S-1 + celecoxib

S-1 + celecoxib is a combination therapy consisting of S-1, an oral fluoropyrimidine-based anticancer agent, and celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor. **S-1** is composed of tegafur (a prodrug of 5-fluorouracil), gimeracil (an inhibitor of dihydropyrimidine dehydrogenase to increase 5-FU bioavailability), and oteracil (to reduce gastrointestinal toxicity). It acts as an antimetabolite by inhibiting thymidylate synthase, thereby interfering with DNA synthesis in rapidly dividing cancer cells. **Celecoxib** is a nonsteroidal anti-inflammatory drug that selectively inhibits COX-2, reducing the production of prostaglandins involved in inflammation and pain. In oncology settings, COX-2 inhibition may also suppress tumor growth and angiogenesis due to the role of prostaglandins in cancer progression[3][4]. This combination has been investigated primarily for its potential synergistic effects in treating various cancers—especially gastrointestinal malignancies such as gastric or colorectal cancer—by combining cytotoxic chemotherapy with anti-inflammatory/anti-tumor properties.