My Husband Had Rectal Cancer That Spread To The Bone

My husband had rectal cancer that spread to the bone after surgery 2 years ago. He also had 2 spots on upper lung that were always there and grew and were surgically removed this June. A third upper tumor on lower lung was radiated in August because it was very small and could not be found during surgery. Pathology gave clear margins on what was surgically removed. Started back on drip and oral chemo. Today he had second drip chemo, but blood work shows CEA markers up to 68. Have never been above 26. Could radiation cause an increase in CEA? Does not get CT Scan until Oct. 7th.