Circulating immune complexes (CIC) as tumor marker in the follow-up of breast cancer.

We report on the possible diagnostic and prognostic role of circulating immune complexes (CIC) determination in breast cancer. A sensitivity of 87% and a specificity of 90% were observed in a case-control study of 15 cancers and 25 noncancer healthy controls. A direct correlation of CIC level to the presence and probably to the entity of the tumor mass was assessed by comparing preoperative to postoperative CIC determinations in cancer cases: CIC levels were significantly lower after tumor removal. These preliminary results suggest further studies on the use of CIC determination in the follow-up of breast cancer for the early diagnosis of recurrent disease.