Long-term outcomes of patients with conjunctival extranodal marginal zone lymphoma

Comprehensive information on clinical features and long-term outcomes of primary conjunctival extranodal marginal zone lymphoma (PCEMZL) is scarce. We present a large single-institution retrospective study of 72 patients. The median age was 64 years, and 63.9% were female. Stage I was present in 87.5%. Radiation therapy (RT) alone was the most common treatment (70.8%). Complete response (CR) was 87.5%, and 100% in RT-treated patients. With a median follow-up of 6.7 years, relapse/progression and death occurred in 19.4% each, with one relapse within the RT field. The 10-year progression-free survival (PFS) and overall survival (OS) were 68.4% (95% CI 52.8%–79.8%) and 89.4% (95% CI 77.4%–95.2%), respectively. The 10-year rate for time to progression from diagnosis was 22.5% (95% CI 11.6%–35.7%). The 10-year PFS and OS of MALT-IPI 0 versus 1–2 were 83.3% versus 51.3%, (p =.022) and 97.6% versus 76.6%, (p =.0052), respectively. The following characteristics were associated with shorter survival: age > 60 years (PFS: HR = 2.93, 95% CI 1.08–7.95; p =.035, OS: HR = 9.07, 95% CI 1.17–70.26; p =.035) and MALT-IPI 1–2 (PFS: HR = 2.67, 95% CI 1.12–6.31; p =.027, OS: HR = 6.64, 95% CI 1.45–30.37; p =.015). CR following frontline therapy was associated with longer PFS (HR = 0.13, 95% CI 0.04–0.45; p =.001), but not OS. Using the Fine and Gray regression model with death without relapse/progression as a competing risk, RT and CR after frontline therapy were associated with lower risk of relapse (SHR = 0.34, 95% CI 0.12–0.96 p =.041 and SHR = 0.11, 95% CI 0.03–0.36; p <.001, respectively). Patients with PCEMZL treated with frontline RT exhibit excellent long-term survival, and the MALT-IPI score appropriately identifies patients at risk for treatment failure.