Long-term outcome for gastric marginal zone lymphoma treated with radiotherapy: a retrospective, multi-centre, International Extranodal Lymphoma Study Group study.

Background We evaluated the long-term results of radiotherapy for patients with gastric marginal zone lymphoma (GMZL). Patients and methods We carried out a retrospective, multi-centre study of patients with low-grade GMZL treated by radiotherapy between 17 July 1981 and 25 March 2004. Results There were 102 eligible patients. Fifty-eight patients were previously untreated and 44 had recurrent/residual disease after prior treatment (HP eradication, chemotherapy and surgery in 35, 9 and 8 patients, respectively, and 7 had >1 prior therapy). Radiation fields included the stomach /involved nodes in 61 patients and whole abdomen in 41. The median radiotherapy dose to stomach was 40 Gy (range 26–46 Gy) in a median 22 fractions. With a median follow-up after radiotherapy of 7.9 years (range 0.3–24 years), 10- and 15-year freedom from treatment failure (FFTF) was 88% (95% CI 82%–95%). Risk factors for TF were a large-cell component (P = 0.036) and an exophytic growth pattern (P = 0.042). Radiotherapy field size, radiotherapy dose, and failure of prior therapy were not associated with inferior FFTF. Ten-year overall survival was 70% (95% CI 60%–82%). Conclusions Radiotherapy achieves cure for the majority of patients with low-grade GMZL, including patients who have had prior therapy. Several features may predict a poorer outcome. [ABSTRACT FROM AUTHOR]