The present invention relates to neoadjuvant prior to chemotherapy. The present invention relates to sphingosine-1-phosphate pathway activator for use in the treatment of cancer as neoadjuvant prior to chemotherapy selected from sphingosine-1-phosphate lyase inhibitors. The sphingosine-1-phosphate pathway activator enhances the chemotherapy efficiency through the normalization of intratumoral vascular network, promoting the effects of the sequential administration of an anticancer agent or a sequential radiotherapy.
