Impact of relative dose intensity of R-CCOP regimen in elderly patients with diffuse large B-cell lymphoma in China.

BACKGROUND: The actual relative dose intensity (RDI) of the attenuated R-CCOP regimen (rituximab, cytoxan, pegylated liposomal doxorubicin [PLD], vincristine, and prednisone) has not been fully investigated in Chinese geriatric patients with diffuse large B-cell lymphoma (DLBCL). In particular, the optimum dose for PLD remains unclear. METHODS: We retrospectively collected clinical data from patients with untreated DLBCL aged 65-80 years subsequently treated with the R-CCOP. The restricted cubic spline model (RCS) was used to test the non-linear relationship between the predictors and outcomes. RESULTS: Eighty-four patients were enrolled, with a median age of 73.5 years. More than half of the patients (54.8%) received at least 6 cycles. The median dose per cycle of cytoxan and PLD were 605.5 and 19.9 mg/m2. The 5-year progression-free survival (PFS), overall survival rate, and disease-specific survival rates were 38.7%, 44.8%, and 57.2%, respectively. The RDI of PLD (PLD-RDI, <70% vs ≥ 70%) was only significant in the univariate analysis (P = 0.002) but not in the multivariate analysis. The RCS model showed a decreasing trend of hazards with an increasing PLD dose per cycle after adjustment. No significant difference was observed between the low- and high-risk groups with PLD-RDI ≥ 70% (P = 0.548). However, patients in the high-risk group had unfavorable PFS with PLD-RDI < 70% (P = 0.006). CONCLUSION: The optimal dose of PLD for elderly patients with DLBCL in China remains to be determined. Evaluating the tolerance and identifying risk categories are critical for clinical decision-making in this population.