Initial (univariate) log-rank tests were performed to determine the predictive value of categorized versions of the first post-CRT CA 19-9. Univariate and multivariate statistical methodologies were used to determine significant prognostic factors for overall survival. The Kaplan-Meier method was used to obtain overall survival and
recurrence free survival estimates while survival was compared between groups using the log-rank test. Inhibitors,research,lifescience,medical P values for multiple comparison were adjusted using the method developed by Lausen and Schumacher (13). Values for continuous variables are given as median (range). Values for categorical data are specified as frequency (percent). Statistical Analysis Inhibitors,research,lifescience,medical was performed using SAS Statistical analysis software version 9.2 (SAS Institute Inc, Cary, NC, USA). A nominal significance level of 0.05 was used. Results Patient and treatment CDK assay characteristics Of 116 patients, 84 underwent CRT and 32 received chemotherapy alone. Of the 84 patients that underwent CRT, 54 patients had available pre and post CRT CA 19-9 levels and a bilirubin of less than 2 mg/dL at the time the CA 19-9 was measured. The characteristics of the patients are shown in Table 1. Table 1 Patient and treatment characteristics The median follow up was 7.15 months (range, 3.0-10.6 months). The median pre-CRT Ca 19-9 level was 363.7 and the median Inhibitors,research,lifescience,medical post CRT CA 19-9 level was 85.5. Median time from the end of RT to post
CRT CA 19-9 was 35.89 days (range, 0.00-168.81 days). CA 19-9 values ranging from 50-1,000 were tested in 50 point increments and % change was tested in 10% increments (Tables 2,,33). Table 2 First post-CRT CA 19-9 level in
increments of 50 Table 3 Percent change in pre Inhibitors,research,lifescience,medical to post CRT CA 19-9 level Patient characteristics including age, sex, race, performance status, weight loss >10% were tested and not statistically significant on univariate analysis. Tumor and treatment factors including chemo regimen, T stage, node status, grade 3-4 toxicity, tumor >30 mm, Inhibitors,research,lifescience,medical and tumor location were tested and not statistically significant. On univariate analysis, post CRT CA 19-9 <50, postCRT CA 19-9 <85.5, percent change ≥90%, and histologic grade all showed prognostic significance (Table 4). Table 4 Univariate Analysis of prognostic factors associated with survival in patients with locally advanced pancreatic carcinoma The median survival of patients with a postCRT CA 19-9 level <85.5 U/mL was 10.3 months compared with 7.1 months in patients with higher levels CYTH4 (P=0.0242) (Figure 1). The median survival of patients with a decrease in CA 19-9 of >90% post CRT was 16.3 months compared with 7.5 months in those with a <90% post CRT CA 19-9 change (P=0.0179) (Figure 2). The median survival of patients with a post CRT CA 19-9 levels <50 U/mL was 11.1 months compared with 7.1 months in patients with levels ≥50 U/mL (P=0.0287) Figure 1 Median survival of patients with postCRT CA 19-9 level <85.