11677
AIMS : To establish a baseline and intraindividual fluctuations of the tumour markers CEA , CA 50 and CA 242 in patients cured from colorectal cancer , and to test the hypothesis that serum concentrations and intraindividual fluctuations do not differ from the concentrations in cancer - free individuals .
 CEA, CA 50, CA 242
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 CEA, CA 50, CA 242