Prospective evaluation of carcinoembryonic antigen levels and alternating chemotherapeutic regimens in metastatic breast cancer.

Ninety-seven eligible and evaluable women with metastatic breast cancer were placed on a prospective clinical protocol to evaluate the use of continuous cyclic therapy with dibromodulcitol, doxorubicin, vincristine, tamoxifen, and fluoxymesterone (DAVTH) v DAVTH alternating with cyclophosphamide, methotrexate, 5-fluorouracil, and prednisone (CMFP); and the use of pretreatment and serial carcinoembryonic antigen (CEA) levels in these patients. Continuous DAVTH and DAVTH/CMFP were equivalent therapies with respect to response rates, time to treatment failure (TTF), and survival. Pretreatment CEA levels were elevated (greater than 5 ng/mL) in 42/97 patients and less than 5 ng/mL in the remaining patients. Patients with elevated pretreatment CEA levels were more likely to be estrogen receptor (ER) positive (P = .006), to have prolonged disease-free intervals (P = .017), to have hepatic (P = .004) and/or osseous (P = .01) metastases, and to have multiple sites of metastatic disease (P = .004). Pretreatment CEA...