Kim, Harold

119 Background: Radiotherapy (RT) interruptions have a negative impact on outcomes in many epithelial malignancies treated with definitive RT. The purpose of this study was to analyze the impact of RT duration on outcomes in patients (pts) with esophageal cancer treated with definitive chemoradiotherapy (CRT). Methods: Pts treated with definitive CRT on RTOG trials 8501 and 9405 were included. Separate analyses were performed in pts receiving standard dose (SD-CRT; 50 Gy + 5FU + cisplatin) and high dose (HD-CRT; 64.8 Gy + 5FU + cisplatin) CRT. Local (LF) and regional (RF) failure were estimated by the cumulative incidence method. Disease-free (DFS) and overall (OS) survival were estimated by the Kaplan-Meier method. Univariate (UVA) and multivariate (MVA) Cox proportional hazards models were utilized to examine for correlation between RT duration (< vs. ≥ median) with LF, RF, DFS and OS. Results: In the SD-CRT cohort (n=235), 96 pts (41%) had ≥ 1 RT interruption for a median of 3 (IQR 1-6) days. The median RT duration was 39 (IQR 37-43) days. In UVA and MVA, RT duration was not associated with LF, RF, DFS, or OS. Estimated outcome rates are in the table. In the HD-CRT cohort (n=107), 64 pts (60%) had ≥ 1 RT interruption for a median of 3.5 (IQR 2-7.5) days. The median RT duration was 52 (IQR 50-57) days. In UVA, RT duration ≥ 52 days was associated with a 33% reduction in risk of DFS failure (HR=0.66, 95% CI [0.44-0.98], p=0.039) and a 29% reduction in risk of death (HR=0.71, 95% CI [0.48-1.06], p=0.09). When excluding the 25 pts with RT dose < 64.8 Gy, RT duration was not associated with DFS or OS. Conclusions: In pts with esophageal cancer receiving definitive SD-CRT, an association between RT duration and outcomes was not observed. In pts receiving HD-CRT, longer RT duration was associated with improved DFS, which may have been due to a significant number of deaths at RT dose < 64.8 Gy. Supported by NCI U10 grants CA21661, CA180868, CA180822, CA37422. Clinical trial information: NCT00002631. [Table: see text]

BACKGROUNDProspective quality metrics for neck dissection have not been established for patients with head and neck squamous cell carcinoma. The purpose of this study was to investigate the association between lymph node counts from neck dissection, local‐regional recurrence, and overall survival.METHODSThe number of lymph nodes counted from neck dissection in patients treated in 2 NRG Oncology trials (Radiation Therapy Oncology Group [RTOG] 9501 and RTOG 0234) was evaluated for its prognostic impact on overall survival with a multivariate Cox model adjusted for demographic, tumor, and lymph node data and stratified by the postoperative treatment group.RESULTSFive hundred seventy‐two patients were analyzed at a median follow‐up of 8 years. Ninety‐eight percent of the patients were pathologically N+. The median numbers of lymph nodes recorded on the left and right sides were 24 and 25, respectively. The identification of fewer than 18 nodes was associated with worse overall survival in comparison with 18 or more nodes (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.09‐1.74; P = .007). The difference appeared to be driven by local‐regional failure (HR, 1.46; 95% CI, 1.02‐2.08; P = .04) but not by distant metastases (HR, 1.08; 95% CI, 0.77‐1.53; P = .65). When the analysis was limited to NRG Oncology RTOG 0234 patients, adding the p16 status to the model did not affect the HR for dissected nodes, and the effect of nodes did not differ with the p16 status.CONCLUSIONSThe removal and identification of 18 or more lymph nodes was associated with improved overall survival and lower rates of local‐regional failure, and this should be further evaluated as a measure of quality in neck dissections for mucosal squamous cell carcinoma. Cancer 2016;122:3464–71. © 2016 American Cancer Society.