Burden of illness of follicular lymphoma and marginal zone lymphoma.

Follicular lymphoma (FL) and marginal zone lymphoma (MZL) are two subtypes of indolent B cell non-Hodgkin lymphoma (NHL) that account for approximately 20% and 12% of all NHLs, respectively. FL and MZL are rare conditions with orphan disease designations. We conducted a comprehensive review of the burden of FL and MZL that encompasses the epidemiological, real world clinical, economic, and humanistic impact of these diseases globally. A targeted literature search identified 31 eligible studies for review. Epidemiological coverage was poor, with data obtained for studies from only seven countries. The incidences of both subtypes were low: age-standardized incidence rates of FL ranged from 2.1/100,000 in France to 4.3/100,000 in the USA, while for MZL it varied geographically from 0.5/100,000 in Australia to 2.6/100,000 in the UK. The cumulative total direct healthcare costs for FL were higher for patients with progressive disease compared to those without ($30,890 vs. $8704 at 12 months, respectively) and main driver of costs related to the use of chemotherapy. Five-year overall survival was improved in patients with FL compared with MZL (e.g., 76.5% vs 60.7% in one study that reported on both subtypes). Mortality rates were particularly lower in female patients with FL aged < 60 years. However, limited outcome data for MZL patients were identified. FL and MZL contribute significant burden on healthcare systems and on patients globally, with delays in progression potentially leading to cost savings. More rigorous characterization of these two NHL subtypes, new and more effective treatments, and standardization of reporting would lead to a more robust understanding of future data in this disease area.