ABSTRACT: BACKGROUND:Cytoreductive surgery is considered controversial for primary central nervous system lymphoma (PCNSL). OBJECTIVE:To investigate survival following craniotomy or biopsy for PCNSL. METHODS:The National Cancer Database-Participant User File (NCDB, n = 8936), Surveillance, Epidemiology, and End Results Program (SEER, n = 4636), and an institutional series (IS, n = 132) were used. We retrospectively investigated the relationship between craniotomy, prognostic factors, and survival for PCNSL using case-control design. RESULTS:In NCDB, craniotomy was associated with increased median survival over biopsy (19.5 vs 11.0 mo), independent of subsequent radiation and chemotherapy (hazard ratio [HR] 0.80, P < .001). We found a similar trend with survival for craniotomy vs biopsy in the IS (HR 0.68, P = .15). In SEER, gross total resection was associated with increased median survival over biopsy (29 vs 10 mo, HR 0.68, P < .001). The survival benefit associated with craniotomy was greater within recursive partitioning analysis (RPA) class 1 group in NCDB (95.1 vs 29.1 mo, HR 0.66, P < .001), but was smaller for RPA 2-3 (14.9 vs 10.0 mo, HR 0.86, P < .001). A surgical risk category (RC) considering lesion location and number, age, and frailty was developed. Craniotomy was associated with increased survival vs biopsy for patients with low RC (133.4 vs 41.0 mo, HR 0.33, P = .01), but not high RC in the IS. CONCLUSION:Craniotomy is associated with increased survival over biopsy for PCNSL in 3 retrospective datasets. Prospective studies are necessary to adequately evaluate this relationship. Such studies should evaluate patients most likely to benefit from cytoreductive surgery, ie, those with favorable RPA and RC.