We report gene targeting via homologous recombination in zebrafish. We co-injected fertilized eggs with transcription activator-like effector nuclease mRNAs and a donor vector with long homologous arms targeting the tyrosine hydroxylase (th) locus, and we observed effective gene modification that was transmitted through the germ line. We also successfully targeted two additional genes. Homologous recombination in zebrafish with a dsDNA donor expands the utility of this model organism.

Purpose National Comprehensive Cancer Network guidelines recommend patients with head and neck cancer (HNC) receive treatment at centers with expertise, but whether provider experience affects survival is unknown. Patients and Methods The effect of institutional experience on overall survival (OS) in patients with stage III or IV HNC was investigated within a randomized trial of the Radiation Therapy Oncology Group (RTOG 0129), which compared cisplatin concurrent with standard versus accelerated fractionation radiotherapy. As a surrogate for experience, institutions were classified as historically low- (HLACs) or high-accruing centers (HHACs) based on accrual to 21 RTOG HNC trials (1997 to 2002). The effect of accrual volume on OS was estimated by Cox proportional hazards models. Results Median RTOG accrual (1997 to 2002) at HLACs was four versus 65 patients at HHACs. Analysis included 471 patients in RTOG 0129 (2002 to 2005) with known human papillomavirus and smoking status. Patients at HLACs versus HHACs had better performance status (0: 62% v 52%; P = .04) and lower T stage (T4: 26.5% v 35.3%; P = .002) but were otherwise similar. Radiotherapy protocol deviations were higher at HLACs versus HHACs (18% v 6%; P < .001). When compared with HHACs, patients at HLACs had worse OS (5 years: 51.0% v 69.1%; P = .002). Treatment at HLACs was associated with increased death risk of 91% (hazard ratio [HR], 1.91; 95% CI, 1.37 to 2.65) after adjustment for prognostic factors and 72% (HR, 1.72; 95% CI, 1.23 to 2.40) after radiotherapy compliance adjustment. Conclusion OS is worse for patients with HNC treated at HLACs versus HHACs to cooperative group trials after accounting for radiotherapy protocol deviations. Institutional experience substantially influences survival in locally advanced HNC.