This study aims to investigate the effects of ferulic acid (FA) and cis-diaminodichloroplatinum (CDDP) containing serum (FCCS) on the invasion and migration of breast cancer cells by regulating the epidermal growth factor receptor (EGFR)/phosphatidylinositol 3-kinase (PI3K) pathway. Different groups of FCCS were prepared, and both CBX2 knockdown and normal MDA-MB-453 and 4T1 cells were divided into the following groups: control (Con), Con＋CBX2 of short hairpin RNA (Con+shCBX2), FCCS, FCCS+shCBX2, FCCS+shCBX2+LY294002(PI3K inhibitor), and CDDP. After 48 hours of intervention, cell proliferation inhibition was assessed using the CCK-8 assay; apoptosis was detected by flow cytometry; cell migration and invasion were evaluated using transwell chambers; ELISA was used to measure the expression of E-cadherin, N-cadherin, and VE-cadherin in cell culture supernatants; Western blot was performed to analyze the expression of phosphorylated EGFR (p-EGFR), phosphorylated PI3K (p-PI3K), E-cadherin, and N-cadherin in cells. Compared with Con group, Con+shCBX2, FCCS, FCCS+shCBX2, and FCCS+shCBX2+LY294002 groups significantly inhibited the proliferation of 4T1 and MDA-MB-453 cells, with the strongest inhibition observed in the FCCS+shCBX2+LY294002 group (all P < 0.05). Annexin V-FITC/PI staining, ELISA, and Western blot results showed that, compared with Con group, FCCS, FCCS+shCBX2, and FCCS+shCBX2+LY294002 groups exhibited significantly increased apoptosis rates (P < 0.05). The EGFR/PI3K signaling pathway was involved in FCCS-mediated suppression of proliferation, apoptosis, and invasion in 4T1 and MDA-MB-453 cells.