Canagliflozin Plus Progestin for Atypical Endometrial Hyperplasia and Early-Stage Endometrial Cancer

1. Female, aged 18-45 years, with a definite desire for fertility preservation
2. First-time diagnosis of atypical endometrial hyperplasia (AH) or grade 1 endometrioid endometrial carcinoma (G1 EEC), confirmed by pathologists at the study center
3. For patients with EEC, MRI or ultrasound confirming that the lesion is confined to the endometrium or invades less than 1/2 of the myometrium, without distant metastasis
4. Positive expression of both estrogen receptor (ER) and progesterone receptor (PR)
5. Normal hepatic and renal function
6. No contraindications to progestin or canagliflozin therapy
7. No hormonal therapy or SGLT2 inhibitor treatment lasting more than 1 month within the previous 6 months
8. Presence of any of the following: diagnosed polycystic ovary syndrome (PCOS), overweight (BMI ≥ 24), impaired glucose tolerance, or diabetes mellitus
9. No other fertility disorders and no contraindications to pregnancy
10. Not currently pregnant
11. Good compliance, willing to comply with subsequent assessments, treatment, and follow-up, with understanding and signing of the informed consent form

Exclusion Criteria:

1. History of allergy to LNG-IUS, SGLT2 inhibitors, or metformin, or any contraindication to these treatments;
2. Overly large uterine cavity (mean diameter > 7 cm) or a history of LNG-IUS (Mirena) expulsion;
3. Type 2 diabetes mellitus requiring insulin therapy, or glycated hemoglobin (HbA1c) > 8.5% (insulin users are excluded owing to the increased risk of ketoacidosis);
4. History of type 1 diabetes mellitus, diabetic ketoacidosis, peripheral vascular disease, or diabetic foot ulcers;
5. Long-term use of corticosteroids or insulin/insulin sensitizers;
6. Baseline blood pressure below 90/60 mmHg;
7. Severe chronic diseases with cardiac, hepatic, pulmonary, or renal insufficiency (alanine aminotransferase [ALT] or aspartate aminotransferase [AST] > 3 × the upper limit of normal [ULN], or serum bilirubin > 3 × ULN), or renal insufficiency (estimated glomerular filtration rate [eGFR] \< 60 ml/min/1.73 m²);
8. Active infection, or a history of recurrent urinary tract infections (≥ 3 episodes within the previous 12 months, or ≥ 2 episodes within the previous 6 months);
9. Genital tract inflammation within 2 weeks before enrollment, or abnormal vaginal discharge that has not been treated;
10. Concomitant malignant tumor at any other site;
11. Other reproductive disorders;
12. Alcohol abuse (> 20 g/day) or smoking.