Association of Serum Creatine/Cystatin C Ratio and Adverse Events With Platinum Therapies

prospective cohort study to be presented at the National Kidney Foundation Spring Clinical Meetings explored the association between serum creatinine (SCr)/cystatin C (CYS) ratio and adverse events (AEs) associated with the platinum-based cancer therapies cisplatin and carboplatin. These AEs included cytopenia, acute kidney injury (AKI), hospitalization, and mortality within 90 days of initiating the therapy.

The cohort comprised 441 adults with cancer who started treatment with cisplatin or carboplatin between 2023 and 2025 at a cancer center in Boston, Massachusetts. Mean (±SD) patient age was 65±12 years and 201 (45.6%) were men. Patients’ SCr and CYS levels were measured before the first dose was given.

To evaluate the association of a SCr/CYS ratio less than 0.7 with the development of AEs grade 2 or greater or grade 3 or greater (according to the National Cancer Institute’s Common Terminology Criteria for Adverse Events), the researchers used a Fine-Gray subdistribution hazard model that was adjusted for age, sex, Charlson comorbidity index, and cancer stage. In addition, they used a Kaplan-Meier curve to assess 90-day survival.

One hundred twenty-five participants (28.5%) had a SCr/CYS ratio less than 0.7, which was independently associated with AEs and hospitalization. This included grade 2 or higher and grade 3 or higher anemia and thrombocytopenia, grade 3 or higher AKI, all-cause hospitalizations, and hospitalizations for AEs within 90 days. In addition, patients with a SCr/CYS ratio less than 0.7 had a 6.61-fold higher risk of death within 90 days (95% CI, 2.27-19.20).

Given the prevalence of SCr/CYS ratios less than 0.7 and their association with AEs, the authors suggested that studies should examine whether platinum dose reductions might benefit patients in this category.

Source: Lyu J, Khor SY, Mejia S, et al. Association between baseline serum creatinine/cystatin C (SCr/CYS) ratio and adverse events in patients receiving cisplatin or carboplatin: a prospective cohort study. Abstract #LB-04. Presented at the National Kidney Foundation Spring Clinical Meetings 2025; April 10-13, 2025; Boston, MA.