Gene expression profiling of primary vitreoretinal lymphoma.

The characteristics of tumor cells of primary vitreoretinal lymphoma (PVRL) have not been defined, although researches have shown that most cases are of diffuse large B-cell lymphoma (DLBCL). To determine the subtype and biological characteristics of tumor cells of PVRL, we performed a gene expression profiling analysis. RNA was extracted from the vitreous fluid of 7 PVRL patients and from nodal samples of 10 DLBCL patients: 6 of germinal center B-cell (GCB) type and 4 of activated B-cell (ABC) type determined by Hans' criteria. Six PVRL samples showed gene expression profiles that were similar to each other. The patterns were different from those of the ABC-type nodular DLBCL but relatively close to those of the GCB-type nodular DLBCL. Interestingly, all of the 6 examined PVRL samples had either MYD88L265P or mutation in the immunoreceptor tyrosine-based activation motif (ITAM) region of CD79B. Five PVRL patients with similar gene expression profiles were treated with a standardized regimen: intravitreal administration of methotrexate (MTX) followed by six courses of systemic high doses of MTX. As a result, 2 patients had CD79B mutations and showed early central nervous system (CNS) progression. Patients without CNS progression did not have this mutation. In conclusion, PVRL had unique genetic features: an expression pattern different from ABC-type and relatively close to GCB-type DLBCL. CD79B mutations showed potential to serve as prognostic markers for CNS progression.

GCB-type is a favorable prognostic factor in primary CNS diffuse large B-cell lymphomas.

Primary CNS lymphomas (PCNSLs) are aggressive diffuse large B-cell lymphomas (DLBCLs) limited to the CNS that generally have a poor prognosis. Classification of DLBCL into germinal center B-cell (GCB) and activated B-cell (non-GCB) subtypes has prognostic value in systemic DLBCL, with GCB-type having a better prognosis. The aim of this study was to determine whether GCB versus non-GCB classification in PCNSLs has similar prognostic value. We analyzed clinical, radiological and histologic data from 24 patients with biopsy confirmed DLBCL of the CNS with classification into GCB versus non-GCB subtypes. We found that after a median follow-up of 15 months, only 39% of patients with non-GCB-type PCNS DLBCL were alive, whereas all patients with GCB-type were alive. Non-GCB-type had a median survival of 11 months, whereas all GCB-type patients were alive after a median follow-up of 22 months. As previously reported, we also found that patients younger than 70 years had longer survival (median 29 months) compared to older patients (median 8.8 months). There was no statistically significant difference between the ages, gender, focality, size or location of lesions, or treatment of non-GCB and GCB-type patients. Our findings suggest that classifying PCNSLs into GCB versus non-GCB subtype using the Hans algorithm may help stratify patients into two groups with different prognosis.

Impact of Omission/Reduction of Vincristine From R-CHOP in Treatment of DLBCL.

BACKGROUND: The R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) is the standard therapy for patients with diffuse large B-cell lymphoma (DLBCL). However, vincristine is sometimes omitted or reduced owing to side effects. MATERIALS AND METHODS: We retrospectively reviewed newly diagnosed patients with DLBCL with R-CHOP-like chemotherapy in our institute from January 2005 to February 2018 to investigate whether the omission/reduction of vincristine reduced the efficacy of the treatment. We compared the overall survival (OS) with and without the omission/reduction of vincristine from the R-CHOP regimen. RESULTS: A total of 576 cases were reviewed, and vincristine was omitted/reduced in 50 (9%) patients. The 4-year OS with and without vincristine omission/reduction for relative dose intensity < 80%, 50%, and 25% was 70% versus 82% (P = .035), 70% versus 82% (P = .085), and 53% versus 82% (P = .0007). In a multivariate analysis, adjusting for international prognostic index risk factors, a statistically significant, poor OS was indicated in the patients with relative dose intensity < 25%. CONCLUSIONS: Excessive dose omission/reduction of vincristine might lead to a substantial loss of efficacy of R-CHOP therapy.