Five year results of US intergroup/RTOG 9704 with postoperative CA 19-9 ≤90 U/mL and comparison to the CONKO-001 trial

Int J Radiat Oncol Biol Phys. 2012 Nov 1;84(3):e291-7. doi: 10.1016/j.ijrobp.2012.04.035. Epub 2012 Jun 9.

Abstract

Purpose: Radiation Therapy Oncology Group (RTOG) trial 9704 was the largest randomized trial to use adjuvant chemoradiation therapy for patients with pancreatic cancer. This report analyzes 5-year survival by serum level of tumor marker CA 19-9 of ≤90 vs >90 U/mL and compares results to the those of the CONKO-001 trial.

Methods and materials: CA 19-9 expression was analyzed as a dichotomized variable (≤90 vs >90 U/mL). Cox proportional hazard models were used to identify the impact of the CA 19-9 value on overall survival (OS). Actuarial estimates of OS were calculated using the Kaplan-Meier method.

Results: Both univariate (hazard ratio [HR] = 3.2; 95% confidence interval [CI], 2.3-4.3, P<.0001) and multivariate (HR = 3.1; 95% CI, 2.2-4.2, P<.0001) analyses demonstrated a statistically significant decrease in OS for CA 19-9 serum level of ≥90 U/mL. For patients in the gemcitabine (Gem) treatment arm with CA 19-9 <90 U/mL, median survival was 21 months. For patients with CA 19-9 ≥90 U/mL, this number dropped to 10 months. In patients with pancreatic head tumors in the Gem treatment arm with RT quality assurance per protocol and CA 19-9 of <90 U/mL, median survival and 5-year rate were 24 months and 34%. In comparison, the median survival and 5-year OS rate for patients in the Gem arm of the CONKO trial were 22 months and 21%.

Conclusions: This analysis demonstrates that patients with postresection CA 19-9 values ≥90 U/mL had a significantly worse survival. Patients with pancreatic head tumors treated with Gem with CA 19-9 serum level of <90 U/mL and per protocol RT had favorable survival compared to that seen in the CONKO trial. CA 19-9 is a stratification factor for the current RTOG adjuvant pancreas trial (0848).

Publication types

  • Clinical Trial, Phase III
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Antimetabolites, Antineoplastic / therapeutic use
  • CA-19-9 Antigen / blood*
  • Chemoradiotherapy, Adjuvant / methods*
  • Deoxycytidine / analogs & derivatives
  • Deoxycytidine / therapeutic use
  • Female
  • Follow-Up Studies
  • Gemcitabine
  • Humans
  • Lymphatic Metastasis
  • Male
  • Neoplasm Staging
  • Pancreatic Neoplasms / blood*
  • Pancreatic Neoplasms / mortality
  • Pancreatic Neoplasms / pathology
  • Pancreatic Neoplasms / therapy*
  • Proportional Hazards Models
  • Survival Rate

Substances

  • Antimetabolites, Antineoplastic
  • CA-19-9 Antigen
  • Deoxycytidine
  • Gemcitabine