Quality of life symptom burden heterogeneity in papillary thyroid cancer survivors: latent profiles and the mediating role of decision regret

Papillary thyroid cancer (PTC) survivors report substantial quality of life (QoL) impairments despite excellent prognosis. However, the psychological mechanisms through which social support influences QoL remain poorly understood. This study aimed to identify distinct QoL symptom burden profiles among PTC survivors and to examine whether decision regret mediates the association between social support and QoL. This cross-sectional study enrolled 737 PTC survivors from three tertiary hospitals in Chongqing, China, between March and June 2025. Latent profile analysis was used to identify subgroups based on the Thyroid Cancer-Specific Quality of Life Questionnaire (ThyCA-QoL). Bootstrap mediation analysis examined decision regret as a mediator, and E-value sensitivity analysis assessed robustness to unmeasured confounding. Four profiles emerged: Low Symptom Burden (30.0%), Psychological Distress Dominant (25.6%), Physical Symptom Dominant (22.5%), and High Symptom Burden (21.8%). Social support and decision regret differed significantly across profiles ( p < .001). Decision regret statistically accounted for 44.3% of the association between social support and QoL (indirect effect B = − 0.121, 95% bootstrap CI [− 0.158, − 0.089]; completely standardized indirect effect β = −0.150, 95% bootstrap CI [− 0.194, − 0.110]). The E-value of 1.56 indicates that only modest unmeasured confounding would be required to explain away this finding. PTC survivors exhibit marked heterogeneity in QoL symptom burden patterns. Decision regret, a potentially modifiable psychological factor, partially accounted for the association between social support and QoL, suggesting that decisional support interventions merit consideration in survivorship care.