Are serial CA 19-9 kinetics helpful in predicting survival in patients with advanced or metastatic pancreatic cancer treated with gemcitabine and cisplatin?

Background: Serial kinetics of serum CA 19-9 levels have been
reported to reflect response and survival in patients with
pancreatic cancer undergoing surgery, radiotherapy, and
chemotherapy. We prospectively studied serial kinetics of serum CA
19-9 levels of patients with locally advanced or metastatic disease
treated with gemcitabine and cisplatin. Patients and Methods:
Enrolled in the study were 87 patients (female/male = 26/61; stage
III/IV disease = 24/63). Patients received gemcitabine 1,000
mg/m(2) on days 1, 8, and 15 plus cisplatin 50 mg/m(2) on days 1
and 15, every 4 weeks. Serum samples were collected at the onset of
chemotherapy and before the start of a new treatment cycle (day
28). Results: 77 of 87 patients (88.5%) with initially elevated CA
19-9 levels were included for evaluation. According to imaging
criteria, 4 (5.2%) achieved a complete remission and 11 (14.3%)
achieved partial remission, yielding an overall response rate of
19.5%. 43 (55.8%) patients were CA 19-9 responders, defined by
greater than or equal to50% decrease in CA 19-9 serum levels within
2 months after treatment initiation. Except for one, all patients
who had responded by imaging criteria (n = 14) fulfilled the
criterion of a CA 19-9 responder. Despite being characterized as
non-responders by CT-imaging criteria (stable/progressive disease),
29 patients were classified as CA 19-9 responders (positive
predictive value 32.5%). Independent of the response evaluation by
CT, CA 19-9 responders survived significantly longer than CA 19-9
non-responders (295 d; 95% CI: 285-445 vs. 174 d; 95% CI: 134-198;
p = 0.022). Conclusion: CA 19-9 kinetics in serum serve as an early
and reliable indicator of response and help to predict survival in
patients with advanced pancreatic cancer receiving effective
treatment with gemcitabine and cisplatin.