SPARC-positive macrophages are the superior prognostic factor in the microenvironment of diffuse large B-cell lymphoma and independent of MYC rearrangement and double-/triple-hit status.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with respect to outcome. Features of the tumor microenvironment (TME) are associated with prognosis when assessed by gene expression profiling. However, it is uncertain whether assessment of the microenvironment can add prognostic information to the most relevant and clinically well-established molecular subgroups when analyzed by immunohistochemistry (IHC). PATIENTS AND METHODS: We carried out a histopathologic analysis of biomarkers related to TME in a very large cohort (n = 455) of DLBCL treated in prospective trials and correlated with clinicopathologic and molecular data, including chromosomal rearrangements and gene expression profiles for cell-of-origin and TME. RESULTS: The content of PD1+, FoxP3+ and CD8+, as well as vessel density, was not associated with outcome. However, we found a low content of CD68+ macrophages to be associated with inferior progression-free survival (PFS) and overall survival (OS; P = 0.023 and 0.040, respectively) at both univariable and multivariable analyses, adjusted for the factors of the International Prognostic Index (IPI), MYC break and BCL2/MYC and BCL6/MYC double-hit status. The subgroup of PDL1+ macrophages was not associated with survival. Instead, secreted protein acidic and cysteine rich (SPARC)-positive macrophages were identified as the subtype of macrophages most associated with survival. SPARC-positive macrophages and stromal cells directly correlated with favorable PFS and OS (both, P[log rank] <0.001, P[trend] < 0.001). The association of SPARC with prognosis was independent of the factors of the IPI, MYC double-/triple-hit status, Bcl2/c-myc double expression, cell-of-origin subtype and a recently published gene expression signature [lymphoma-associated macrophage interaction signature (LAMIS)]. CONCLUSIONS: SPARC expression in the TME detected by a single IHC staining with fair-to-good interobserver reproducibility is a powerful prognostic parameter. Thus SPARC expression is a strong candidate for risk assessment in DLBCL in daily practice.

Optimization of rituximab for the treatment of DLBCL (I): dose-dense rituximab in the DENSE-R-CHOP-14 trial of the DSHNHL.

BACKGROUND: To improve outcome of elderly patients with diffuse large B-cell lymphoma, dose-dense rituximab was evaluated in the prospective DENSE-R-CHOP-14 trial. PATIENTS AND METHODS: Rituximab (375 mg/m(2)) was given on days 0, 1, 4, 8, 15, 22, 29, 43, 57, 71, 85, and 99 together with six CHOP-14 cycles. Results were to be compared with patients who had received the same chemotherapy in combination with eight 2-week applications of rituximab in RICOVER-60. RESULTS: One hundred twenty-four patients are assessable. Dose-dense rituximab resulted in considerably higher serum levels during the first 50 days of treatment, but rituximab exposure time was not prolonged. Grade 3 and 4 infections were exceptionally high in the first 20 patients without anti-infective prophylaxis, but decreased after introduction of prophylaxis with aciclovir and cotrimoxazole in the remaining 104 patients (from 13% to 6% per cycle and from 35% to 18% per patient; P = 0.007 and P = 0.125, respectively). Patients with international prognostic index = 3-5 had higher complete response/complete response unconfirmed rates (82% versus 68%; P = 0.033) than in the respective RICOVER-60 population, but this did not translate into better long-term outcome, even though male hazard was decreased (event-free survival: from 1.5 to 1.1; progression-free survival: from 1.7 to 1.1; overall survival: from 1.4 to 1.0). CONCLUSIONS: Dose-dense rituximab achieved higher rituximab serum levels, but was not more effective than eight 2-week applications in the historical control population, even though minor improvements in poor-prognosis and male patients cannot be excluded. The increased, though manageable toxicity, precludes its use in routine practice. Our results strongly support anti-infective prophylaxis with aciclovir and cotrimoxazole for all patients receiving R-CHOP.