Local Disease Control in Ocular Adnexal Lymphoproliferative Disorders: Comparative Outcomes of MALT Versus Non-MALT Histologies.

INTRODUCTION: Ocular adnexal lymphoproliferative disorders (OALDs) are almost exclusively of B-cell origin, with the majority being extra-nodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT). The comparative efficacy of involved field radiation therapy (IFRT) in MALT vs. non-MALT OALDs is not known. MATERIALS AND METHODS: We present a single-center, large cohort, retrospective study of the efficacy of IFRT in OALDs. Failure-free survival (FFS), complete remission, and local, regional, and distant failure were determined for 112 patients with MALT OALDs (n = 71) and non-MALT OALDs (n = 41) cohorts. RESULTS: Fifty-six patients with MALT OALD and 26 patients with non-MALT OALD received IFRT only (without any planned concurrent or sequential systemic chemothereapy or chemo-immunotherapies). Among the OALD cohorts treated with only IFRT, complete remission was achieved in 49 (87.5%) patients in the MALT cohort and 23 (88.4%) in the non-MALT cohort (P = .99). Clinically, resolution of symptoms occurred in 83.3% and 93.3% of the patients in the MALT and non-MALT cohorts, respectively. Local failure occurred in 4 (7.1%) patients in the MALT cohort, compared with 4 (15.3%) patients in the non-MALT cohort (P = .24). Regional failure (or extra-orbital failure) occurred in 5 (8.9%) patients in the MALT cohort and in 3 (11.5%) patients in the non-MALT cohort (P = .71). Distant failure was reported in 1 (1.7%) and 2 patients (7.6%) in the MALT and non-MALT cohorts, respectively (P = .18). The median follow-up of survivors was 5.1 years (range, 0.1-22.5 years) in the MALT cohort and 3.9 years (range, 0.1-22.9 years) in the non-MALT cohort. The 5-year and 10-year FFS was 95% (95% confidence interval [CI], 88%-100%) and 83% (95% CI, 70%-98%) for the ocular MALT and 67% (95% CI, 48%-94%) and 56% (95% CI, 34%-91%) for the non-MALT cohorts, respectively (log rank for P = .025). On multivariate analyses, age (hazard ratio [HR], 1.06; 95% CI, 1.10-1.12; P = .03), presence of non-MALT histology (HR, 13.9; 95% CI, 2.05-94.4; P = .007), and radiation dose < 30.6 Gy (HR, 5.27; 95% CI, 1.14-24.3; P = .03) were associated with worse FFS. The 5-year and 10-year overall survival was 92% (95%, CI 83%-100%) and 80% (95% CI, 66%-96%) for the MALT and 78% (95% CI, 61%-100%) and 62% (95% CI, 38%-100%) for the non-MALT cohorts, respectively (P = .80). CONCLUSION: Our results reveal that IFRT provided excellent disease control with superior FFS in the MALT cohort when compared with the non-MALT group.