. Comorbidity burden by CI showed that 58% of pts had a score >2 (i.e. had ≥1 comorbid disease other than the current cancer). By ACE-27, 20% of pts had a score of 2 or 3 (mod or severe decompensation). Higher co-morbidity scores predicted worse survival. By CI, MS was 30 mos if score ≤2 vs. 14 mos if score >2 (p=0.003). By ACE-27, MS was 19 mos if score 0-1 vs. 12 mos if score 2 or 3 (p=0.004). Using Cox model, this remained significant after adjusting for ReRT dose and tumor bulk, which were also survival predictors (p=0.007, 0.001). Time from previous RT, new primary, IMRT/3-D RT, or salvage surgery were not significant predictors. Grade ≥3 toxicities were 36% at baseline & 68% at follow-ups (dysphagia most common). Late toxicities including trismus, fistula, and soft tissue necrosis occurred in 7, 2, and 4 pts.,Co-morbidity burden is a strong, independent predictor of survival among selected pts undergoing salvage ReRT. This information, along with other prognostic factors, may help refine patient selection and improve future treatment outcome. No significant financial relationships to disclose.