Inflammatory breast recurrence after breast conserving surgery often compromises patient quality of life(QOL)and is associated with a poor prognosis. For this type of recurrence, the immunological situation of the patient is uncertain. We evaluated the clinical significance of immunosuppressive acidic protein(IAP)in the serum of patients with inflammatory breast recurrence during treatment. We collected serum from 3 patients at three different time points: the pre-treatment phase, recurrence phase, and the post-treatment phase. IAP was then measured from these multiple serum samples. There was a significant difference between serum IAP values in the pre-treatment and recurrence phases. The recurrence phase had a mean IAP value that was higher than the pre-treatment phase. The IAP values were indicative of the disease condition. These results suggest that serum IAP is a useful quantification of the immunological condition of patients with inflammatory breast recurrence.