Fertility-sparing treatment (FST) represents a valuable option for young women diagnosed with early-stage, low-grade endometrial cancer or atypical hyperplasia. Among the available approaches, hysteroscopic resection combined with progestin therapy has shown the most favorable outcomes in both remission and pregnancy rates so far. Treatment success is influenced by various individual factors, including BMI, medication dosage, side effects, surgical technique, and most importantly, the patient’s personal priorities—fertility preservation vs. oncologic safety. To support personalized treatment decisions, molecular classification systems such as ProMisE are gaining attention for their potential to predict treatment response. Looking ahead, ongoing clinical trials like FELICIA are expected to strengthen the evidence base and help establish clear, long-term recommendations for FST.