Serial CEA levels in colorectal carcinoma on adjuvant immuno(chemo)therapy. Further follow-up. Modulation of adjuvant treatment

Serial plasma CEA levels have been studied preoperatively (testing A); 1 day after surgery (B); 10-15 days after surgery (C); 4 (D), 8(E), 12 (F), 16-18 (G), and 22-24 (H) mth after surgery in a series of 45 patients affected by colorectal carcinoma who started soon after surgery a protocol of adjuvant immuno(chemo)therapy with Levamisole and BCG. Postoperative follow-up was from 1 to 26 mth, with 28 patients followed for at least 1 yr. Fourteen patients had recurrences: 2 of these had false-negative CEA tests, 3 had persistent high CEA levels after surgery, 9 had increasing levels 9-12 mth before clinical recurrence; and 9 of these 14 patients showed frankly pathologic preoperative plasma CEA levels. Six patients who did not have a recurrence but (both at clinical and instrumental evaluation) who had 2 consecutive high plasma CEA levels, were put on prophylactic polychemotherapy. The prognostic importance of CEA levels both pre- and postoperatively, the possibility of 'modulating' postoperative adjuvant treatments on the basis of CEA levels, and the problem of unexplained fluctuations of plasma CEA levels with the putative metabolic linkages are discussed.