7919
We observed increased levels of biomarkers of oxidative / nitrative stress in plasma from patients with breast cancer ( before or after surgery and after various phases of chemotherapy ) in comparison to healthy group .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None