Celecoxib for Prevention of Progression in Peutz-Jeghers Syndrome

Inclusion Criteria: \- Patients with PJS ≥ 8 years of age Diagnostic criteria for PJS: meeting any of the following criteria or presence of an STK11 gene variant: 1. Two or more histologically confirmed PJS hamartomatous polyps; 2. Any number of PJS polyps detected in an individual with a family history of PJS in close relative(s); 3. Characteristic mucocutaneous pigmentation in an individual with a family history of PJS in close relative(s); 4. Any number of PJS polyps in an individual with characteristic mucocutaneous pigmentation. Exclusion Criteria: 1. Allergy to NSAIDs; 2. Long-term use of any dose of NSAIDs, including aspirin or celecoxib, within 6 months prior to enrollment (willing to undergo a 3-month washout period to restore eligibility); 3. Imaging indicate small intestinal polyps ≥ 3 cm in diameter, intestinal intussusception, intestinal obstruction or intestinal tumor at the time of enrollment; 4. Surgical treatment for small intestinal polyps within 2 years prior to enrollment; 5. Anticipated small bowel resection due to severe polyps within 6 months of enrollment; 6. Receiving other medications for gastrointestinal polyps; 7. Peptic ulcer within 3 months prior to enrollment; 8. Unstable cardiorespiratory condition; 9. Serious renal, hepatic or haematological dysfunction (creatinine \>1.5 × ULN; ALT \>1.5 × ULN, AST \>1.5 × ULN, ALP \>1.5 × ULN, TBIL \>2 × ULN; haemoglobin \<10 g/dL, platelet count \<100,000/mL, white blood cells \<3000/mL) or other systemic diseases are unsuitable for participation in this study; 10. Pregnancy or breastfeeding; 11. Unwilling or unable to sign the informed consent form