Longitudinal changes in coping among early phase cancer clinical trial (EPCT) participants.

11035 Background: EPCT participants use varying strategies to cope with uncertainty related to their cancer, treatment, and prognosis. However, little is known about how coping strategies change over time among EPCT participants and how longitudinal changes correlate with patient-reported outcomes (PROs) and clinical outcomes. Methods: We prospectively enrolled adults with cancer participating in EPCTs at Massachusetts General Hospital from 4/2021-1/2023. Participants completed monthly PROs assessing coping strategies (Brief COPE), symptoms (Edmonton Symptom Assessment System [ESAS]), quality of life (QOL; Functional Assessment of Cancer Therapy General), hope (Herth Hope Index), and financial wellbeing (COST tool). We used regression models to assess associations of baseline (B/L) PROs with changes in coping scores over time (B/L to month 1 [M1] and B/L to month 2 [M2]). We also explored how changes in coping predicted clinical outcomes (time on trial [ToT], overall survival [OS]). Results: We enrolled 195 of 251 eligible patients (78% enrollment), and 188 completed the B/L surveys (96% response, median age=63 [range: 32-89], 56% female, most common cancer types: gastrointestinal [34%] and breast [21%]). Higher B/L QOL predicted decreased behavioral disengagement coping at M1 (B=-0.01, p=.037) & M2 (B=-0.02, p=.001) and self-blame at M2 (B=-0.02, p=.038), as well as increased emotional support (B=0.22, p=.001) and religion (B=0.02, p=.024) coping at M1. Higher B/L ESAS symptoms predicted decreased use of emotional support coping at M1 (B=-0.01, p=.048). Higher B/L ESAS physical symptoms predicted decreased use of emotional support at M1 (B=-0.02, p=.046) & M2 (B=-0.03, p=.016). Higher B/L psychological symptoms predicted increased use of self-blame at M2 (B=0.08, p=.007). Higher B/L financial wellbeing predicted increased emotional support at M1 (B=0.02, p=.025). Higher B/L hope predicted increased positive reframing at M1 (B=0.07, p=.010) and religion coping at M2 (B=0.05, p=.038) as well as decreased behavioral disengagement at M1 (B=-0.04, p=.001) & M2 (B=-0.06, p=.001). For clinical outcomes, increased acceptance (HR=0.85, p=.028) and religion (HR=0.85, p=.016) coping at M1 and increased positive reframing (HR=0.84, p=.010) at M2 predicted longer ToT. Increased use of behavioral disengagement at M1 predicted shorter ToT (HR=1.42, p=.002). Increased use of positive reframing (HR=0.83, p=.009) and self-blame (HR=0.78, p=.012) coping at M1 predicted better OS; increased use of behavioral disengagement (HR=1.41, p=.007) predicted worse OS. Conclusions: In this longitudinal cohort study, EPCT participants’ B/L PROs correlated with changes in their coping over time. We also found longitudinal changes in coping predicted ToT and OS. These findings highlight opportunities to enhance care delivery and outcomes for EPCT participants by addressing their PROs and coping behavior over time.