Prognostic Significance of the Prothrombin Time-international Normalized Ratio to Albumin Ratio in Cancer patients with complication of Sepsis: A Retrospectively Cohort Study.

BACKGROUND Accumulating evidence supports the use of the prothrombin time-international normalized ratio-to-albumin ratio (PTAR) as a prognostic biomarker in various diseases. This study evaluated whether PTAR, an easily measurable index, predicts short- and long-term all-cause mortality in cancer patients with sepsis (cancer sepsis).

METHODS This retrospective cohort study used data from 1,584 adult cancer-sepsis patients in the ICU from the MIMIC-IV database (v3.1) and 82 patients from a Chinese tertiary oncology hospital. Mortality at 28 and 365 days was analyzed using multivariable Cox models, restricted cubic splines, Kaplan-Meier curves, and subgroup analyses. Discriminatory performance was assessed with the area under the receiver operating characteristic curve (AUC), comparing PTAR with the Sequential Organ Failure Assessment (SOFA) score, international normalized ratio (INR), and serum albumin (ALB). AUC differences were tested using DeLong's test.

RESULTS In the MIMIC-IV cohort, patients in the highest PTAR quartile (Q4) had significantly higher risks of 28-day (adjusted HR = 2.038) and 365-day mortality (adjusted HR = 1.615). PTAR showed superior discrimination compared to the SOFA score and INR at both time points. In the Chinese cohort, PTAR also predicted 28-day mortality (adjusted HR = 4.682), with better AUC (0.721) than SOFA (0.564).

CONCLUSIONS PTAR at ICU admission independently predicts 28-day mortality in cancer patients with sepsis in both the MIMIC-IV and Chinese cohorts, outperforming SOFA and INR. The 365-day mortality was validated only in the MIMIC-IV cohort, where PTAR demonstrated stronger predictive performance compared to INR and SOFA. Therefore, PTAR can serve as a complementary biomarker to be used in conjunction with existing clinical scoring systems and laboratory indicators, providing additional risk assessment information for cancer-sepsis.