The Impact of Carboplatin Dosing Design Using Adjusted Serum Creatinine on Carboplatin Plus Paclitaxel Therapy for Ovarian Cancer

Background

Carboplatin (CBDCA) is a mainstay of chemotherapy for ovarian cancer and its dose is determined in proportion to the estimated creatinine clearance (CCr). Serum creatinine (SCr) values necessary to estimate CCr vary by measurement method: adding 0.2 mg/dL to SCr by enzymatic methods commonly used in Japan equates to SCr calculated using the Jaffe method, which is widely adopted outside Japan. Although adjustment by adding 0.2 mg/dL to SCr by enzymatic methods may avoid the potential overdose of CBDCA, its impact on the dose intensity (DI) of chemotherapy is unclear.

Methods

We retrospectively studied patients with ovarian cancer treated with CBDCA + paclitaxel (PTX) (TC) after primary surgery. Patients were classified into Cohort A (dose-dense [dd-]TC, SCr-adjusted, n = 18), B (dd-TC, non-adjusted, n = 8), C (tri-weekly [tw-]TC, SCr-adjusted, n = 6), and D (tw-TC, non-adjusted, n = 15), and DI and DI-related measures including average relative DI (ARDI, [RDI of CBDCA + RDI of PTX]/2]) known to correlate with patients’ prognoses were compared.

Results

Although the DI of CBDCA did not differ between Cohorts A and B, the DI of PTX and proportion of patients with ARDI ≥ 85% were higher in Cohort A than B (78 vs. 13%, p = 0.002) as a result of less frequent treatment modification. There was no difference in these measures between Cohorts C and D.

Conclusion

Adjustment of SCr when calculating the CBDCA dose did not compromise the DI of total CBDCA and may rather contribute to maintaining DI in patients receiving dd-TC.