PROGNOSTIC VALUE OF CA-19-9 LEVELS IN PATIENTS WITH CARCINOMA OF THE PANCREAS TREATED WITH RADIOTHERAPY

Purpose: CA 19-9 has been identified as a tumor marker for pancreatic carcinoma and has been shown to have some utility in predicting outcom e in surgically treated patients. The purpose of this study was to eva luate its usefulness as a prognostic indicator in patients treated wit h radiotherapy. Materials and Methods: A retrospective review of all p atients treated with radiotherapy of definitive intent (n = 104) for c arcinoma of the pancreas at Fox Chase Cancer Center from 1980-1994 was undertaken. Patients were categorized into four groups: Planned preop erative radiation with resection (n = 25); planned preoperative radiat ion without successful resection (n = 35); postoperative radiation (n = 21); and radiation without planned resection (n = 23). For each grou p, except those treated without planned resection, median dose for ext ernal beam radiotherapy was 50.4 Gy (range = 21.6-63.0 Gy). Those in t he remaining fourth group were treated with a median dose of 55.8 Gy ( range = 36.0-60.4 Gy). 97% of patients in the first three groups were also treated with 5-FU-based chemotherapy, as were 61% of those in the fourth group. Pretreatment and follow-up CA 19-9 levels were availabl e for 69 patients. Results: Median survival time for all groups was 10 months (range = 1-67 months). Univariate analysis showed significant differences in survival among the groups: Preop with resection 22 mont hs; preop without resection 10 months, postop 17 months; and without p lanned resection 12 months (p = 0.0005). Overall, patients who underwe nt resection had a median survival time of 19 months, compared to 11 m onths in those who did not (p = 0.0006). CA 19-9 level at diagnosis wa s found to be a significant prognostic indicator on univariate analysi s, with a median survival time of 8 months in those having a level gre ater than the median! of 680 U/ml, compared to 20 months in those who did not (p = 0.0003). Similarly, the posttreatment nadir was significa nt, with a median survival time of 11 months in those with levels abov e the median of 162.5 U/ml, vs. 26 months in those with levels below 1 62.5 U/ml (p = 0.001). The median survival time for patients whose CA 19-9 levels decreased in response to treatment by more than 75% was 23 months (range = 6-34 months) vs. 8 months (range = 3-21) in those wit h 75% or less response (p = 0.003). On stepwise multivariate analysis, pretreatment CA 19-9 level was found to be a significant predictor of survival (p = 0.005). Other potential indicators of outcome, includin g age, gender, KPS, prediagnosis weight loss, location of tumor, clini cal TNM staging, size of lesion, vascular involvement on angiography, and sequence of radiation with respect to resection, were evaluated an d were not found to be significant. Conclusion: CA 19-9 was demonstrat ed to be a useful prognostic indicator in patients treated with radiot herapy; other, more traditional, indicators of outcome were of less ut ility. (C) 1998 Elsevier Science Inc.