Hayes, D Neil

Abstract Purpose: NFE2L2/KEAP1/CUL3 mutations have been validated for radioresistance in cell-based assays and animal models. However, clinical validation of these biomarkers has been challenging because of multimodality treatment regimens. This study aims to investigate the association between NFE2L2/KEAP1/CUL3 mutations and patient outcomes, including local failure, locoregional failure, disease-free survival (DFS), and overall survival, using samples from a phase III trial in which patients were treated with radiation monotherapy at two controlled doses. Patients and Methods: We investigated NFE2L2/KEAP1/CUL3 mutations in 250 randomized patients with T2N0 glottic squamous cell carcinoma receiving definitive radiotherapy in the NRG/RTOG 9512 trial. A total of 119 patients had available biospecimens that were subjected to amplicon-based next-generation sequencing to assess for the presence of NFE2L2/KEAP1/CUL3 mutations without regard to outcomes. Mutations in NFE2L2/KEAP1/CUL3 were assessed blinded to clinical outcomes. Cox models (two-sided α = 0.05) were used to evaluate the association with clinical outcomes, performed by an independent statistical team. Results: Nineteen of 119 patients (16.0%) had NFE2L2/KEAP1/CUL3 mutations. Patient, treatment, and tumor characteristics were similar between those with and without mutations. Patients with mutation compared with those without had significantly more local failure [HR = 3.50; 95% confidence interval (CI), 1.56–7.89; P = 0.0025] and locoregional failure (HR = 3.80; 95% CI, 1.80–8.03; P = 0.0005). DFS was significantly worse for the mutated compared with the nonmutated group in the first 2 years (HR = 2.88; 95% CI, 1.46–5.66; P = 0.0022). The median DFS was shorter in the mutation group (10.3 months) versus those with intact NFE2L2/KEAP1/CUL3 (4.2 years). Conclusions: NFE2L2/KEAP1/CUL3 mutations may predict radiation treatment failure in T2N0 glottic cancer. See related commentary by Rao, p. 1563

8008 Background: Morphology remains the best biomarker for chemotherapy selection in NSCLC. Both bevacizumab and pemetrexed (in first line) are FDA indicated for non-SC histology only, making precise diagnosis key, although data are few on the reproducibility of their categorization. The standard of care, consensus-based World Health Organization diagnostic classification system, Ed. 4 (WHOC) includes 44 diagnostic categories (DC), does not include immunohistochemical (IHC) data, and is not independently validated. In this study, we estimate the reproducibility of SC versus non-SC classification to be only moderately precise. Methods: Pathologists (P) assigned WHOC diagnoses to virtual H&E slides from an incident surgical cohort of 96 primary lung tumors. At a power of 80% we estimated 24 P reviewing 48 slides each would allow for a reproducibility measure in the clinically useful range kappa=0.7, standard error=0.09. In addition to the 44 DC, we also considered the reproducibility of a simplified 10 category system and a chemotherapy-directed 2 class system. Results: 12 self-identified “lung experts” (E) and 12 community (C) P scored slides based on the 44 possible WHOC DC totaling 222 pathologist-pairs and 7130 slides-pairs. P rated confidence in their choices as: high 53%, somewhat 38%, and not confident 8%. 92% of slides were rated as having sufficient quality. Distribution of DC included SC 30% and adenocarcinoma 36%. Conclusions: To our knowledge this is the largest study ever performed of the WHOC, the only one to consider all 44 DC and to distinguish E vs C P. Although this model tests the reproducibility of the WHOC, not clinical lung cancer diagnoses, it shows that reproducible diagnosis of SC based on H&E morphology alone is inadequate. In the era of histology guided therapy, it highlights the need for strict diagnostic criteria and confirmatory IHC stains in the diagnosis of SC. [Table: see text] No significant financial relationships to disclose.

6010 Background: An evolutionary action scoring algorithm (EAp53) based on phylogenetic sequence variations and speciation stratifies head and neck squamous cell carcinoma (HNSCC) patients bearing TP53 missense mutations as high-risk (high, EAp53≥75), associated with poor outcomes, or low-risk (low), with similar outcomes as TP53 wild-type (wt), and has been validated as a reliable prognostic marker. This study is designed to further validate prior findings that EAp53 is a prognostic marker for locally advanced HNSCC patients, and assess its predictive value for treatment outcomes to adjuvant bio-chemoradiotherapy. Methods: Eighty one resection specimens from patients treated surgically for stage III or IV human papillomavirus-negative (HPV(-)) HNSCC with high-risk pathologic features, who received either Arm 1) radiotherapy(RT)+cetuximab(CTX)+cisplatin or Arm 2) RT+CTX+docetaxel, as adjuvant treatment in a phase II randomized clinical trial (RTOG 0234) underwent TP53 targeted sequencing, and EAp53 scoring. The EAp53 scores were correlated with clinical outcomes. Due to limited sample sizes, patients were combined into 2 EAp53 groups: wt/low and high/other. Results: At median follow-up of 10 years, there was a significant interaction between treatment and EAp53 group for overall survival (OS) (p = 0.008), disease-free survival (DFS) (p = 0.05) and distant metastasis (DM) (p = 0.004). Within arm 2, high/other showed worse OS [HR 4.69 (1.52-14.50)], DFS [HR 2.69 (1.16-6.21)], and had higher DM [HR 11.71 (1.50-91.68)] than wt/low. Within arm 1, there was no significant difference by EAp53 in OS, DFS and DM. Within the wt/low group, arm 2 had better OS [HR 0.11 (0.03-0.36)], DFS [HR 0.24 (0.09-0.61)], and DM [HR 0.04 (0.01-0.31)] than arm 1 but this was not found in high/other. Conclusions: High/other EAp53 scores were associated with worse survival for patients in arm 2. Arm 2 is associated with better survival than arm 1 for patients with wt/low EAp53. This benefit appears to be largely driven by a reduction in DM. Further validation is required to determine whether EAp53 can be used for personalized post-operative treatment decisions in HPV(-) HNSCC.