Evolutionary Action Score Of Tp53 Analysis In Pathologically High-Risk Hpv-Negative Head And Neck Cancer From A Phase Ii Clinical Trial: Nrg Oncology Rtog 0234.

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.