Hi and welcome to HCM,thank you for your query.
Yes,smokinmg can raise CEA markers ut this fginding necessiate further diagnostic tests.It is mainly used as a tumor marker
of colorectal carcinoma
,but other tumors and some benign condtiitons can be cause of its elevation as well. In every case your mother should do colonoscopy
and abdominal ct scan just to ruile out cancer. if this is negative then it may indicate some cirrhosis,pancreatitis
and RA too. but I suggest to do these tests to be sure.
Wish you good health. Regards