As more efficient agents for stem cell mobilization are being developed, there is an urgent need to define which patient population might benefit from these novel drugs. For a precise and prospective definition of "poor mobilization" (PM), we have analyzed the efficiency of mobilization in patients intended to receive autologous transplantation at our center in the past 6 years. Between January 2003, and December 2008, 840 patients with the following diagnoses were scheduled to undergo leukapheresis: multiple myeloma (MM, n = 602) and non-Hodgkin lymphoma (NHL, n= 238). Most patients mobilized readily: close to 85% of the patients had a level of 20/microL to >500/microL of CD34(+) cells at the peak of stimulation. Of the 840 patients, 129 (15.3%) were considered to be PMs, defined as patients who had a peak concentration of 20/nL was 11 days with a range of 6 to 17 days for the good mobilizers, whereas for the PM it was 11 days with a range of 7 to 32 days. Again, this difference was not significant. The majority of the patients today intended for autologous transplantations were able to mobilize readily. As long as > or =2.0 x 10(6) of CD34(+) cells/kg b.w. have been collected, PM was not associated with inferior engraftment.

In a previous systematic review and meta-analysis of five randomized controlled trials comparing rituximab maintenance with no maintenance (observation or rituximab at progression) for patients with follicular lymphoma, we reported that rituximab maintenance treatment improved the overall survival of patients. In this study, we did a similar search of the electronic databases updated through December 31, 2010, and included nine trials and 2586 follicular lymphoma patients. Hazard ratios (HRs) for time-to-event data were estimated and pooled using the inverse variance method. Risk ratios for dichotomous data were pooled using a fixed effect model. Patients treated with rituximab maintenance had improved overall survival (pooled HR of death = 0.76, 95% confidence interval [CI] = 0.62 to 0.92) compared with patients in the no maintenance group. Patients with refractory or relapsed (ie, previously treated) follicular lymphoma treated with rituximab maintenance had improved overall survival (pooled HR of death = 0.72, 95% CI = 0.57 to 0.91), whereas previously untreated patients had no survival benefit (pooled HR of death = 0.86, 95% CI = 0.60 to 1.25). The rate of infection-related adverse events was higher in the rituximab maintenance group (pooled risk ratio = 1.67, 95% CI = 1.40 to 2.00). These results further support the use of rituximab maintenance in the standard of care for refractory or relapsed follicular lymphoma.

Key Points: HDAC inhibitors downregulate expression of the activating NKp30 ligand B7-H6, reducing NKp30-dependent tumor cell recognition by NK cells. Our results have implications for the design of potential cancer treatments combining immunotherapy with HDAC inhibitors.

Purpose: To study clinical presentation, outcome, and the role of radiotherapy in patients with aggressive B-cell lymphoma and skeletal involvement treated with and without rituximab. Patients and Methods: Outcome of patients with skeletal involvement was analyzed in a retrospective study of nine consecutive prospective trials of the German High-Grade Non-Hodgkin lymphoma Study Group. Results: Of 3,840 patients, 292 (7.6%) had skeletal involvement. In the MabThera International Trial (MInT) for young good-prognosis patients and the Rituximab With CHOP Over 60 Years (RICOVER-60) study for elderly patients, the randomized addition of rituximab improved event-free survival (EFS; hazard ratio for MInT [HR_MInT] = 0.4, P > 001; hazard ratio for RICOVER-60 [HR_RICOVER-60] = 0.6, P > .001) and overall survival (OS; HR_MInT = 0.4, P < .001; HR_RICOVER-60 = 0.7, P = .002) in patients without skeletal involvement, but failed to improve the outcome of patients with skeletal involvement (EFS: HR_MInT = 1.4, P = .444; HR_RICOVER-60 = 0.8, P = .449; OS: HR_MInT = 0.6, P = .449; HR_RICOVER-60 = 1.0, P = .935). Skeletal involvement was associated with a worse outcome after cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus rituximab (HR_EFS = 1.5, P = .048; HR_OS = 1.1; P = .828), but not after CHOP without rituximab (HR_EFS = 0.8, P = .181; HR_OS = 0.7, P = .083). In contrast to rituximab, additive radiotherapy to sites of skeletal involvement was associated with a decreased risk (HR_EFS = 0.3, P = .001; HR_OS = 0.5; P = .111). Conclusion: Rituximab failed to improve the outcome of patients with diffuse large B-cell lymphoma with skeletal involvement, although our data suggest a beneficial effect of radiotherapy to sites of skeletal involvement. Whether radiotherapy to sites of skeletal involvement can be spared in cases with a negative positron emission tomography after immunochemotherapy should be addressed in appropriately designed prospective trials.