2392
With a median follow up of 22 months , median time to progression , progression - free survival ( PFS ) and overall survival ( OS ) were 8 . 9 , 8 . 7 , and 22 months , respectively .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 None