To investigate the efficacy and safety of pemetrexed combined with cinobufacini in the first-line treatment of patients with advanced or metastatic breast cancer.

A total of one hundred and thirty-eight women with advanced or metastatic breast cancer were randomly divided into two groups: observation group and control group, treated with pemetrexed combined with cinobufacini and pemetrexed in combination with cisplatin (DDP), respectively. The therapeutic effect, adverse reactions, carcinoembryonic antigen (CEA) and CA153 were observed and compared, and the curative effect evaluation standard (RECIST 1.0) was used to evaluate the curative effect.

In the observation group, the level of CA153 was decreased from (47.63±5.28) U/ml to (26.51±4.34) U/ml, and CEA decreased from (24.68±3.14) μg/L to (8.83±2.45) μg/L. The level of CA153 in the control group was decreased from (47.52±5.44) U/ml to (34.58±4.92) U/ml, and CEA decreased from (23.75±3.20) μg/L to (16.58±2.17) μg/L. There were significant differences between two groups after the treatment (t=10.218, 19.670, both P=0.000). The control rate and efficacy of the observation group was 65.22%(45/69) and 33.33%(23/69), while the control group 44.93%(31/69) and 20.29%(14/69), with significant differences (χ²=5.740, 4.333, P=0.017, 0.037). The incidence of nausea and vomiting, thrombocytopenia, granulocyte reduction, liver and kidney dysfunction and hair loss was 46.38%, 23.19%, 37.68%, 17.39%, 2.90% in the observation group, while 73.91%, 47.83%, 65.22%, 36.23%, 15.94% in the control group, with significant difference (χ²=14.935, P<0.001).

Pemetrexed combined with cinobufacini shows good efficacy as a first-line treatment for late or metastatic breast cancer patients, and can effectively reduce the incidence of adverse reactions, with high safety and suitable for clinical promotion.