Prognostic Value of the Objective Prognostic Score and Palliative Prognostic Index for Short-Term Mortality in...

Background: Accurate prognostication in terminal cancer patients receiving best supportive care (BSC) is essential for guiding end-of-life decision-making and avoiding non-beneficial interventions. Several prognostic models have been developed for advanced cancer, including the Palliative Prognostic Index (PPI) and the Objective Prognostic Score (OPS). However, prospective data evaluating their performance specifically in patients managed with BSC are limited. This study evaluated the prognostic performance of PPI and OPS in terminal cancer patients receiving BSC. It also examined whether their combined use provides additional value for short-term mortality risk stratification. Methods: This prospective observational cohort study included hospitalized adult patients with terminal-stage cancer and a documented BSC decision. Terminal-stage cancer was operationally defined as stage IV malignancy with poor performance status and no remaining feasible disease-directed oncological treatment option due to severe clinical deterioration and/or major organ dysfunction. Patients were prospectively enrolled from 12 April 2024 to 13 December 2024 and followed until death. Eligible patients had poor Eastern Cooperative Oncology Group performance status (ECOG 3-4) and had not received oncologic treatment within the preceding month. PPI and OPS were calculated at baseline using predefined criteria. Survival time was defined as the interval between baseline assessment and death. The prognostic performance of the scores for 3-, 4-, and 6-week mortality was evaluated, and survival outcomes were analyzed using standard survival analysis methods. Results: A total of 112 patients were included in the final analysis. The mean age was 62.3 ± 12.3 years; 66 patients (58.9%) were male and 46 (41.1%) were female. The most common primary tumor sites were colon cancer (20.5%), non-small cell lung cancer (17.0%), and gastric cancer (15.2%). Both PPI > 6 and OPS ≥ 3 were associated with higher short-term mortality, although their individual discriminatory performance was modest. The combined OPS-PPI approach showed statistically significant but still modest discrimination at all time points. Although this difference was limited, the combined approach supported the stratification of a clinically relevant subgroup at particularly high risk of imminent death. Patients with both OPS ≥ 3 and PPI > 6 had the poorest survival, with a median overall survival (OS) of 11 days. In multivariable Cox regression analysis, the combined high-risk group remained independently associated with poorer OS (HR 1.53, 95% CI 1.01-2.31; p = 0.046). Conclusions: Although the individual discriminatory performance of PPI and OPS was modest, their combined use may provide additional risk stratification value and may help identify patients at particularly high risk of short-term mortality among terminal cancer patients receiving BSC. These findings should be interpreted as supporting bedside risk stratification rather than indicating a definitive individual-level prediction model.