Clinical features, radiological profiles, and surgical outcomes of primary intracranial solitary plasmacytomas: a report of 17 cases and a pooled analysis of individual patient data.

PURPOSE: We aim to delineate the clinical characteristics of patients with primary intracranial solitary plasmacytoma (PISPC) and prognostic factors for their outcomes.

METHODS

This study retrospectively reviewed 17 patients with PISPC from our center and an additional 70 cases of PISPC published previously to analyze outcome predictors.

RESULTS

The entire cohort included 38 (43.7%) males and 49 (56.3%) females with a mean age of 54 years. Skull base tumors were found in 49 (56.3%) patients. Gross total resection (GTR) was achieved in 31 (35.6%) patients. Postoperative adjuvant treatments, including radiotherapy (RT) alone, chemotherapy (CMT) alone, and RT + CMT were administered in 49 (56.3%) patients, 3 (3.5%) patients, and 16 (18.4%) patients, respectively. After a median follow-up of 24 (mean 42.4) months, the 5-year disease progression-free survival (PFS), recurrence-free survival (RFS), multiple myeloma (MM)-free survival (MMFS), and overall survival (OS) were 52.9%, 76.2%, 69.6%, and 76.1%, respectively. Multivariate analysis unveiled that a skull base tumor location (HR 2.395, p = 0.040) and no RT (HR 3.115, p = 0.004) were negative prognostic factors for PFS, no RT (HR 10.526, p = 0.003) for RFS, each 1-year increase in age (HR 1.039, p = 0.049) for MMFS, and increasing age (HR 1.052, p = 0.043) and CMT (HR 6.022, p = 0.005) were risk factors for OS. However, GTR did not benefit the aforementioned outcomes.

CONCLUSION

For patients with presumed PISPC, a biopsy followed by RT is recommended for skull base PISPC. However, the role of CMT is still not clear. Our findings need to be verified in a larger prospective cohort in the future. Systematic review registration number CRD42018098782.