4678
The aim of this retrospective study was to evaluate the efficacy of levonorgestrel intrauterine system - releasing ( LNG - IUS ) insertion in preventing atypical endometrial hyperplasia ( AH ) and endometrial cancer ( EC ) in symptomatic postmenopausal overweight / obese women .
 Chemical: levonorgestrel; Chemical: LNG
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: levonorgestrel; Chemical: LNG