Prospective Phase II trial of radiation therapy in localised non-gastric marginal zone lymphoma with prospective evaluation of autoimmunity and Helicobacter pylori status: TROG 05.02/ALLG NHL15.

ABSTRACT

BACKGROUND: This Phase 2 multicentre trial in localised non-gastric marginal zone lymphoma (MZL) evaluated the effectiveness and safety of radiotherapy and documented markers of autoimmunity and Helicobacter pylori infection. PATIENTS AND METHODS: Eligible patients had Stages I and II or paired-organ, non-gastric MZL. Bone marrow evaluation, autoantibody panel, and H. pylori evaluation were mandatory. Involved-field or involved-site radiotherapy was delivered to 24-30.6 Gy. Detected H. pylori infections underwent eradication. RESULTS: Between 2006 and 2014, six centres enrolled 70 patients, and 68 commenced treatment. The median age was 59 (range 23-84) years, and 31 (46%) were male. Overall, 55 patients had Stage I disease, nine patients had Stage II disease, and four patients had paired organ-confined disease. Involved extranodal sites with three or more cases were orbital (n = 18), conjunctiva (n = 13), lacrimal (n = 8), skin (n = 8), salivary (n = 7), and muscle (n = 4). Eight patients had primary nodal MZL. At the median follow-up of 5 years (range 0.7-9.4), progression-free survival and overall survival were 79% and 95%, respectively. One lymphoma-related death and two in-field failures (after 25 and 30 Gy, respectively) occurred. Distant relapse sites were skin (n = 2), lymph nodes (n = 2), duodenum, stomach, muscle, and conjunctiva (1 each). No paired-organ MZL relapsed. Apart from cataracts (n = 18), only three treatment-related late grade ≥3 adverse events occurred. Autoantibodies or autoimmune events were detected in 26 of 68 patients (38%). H. pylori infection was detected in 15 of 63 patients (24%) tested. Neither autoimmunity nor H. pylori was detected in 27 of 68 patients (40%). CONCLUSIONS: Radiotherapy was a potentially curative treatment with low toxicity in localised non-gastric MZL. Autoimmunity, H. pylori infection or both were detected in 60% of patients.