Initial TPS serum level as an indicator of relapse and survival in colorectal cancer

Background. Tissue polypeptide specific antigen (TPS) measures a soluble fragment of cytokeratine 18 and may be regarded as a proliferative marker. Materials and Methods. TPS was measured in 173 consecutive patients with colorectal cancer. Median follow up time was 36 months. Of 137 evaluable patients 39 developed metastases (P.D.) and 98 remained with no evidence of disease (N.E.D.). Results. Initial TPS levels were elevated in 75% of P.D. patients compared to 32% of N.E.D. patients (p < 0.001), CEA levels were elevated in 26% of P.D. patients compared to 2% of N.E.D. In Dukes' B2 92.8% of P.D. patients had elevated initial TPS compared to 35.5% of N.E.D. patients (p < 0.001) and CEA was elevated in 33.3% of the P.D. patients compared to 1.3% of N.E.D. patients (p < 0.001). Survival and disease free survival were significantly shorter for patients with initial high TPS level. TPS was more sensitive than CEA in predicting relapse. Conclusions. These preliminary data suggest that TPS may be a prognostic factor for relapse and may help to allocate Dukes' B2 patients for adjuvant chemotherapy.