Electronic patient-reported outcome monitoring and quality of life during later-line nivolumab therapy for advanced gastric cancer

Background Health-related quality of life (HRQoL) often deteriorates during later-line treatment for advanced gastric cancer. Although nivolumab monotherapy has been an established treatment option in this setting, HRQoL data remain limited. This study aimed to examine associations between symptomatic adverse events (AEs) and HRQoL deterioration and to evaluate the feasibility of home-based electronic patient-reported outcome (ePRO) monitoring. Methods This prospective observational study enrolled patients aged ≥ 20 years with an ECOG performance status of 0–2 who were scheduled to receive later-line nivolumab monotherapy in clinical practice. Patients self-reported symptomatic AEs using PRO-CTCAE and assessed HRQoL weekly using FACT-Ga via a smartphone-based ePRO system for 12 weeks. The association between symptom deterioration and HRQoL decline was analyzed using a general linear model. Digital literacy and impressions of ePRO were also surveyed. Results Among 29 evaluable patients, 20 completed the 12-week monitoring period. Median time to HRQoL deterioration was 9 weeks. Several symptomatic AEs, including stomatitis, dysgeusia, pain, malaise, and depression, showed nominal associations with HRQoL decline in unadjusted exploratory analyses (all nominal p < 0.05). Despite 37.9% of patients not regularly using smartphones, adherence to ePRO reporting was high, with only 0.95% missing data. Conclusions Exploratory analyses suggested potential associations between specific symptomatic AEs and HRQoL deterioration during later-line nivolumab therapy for advanced gastric cancer. ePRO monitoring achieved high data completeness, although patient acceptability was limited. These findings support further evaluation of ePRO as a tool for timely symptom recognition, alongside strategies to improve acceptability.