Citations

More than 30 years ago, Darley, Aronson, and Brown (1969) proposed clinicoanatomic correlations for seven perceptual types of dysarthria. These correlations have not been systematically re-examined even though imaging technologies developed in recent years provide the means to do so. This review considers data from published imaging studies as well as data from selected medical interventions to evaluate the current state of knowledge that relates lesion site to the nature of a speech disturbance. Although the extant data are not sufficient to allow a complete evaluation of the seven types of dysarthria described by Darley et al., relevant information has been reported on lesions of the pyramidal pathway, extrapyramidal pathway, and cerebellum. In general, the results are best explained by an equivalence mode of brain-behavior relationship in which a type of dysarthria is associated with a lesion in one of two or more brain structures. Criteria also are proposed for future studies of clinicoanatomic relationships in neurogenic communication disorders.

Multiple myeloma is a highly radiosensitive skeletal malignancy, but bone-seeking radionuclides have not yet found their place in disease management. We previously reported that the proteasome inhibitor PS-341 selectively sensitizes myeloma cells to the lethal effects of ionizing radiation. To extend these observations to an in vivo model, we combined PS-341 with the bone-seeking radionuclide 153-Sm-EDTMP. In vitro clonogenic assays demonstrated synergistic killing of myeloma cells exposed to both PS-341 and 153-Sm-EDTMP. Using the orthotopic, syngeneic 5TGM1 myeloma model, the median survivals of mice treated with saline, 2 doses of PS-341 (0.5 mg/kg), or a single nonmyeloablative dose of 153-Sm-EDTMP (22.5 MBq) were 21, 22, and 28 days, respectively. In contrast, mice treated with combination therapy comprising 2 doses of PS-341 (0.5 mg/kg), 1 day prior to and 1 day following 153-Sm-EDTMP (22.5 MBq) showed a significantly prolonged median survival of 49 days (P < .001). In addition to prolonged survival, this treatment combination yielded reduced clonogenicity of bone marrow–resident 5TGM1 cells, reduced serum myeloma–associated paraprotein levels, and better preservation of bone mineral density. Myelosuppression, determined by peripheral blood cell counts and clonogenicity assays of hematopoietic progenitors, did not differ between animals treated with 153-Sm-EDTMP alone versus those treated with the combination of PS-341 plus 153-Sm-EDTMP. PS-341 is a potent, selective in vivo radiosensitizer that may substantially affect the efficacy of skeletal-targeted radiotherapy in multiple myeloma.

AbstractThe immunoglobulin free light chain (FLC) is the precursor protein of amyloid in primary systemic amyloidosis (AL). Historically, the ability to monitor the amyloid protein precursor protein has been crude. We evaluated the utility of the FLC assay in a retrospective analysis of patients with AL undergoing peripheral blood stem cell transplantation (PBSCT). Ninety-three such patients had serial FLC measurements performed. The prognostic effects of the initial concentration and the extent of reduction of monoclonal FLC on survival were studied. There was a significantly higher risk of death in patients with higher baseline FLC (hazard ratio 2.6, P < .04). Baseline FLC correlated with serum cardiac troponin levels, and higher FLC levels were associated with more organs involved by amyloid, suggesting that high FLC levels may be associated with more advanced disease. The percent FLC reduction did not predict for survival, but the absolute level of FLC achieved after therapy did. Normalization of FLC level after PBSCT predicted for both organ response and complete hematologic response. Achievement of FLC response was a better predictor of survival than achievement of complete hematologic response or normalization of the FLC ratio. FLC measurements both before and after PBSCT are important predictors of patient outcome.

The mechanisms underlying aneuploidy in multiple myeloma (MM) are unclear. Centrosome amplification has been implicated as the cause of chromosomal instability in a variety of tumors and is a potential mechanism causing aneuploidy in MM. Using immunofluorescent (IF) staining, centrosome amplification was detected in 67% of monoclonal gammopathies, including monoclonal gammopathy of undetermined significance (MGUS). We also investigated the gene expression of centrosome proteins. Overall, gene expression data correlated well with IF-detected centrosome amplification, allowing us to derive a gene expression-based centrosome index (CI) as a surrogate for centrosome amplification. Clinically, MM patients with high CI (> 4) are associated with poor prognostic genetic and clinical subtypes (chromosome 13 deletion, t(4; 14), t(14;16), and PCLI > 1%, P < .05) and are shown here to have short survival (11.1 months versus 39.1 months, P < .001). On multivariate regression, a high CI is an independent prognostic factor. Given that centrosome amplification is already observed in MGUS and probably integral to early chromosomal instability and myeloma genesis, and patients with more extensive centrosome amplification have shorter survival, the mechanisms leading to centrosome amplification should be investigated because these may offer new avenues for therapeutic intervention.

AbstractDetection of circulating myeloma cells (CMCs) by flow cytometry in patients with multiple myeloma (MM) indicates active disease. We hypothesized that detection of CMCs at the time of stem-cell collection prior to autologous stem-cell transplantation (ASCT) identifies patients at high risk of rapid progression. A cohort of patients undergoing ASCT was identified. CMCs were determined by gating on CD38+/CD45- cells using flow cytometry. The impact of CMCs on overall survival (OS) and time to progression (TTP) was evaluated in univariate and multivariate analyses. Of 246 patients undergoing ASCT, 95 had CMCs. Complete response (CR) rates after transplantation were 32% and 36% for patients with and without CMCs, respectively (P = .50). OSs were 33.2 and 58.6 months (P = .01) whereas TTPs were 14.1 and 22 months, respectively (P = .001). On multivariate analysis, CMCs remained independent of cytogenetics and disease status at time of transplantation (P = .03). CMCs and cytogenetics were combined in a new scoring system. Patients with neither, one, or both parameters had a median OS of 55, 48, and 21.5 months and a median TTP of 22, 15.4, and 6.5 months, respectively. CMCs at the time of ASCT is an independent prognostic factor and in combination with cytogenetics provides a powerful scoring system that stratifies patients and guides management.

Abstract Purpose: To optimize treatment strategies for postmenopausal breast cancer patients, we investigated the efficacy of the steroidal aromatase inhibitor exemestane alone or in combination with the antiestrogen tamoxifen in a xenograft model of postmenopausal breast cancer. We also determined the effects of these agents in sequential second-line therapy and the effect of the nonsteroidal aromatase inhibitor letrozole on tumors that progressed on the above treatments. Experimental: Aromatase-transfected human estrogen receptor-positive breast cancer cells (MCF-7Ca) were grown as tumors in ovariectomized athymic mice. Animals received subcutaneous injection with vehicle, tamoxifen, exemestane, tamoxifen plus exemestane, and letrozole. Tumor volumes were measured weekly. Results: All treatments were effective initially in suppressing tumor growth as first-line therapy compared with vehicle treatment. Exemestane suppressed tumor growth to a greater extent than tamoxifen. However, the combination of tamoxifen plus exemestane was more effective than either drug alone. After tumor volumes doubled on initial treatment, the mice were crossed over to receive exemestane or tamoxifen. Tumor growth slowed briefly in mice treated with tamoxifen and crossed over to exemestane, but tumor growth continued unabated in those changed from exemestane to tamoxifen. However, letrozole was effective in both groups as third-line therapy for a limited period. Letrozole as initial single agent was the best overall treatment in terms of the degree of tumor suppression and the length of effectiveness of treatment. Conclusion: Exemestane was more effective in controlling tumor growth than tamoxifen. In addition, the combination of exemestane plus tamoxifen was clearly more effective than sequential use of these agents in the tumor model. However, the nonsteroidal aromatase inhibitor letrozole as first-line therapy was overall the most effective treatment in controlling tumor growth.

We report the results of a phase 2 trial using lenalidomide plus dexamethasone (Rev/Dex) as initial therapy for myeloma. Thirtyfour patients were enrolled. Lenalidomide was given orally 25 mg daily on days 1 to 21 of a 28-day cycle. Dexamethasone was given orally 40 mg daily on days 1 to 4, 9 to 12, and 17 to 20 of each cycle. Objective response was defined as a decrease in serum monoclonal protein level by 50% or greater and a decrease in urine M protein level by at least 90% or to a level less than 200 mg/24 hours, confirmed by 2 consecutive determinations at least 4 weeks apart. Thirty-one of 34 patients achieved an objective response, including 2 (6%) achieving complete response (CR) and 11 (32%) meeting criteria for both very good partial response and near complete response, resulting in an overall objective response rate of 91%. Of the 3 remaining patients not achieving an objective response, 2 had minor response (MR) and one had stable disease. Fortyseven percent of patients experienced grade III or higher nonhematologic toxicity, most commonly fatigue (15%), muscle weakness (6%), anxiety (6%), pneumonitis (6%), and rash (6%). Rev/Dex is a highly active regimen with manageable side effects in the treatment of newly diagnosed myeloma.

Purpose Monoclonal gammopathy of undetermined significance (MGUS) progresses to multiple myeloma or another related plasma cell disorder (PCD) at a rate of approximately 1% per year. Identification of patients with MGUS at high risk of progression will allow development of preventive strategies. We studied the prognostic value of circulating plasma cells (PCs) in patients with MGUS to predict progression. Patients and Methods Patients were eligible for this retrospective analysis if they were seen at the Mayo Clinic between 1984 and 1997, were diagnosed with MGUS, and had an analysis of the peripheral blood for circulating PCs by the slide-based immunofluorescence method. Patients were observed for progression to another PCD. Results Three hundred twenty-five patients were eligible and 63 (19%) had circulating PCs. Patients with circulating PCs were twice as likely (hazard ratio, 2.1) to experience progression to another PCD (most commonly myeloma), compared with those without circulating PCs (95% CI, 1.1 to 4.3; P = .03). In patients with circulating PCs, the median progression-free survival was 138 months compared with a median not yet reached for those without circulating PCs (P = .028). The median overall survival also was shorter for those with circulating PCs. Other factors with prognostic value were high levels of M protein and non–immunoglobulin G heavy-chain type. Conclusion The presence of circulating PCs, especially when combined with other known prognostic factors such as M protein concentration and immunoglobulin isotype, identify a group of individuals with MGUS at higher risk of progression to overt multiple myeloma.