title: CA 19-9 is an index of response to neoadjunctive chemoradiation therapy in pancreatic cancer.
abstract: OBJECTIVE
  This study examines the changes of serum levels of CA 19-9 in patients with pancreatic cancer following neoadjuvant irradiation and chemotherapy to define the potential role of this tumor marker in preoperative management of these patients.
  
  
  METHODS
  Serum CA 19-9 levels were measured in 42 patients before receiving external beam irradiation with concurrent 5-fluorouracil in preparation for laparotomy and Whipple procedure or intraoperative irradiation (IORT). The CA 19-9 levels were determined again after irradiation, and changes were correlated with findings of restaging computed tomography (CT) scan and laparotomy.
  
  
  RESULTS
  Following preoperative irradiation, 10 patients (24%) experienced an increase in CA 19-9 levels whereas 29 patients (69%) showed a decrease in CA 19-9. There was no change in the CA 19-9 levels of 3 patients (7%) after treatment. Of the 10 patients with increased CA 19-9 levels after irradiation, 9 (90%) had developed distant metastases or local tumor progression as determined by restaging CT scan or at laparotomy. In contrast, only 6 of 29 patients (21%) with declining CA 19-9 levels after irradiation demonstrated metastases or local tumor progression on restaging CT scan or at laparotomy. The correlation of CA 19-9 increase or decrease with disease progression or control, respectively, was statistically significant (P = 0.009).
  
  
  CONCLUSIONS
  Serum CA 19-9 levels may rise or fall during neoadjuvant therapy. A rising CA 19-9 reliably indicates cancer progression while a falling CA 19-9 connotes disease control in the majority of patients. In developing strategies for application of neoadjuvant therapy for pancreatic cancer, monitoring of CA 19-9 appears most useful for the identification of patients who manifest progressive tumor growth and metastasis in spite of this treatment.
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, USA.
authors.forename: C G
authors.initials: CG
authors.lastname: Willett
authors.forename: W J
authors.initials: WJ
authors.lastname: Daly
authors.forename: A L
authors.initials: AL
authors.lastname: Warshaw
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D003131:Combined Modality Therapy; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D007813:Laparotomy; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000628:therapy*; D010534:Peritoneal Neoplasms / Q000556:secondary; D011879:Radiotherapy Dosage; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D005472:Fluorouracil