["The search for new tumor markers for breast carcinoma has been an area of vigorous study; nonetheless, to the authors' knowledge little new information has emerged beyond the clinical usefulness of CA 15-3. The authors studied serum CYFRA 21-1 in breast carcinoma based on evidence that breast carcinoma expresses cytokeratin 19 fragments and that CYFRA 21-1 is a specific antigen for cytokeratin 19 fragments.", 'The serum samples of 86 patients with primary breast carcinoma, 14 patients with recurrent breast carcinoma, 22 patients with benign mammary disease, and 25 healthy controls were provided for measurements of CYFRA 21-1, carcinoembryonic antigen (CEA), and CA 15-3. The relation between clinicopathologic features, prognosis, and disease free survival with serum CYFRA 21-1 titers was studied.', 'There was no difference between the serum CYFRA 21-1 titers from patients with benign mammary disease and those from healthy controls. The sensitivities of CYFRA 21-1 for patients with International Union Against Cancer Stage IV and recurrent tumors were 60% and 64.2%, respectively, which were as high as those for CA 15-3 and superior to those for CEA. The hematogenous recurrence showed a very high sensitivity of 89%. According to the increments of T, N, and M factor numbers, the serum CYFRA 21-1 titers were elevated. No correlation between CYFRA 21-1 and CEA was observed and the correlation between CYFRA 21-1 and CA 15-3 was weak. The univariate and multivariate analyses for survival revealed that serum CYFRA 21-1 levels were an independent indicator of prognosis.'] Is serum CYFRA 21-1 one of the most reliable tumor markers for breast carcinoma?