ERBB2 and cancer: •Levels of S1P in breast cancer tissues were significantly higher in patients with high white blood cell count in the blood than those patients without•S1P levels were lower in patients with human epidermal growth factor receptor 2 over-expression and/or amplification than those patients without•Cancer tissues with high pSPHK1 expression showed significantly higher levels of S1P than cancer tissues without•Patients with lymph node metastasis showed significantly higher levels of S1P in tumor tissues than the patients with negative nodes