Postresection CA 19-9 predicts overall survival in patients with pancreatic cancer treated with adjuvant chemoradiation: a prospective validation by RTOG 9704.
OBJECTIVE
CA 19-9 is an important tumor marker in patients with pancreatic adenocarcinoma. A secondary end point of Radiation Therapy Oncology Group trial 9704 was prospective evaluation of the ability of postresectional CA 19-9 to predict survival.


METHODS
CA 19-9 expression was analyzed as a dichotomized variable (< 180 v > or = 180) or (< or = 90 v > 90). Cox proportional hazards models were utilized to identify the impact of CA 19-9 expression on overall survival (OS). Actuarial estimates for OS were calculated using Kaplan-Meier methods.


RESULTS
Three hundred eighty-five patients patients had assessable CA 19-9 levels. The majority had a CA 19-9 level lower than 180 or < or = 90 (n = 220 and 200, respectively), while 34% were Lewis Antigen negative and 33 (9%) and 53 (14%) patients had levels higher than 180 and higher than 90. When CA 19-9 was analyzed as a dichotomized variable, there was a significant survival difference favoring patients with CA 19-9 lower than 180 (hazard ratio [HR], 3.53; P < .0001). This corresponds to a 72% reduction in the risk of death for patients with a CA 19-9 lower than 180. This was also true for patients with CA 19-9 < or = 90 (HR, 3.4; P < .0001). Multivariate analyses confirmed that CA 19-9, when analyzed as both a continuous and a dichotomized variable, is a highly significant predictor of OS in patients with resected pancreatic cancer.


CONCLUSIONS
To our knowledge, this is the first phase III trial to perform prospective analysis of CA 19-9 levels in patients treated with adjuvant chemoradiotherapy. It definitively confirms the prognostic importance of postresectional CA 19-9 levels after surgery with curative intent in patients with pancreatic cancer.
Berger
Adam C
AC
Thomas Jefferson University, Philadelphia, PA, USA. adam.berger@jefferson.edu
Garcia
Miguel
M
Hoffman
John P
JP
Regine
William F
WF
Abrams
Ross A
RA
Safran
Howard
H
Konski
Andre
A
Benson
Alan B
AB
MacDonald
John
J
Willett
Christopher G
CG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000097:blood; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000601:surgery / Q000628:therapy*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant
D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D007983:Lewis Blood Group Antigens