[Feasibility and toxicity of EC-T dose-dense adjuvant chemotherapy: A real world study in Chinese early-stage breast cancer patients with high recurrence risk].

Objective

We aimed to examine the feasibility and toxicity of EC-T dose-dense regimen and to demonstrate the suitable dose of epirubicin in a Chinese early-stage breast cancer population with high recurrence risk.

Methods

370 patients with early-stage breast cancer at high risk of recurrence were treated with EC-T dose-dense adjuvant chemotherapy and prophylactic administration of recombinant human granulocyte stimulating factor (G-CSF). The incidence of delayed chemotherapy, drug reduction and adverse reactions were retrospectively analyzed.

Results

370 patients completed the planned eight cycles of chemotherapy, 50 patients experienced chemotherapy delay, and 90 had chemotherapy dose reductions. Overall, 61.1% of the patients experienced grade 3 or 4 hematology toxicities, 4.1% of the patients experienced grade 3 gastrointestinal toxicity, 16.3% experienced grade 3 or 4 liver malfunction, and 1.9% experienced grade 3 alopecia. In the multivariate analysis, pretreatment epirubicin levels were associated with comprehensive and hematology toxicity risk (OR=1.268, P=0.046; OR=1.244, P=0.036). With G-CSF support, the probability of grade 3-4 dose limiting toxicity, i. e. neutropenia, abnormal liver function, and gastrointestinal adverse effects did not increase as the epirubicin dose level increased(P>0.05). However, there were no statistically significant associations between epirubicin grade and treatment delay (P=0.814) or dose reduction (P=0.282).

Conclusions

EC-T dose-dense chemotherapy shows tolerable toxicity. High dose level is not a limiting factor for this regimen. With G-CSF support, epirubicin 85-90 mg/m(2) is appropriate tolerance dose for Chinese early breast cancer patients with high recurrence risk.