Comparative evaluation of carcinoembryonic antigen and gross cystic disease fluid protein as plasma markers for human breast carcinoma.

A comparative evaluation of carcinoembryonic antigen (CEA) and gross cystic disease fluid protein (GCDFP) as plasma markers for human breast carcinoma has been performed. Both assays appear to be useful in patients with metastatic breast carcinoma. Of 216 patients under treatment for metastatic disease, 111 (51%) had abnormal plasma levels of CEA and/or GCDFP. Abnormal plasma levels of CEA were present in 73 patients whereas abnormal GCDFP levels were present in 67. Twenty-nine patients had increased plasma levels of both markers simultaneously, 44 patients had increased CEA levels only and 38 patients had increased GCDFP levels only. Thus, of the 111 patients with elevated levels of either CEA or GCDFP, the two markers varied independently of each other in 74%. Utilizing both assays, abnormal plasma levels were present in 79% of patients with osseous metastasis, 53% of patients with visceral metastasis and 26% with soft tissue metastasis. Both assays, when performed serially in patients treated for metastatic breast carcinoma, were found to have utility in monitoring responsiveness; and increasing CEA or GCDFP plasma level indicated disease progression and a decreasing plasma level indicated regression.