The Influence Of Institutional Head And Neck Cancer (Hnc) Clinical Trial Accrual On Overall Survival (Os): An Analysis Of Rtog 0129.

5530 Background: NCCN recommends HNC patients (pts) be treated by providers with experience in HNC management. Whether treatment by experienced providers (measured by no. of pts treated) is associated with HNC survival outcome is unknown. Methods: Analysis included 471 pts in RTOG 0129 with stage III-IVa HNC with known tumor HPV and smoking status randomized to cisplatin concurrent with standard or accelerated fractionation radiotherapy (RT). Participating centers were stratified into pt accrual tertiles (ATs) to 21 RTOG HNC trials from 1997-2002. As a surrogate for experience, we investigated the independent effect of AT on OS and progression-free survival (PFS) in multivariable cox proportional hazards models. Results: Median follow up was 4.8 yrs (range 1.1 - 6.5). In Kaplan-Meier analysis, OS and PFS for pts at centers in the two lower AT (low accruing centers [LAC]) were similar and compared to the upper AT (high accruing centers [HAC]). Median accrual in LAC vs HAC was 11 vs 82 pts. Pts treated at LAC and HAC had similar age, HPV status, pack-years, N stage, comorbidities and study arm assignment (SAA), but pts at LAC had better performance status (PS)(Zubrod 0; 62% vs 52%; p=0.04), fewer T4 tumors (27% vs. 35%; p=0.05) and were more likely uninsured (12% vs 4%; p=0.009). Compared to HAC, LAC pts had significantly worse OS, (5 yr 51.0% vs 69.1%; p = 0.002), and PFS (5 yr 42.7% vs 61.8%; p = 0.001) and more locoregional failure (5 yr 36.4% vs 20.8%; p <0.001). Treatment at LAC was associated with ~90% increase in risk of death (OS HR 1.91, 95%CI 1.37-2.65) and progression (PFS HR 1.89, 95%CI 1.39-2.56) when compared to pts treated at HAC, after adjustment for age, PS, pack-years, T and N stage, SAA and HPV status. Acute and chronic toxicities, RT dose, fractions, and treatment duration did not differ for pts at LAC vs HAC. RT at LAC was more likely than HAC to differ from protocol (18% [16.8% acceptable variation {AV}, 1.2% unacceptable deviation {UD}] vs 6% [4.7% AV, 1.3% UD]; p<0.001). Conclusions: Pts with HNC treated at LAC in RTOG trials were associated with significantly worse survival outcomes compared to pts treated at HAC.