Patient Reported Outcomes (PROs) in MC1675, De-Escalated Adjuvant Radiation Therapy (DART) vs. Standard of Care Adjuvant Radiation Therapy (SOC) for HPV Associated Oropharyngeal Squamous Cell Carcinoma

Abstract

<h3>Purpose/Objective(s)</h3> We previously reported the results of a phase III clinical trial (MC1675) evaluating 30-36 Gy of adjuvant radiation therapy (RT) with weekly docetaxel (DART) vs standard of care (SOC) adjuvant (chemo)RT. Here we report patient reported outcomes (PROs) of this randomized study. <h3>Materials/Methods</h3> The DART regimen consists of transoral robotic-assisted surgery (TORS) & neck dissection for a margin negative resection. Patients (pts) with intermediate risk factors received 30 Gy/1.5 Gy b.i.d. + docetaxel 15 mg/m² days 1 & 8, while pts with extranodal extension (ENE) received a simultaneous boost to 36 Gy/1.8 Gy b.i.d. to ENE+ nodal levels. Pts randomized to SOC received 60 Gy/2.0 Gy qd +/- cisplatin. Pts completed PROs consisting of the FACT-HN, EQ5D, XEQOLS, and EORTC HN-35 post operatively (prior to adjuvant RT), immediately post RT, and at 1-, 3-, 12-, and 24-months post treatment. Mixed models with contrast statements were utilized to test the effect of treatment arm over time and their interaction by analyzing mean difference change from baseline. <h3>Results</h3> Of the 194 patients (DART: 130, SOC: 64) 189 patients completed post-op PROs, 179 immediately post RT, 175 at 1-month, 166 at 3-months, 140 at 12-months, and 74 at 24-months, with no differences in completion rate by study arm (p=.9). Compared to post-op, PROs revealed significant symptom burden post RT and improvement over time, with the DART arm having significantly fewer symptoms in multiple domains of the PROs: FACT-HN Total (p=0.004), FACT-HN Trial Outcome Index (p<0.001, <b>Table 1</b>), and XEQOLS Total Score (p<0.001). Additional significant differences (all favoring DART, all p<0.02) were the EQ5D Index Score, EORTC scales of pain, swallow, speech, social eating, social contact, sex score, dry mouth, open mouth, sticky saliva, felt ill score, and coughing score. Measures of clinically meaningful change and correlation to objective measures of modified barium swallow will be presented. <h3>Conclusion</h3> DART was associated with significantly fewer patient reported symptoms compared to SOC as evidenced by PROs across multiple domains. PROs normalized as expected over time, yet evidence of decreased symptom burden with DART compared to SOC persisted at 12 to 24 months by patient report. If deemed oncologically equivalent for lower risk patients, DART should be considered based on this superiority in PROs and previously reported objective swallowing measures.