Which therapeutic strategy is less cardiotoxic in the treatment of breast cancer: Using paclitaxel before or after doxorubicin?

• Published in: Journal of clinical oncology Vol. 39; no. 15_suppl; p. e12617
• Main Authors: de Melo, Marcelo Dantas Tavares, Almeida, André L.C., Neto, Aluisio Jose de Oliveira Monteiro, Júnior, Edval Gomes dos Santos, Reis, Israel Costa, Mota, Ludmila, Lopes, Nilson Lima, De Afonseca, Samuel Oliveira, do Espírito Santo, Thyago Monteiro
• Format: Journal Article
• Language: English
• Published: 20.05.2021
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2021.39.15_suppl.e12617

Abstract only e12617 Background: The combination of doxorubicin (DOX) with paclitaxel (PTX) is effective in the treatment of breast cancer (BC). However, DOX-associated cardiotoxicity (CTX) is aggravated by the use of PTX. There´s no consensus on which sequence is most safe. Methods: Prospective study of women with primary BC. All of participants received four cycles of DOX and 12 infusions of PTX. Participants were divided into two groups, at the discretion of the oncologist: Group 1-PTX before DOX and Group 2-DOX before PTX. CTX was defined as an absolute reduction in left ventricular ejection fraction (LVEF)>10% to a value <53%. Patients underwent clinical evaluation and echocardiography before treatment (phase 1) and one year after treatment (phase 2). Results: Sixty-nine women were evaluated: 19 in G1 and 50 in G2. The groups had similar clinical characteristics. The doses of radiation, DOX and PTX used were similar. Eight (11.6%) patients developed CTX: two (10.5%) in G1 and six (12.0%) in G2 (p=0.62). LVEF was similar between the groups in phase 1 (G1=65.1±3.5; G2=65.2±3.9; p=0.96), with a significant reduction after one year in both groups: G1=61.4±8.1% (p=0.021) and G2=60.8±7.6% (p<0.001). Although lower, LVEF remained similar between groups after phase 2 (p=0.79). Conclusions: In women with BC who underwent chemotherapy, the incidence of CTX at the end of the first year of treatment was similar regardless of whether DOX was used before or after PTX. [Table: see text]