SOHO State of the Art Updates and Next Questions | Does Limited Stage Diffuse Large B-cell Lymphoma Matter?

Limited stage diffuse large B-cell lymphoma (LSDLBCL) has excellent outcomes, but progress in management has been plagued by lack of standard definitions and exclusion from many trials evaluating novel agents in advanced stage DLBCL (ASDLBCL) which increasingly target high-risk populations. LSDLBCL definition varies but is most commonly defined as Ann Arbor stage I-II nonbulky disease (< 10 cm). LSDLBCL patient long-term survival exceeds 90% when treated with standard courses (6-8 cycles) of chemoimmunotherapy (CIT). Attempts have therefore been made to minimize CIT toxicity via fewer cycles, employing radiotherapy or positron emission tomography (PET)-adapted CIT instead. This has led to significant variation and complexity in LSDLBCL treatment, not least because LSDLBCL definition and trial eligibility have lacked consistency. Four key dedicated LSDLBCL treatment paradigms have evolved beyond the standard 6-8 RCHOP cycles given to ASDLBCL, such as Combined Modality Treatment (CMT), PET-adapted CMT and PET-directed RT, abbreviated RCHOP for young patients with no poor risk factors and PET-adapted CIT. Greater understanding of the biology and risk profiles of LSDLBCL matters, as does tailoring treatment in this unique disease. Ongoing international collaborative efforts to refine treatment paradigms according to risk are required to improve outcomes in these patients. Novel therapy studies should also be part of the immediate research agenda.