Abstract
Primary gastrointestinal (GI) mantle cell lymphoma (MCL) is rare and the optimal management is unknown. We reviewed 800 newly diagnosed MCL cases and found 22 primary (2.8%) and 79 (9.9%) secondary GI MCL cases. Age, sex, and performance status were similar between primary and secondary cases. Secondary cases had more elevations in lactate dehydrogenase (28% vs 0%, P = 0.03) and a trend for a higher MCL international prognostic index (P = 0.07). Observation or local therapy was more common for primary GI MCL (29% vs 8%, P < 0.01), and autologous stem-cell transplant was more common for secondary GI MCL (35% vs 14%, P < 0.05). The median follow-up was 85 months. Primary and secondary GI MCL had similar 5-year progression-free survival (PFS) (30% vs 28%, P = 0.59) and overall survival (OS) (65% vs 66%, P = 0.83). The extent of GI involvement in primary GI MCL affected treatment selection but not outcome, with a 5-year PFS of 43% vs 14% vs 31% (P = 0.48) and OS of 57% vs 71% vs 69% (P = 0.54) in cases with single lesion vs multiple lesions in 1 organ vs multiple lesions in ≥2 organs. Less aggressive frontline treatment for primary GI MCL is reasonable. It is unknown whether more aggressive treatment can result in improved outcomes.