Good CT scan results but increase in CA 15-3

grrifff

Friday I had my first CT scan since my de novo Stage IV diagnosis. Onc said it may light up like a Christmas tree where there is sclerotic bone over previously lytic lesions. That did not happen. Results state stable but most previous lesions appear corticated. My CA 15-3 went up from 139 to 170. Onc said marker may plateau. Anyone else have good results on scan but an increase in tumor marker? He said CT scan shows reality, what is happening inside my body where as the blood test is sometime variable, inaccurate. No evidence of soft tissue metastasis also stated.Previous CA 15-3 values over the last 7months-581, 524, 320, 224, 167, 139, 170. Any thoughts?