Concurrent radiotherapy and gemcitabine for unresectable pancreatic adenocarcinoma: impact of adjuvant chemotherapy on survival

Int J Radiat Oncol Biol Phys. 2012 Jun 1;83(2):559-65. doi: 10.1016/j.ijrobp.2011.07.013. Epub 2011 Oct 20.

Abstract

Purpose: To retrospectively analyze results of concurrent chemoradiotherapy (CCRT) using gemcitabine (GEM) for unresectable pancreatic adenocarcinoma.

Methods and materials: Records of 108 patients treated with concurrent external beam radiotherapy (EBRT) and GEM were reviewed. The median dose of EBRT in all 108 patients was 50.4 Gy (range, 3.6-60.8 Gy), usually administered in conventional fractionations (1.8-2 Gy/day). During radiotherapy, most patients received GEM at a dosage of 250 to 350 mg/m(2) intravenously weekly for approximately 6 weeks. After CCRT, 59 patients (54.6%) were treated with adjuvant chemotherapy (AC), mainly with GEM. The median follow-up for all 108 patients was 11.0 months (range, 0.4-37.9 months).

Results: Initial responses after CCRT for 85 patients were partial response: 26 patients, no change: 51 patients and progressive disease: 8 patients. Local progression was observed in 35 patients (32.4%), and the 2-year local control (LC) rate in all patients was 41.9%. Patients treated with total doses of 50 Gy or more had significantly more favorable LC rates (2-year LC rate, 42.9%) than patients treated with total doses of less than 50 Gy (2-year LC rate, 29.6%). Regional lymph node recurrence was found in only 1 patient, and none of the 57 patients with clinical N0 disease had regional lymph node recurrence. The 2-year overall survival (OS) rate and the median survival time in all patients were 23.5% and 11.6 months, respectively. Patients treated with AC had significantly more favorable OS rates (2-year OS, 31.8%) than those treated without AC (2-year OS, 12.4%; p < 0.0001). On multivariate analysis, AC use and clinical T stage were significant prognostic factors for OS.

Conclusions: CCRT using GEM yields a relatively favorable LC rate for unresectable pancreatic adenocarcinoma, and CCRT with AC conferred a survival benefit compared to CCRT without AC.

Publication types

  • Multicenter Study

MeSH terms

  • Adenocarcinoma / mortality
  • Adenocarcinoma / pathology
  • Adenocarcinoma / therapy*
  • Adult
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Antimetabolites, Antineoplastic / administration & dosage
  • Antimetabolites, Antineoplastic / therapeutic use*
  • Chemoradiotherapy / methods*
  • Chemoradiotherapy / mortality
  • Chemotherapy, Adjuvant / mortality
  • Deoxycytidine / administration & dosage
  • Deoxycytidine / analogs & derivatives*
  • Deoxycytidine / therapeutic use
  • Drug Administration Schedule
  • Female
  • Gemcitabine
  • Humans
  • Japan
  • Male
  • Middle Aged
  • Pancreatic Neoplasms / mortality
  • Pancreatic Neoplasms / pathology
  • Pancreatic Neoplasms / therapy*
  • Radiation-Sensitizing Agents / administration & dosage
  • Radiation-Sensitizing Agents / therapeutic use*
  • Radiotherapy Dosage
  • Retrospective Studies
  • Tumor Burden

Substances

  • Antimetabolites, Antineoplastic
  • Radiation-Sensitizing Agents
  • Deoxycytidine
  • Gemcitabine