Evaluation of Adjuvant Radiation Therapy for Resected Gallbladder Carcinoma: A Multi-institutional Experience.

Purpose: The role of adjuvant radiation for gallbladder carcinoma (GBC) is uncertain. We combine the experience of six National Cancer Institute-designated cancer centers to explore the impact of adjuvant radiation following oncologic resection of GBC.

Methods: Patients who underwent extended surgery for GBC at Johns Hopkins, Mayo Clinic, Duke University, Oregon Health & Science University, University of Michigan, and University of Texas MD Anderson between 1985 and 2008 were reviewed. Patients with metastatic disease at surgery, gross residual disease, or missing pathologic information were excluded.

Results: Of the 112 patients identified, 61 % received adjuvant radiation, 93 % of whom received concurrent chemotherapy. Median follow-up of surviving patients was 47.3 (range 2.2-167.7) months. Patients who received adjuvant radiation had a higher rate of advanced T-stage (57 vs. 16 %, p < 0.01), lymph node involvement (63 vs. 18 %, p < 0.01), and positive microscopic margins (37 vs. 9 %, p < 0.01) compared with patients managed with surgery alone, but overall survival (OS) was comparable between the two cohorts (5-year OS: 49.7 vs. 52.5 %, p = 0.20). Lymph node involvement had the strongest association with poor OS (p < 0.01). Adjuvant radiation was associated with decreased isolated local failure (hazard ratio 0.17, 95 % confidence interval 0.05-0.63, p = 0.01). However, 71 % of recurrences included distant failure.

Conclusions: Following oncologic resection for GBC, adjuvant radiation may offer improved local control compared with observation. The benefit of adjuvant radiation beyond chemotherapy alone should therefore be explored. Certainly, the high rate of distant failure highlights the need for more effective systemic therapy.