RESUMEN
BACKGROUND: Diagnosing patients with signs or symptoms suggestive of cancer is difficult. Serum tumor markers (TM) may be useful, but it is known that a range of pathologies other than cancer can increase their concentrations and so TM data must be interpreted with caution. The aim of this study is to determine the diagnostic accuracy of TMs in patients with signs or symptoms of cancer. METHODS: We prospectively studied 234 patients seen at rapid diagnostic units who presented signs or symptoms suggestive of cancer. Ninety patients had wasting syndrome, 74 had pulmonary symptoms and 70 other presentations. CYFRA21-1, CEA, CA19-9, total bilirubin and creatinine were determined. The final diagnosis was obtained after 6 months' follow-up. Patients were classified according to the absence (group A) or presence (group B) of abnormal bilirubin or creatinine. RESULTS: Of the 234 patients studied, 103 (44.0%) had tumors diagnosed. Cut-off points for each TM were calculated for a specificity of 100%. For the total group, the values were CYFRA21-1, 15 µg/L, CEA, 43.8 µg/L and CA19-9, 7428 KU/L, with an overall sensitivity of 46.6%. For group A (n=142), the following cut-off points were established: CYFRA21-1, 7.8 µg/L, CEA, 13.8 µg/L and CA19-9, 101 KU/L, obtaining a sensitivity of 68.6%. For group B (n=92), the values were the same as for the whole group, and a sensitivity of 42.4% was achieved. CONCLUSIONS: We conclude that TMs can aid diagnosis in these patients with signs or symptoms suggestive of cancer. Their sensitivity can be improved by using different cut-off points in the presence and absence of renal and hepatic dysfunction.