Elevated CA19‐9 as the most significant prognostic factor in advanced colorectal carcinoma

Abstract

Tumor markers such as carcinoembryonic antigen (CEA) and CA19‐9 were analyzed as response indicators and prognostic factors in advanced colorectal carcinoma. Eighty‐five patients participated in a phase II chemotherapy study from October 1984 to July 1990. A three‐drug schedule was administered including low dose epirubicin and sequential methotrexate 5‐fluorouracil, followed by leucovorin rescue. Serum specimens for CEA and CA19‐9 were obtained prior to the initiation of chemotherapy, and subsequently at 4‐6 weeks' intervals. In univariate analysis Karnofsky, the site of the primary tumor, the extent of metastases, the presence of abdominal or liver metastases, serum CEA (cut‐off of 20 μg/1), and CA19‐9 levels correlated with survival. In stepwise multivariate analysis an elevated CA19‐9 level, a poor Karnofsky, and the presence of liver metastases were independent adverse prognostic factors. Tumors originating from the left colon had a better prognosis than the others. This was related to a higher response rate in this patient group. Serum CA19‐9 level was the most significant prognostic factor whether it was entered as a continuous or as a dichotomized variable into the model. The median survival of patients with a normal CA19‐9 level was 30.0 months (lower 95% confidence interval: 16.4 months; upper limit was not calculable), and with an elevated CA19‐9 value 10.3 months (8.0‐12.6 months, 95% confidence interval). Five of 85 patients had a complete response and 20 a partial response, the overall response rate being 29%. When compared with tumor shrinkage, “CEA response” and “CA19‐9 response” had a sensitivity of 84% and 88% and specificity of 77% and 67%, respectively. In conclusion, serum CEA value seems to be the best tumor marker for response prediction, while CA19‐9 level is one of the best available prognostic indicators in advanced colorectal carcinoma.