Evaluation of Circulating Endothelial Cells as Direct Marker of Endothelial Damage in Allo-Transplant Recipients at High Risk of Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome

Sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease (VOD), is a rare but potentially fatal complication following allogenic hematopoietic cell transplantation (allo-HCT). Timely identification of SOS/VOD to allow for prompt treatment is critical, but identifying a VOD-predictive biomarker remains challenging. Given the pivotal role of endothelial dysfunction in SOS/VOD pathophysiology, the CECinVOD study prospectively evaluated levels of circulating endothelial cells (CECs) in patients undergoing allo-HCT with a myeloablative conditioning (MAC) regimen to investigate the potential of CEC level in predicting and diagnosing SOS/VOD. A total of 150 patients from 11 Italian bone marrow transplantation units were enrolled. All participants were age >18 years and received a MAC regimen, putting them at elevated risk of developing SOS/VOD. Overall, 6 cases of SOS/VOD (4%) were recorded. CECs were detected using the Food and Drug Administration-approved CellSearch system, an immunomagnetic selection-based platform incorporating ferrofluid nanoparticles and fluorescent-labeled antibodies, and were defined as CD146+, CD105+, DAPI+, or CD45-. Blood samples were collected at the following time points: before (T0) and at the end of conditioning treatment (T1), at neutrophil engraftment (T2), and at 7 to 10 days postengraftment (T3). For patients who developed VOD, additional samples were collected at any suspected or proven VOD onset (T4) and weekly during defibrotide treatment (T5 to T8). A baseline CEC count >17/mL was associated with an elevated risk of SOS/VOD (P = .04), along with bilirubin level >1.5 mg/mL and a haploidentical donor hematopoietic stem cell source. Postconditioning regimen (T1) CEC levels were elevated (P = .02), and levels were further increased at engraftment (P < .0001). Additionally, patients developing SOS/VOD after engraftment, especially those with late-onset SOS/VOD, showed a markedly higher relative increase (>150%) in CEC count. Multivariate analysis supported these findings, along with a high Endothelial Activation and Stress Index (EASIX) score at engraftment (T2). Finally, CEC kinetics corresponded with defibrotide treatment. After the start of therapy (T4), CEC levels showed an initial increase in the first week (T5), followed by a progressive decrease during VOD treatment (T6 and T7) and a return to pre-SOS/VOD onset levels at resolution of the complication. This prospective multicenter study reveals a low incidence of SOS/VOD in high-risk patients compared to historical data, in line with recent reports. The results from the CECinVOD study collectively confirm the endothelial injury in allo-HCT and its role in in the development of SOS/VOD, suggesting that CEC level can be a valuable biomarker for diagnosing SOS/VOD and identifying patients at greater risk of this complication, especially late-onset SOS/VOD. Furthermore, CEC kinetics may support treatment strategies by providing insight into the optimal timing for discontinuing defibrotide treatment.

High risk-myelodysplastic syndrome following CAR T-cell therapy in a patient with relapsed diffuse large B cell lymphoma: A case report and literature review

Background

Chimeric antigen receptor (CAR) T-cell therapy represents the most advanced immunotherapy against relapsed/refractory B cell malignancies. While cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome are distinctive, known CAR T-cell acute adverse events, hematological toxicity has been increasingly reported. Cytopenia following CAR T-cell treatment is attributed in most cases to lymphodepletion regimens, bridging chemotherapy, or radiotherapy. However, when cytopenia becomes prolonged, the development of myelodysplastic syndrome (MDS) should be considered.

Case presentation

We report a case of high risk (HR)-MDS following CAR T-cell therapy in a patient with relapsed diffuse large B cell lymphoma. Eight months after CAR T-cell infusion, the blood count showed progressive, worsening cytopenia and the bone marrow biopsy revealed multilineage dysplasia without excess of blasts associated with chromosome 7 deletion and RUNX1 mutation. Next generation sequencing analysis, retrospectively performed on stored samples, showed a germ line CSF3R mutation, CEBPA clonal hematopoiesis, but no RUNX1 lesion.

Conclusion

We describe a case of HR-MDS, with deletion of chromosome 7 and acquisition of RUNX1 mutation, developing after CAR T-cell therapy in a patient with clonal hematopoiesis (CH). Previous chemotherapy favored MDS onset; however, we could not exclude the fact that the impairment of immunosurveillance related to either lymphodepletion or CAR T-cell infusion may play a role in MDS development. Thus, we designed a multicenter prospective study (ClonHema-CAR-T-Study) to investigate if cytopenia after CAR T-cell treatment may be due to underling CH as well as the presence of secondary myeloid malignancies.

Timely Leukapheresis May Interfere with the "Fitness" of Lymphocytes Collected for CAR-T Treatment in High Risk DLBCL Patients

The development of chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment of hematological diseases. However, approximately 60% of patients relapse after CAR-T cell therapy, and no clear cause for this failure has been identified. The objective of the Bio-CAR-T BS study (ClinicalTrials.gov: NCT05366569) is to improve our understanding of the lymphocyte harvest to maximize the quality of the CAR-T cell product. Of the 14 patients enrolled, 11 were diagnosed with DLBCL, 2 with PMBCL, and 1 with ALL. Five of 11 DLBCL patients met the criteria for "pre-emptive" Lymphocytes-apheresis (being at high risk of second relapse), and 6 were included in the standard-of-care Lymphocytes-apheresis group. Previous autologous stem cell transplantation (ASCT) and age were significantly different between the two groups. At the time of Lymphocyte-apheresis, patients in the "pre-emptive" group had more "fit" lymphocytes (higher CD4+/CD8+ ratio; higher naïve T cells levels) compared with standard group, probably due to the impact of ASCT. At the same time, also being older than 60 years results in a more "exhausted" lymphocyte profile. Overall, "pre-emptive" Ly-apheresis in DLBCL patients at high risk of relapse appears to be feasible and may allow the timely collection of "fit" lymphocytes for CAR-T cell manufacturing.

Mineralization of 3D Osteogenic Model Based on Gelatin-Dextran Hybrid Hydrogel Scaffold Bioengineered with Mesenchymal Stromal Cells: A Multiparametric Evaluation

Gelatin–dextran hydrogel scaffolds (G-PEG-Dx) were evaluated for their ability to activate the bone marrow human mesenchymal stromal cells (BM-hMSCs) towards mineralization. G-PEG-Dx1 and G-PEG-Dx2, with identical composition but different architecture, were seeded with BM-hMSCs in presence of fetal bovine serum or human platelet lysate (hPL) with or without osteogenic medium. G-PEG-Dx1, characterized by a lower degree of crosslinking and larger pores, was able to induce a better cell colonization than G-PEG-Dx2. At day 28, G-PEG-Dx2, with hPL and osteogenic factors, was more efficient than G-PEG-Dx1 in inducing mineralization. Scanning electron microscopy (SEM) and Raman spectroscopy showed that extracellular matrix produced by BM-hMSCs and calcium-positive mineralization were present along the backbone of the G-PEG-Dx2, even though it was colonized to a lesser degree by hMSCs than G-PEG-Dx1. These findings were confirmed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), detecting distinct lipidomic signatures that were associated with the different degree of scaffold mineralization. Our data show that the architecture and morphology of G-PEG-Dx2 is determinant and better than that of G-PEG-Dx1 in promoting a faster mineralization, suggesting a more favorable and active role for improving bone repair.

A Blood Bank Standardized Production of Human Platelet Lysate for Mesenchymal Stromal Cell Expansion: Proteomic Characterization and Biological Effects

Human platelet lysate (hPL) is considered a valid substitute to fetal bovine serum (FBS) in the expansion of mesenchymal stromal cells (MSC), and it is commonly produced starting from intermediate side products of whole blood donations. Through freeze-thaw cycles, hPL is highly enriched in chemokines, growth factors, and adhesion and immunologic molecules. Cell therapy protocols, using hPL instead of FBS for the expansion of cells, are approved by regulatory authorities without concerns, and its administration in patients is considered safe. However, published data are fairly difficult to compare, since the production of hPL is highly variable. This study proposes to optimize and standardize the hPL productive process by using instruments, technologies, and quality/safety standards required for blood bank activities and products. The quality and improved selection of the starting material (i.e., the whole blood), together with the improvement of the production process, guarantee a product characterized by higher content and quality of growth factors as well as a reduction in batch-to-batch variability. By increasing the number of freeze/thaw cycles from one (hPL1c) to four (hPL4c), we obtained a favorable effect on the release of growth factors from platelet α granules. Those changes have directly translated into biological effects leading to a decreasing doubling time (DT) of MSC expansion at 7 days (49.41 ± 2.62 vs. 40.61 ± 1.11 h, p < 0.001). Furthermore, mass spectrometry (MS)-based evaluation has shown that the proliferative effects of hPL4c are also combined with a lower batch-to-batch variability (10-15 vs. 21-31%) at the proteomic level. In conclusion, we have considered lot-to-lot hPL variability, and by the strict application of blood bank standards, we have obtained a standardized, reproducible, safe, cheap, and ready-to-use product.

Polysaccharides on gelatin-based hydrogels differently affect chondrogenic differentiation of human mesenchymal stromal cells

Selection of feasible hybrid-hydrogels for best chondrogenic differentiation of human mesenchymal stromal cells (hMSCs) represents an important challenge in cartilage regeneration. In this study, three-dimensional hybrid hydrogels obtained by chemical crosslinking of poly (ethylene glycol) diglycidyl ether (PEGDGE), gelatin (G) without or with chitosan (Ch) or dextran (Dx) polysaccharides were developed. The hydrogels, namely G-PEG, G-PEG-Ch and G-PEG-Dx, were prepared with an innovative, versatile and cell-friendly technique that involves two preparation steps specifically chosen to increase the degree of crosslinking and the physical-mechanical stability of the product: a first homogeneous phase reaction followed by directional freezing, freeze-drying and post-curing. Chondrogenic differentiation of human bone marrow mesenchymal stromal cells (hBM-MSC) was tested on these hydrogels to ascertain whether the presence of different polysaccharides could favor the formation of the native cartilage structure. We demonstrated that the hydrogels exhibited an open pore porous morphology with high interconnectivity and the incorporation of Ch and Dx into the G-PEG common backbone determined a slightly reduced stiffness compared to that of G-PEG hydrogels. We demonstrated that G-PEG-Dx showed a significant increase of its anisotropic characteristic and G-PEG-Ch exhibited higher and faster stress relaxation behavior than the other hydrogels. These characteristics were associated to absence of chondrogenic differentiation on G-PEG-Dx scaffold and good chondrogenic differentiation on G-PEG and G-PEG-Ch. Furthermore, G-PEG-Ch induced the minor collagen proteins and the formation of collagen fibrils with a diameter like native cartilage. This study demonstrated that both anisotropic and stress relaxation characteristics of the hybrid hydrogels were important features directly influencing the chondrogenic differentiation potentiality of hBM-MSC.

Impedance-Based Monitoring of Mesenchymal Stromal Cell Three-Dimensional Proliferation Using Aerosol Jet Printed Sensors: A Tissue Engineering Application

One of the main hurdles to improving scaffolds for regenerative medicine is the development of non-invasive methods to monitor cell proliferation within three-dimensional environments. Recently, an electrical impedance-based approach has been identified as promising for three-dimensional proliferation assays. A low-cost impedance-based solution, easily integrable with multi-well plates, is here presented. Sensors were developed using biocompatible carbon-based ink on foldable polyimide substrates by means of a novel aerosol jet printing technique. The setup was tested to monitor the proliferation of human mesenchymal stromal cells into previously validated gelatin-chitosan hybrid hydrogel scaffolds. Reliability of the methodology was assessed comparing variations of the electrical impedance parameters with the outcomes of enzymatic proliferation assay. Results obtained showed a magnitude increase and a phase angle decrease at 4 kHz (maximum of 2.5 kΩ and -9 degrees) and an exponential increase of the modeled resistance and capacitance components due to the cell proliferation (maximum of 1.5 kΩ and 200 nF). A statistically significant relationship with enzymatic assay outcomes could be detected for both phase angle and electric model parameters. Overall, these findings support the potentiality of this non-invasive approach for continuous monitoring of scaffold-based cultures, being also promising in the perspective of optimizing the scaffold-culture system.

Chitosan-based scaffold counteracts hypertrophic and fibrotic markers in chondrogenic differentiated mesenchymal stromal cells

Cartilage tissue engineering remains problematic because no systems are able to induce signals that contribute to native cartilage structure formation. Therefore, we tested the potentiality of gelatin-polyethylene glycol scaffolds containing three different concentrations of chitosan (CH; 0%, 8%, and 16%) on chondrogenic differentiation of human platelet lysate-expanded human bone marrow mesenchymal stromal cells (hBM-MSCs). Typical chondrogenic (SOX9, collagen type 2, and aggrecan), hypertrophic (collagen type 10), and fibrotic (collagen type 1) markers were evaluated at gene and protein level at Days 1, 28, and 48. We demonstrated that 16% CH scaffold had the highest percentage of relaxation with the fastest relaxation rate. In particular, 16% CH scaffold, combined with chondrogenic factor TGFβ3, was more efficient in inducing hBM-MSCs chondrogenic differentiation compared with 0% or 8% scaffolds. Collagen type 2, SOX9, and aggrecan showed the same expression in all scaffolds, whereas collagen types 10 and 1 markers were efficiently down-modulated only in 16% CH. We demonstrated that using human platelet lysate chronically during hBM-MSCs chondrogenic differentiation, the chondrogenic, hypertrophic, and fibrotic markers were significantly decreased. Our data demonstrate that only a high concentration of CH, combined with TGFβ3, creates an environment capable of guiding in vitro hBM-MSCs towards a phenotypically stable chondrogenesis.

3D gelatin-chitosan hybrid hydrogels combined with human platelet lysate highly support human mesenchymal stem cell proliferation and osteogenic differentiation

Bone marrow and adipose tissue human mesenchymal stem cells were seeded in highly performing 3D gelatin–chitosan hybrid hydrogels of varying chitosan content in the presence of human platelet lysate and evaluated for their proliferation and osteogenic differentiation. Both bone marrow and adipose tissue human mesenchymal stem cells in gelatin–chitosan hybrid hydrogel 1 (chitosan content 8.1%) or gelatin–chitosan hybrid hydrogel 2 (chitosan 14.9%) showed high levels of viability (80%–90%), and their proliferation and osteogenic differentiation was significantly higher with human platelet lysate compared to fetal bovine serum, particularly in gelatin–chitosan hybrid hydrogel 1. Mineralization was detected early, after 21 days of culture, when human platelet lysate was used in the presence of osteogenic stimuli. Proteomic characterization of human platelet lysate highlighted 59 proteins mainly involved in functions related to cell adhesion, cellular repairing mechanisms, and regulation of cell differentiation. In conclusion, the combination of our gelatin–chitosan hybrid hydrogels with hPL represents a promising strategy for bone regenerative medicine using human mesenchymal stem cells.

The clinical use of circulating tumor cells (CTCs) enumeration for staging of metastatic breast cancer (MBC): International expert consensus paper

BACKGROUND

The heterogeneity of metastatic breast cancer (MBC) necessitates novel biomarkers allowing stratification of patients for treatment selection and drug development. We propose to use the prognostic utility of circulating tumor cells (CTCs) for stratification of patients with stage IV disease.

METHODS

In a retrospective, pooled analysis of individual patient data from 18 cohorts, including 2436 MBC patients, a CTC threshold of 5 cells per 7.5 ml was used for stratification based on molecular subtypes, disease location, and prior treatments. Patients with ≥ 5 CTCs were classified as Stage IVaggressive, those with < 5 CTCs as Stage IVindolent. Survival was analyzed using Kaplan-Meier curves and the log rank test.

RESULTS

For all patients, Stage IVindolent patients had longer median overall survival than those with Stage IVaggressive (36.3 months vs. 16.0 months, P < 0.0001) and similarly for de novo MBC patients (41.4 months Stage IVindolent vs. 18.7 months Stage IVaggressive, p < 0.0001). Moreover, patients with Stage IVindolent disease had significantly longer overall survival across all disease subtypes compared to the aggressive cohort: hormone receptor-positive (44 months vs. 17.3 months, P < 0.0001), HER2-positive (36.7 months vs. 20.4 months, P < 0.0001), and triple negative (23.8 months vs. 9.0 months, P < 0.0001). Similar results were obtained regardless of prior treatment or disease location.

CONCLUSIONS

We confirm the identification of two subgroups of MBC, Stage IVindolent and Stage IVaggressive, independent of clinical and molecular variables. Thus, CTC count should be considered an important tool for staging of advanced disease and for disease stratification in prospective clinical trials.

Collapse of the Plasmacytoid Dendritic Cell Compartment in Advanced Cutaneous Melanomas by Components of the Tumor Cell Secretome

Melanoma is an immunogenic neoplasm infiltrated by T cells, although these adaptive T cells usually fail to eradicate the tumor. Plasmacytoid dendritic cells (PDCs) are potent regulators of the adaptive immune response and can eliminate melanoma cells via TLR-mediated effector functions. The PDC compartment is maintained by progressively restricted bone marrow progenitors. Terminally differentiated PDCs exit the bone marrow into the circulation, then home to lymph nodes and inflamed peripheral tissues. Infiltration by PDCs is documented in various cancers. However, their role within the melanoma immune contexture is not completely known. We found that in locoregional primary cutaneous melanoma (PCM), PDC infiltration was heterogeneous, occurred early, and was recurrently localized at the invasive margin, the site where PDCs interact with CD8+ T cells. A reduced PDC density was coupled with an increased Breslow thickness and somatic mutations at the NRAS p.Q61 codon. Compared with what was seen in PCM, high numbers of PDCs were found in regional lymph nodes, as also identified by in silico analysis. In contrast, in metastatic melanoma patients, PDCs were mostly absent in the tumor tissues and were significantly reduced in the circulation, particularly in the advanced M1c group. Exposure of circulating PDCs to melanoma cell supernatant (SN-mel) depleted of extracellular vesicles resulted in significant PDC death. SN-mel exposure also resulted in a defect of PDC differentiation from CD34+ progenitors. These findings indicate that soluble components released by melanoma cells support the collapse of the PDC compartment, with clinical implications for refining TLR agonist-based trials.

A standardized flow cytometry network study for the assessment of circulating endothelial cell physiological ranges

Circulating endothelial cells (CEC) represent a restricted peripheral blood (PB) cell subpopulation with high potential diagnostic value in many endothelium-involving diseases. However, whereas the interest in CEC studies has grown, the standardization level of their detection has not. Here, we undertook the task to align CEC phenotypes and counts, by standardizing a novel flow cytometry approach, within a network of six laboratories. CEC were identified as alive/nucleated/CD45negative/CD34bright/CD146positive events and enumerated in 269 healthy PB samples. Standardization was demonstrated by the achievement of low inter-laboratory Coefficients of Variation (CVL), calculated on the basis of Median Fluorescence Intensity values of the most stable antigens that allowed CEC identification and count (CVL of CD34bright on CEC ~ 30%; CVL of CD45 on Lymphocytes ~ 20%). By aggregating data acquired from all sites, CEC numbers in the healthy population were captured (medianfemale = 9.31 CEC/mL; medianmale = 11.55 CEC/mL). CEC count biological variability and method specificity were finally assessed. Results, obtained on a large population of donors, demonstrate that the established procedure might be adopted as standardized method for CEC analysis in clinical and in research settings, providing a CEC physiological baseline range, useful as starting point for their clinical monitoring in endothelial dysfunctions.

Circulating Tumor Cells as Predictors of Prognosis in Metastatic Breast Cancer: Clinical Application outside a Clinical Trial

Aims and Background

Circulating tumor cells have a prognostic role in metastatic breast cancer. The aim of the study was to confirm the ability of circulating tumor cells, detected by the US Food and Drug Administration approved Cell Search assay, to predict the outcome of patients treated in a community general hospital.

Patients and Methods.

A prospective mono-institutional study was conducted at the Department of Medical Oncology at Spedali Civili, Brescia, Italy, from January 2009 to September 2010. A total of 93 consecutive patients with metastatic breast cancer were enrolled. Patients underwent a blood sample collection to detect circulating tumor cells at baseline and, subsequently, at the first follow-up examination (after 3-4 weeks from the beginning of a systemic therapy). A third sample was drawn at disease progression (at the beginning of a subsequent new course of therapy). The prognostic cutoff value of circulating tumor cells was fixed at 5 cells/7.5 ml of blood.

Results

At baseline, median overall survival and progression-free survival in the subgroup ≥5 circulating tumor cells/7.5 ml of blood were significantly shorter (5 months and 3 months, respectively) than in the subgroup with <5 circulating tumor cells (8 months and 7 months, respectively) (P = 0.003 and P <0.001). At the first follow-up, the subgroup with more than 5 circulating tumor cells/7.5 ml of blood had a median overall survival of 4 months versus 8 months in the subgroup with <5 circulating tumor cells (P <0.001) and a median progression-free survival of 3 months versus 7 months respectively (P <0.001). At multivariate analysis, the level of circulating tumor cells at the first follow-up and at baseline remained significant as a predictor of progression-free and overall survival. The number of metastatic sites was significantly associated with overall and progression-free survival and correlated with the number of circulating tumor cells.

Conclusions

Our study confirms the role of circulating tumor cells as predictors of prognosis in metastatic breast cancer patients treated in general clinical practice.

Circulating endothelial cell count: a reliable marker of endothelial damage in patients undergoing hematopoietic stem cell transplantation

The physio-pathologic interrelationships between endothelium and GvHD have been better elucidated and have led to definition of the entity 'endothelial GvHD' as an essential early phase prior to the clinical presentation of acute GvHD. Using the CellSearch system, we analyzed circulating endothelial cells (CEC) in 90 allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients at the following time-points: T1 (pre-conditioning), T2 (pre-transplant), T3 (engraftment), T4 (onset of GvHD) and T5 (1 week after steroid treatment). Although CEC changes in allo-HSCT represent a dynamic phenomenon influenced by many variables (that is, conditioning, immunosuppressive treatments, engraftment syndrome and infections), we showed that CEC peaks were constantly seen at onset of acute GvHD and invariably returned to pre-transplant values after treatment response. Since we showed that CEC changes during allo-HSCT has rapid kinetics that may be easily missed if blood samples are drawn at pre-fixed time-points, we rather suggest an 'on demand' evaluation of CEC counts right at onset of GvHD clinical symptoms to possibly help differentiate GvHD from other non-endothelial complications. We confirm that CEC changes are a suitable biomarker to monitor endothelial damage in patients undergoing allo-transplantation and hold the potential to become a useful tool to support GvHD diagnosis (ClinicalTrials.gov NCT02064972).

Mesenchymal stromal cells (MSCs) induce ex vivo proliferation and erythroid commitment of cord blood haematopoietic stem cells (CB-CD34+ cells)

A human bone marrow-derived mesenchymal stromal cell (MSCs) and cord blood-derived CD34+ stem cell co-culture system was set up in order to evaluate the proliferative and differentiative effects induced by MSCs on CD34+ stem cells, and the reciprocal influences on gene expression profiles. After 10 days of co-culture, non-adherent (SN-fraction) and adherent (AD-fraction) CD34+ stem cells were collected and analysed separately. In the presence of MSCs, a significant increase in CD34+ cell number was observed (fold increase = 14.68), mostly in the SN-fraction (fold increase = 13.20). This was combined with a significant increase in CD34+ cell differentiation towards the BFU-E colonies and with a decrease in the CFU-GM. These observations were confirmed by microarray analysis. Through gene set enrichment analysis (GSEA), we noted a significant enrichment in genes involved in heme metabolism (e.g. LAMP2, CLCN3, BMP2K), mitotic spindle formation and proliferation (e.g. PALLD, SOS1, CCNA1) and TGF-beta signalling (e.g. ID1) and a down-modulation of genes participating in myeloid and lymphoid differentiation (e.g. PCGF2) in the co-cultured CD34+ stem cells. On the other hand, a significant enrichment in genes involved in oxygen-level response (e.g. TNFAIP3, SLC2A3, KLF6) and angiogenesis (e.g. VEGFA, IGF1, ID1) was found in the co-cultured MSCs. Taken together, our results suggest that MSCs can exert a priming effect on CD34+ stem cells, regulating their proliferation and erythroid differentiation. In turn, CD34+ stem cells seem to be able to polarise the BM-niche towards the vascular compartment by modulating molecular pathways related to hypoxia and angiogenesis.

Analysis of Circulating Tumor Cells in Prostate Cancer Patients at PSA Recurrence and Review of the Literature

BACKGROUND

Circulating tumor cells have been described in prostate cancer patients at diagnosis and in the metastatic phase but little is known on their role at biochemical PSA recurrence.

PATIENTS AND METHODS

Patients radically cured with either prostatectomy or radiotherapy were sequentially included at PSA recurrence. The presence of CTCs was evaluated by the CellSearch system.

RESULTS

Twenty-nine patients were accrued at PSA recurrence. Median PSA at recurrence was 7.2 ng/ml (range=3.86-51.0 ng/ml). The median time to PSA progression was 4.66 years (range=0.1-16 years). CTCs were detected in one patient (3%) with low numbers (1 CTC/7.5 ml).

CONCLUSION

In patients radically cured for prostate cancer at biochemical recurrence, CTCs are detected at very low levels in a minority of patients. Further studies are required to investigate alternative methods of CTC detection and the possible role of the bone marrow pre-metastatic niche at biochemical recurrence.

Abstract P2-08-08: Circulating tumor cells count-based nomograms to predict survival of metastatic breast cancer patients: Results from the European pooled analysis

Background: The European Pooled Analysis of CTC (EPAC) in metastatic breast cancer, based on 1,944 individual data from patients with various tumor types and clinical settings (Bidard et al, Lancet Oncol 2014), has established CTC count (CellSearch) at baseline and during therapy as a level of evidence 1 independent prognostic biomarker and demonstrated its superiority over serum blood markers. As part of the study pre-planned objectives, we sought to establish nomograms allowing accurate individual survival predictions.

Methods: Using individual data from 17 centers, we built simplified multivariate prognostic models taking into account the independent prognostic clinico-pathological (CP) characteristics including CTC count, dichotomized using the 5CTC/7.5ml threshold, at baseline and at 3-5 weeks after the start of a new treatment regimen, and derived nomograms for progression-free survival (PFS) and overall survival (OS) prediction at baseline and after 3-5 weeks of treatment. We report here the internal validation of these nomograms. Discrimination of the models was assessed using the c-index estimated by a jackknife procedure and the calibration was visually assessed through 10-fold crossvalidated calibration plots at 1,2,3 years for OS and 1,2 years for PFS.

Results: Multivariate models at baseline for PFS and OS were fitted on 1501 and 568 individual patient data with CTC count at baseline and CTC count at baseline and after 3-5 weeks, respectively. Models include tumor subtype, the number of previous chemotherapy lines (0/1/≥2), PS, age (&lt;=50/&gt;50-65/&gt;65 years), metastasis-free intervals (0/&gt;0-3/&gt;3 years), metastatic sites (liver and CNS) and CTC count at baseline and eventually at 3-5 weeks of treatment. The C-index increased from 0.722 to 0.755 (increase in C-index:0.033, 95% CI [0.019;0.045]) when adding baseline CTC to the CP only model for OS (n=1501). For those patients with CTC values at 3-5 weeks (n=568), there was an additional increase in the C-index when adding CTC at 3-5 weeks to a model with already CP and baseline CTC from 0.731 to 0.743 (increase in C-index 0.013, 95% CI [-0.004;0.025]). The model with CP and baseline CTC counts showed a good calibration for OS at 1,2,3 years and the model with CP, baseline CTC and CTC count at 3-5 weeks a moderately good calibration. Similar results were obtained for PFS.

Conclusion: From the largest database with individual CTC data, we were able to build PFS and OS survival nomograms, with satisfactory discrimination and calibration. Our planned next step is to validate the nomogram in an additional cohort.

Citation Format: Bidard F-C, Peeters D, Fehm T, Nole F, Gisbert-Criado R, Mavroudis D, Grisanti S, Generali D, Garcia-Saenz JA, Stebbing J, Caldas C, Gazzaniga P, Manso L, Zamarchi R, Fernandez de Lascoiti A, de Mattos-Arruda L, Ignatiadis M, van Laere SJ, Meier-Stiegen F, Sandri M-T, Vidal-Martinez J, Politaki E, Consoli F, Bottini A, Diaz-Rubio E, Krell J, Dawson S-J, Raimondi C, Rutten A, Janni W, Munzone E, Carañana V, Agelaki S, Almici C, Dirix L, Solomayer E, Zorzino L, Reis-Filho JS, Squifflet P, Pantel K, Beije N, Sleijfers S, Pierga J-Y, Michiels S. Circulating tumor cells count-based nomograms to predict survival of metastatic breast cancer patients: Results from the European pooled analysis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-08.

Circulating tumor cells in patients with recurrent or metastatic head and neck carcinoma: prognostic and predictive significance

Introduction

We investigated the frequency of detection and the prognostic and predictive significance of circulating tumor cells (CTCs) in patients with recurrent/metastatic (R/M) head and neck carcinoma (HNC) before starting systemic therapy.

Patients and methods

Using the CellSearch technology, CTCs were assessed prospectively in peripheral blood of 53 R/M-HNC patients. We performed spiking experiments to test the diagnostic performance of the CellSearch platform in identifying squamous carcinoma cells.

Results

CTCs were identified in 14 (26%) and 22 (41%) patients at baseline and at any time point, respectively. In univariate analysis ≥2 CTCs had a poorer prognostic role than 0–1 CTC. In multivariate analysis, the presence of one CTC or more was associated with a poor prognosis both in terms of progression-free survival (PFS) [Hazard Ratio (HR): 3.068, 95% confidence interval (CI): 1.53–6.13, p 0.002] and overall survival (OS) [HR: 3.0, 95% CI: 1.48–6.0, p 0.002]. A disease control after systemic therapy was obtained in 8% of CTC-positive patients as opposed to 45% in CTC-negative ones (p 0.03). The epidermal growth factor receptor (EGFR) expression was identified in 45% of CTC-positive patients.

Discussion

In conclusion, CTCs are detected in one out of three patients with RM-HNC. CTC detection is a strong prognostic parameter and may be predictive of treatment efficacy. The frequency of EGFR expression in CTCs seems to be lower than that expected in the primary tumor.

PBSC mobilization in lymphoma patients: analysis of risk factors for collection failure and development of a predictive score based on the kinetics of circulating CD34+ cells and WBC after chemotherapy and G-CSF mobilization

Autologous stem cell transplantation (ASCT) is a potentially curative treatment of lymphoma, but peripheral blood stem cell (PBSC) mobilization fails in some patients. PBSC mobilizing agents have recently been proved to improve the PBSC yield after a prior mobilization failure. Predictive parameters of mobilization failure allowing for a preemptive, more cost-effective use of such agents during the first mobilization attempt are still poorly defined, particularly during mobilization with chemotherapy + granulocyte colony-stimulating factor (G-CSF). We performed a retrospective analysis of a series of lymphoma patients who were candidates for ASCT, to identify factors influencing PBSC mobilization outcome. Premobilization parameters-age, histology, disease status, mobilizing protocol, and previous treatments-as well as white blood cell (WBC) and PBSC kinetics, markers potentially able to predict failure during the ongoing mobilization attempt, were analyzed in 415 consecutive mobilization procedures in 388 patients. We used chemotherapy + G-CSF in 411 (99%) of mobilization attempts and PBSC collection failed (<2 × 10(6) CD34+ PBSC/kg) in 13%. Multivariable analysis showed that only a low CD34+ PBSC count and CD34+ PBSC/WBC ratio, together with the use of nonplatinum-containing chemotherapy, independently predicted mobilization failure. Using these three parameters, we established a scoring system to predict risk of failure during mobilization ranging from 2 to 90%, thus allowing a selective use of a preemptive mobilization policy.

Clinical validity of circulating tumour cells in patients with metastatic breast cancer: a pooled analysis of individual patient data

BACKGROUND

We aimed to assess the clinical validity of circulating tumour cell (CTC) quantification for prognostication of patients with metastatic breast cancer by undertaking a pooled analysis of individual patient data.

METHODS

We contacted 51 European centres and asked them to provide reported and unreported anonymised data for individual patients with metastatic breast cancer who participated in studies between January, 2003, and July, 2012. Eligible studies had participants starting a new line of therapy, data for progression-free survival or overall survival, or both, and CTC quantification by the CellSearch method at baseline (before start of new treatment). We used Cox regression models, stratified by study, to establish the association between CTC count and progression-free survival and overall survival. We used the landmark method to assess the prognostic value of CTC and serum marker changes during treatment. We assessed the added value of CTCs or serum markers to prognostic clinicopathological models in a resampling procedure using likelihood ratio (LR) χ(2) statistics.

FINDINGS

17 centres provided data for 1944 eligible patients from 20 studies. 911 patients (46·9%) had a CTC count of 5 per 7·5 mL or higher at baseline, which was associated with decreased progression-free survival (hazard ratio [HR] 1·92, 95% CI 1·73-2·14, p<0·0001) and overall survival (HR 2·78, 95% CI 2·42-3·19, p<0·0001) compared with patients with a CTC count of less than 5 per 7·5 mL at baseline. Increased CTC counts 3-5 weeks after start of treatment, adjusted for CTC count at baseline, were associated with shortened progression-free survival (HR 1·85, 95% CI 1·48-2·32, p<0·0001) and overall survival (HR 2·26, 95% CI 1·68-3·03) as were increased CTC counts after 6-8 weeks (progression-free survival HR 2·20, 95% CI 1·66-2·90, p<0·0001; overall survival HR 2·91, 95% CI 2·01-4·23, p<0·0001). Survival prediction was significantly improved by addition of baseline CTC count to the clinicopathological models (progression-free survival LR 38·4, 95% CI 21·9-60·3, p<0·0001; overall survival LR 64·9, 95% CI 41·3-93·4, p<0·0001). This model was further improved by addition of CTC change at 3-5 weeks (progression-free survival LR 8·2, 95% CI 0·78-20·4, p=0·004; overall survival LR 11·5, 95% CI 2·6-25·1, p=0·0007) and at 6-8 weeks (progression-free survival LR 15·3, 95% CI 5·2-28·3; overall survival LR 14·6, 95% CI 4·0-30·6; both p<0·0001). Carcinoembryonic antigen and cancer antigen 15-3 concentrations at baseline and during therapy did not add significant information to the best baseline model.

INTERPRETATION

These data confirm the independent prognostic effect of CTC count on progression-free survival and overall survival. CTC count also improves the prognostication of metastatic breast cancer when added to full clinicopathological predictive models, whereas serum tumour markers do not.

FUNDING

Janssen Diagnostics, the Nuovo-Soldati foundation for cancer research.

Abstract PD6-5: Pooled analysis of circulating tumor cells in metastatic breast cancer: Findings from 1944 individual patients data

Background: Clinical validity of CTCs (CellSearch®) in metastatic breast cancer (MBC) patients has previously been assessed in studies with limited statistical power. We aimed to pool all European studies to obtain high-level evidence on the prognostic value of CTCs, to investigate their effects across different clinico-pathological characteristics and therapies and to further validate the MD Anderson/Institut Curie/Fox Chase CTC-based prognostic nomogram established in first-line treated MBC patients (Giordano et al, Clin Cancer Res 2013).

Material and methods: Methods were predefined in a written protocol. In December 2012, we searched for eligible studies that accrued patients in 2003-2012. We contacted all European laboratories using CellSearch®. We used likelihood ratio tests (LR) in Cox regression models stratified by study to assess the independent prognostic value of CTC when added to a clinicopathological (CP) model for progression-free (PFS) and overall survival (OS). Landmark analyses were used to assess the prognostic effect of early changes in CTC. The CTC-based nomogram (http://cancernomograms.com/CTCOnline.html) score was retrieved for every patient; we calculated C-indices, drew calibration plots and Kaplan-Meier curves according to quintiles of the nomogram score.

Results: We collected individual data of 1944 MBC patients, from 20 different studies (some unpublished), from 17 centers in 7 European countries. We observed 1507 PFS events and 929 deaths. Baseline CTC count was significantly associated with several patient characteristics, such as performance status (PS, p&lt;10-4), synchronous metastasis (p&lt;10- 2) tumor subtype (p&lt;10-4), liver & bone metastases (p&lt;10-4), CEA & CA15-3 levels (p&lt;10-4). The CP model for OS included PS, MBC subtypes, number of previous lines of treatment, patient's age, metastasis-free interval, metastatic sites (p&lt;0.01 for all). In a multivariate analysis containing the CP model parameters and CTC count at baseline, elevated CTC count (≥5) was a significant independent predictor of OS (n = 1444, HR = 2.7, 95%CI [2.2-3.2], LR p&lt;10-4). Baseline serum markers added either no or marginal effect to the CP plus baseline CTC model for OS. In contrast, early changes in CTC status at week 3-5 significantly added prognostic information for OS to the model with CP factors and baseline CTC+ (n = 569, HR = 1.8 [2.2-3.2], LR p&lt;0.001). In the population of interest (MBC treated by first line chemotherapy, n = 402 patients, 176 deaths), the CTC-based nomogram exhibited a good C-index for OS (0.69), was well calibrated and showed clear separation of the survival curves. Additional results, including subgroup analyses by tumor subtype and treatments will be presented at the meeting.

Conclusions: This pooled analysis is the largest study ever reported on CTC in MBC, with a previously unreached statistical power. It provides a clear level-of-evidence 1 on the independent prognostic value of CTCs before and during treatment in MBC. Also, the CTC-based prognostic nomogram is independently validated.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD6-5.

Stem cell mobilization in HIV seropositive patients with lymphoma

High-dose chemotherapy with autologous peripheral blood stem cell rescue has been reported as feasible and effective in HIV-associated lymphoma. Although a sufficient number of stem cells seems achievable in most patients, there are cases of stem cell harvest failure. The aim of this study was to describe the mobilization policies used in HIV-associated lymphoma, evaluate the failure rate and identify factors influencing mobilization results. We analyzed 155 patients who underwent attempted stem cell mobilization at 10 European centers from 2000-2012. One hundred and twenty patients had non-Hodgkin lymphoma and 35 Hodgkin lymphoma; 31% had complete remission, 57% chemosensitive disease, 10% refractory disease, 2% untested relapse. Patients were mobilized with chemotherapy + G-CSF (86%) or G-CSF alone (14%); 73% of patients collected >2 and 48% >5 × 10(6) CD34(+) cells/kg. Low CD4+ count and refractory disease were associated with mobilization failure. Low CD4(+) count, low platelet count and mobilization with G-CSF correlated with lower probability to achieve >5 × 10(6) CD34(+) cells/kg, whereas cyclophosphamide ≥ 3 g/m(2) + G-CSF predicted higher collections. Circulating CD34(+) cells and CD34/WBC ratio were strongly associated with collection result. HIV infection alone should not preclude an attempt to obtain stem cells in candidates for autologous transplant as the results are comparable to the HIV-negative population.

Circulating tumour cells in locally advanced head and neck cancer: preliminary report about their possible role in predicting response to non-surgical treatment and survival

BACKGROUND AND PURPOSE

The mechanism of dissemination of locally advanced head and neck cancer (LAHNC) is far to be resolved. Circulating tumour cells (CTC) have been identified as a prognostic factor in metastatic breast and prostate cancer. This prospective multi-centric analysis studied the possible role of CTC identification in LAHNC.

MATERIALS AND METHODS

CTC were searched in 73 patients with LAHNC (oropharynx, n=39; nasopharynx, n=10; larynx, n=10; paranasal sinuses, n=6, of whom 3 with sinonasal undifferentiated carcinoma, SNUC; hypopharynx, n=5; oral cavity, n=3). All of them (apart from SNUC) had squamous cell cancers. The relationship between CTC positivity and other clinical prognostic factors has been investigated. Response to treatment and survival has been related with changes in CTC number during the treatment.

RESULTS

CTC were frequently identified in oro- and hypopharyngeal cancer and in SNUC. They were more frequent in stage IV than in stages I-III disease (18% versus 6%, p=NS (not significant)). Partial or complete response (CR) was related with the absence or disappearance of CTC during treatment (p=0.017). A decrease in the CTC number or their absence throughout the treatment seems also related with non-progressive disease, after both complete or incomplete remission and with the proportion of patients alive and NED (no evidence of disease) (p=0.009).

CONCLUSIONS

These preliminary data suggest a possible role of CTC determination in head and neck cancer. Additional and longer follow up data need to be collected to confirm these findings.

Circulating tumor cells as predictors of prognosis in metastatic breast cancer: clinical application outside a clinical trial

AIMS AND BACKGROUND

Circulating tumor cells have a prognostic role in metastatic breast cancer. The aim of the study was to confirm the ability of circulating tumor cells, detected by the US Food and Drug Administration approved Cell Search assay, to predict the outcome of patients treated in a community general hospital.

PATIENTS AND METHODS

A prospective mono-institutional study was conducted at the Department of Medical Oncology at Spedali Civili, Brescia, Italy, from January 2009 to September 2010. A total of 93 consecutive patients with metastatic breast cancer were enrolled. Patients underwent a blood sample collection to detect circulating tumor cells at baseline and, subsequently, at the first follow-up examination (after 3-4 weeks from the beginning of a systemic therapy). A third sample was drawn at disease progression (at the beginning of a subsequent new course of therapy). The prognostic cutoff value of circulating tumor cells was fixed at 5 cells/7.5 ml of blood.

RESULTS

At baseline, median overall survival and progression-free survival in the subgroup ≥5 circulating tumor cells/7.5 ml of blood were significantly shorter (5 months and 3 months, respectively) than in the subgroup with <5 circulating tumor cells (8 months and 7 months, respectively) (P = 0.003 and P <0.001). At the first follow-up, the subgroup with more than 5 circulating tumor cells/7.5 ml of blood had a median overall survival of 4 months versus 8 months in the subgroup with <5 circulating tumor cells (P <0.001) and a median progression-free survival of 3 months versus 7 months respectively (P <0.001). At multivariate analysis, the level of circulating tumor cells at the first follow-up and at baseline remained significant as a predictor of progression-free and overall survival. The number of metastatic sites was significantly associated with overall and progression-free survival and correlated with the number of circulating tumor cells.

CONCLUSIONS

Our study confirms the role of circulating tumor cells as predictors of prognosis in metastatic breast cancer patients treated in general clinical practice.

P4-07-19: Bone Marrow Involvement Is Associated with High Numbers of Circulating Tumor Cells in Peripheral Blood of Metastatic Breast Cancer Patients

Introduction: Circulating Tumor Cells (CTCs) levels are dynamic indicators of prognosis and response to therapy in metastatic breast cancer (MBC) patients (pts). CTCs levels have been reported to be higher in pts with bone than visceral metastases, respectively. However, little is known about CTCs levels in pts with BM involvement. We analysed CTC patterns in patients with either visceral, bone or BM to test the hypothesis that BM involvement would facilitate tumor cells to enter the systemic circulation as CTCs. Patients and methods: Sites and extension of metastatic disease were identified with conventional imaging. Bone metastases were diagnosed with either bone scintigraphy or CT-PET and the BM involvement was documented histologically by BM biopsy and metabolically by CT-PET. A training set of 10 pts was evaluated by both BM biopsy and CT-PET to verify the diagnostic performance of CT-PET in identifying BM metastases (M+). We found a 100% concordance between BM biopsy and CT-PET and we therefore used CT-PET for further analyses. The CellSearch System (Veridex LLC, Raritan, NJ, USA) was used for the isolation and enumeration of CTCs in peripheral blood. The Student's t-test and the two-way ANOVA test were used to compare means of CTCs among patients with different metastatic patterns.

Results: The CTCs mean and median scores of 129 MBC pts were analysed. Final analysis focused on 101 pts with bone M+. Thirty-three pts had bone M+ alone and 68 pts had bone and visceral M+ (including lymphnodes, brain, liver and lung/pleura). Number of metastatic sites was 1, 2, 3, 4, 5 in 30%, 37%, 25%, 6% and 2% of pts, respectively. BM involvement was documented in 27 (27%) of pts in the whole series and in 12 (33%) of pts with bone M+ alone. Mean CTCs score in the whole series was 392 (0-9993) and the median number of CTCs was 20. In the whole series, BM involvement was associated with higher mean CTCs scores (1350 vs 42, p .014). In pts with bone M+ alone, mean CTCs score was 696 (0-7000) and pts with BM involvement had higher mean CTCs scores (1846 vs 39, p 0.37). Among the different metastatic patterns, the association of bone with BM involvement and liver M+ was correlated with the highest CTCs numbers. We could not perform comparisons in the 68 pts with both bone and visceral localizations because of the variety of metastatic patterns. However, the two-way ANOVA showed a significant influence of BM involvement on mean CTCs scores in pts with different metastatic patterns (p &gt;.001).

Conclusions: This work confirms that pts with bone metastases have higher numbers of CTCs than pts with visceral metastases. Extensive bone disease with BM involvement is characterized by an increase in CTCs numbers compared to bone disease without BM involvement. Bone marrow metastases are metabolically more active by CT-PET and can be accurately detected by metabolic imaging without need of BM biopsy. Further studies are ongoing.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-19.

Association between single nucleotide polymorphisms in the XRCC1 and RAD51 genes and clinical radiosensitivity in head and neck cancer

PURPOSE

Individual variability in radiosensitivity is large in cancer patients. Single nucleotide polymorphisms (SNPs) in genes involved in DNA repair and in protection against reactive oxygen species (ROS) could be responsible for such cases of radiosensitivity. We investigated the association between the occurrence of acute reactions in 101 patients with squamous cell carcinoma of the head and neck (SCCHN) after radiotherapy (RT) and five genetic polymorphisms: XRCC1 c.1196A>G, XRCC3 c.722C>T, RAD51 (c.-3429G>C, c.-3392G>T), and GSTP1 c.313A>G.

MATERIALS AND METHODS

Genetic polymorphisms were detected by high resolution melting analysis (HRMA). The development of acute reactions (oral mucositis, skin erythema and dysphagia) associated with genetic polymorphisms was modeled using Cox proportional hazards, accounting for biologically effective dose (BED).

RESULTS

Development of grade ≥2 mucositis was increased in all patients (chemo-radiotherapy and radiotherapy alone) with XRCC1-399Gln allele (HR=1.72). The likelihood of developing grade ≥2 dysphagia was higher in carriers of RAD51 c.-3429 CC/GC genotypes (HR=4.00). The presence of at least one SNP or the co-presence of both SNPs in XRCC1 p.Gln399Arg /RAD51 c.-3429 G>C status were associated to higher likelihood of occurrence of acute toxicities (HR=2.03).

CONCLUSIONS

Our findings showed an association between genetic polymorphisms, XRCC1 c.1196A>G and RAD51 c.-3429 G>C, and the development of radiation-induced toxicities in SCCHN patients.

Circulating tumor cells and cardiac metastasis from esophageal cancer: a case report

We report the case of a 67-year-old man affected by metastatic esophageal cancer. The patient developed a symptomatic heart metastasis presenting as mimicking ST-segment elevation myocardial infarction. Cardiac magnetic resonance imaging (MRI) documented the presence of a mass in the apex and septum of the left ventriculum. The dissemination of cancer was confirmed by the detection of circulating tumor cells (CTCs) in the peripheral blood, measured by the CellSearch System (Veridex, LLC, Raritan, N.J., USA). The blood sample drawn at cardiac disease progression revealed the presence of 2 CTCs per 7.5 ml of blood. This report highlights the potential role of CTCs as markers of metastatic spread.

Uncontrolled-rate freezing of peripheral blood progenitor cells allows successful engraftment by sparing primitive and committed hematopoietic progenitors

BACKGROUND AND OBJECTIVES

Uncontrolled-rate freezing (URF) techniques, which are fast and easy, could represent an attractive alternative to controlled-rate cryopreservation procedures which are time consuming and require high-level technical abilities. It was the aim of the present study to evaluate, on a routine basis, whether URF might spare primitive hematopoietic progenitors and maintain engrafting capacity.

DESIGN AND METHODS

One-hundred and nineteen peripheral blood progenitor cells (PBPC) collections from 104 patients with hematologic malignancies were cryopreserved in bags, with an URF procedure, in a cryoprotectant solution consisting of PBS, HSA and 10% DMSO and stored in liquid nitrogen. PBPC bags were tested before cryopreservation and at thawing for primitive (LTC-IC) and committed hematopoietic progenitors (CFU-Mix, BFU-E, CFU-GM) by means of long- and short-term culture assays, respectively. In addition, PBPC bags were evaluated for CD34+ cell numbers.

RESULTS

Although thawing was associated with a statistically significant reduction of the absolute number of nucleated cells, recovery of LTC-IC, CFU-Mix, BFU-E, CFU-GM and CD34+ cells was not affected by the freezing/thawing procedures. No adverse effects were reported at thawing and only mild transient reactions were recorded in 22 patients during reinfusion of cryopreserved PBPC. All the patients underwent myeloablative therapy followed by reinfusion of PBPC, and prompt and rapid hematopoietic recovery was obtained in all patients.

INTERPRETATION AND CONCLUSIONS

Our freezing procedure is fast and easy, and allows rapid hematopoietic recovery after myeloablative therapy by sparing primitive and committed hematopoietic progenitors. Our study strongly supports technical improvements aimed at cost reduction and feasibility of routine freezing procedures.

Proangiogenic properties of human myeloma cells: production of angiopoietin-1 and its potential relationship to myeloma-induced angiogenesis

Patients with multiple myeloma (MM) have increased bone marrow (BM) angiogenesis; however, the proangiogenic properties of myeloma cells and the mechanisms of MM-induced angiogenesis are not completely clarified. The angiopoietin system has been identified as critical in the regulation of vessel formation. In this study we have demonstrated that myeloma cells express several proangiogenic factors, and, in particular, we found that angiopoietin-1 (Ang-1), but not its antagonist Ang-2, was expressed by several human myeloma cell lines (HMCLs) at the mRNA and the protein levels. In a transwell coculture system, we observed that myeloma cells up-regulated the Ang-1 receptor Tie2 in human BM endothelial cells. Moreover, in an experimental model of angiogenesis, the conditioned medium of HMCLs significantly stimulated vessel formation compared with control or vascular endothelial growth factor (VEGF) treatment. The presence of anti-Tie2 blocking antibody completely blunted the proangiogenic effect of XG-6. Finally, our in vitro results were supported by the in vivo finding of Ang-1, but not Ang-2, mRNA and protein expression in purified MM cells obtained from approximately 47% of patients and by high BM angiogenesis in patients with MM positive for Ang-1, suggesting that the angiopoietin system could be involved, at least in part, in MM-induced angiogenesis.

Acute leukemia following a previous malignancy: do acute lymphoid leukemia and acute myeloid leukemia have common risk factors?

INTRODUCTION

Within the framework of the GIMEMA Study Group, the characteristics of acute lymphoid leukemia and acute myeloid leukemia occurring in patients who have suffered a previous malignancy were studied. Assessment was also made of the clinical course, laboratory features and overall outcome of these conditions.

MATERIALS AND METHODS

A four-year, multi-center retrospective study was conducted to evaluate the effect of treatment for previous hematological malignancy on the development of secondary leukemia. The study collected in the GIMEMA Archive of Adult Acute Leukemia 3934 new cases of acute leukemia (2964 AML, 901 ALL, 60 acute biphenotypic leukemia). Among these cases, data were evaluated from patients with a personal history of a previous malignancy, and included inquiring into demographic data, history of neoplastic diseases in the 1st degree relatives, type and treatment of the previous malignancy, latency until the development of a secondary acute leukemia diagnosis, laboratory features, treatment and outcome at the onset of secondary acute leukemia.

RESULTS

Approximately 200 (5.1%) patients presented a previous malignancy. Twenty-one were affected by ALL and 179 by AML. The proportion of patients with secondary AML was higher than that of patients with secondary ALL (179/2964 vs 21/901, O.R. 2.69-95% C.I. 1.66-4.39, P<0.001). The median latency, from the onset of the previous malignancy to the development of secondary ALL was 27 months and to the development of secondary AML was 52 months (P<0.05). Furthermore, of patients who previously received chemotherapy more developed a second AML (66/127 sAML vs 5/21 sALL; O.R. 3.46-95% C.I. 1.10-11.56, P<0.01).

CONCLUSION

In most cases, chemotherapy treatment for a previous malignancy can play a role in the development of secondary AML. In almost all cases of secondary ALL, the role of previous drugs does not appear to be relevant. On the basis of our analysis, performed systematically for the first time on a large adult series of acute leukemia, we conclude that in these patients a biological predisposition to cancer may be suspected.

Acute myeloid leukemia in patients previously diagnosed with breast cancer: experience of the GIMEMA group

OBJECTIVE

To evaluate in a multicenter retrospective study, the clinical and laboratory characteristics and the outcome of patients with acute myeloid leukemia (sAML) previously diagnosed with breast cancer (BC) among an adult acute leukemia population.

PATIENTS AND METHODS

Between June 1992 and July 1996, 3934 new cases of adults with acute leukemia were recorded in GIMEMA Archive of Adult Acute Leukemia (2964 AML, 901 ALL, 69 acute leukemia expressing both myeloid and lymphoid surface markers).

RESULTS

Two hundred patients (5.1%) presented with a history of previous malignancy (21 of them were affected by ALL and 179 by AML). Among sAML, 37 patients (29%) had a previous breast cancer. They consisted of 36 females and 1 male, median age 56 years, range 34-87. The median latency between the 2 malignancies was 54 months (range 5-379). Twenty-seven patients received chemo- and/or radiotherapy for breast cancer (7 only chemotherapy, 6 only radiotherapy, and 14 combined treatment). All patients were surgically treated but in 10 patients surgical debridement was the sole therapy for breast cancer. The drugs most frequently employed were alkylating agents (18 patients), topoisomerase II inhibitors (9 patients), antimetabolites (20 patients) (CMF, CEF and MMM combinations). At onset of sAML the median WBC count was 7.7 x 10(9)/l (0.8-153) and the median platelet count was 33.5 x 10(9)/l (3-305). Considering morphological features, FAB subtypes were 4 M0, 5 M1, 11 M2, 5 M3, 8 M4, 3 M5, and 1 M6. Cytogenetic study was performed on 28 patients and 12 of them presented abnormalities. It is noteworthy that chromosome 5 or 7 abnormalities (typically observed in those patients treated with alkylating agents) were present only in three cases. Thirty-four patients received chemotherapy for sAML, and twenty-five of them achieved a CR (74%), with a median duration of twenty-eight weeks (5-280+). The overall survival was 8 months (1-80+).

DISCUSSION

The high number of sAML we observed in patients with a previous breast cancer, may be due to the fact that this malignancy is the most frequent neoplasm in women and by the high probability of cure with a consequent long disease-free survival. Our results suggest that the risk of sAML after recovery from breast cancer is increasing due to the rise in the number of patients cured from breast cancer, and in the future could be a relevant problem for haematologists.

High-dose therapy in acute leukemia

The use of intensive induction chemotherapy, primarily with combinations of an anthracycline and cytarabine, allows complete remission rates of greater than 70% in patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). However, with currently available standard-dose therapy, only 20% of young adults are cured. In order to substantially increase the cure rate, adequate post-remission therapeutic strategies are mandatory. Three different therapeutic options are currently available: (i) dose-intensified chemotherapy; (ii) allogeneic stem cell transplantation; (iii) autologous stem cell transplantation. These therapeutic options should be carefully evaluated according to prognostic information, including cytogenetic and molecular abnormalities as well as phenotypic characterization. Randomized trials of intensive postremission therapy have now confirmed improved leukemia-free survival with the use of allogeneic or autologous transplantation. Autologous transplantation appears to be the most promising treatment modality in AML. Improved preparative regimens and purging techniques may be critical factors in determining the effectiveness of autologous transplantation in AML patients. In adult ALL, the role and optimal methods of stem cell transplantation are still under investigation.

Biologic and phenotypic analysis of early hematopoietic progenitor cells in umbilical cord blood

Umbilical cord blood (UCB) is an attractive potential alternative to bone marrow (BM) as a source of hematopoietic progenitor cells since the number of progenitors in UCB is similar or even greater than that in normal BM. It was the aim of the present study to analyze the degree of immaturity of UCB progenitor cells. UCB mononuclear (MNC) and/or CD34+ cells were tested for surface antigen phenotype, expression of cytokines receptor, effect of stem cell factor (SCF) on colony growth, resistance to mafosfamide and replating potential. We have found that 34.9 +/- 3.4% and 77.9 +/- 2.6% of UCB CD34+ cells did not express CD38 and CD45RA antigens, respectively, suggesting that UCB contains a high proportion of immature progenitor cells. By means of three-color analysis, the receptor for SCF was detected on the majority of the CD34+ HLA-DR+ subpopulation; in fact, 81.8% +/- 4.3% of CD34+ HLA-DR+ cells were defined as SCF(low) and 8.1 +/- 1.5% as SCF(high). Colony growth of MNC and CD34+ cells was enhanced by the addition of SCF to methylcellulose mixture, resulting in a statistically significant increase in CFU-GM and CFU-GEMM but not in BFU-E numbers. UCB progenitor cells showed a higher resistance to mafosfamide treatment, in comparison to BM; the addition of SCF to the culture medium resulted in a statistically significant increase in mafosfamide concentration required to inhibit 95% of colony growth (P < or = 0.05). Moreover, as shown by single colony transfer assays, the presence of SCF in primary cultures promoted a significantly higher replating potential for both untreated (42 +/- 3.3% vs 21 +/- 4.6%, P < or = 0.018) and mafosfamide-treated samples (62 +/- 5.6% vs 44 +/- 6.1%, P < or = 0.018). In conclusion, UCB is a source of progenitor cells with immature characteristics in terms of surface antigen expression, distribution of SCF receptor, resistance to mafosfamide and replating potential. Therefore, UCB progenitor cells represent an ideal candidate population for experimental programs involving gene transfer and ex vivo stem cell expansion.

Clonogenic capacity and ex vivo expansion potential of umbilical cord blood progenitor cells are not impaired by cryopreservation

Umbilical cord blood (UCB) progenitor cells have been demonstrated to possess significant advantages over bone marrow (BM), in terms of proliferative capacity and immunologic reactivity. Therefore, UCB has been recently considered an attractive potential alternative to BM as a source of hematopoietic progenitor cells for clinical applications. Since several programs throughout the world are currently evaluating the feasibility of large-scale UCB banking for unrelated transplants, it was the aim of this study to evaluate whether cryopreservation procedures might heavily impair the clonogenic capacity, the feasibility of CD34+ selection and the ex vivo expansion potential of UCB progenitor cells. UCB samples were collected and cryopreserved as unseparated (n = 21) or mononuclear (MNC) cells (n = 15) within 12 h from delivery, and evaluated for viability, immunophenotype, cell and progenitor numbers after a minimum stay in liquid nitrogen of 6 months (range 6-14 months). Viability was always > 97% and no statistically significant difference was detected by flow cytometric analysis. Clonogenic recovery from unseparated cells was 80-87% for HPP-CFC, CFU-GEMM, BFU-E and CFU-GM, and from MNC cells ranged from 82 to 91% for LTC-IC, CFU-GEMM, BFU-E and CFU-GM. CD34+ selection (n = 8) was performed on fresh and cryopreserved MNC cells using the MiniMACS immunomagnetic separation device, showing no difference in yield (68 +/- 7% vs 57 +/- 4%, P < or = 0.4) or in purity (89 +/- 2% vs 81 +/- 6%, < or = 0.4), for fresh in comparison to cryopreserved MNC cells. After 14 days of liquid culture in the presence of different combinations of SCF, IL-3, IL-6 and G-CSF no statistically significant difference was detected in CFC fold-expansion for fresh or cryopreserved MNC cells and for CD34+ cells, either selected and cultured from fresh or cryopreserved MNC cells. In conclusion we can state that UCB is a potential source of primitive progenitor cells that can be cryopreserved unmanipulated or after physical separation without major losses in clonogenic capacity and immunophenotypic composition. Moreover, CD34+ selection from cryopreserved MNC cells is feasible and ex vivo expansion is not impaired. These results have important implications in the large scale UCB banking, in view of the potential applications of ex vivo expanded hematopoietic progenitor cells for the engraftment of adult patients.

In vitro growth of mobilized peripheral blood progenitor cells is significantly enhanced by stem cell factor

The existence of primitive hematopoietic progenitors in mobilized peripheral blood is suggested by clinical, phenotypic and in vitro cell culture evidences. In order to quantify primitive progenitors, 32 leukaphereses from 15 patients with lymphoid malignancies were investigated for the growth of multilineage colony-forming units (CFU-Mix), erythroid burst-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM) in the absence or presence of recombinant stem cell factor (SCF), a cytokine which selectively controls stem cell self-renewal, proliferation and differentiation. Primitive progenitors were also quantitated by means of a long-term assay which allows the growth of cells capable of initiating and sustaining hematopoiesis in long-term culture (LTC-IC). Addition of SCF (50 ng/ml) to methyl-cellulose cultures stimulated with maximal concentrations of G-CSF, GM-CSF, interleukin 3 and erythropoietin significantly increased the growth (mean +/- SE) of CFU-Mix (7.7 +/- 1.7 versus 2.4 +/- 0.6, p < or = 0.0001), BFU-E (47 +/- 10 versus 32 +/- 6, p < or = 0.002) and CFU-GM (173 +/- 31 versus 112 +/- 20, p < or = 0.0001). Mean (+/- SE) percentages of SCF-dependent CFU-Mix, BFU-E and CFU-GM were 60 +/- 5%, 19 +/- 5%, and 33 +/- 4%, respectively. Mean (+/- SE) LTC-IC growth per 2 x 10(6) nucleated cells was 221 +/- 53 (range, 2 to 704). Linear regression analysis demonstrated a statistically significant correlation (r = .87; p < or = 0.0001) between LTC-IC and SCF-dependent progenitors. In conclusion, our data suggest that: A) the optimal quantification of mobilized progenitors requires supplementation of methylcellulose cultures with SCF, and B) in vitro detection of SCF-dependent progenitors might represent a reliable and technically simple method to assess the primitive progenitor cell content of blood cell autografts. Such in vitro evaluation of immature hematopoietic progenitors might be clinically relevant for predicting the reconstituting potential of autografts.

Selection of myeloid progenitors lacking BCR/ABL mRNA in chronic myelogenous leukemia patients after in vitro treatment with the tyrosine kinase inhibitor genistein

Chronic myelogenous leukemia (CML) is a clonal disorder of the hematopoietic stem cell characterized by a chimeric BCR/ABL gene giving rise to a 210-kD fusion protein with dysregulated tyrosine kinase activity. We investigated the effect of genistein, a protein tyrosine kinase inhibitor, on the in vitro growth of CML and normal marrow-derived multi-potent (colony-forming unit-mix [CFU-Mix]), erythroid (burst-forming unit-erythroid [BFU-E]), and granulocyte-macrophage (colony-forming unit-granulocyte-macrophage [CFU-GM]) hematopoietic progenitors. Continuous exposure of CML and normal marrow to genistein induced a statistically significant and dose-dependent suppression of colony formation. Genistein doses causing 50% inhibition of CML and normal progenitors were not significantly different for CFU-Mix (27 mumol/L v 23 mumol/L), BFU-E (31 mumol/L v 29 mumol/L), and CFU-GM (40 mumol/L v 32 mumol/L v 32 mumol/L). Preincubation of CML and normal marrow with genistein (200 mumol/ L for 1 to 18 hours) induced a time-dependent suppression of progenitor cell growth, while sparing a substantial proportion of long-term culture-initiating cells (LTC-IC) from CML (range, 91% +/- 9% to 32% +/- 3%) and normal marrow (range, 85% +/- 8% to 38% +/- 9%). Analysis of individual CML colonies for the presence of the hybrid BCR/ABL mRNA by reverse transcription-polymerase chain reaction (RT-PCR) showed that genistein treatment significantly reduced the mean +/- SD percentage of marrow BCR/ABL+ progenitors both by continuous exposure (76% +/- 18% v 24% +/- 12%, P < or = .004) or preincubation (75% +/- 16% v 21% +/- 10%, P < or = .002) experiments. Preincubation with genistein reduced the percentage of leukemic LTC-IC from 87% +/- 12% to 37% +/- 12% (P < or = .003). Analysis of individual colonies by cytogenetics and RT-PCR confirmed that genistein-induced increase in the percentage of nonleukemic progenitors was not due to suppression of BCR/ABL transcription. Analysis of nuclear DNA fragmentation by DNA gel electrophoresis and terminal deoxynucleotidyl transferase assay showed that preincubation of CML mononuclear and CD34+ cells with genistein induced significant evidence of apoptosis. These observations show that genistein is capable of (1) exerting a strong antiproliferative effect on CFU-Mix, BFU-E, and CFU-GM while sparing the more primitive LTC-IC and (2) selecting benign hematopoietic progenitors from CML marrow, probably through an apoptotic mechanism.

Effect of the protein tyrosine kinase inhibitor genistein on normal and leukaemic haemopoietic progenitor cells

Receptor and nonreceptor protein tyrosine kinases (PTKs) play a key role in the control of normal and neoplastic cell growth. The availability of PTK inhibitors prompted us to evaluate the effects of genistein, a natural inhibitor of PTKs, on in vitro colony formation by normal multilineage colony-forming units (CFU-Mix), erythroid bursts (BFU-E), granulocyte-macrophage colony-forming units (CFU-GM), long-term culture-initiating cells (LTC-IC) and acute myelogenous leukaemia colony-forming units (CFU-AML). Continuous exposure of normal marrow and blood mononuclear non-adherent cells, blood CD34+CD45RA- cells, and leukaemic blasts to increasing doses of genistein (1-100 microM) resulted in a statistically significant (P < or = 0.05) dose-dependent suppression of CFU-Mix, BFU-E, CFU-GM and CFU-AML growth. Regression analysis showed that growth inhibition was linearly related to genistein concentration. Genistein dose causing 50% inhibition (ID50) of CFU-AML was significantly lower compared to CFU-GM ID50 for marrow (19 v 32 microM, P < or = 0.017), unseparated blood (19 v 44 microM, P < or = 0.028) or CD34+CD45RA- blood (19 v 36, P < or = 0.04). Preincubation of leukaemic blasts with genistein (200 microM) for 1-2h confirmed that CFU-AML were significantly more sensitive than normal marrow and blood CFU-GM to genistein. Preincubation conditions which maximally suppressed leukaemic and normal colony growth spared a substantial percentage of marrow (29 +/- 4%) and blood (40 +/- 3%) LTC-IC. In conclusion, our data demonstrate that: (a) genistein strongly inhibits the growth of normal and leukaemic haemopoietic progenitors; (b) growth inhibition is dose- and time-dependent; (c) leukaemic progenitors are more sensitive than normal progenitors to genistein-induced growth inhibition; (d) genistein exerts a direct toxic effect on haemopoietic cells while sparing a substantial proportion of LTC-IC. The potent CFU-AML growth inhibition associated with the relative resistance of normal LTC-IC strongly supports the use of genistein for marrow purging.

BCL2 oncogene protein expression in human hematopoietic precursors during fetal life

BCL2 proto-oncogene encodes a 25-kD protein that is characteristically localized in the inner mitochondrial membrane of the cell. It has been reported that BCL2 protein has the unique functional role of blocking programmed cells death without affecting proliferation. We have analyzed the expression of the BCL2 protein in fetal hematopoietic tissues from the 10th week of gestational age onward. Fetal thymus, liver, and bone marrow and cord blood were investigated. The experiments were performed by the alkaline-antialkaline phosphatase (APAAP) technique by staining air-dried acetone-fixed cytospins and by dual-color immunofluorescent assay by staining mononuclear cell suspensions with monoclonal antibodies detecting BCL2 protein and antigens expressed by different hematopoietic subsets. Flow cytometric analyses were performed on FACSort's Comsort 32 (Becton Dickinson, San Jose, CA). The results have shown that the BCL2 protein is expressed in human fetal ontogenesis at the earliest stages examined. The major conceptual aspects of the results are 1) BCL2 is largely expressed in the hematopoietic cells during ontogenesis. BCL2+ cells include both immature and more differentiated subsets. Moreover, the 25-kD protein is expression in cell subsets well known to be high proliferating. This behavior suggests that BCL2 could have more complex functions than those previously described. 2) The expression in the major part of CD34+ cells suggests that BCL2 could play a role in stem cell survival. 3) BCL2 is expressed in not only medullary but also cortical thymocytes, where it could cooperate in positive selection processes. 4) The involvement of BCL2 in the immunosurveillance is indicated not only by its role in B and T cell lineages but also by its expression in particular subsets like that of the cytoplasmic CD3+ fetal liver NK cells. 5) The discrepancy observed between the results of transgenic mice analysis and in vitro inhibition experiments by antisense oligonucleotides performed for understanding BCL2 functions must stress the importance of the direct immunologic analysis of BCL2 in human hematopoietic cells.

Density separation and cryopreservation of umbilical cord blood cells: evaluation of recovery in short-and long-term cultures

The clonogenic capacity of human umbilical cord blood (UCB) has been evaluated in several studies, which have shown high numbers of primitive hematopoietic progenitor cells. Recently, UCB progenitor cells were demonstrated to possess significant advantages over bone marrow (BM) in terms of proliferative capacity and immunologic reactivity. Therefore, UCB has been considered an attractive source of hematopoietic stem cells for both research and clinical applications. Previous reports have documented a significant loss of progenitor cells by any manipulation other than cryopreservation. We have evaluated the feasibility of fractionating and cryopreserving UCB samples with minimal loss of progenitor cells. We compared separation over three different densities of Percoll (1.069, 1.077 and 1.084 g/ml), sedimentation over poligeline (Emagel), and sedimentation over poligeline followed by separation over Ficoll/Hypaque (F/H). Separated samples (n = 25) were analyzed for recovery of CD34+ cells and progenitor cells (CFU-GEMM, BFU-E, CFU-GM). Separation by sedimentation over poligeline followed by F/H allowed the highest depletion of RBCs (hematocrit of the final cellular suspension 0.4 +/- 0.1%), while maintaining a high recovery of CD34+ cells (85.3%) and total recovery of CFU-GEMM, BFU-E and CFU-GM. After cryopreservation, recovery of clonogenic progenitors was 82% for CFU-GEMM, 94% for BFU-E, 82% for CFU-GM and 90% for colony-forming units after 5 weeks of longterm culture. Moreover, the presence of Stem cell factor significantly increased CFU-GEMM (14 +/- 4 vs. 49 +/- 5, p < or = 0.0005) and CFU-GM (112 +/- 18 vs. 178 +/- 19, p < or = 0.025), but not B FU-E (42 +/- 7 vs. 53 +/- 7, p < or = 0.375) growth. In conclusion, RBC depletion of UCB can be accomplished with minimal loss of committed and primitive hematopoietic progenitors. This procedure may have important implications in the large-scale banking of UCB and in ex vivo expansion/gene therapy protocols.

Density separation of umbilical cord blood and recovery of hemopoietic progenitor cells: implications for cord blood banking

Umbilical cord blood (CB) has been evaluated as a potential source of hematopoietic stem cells suitable for clinical use in the transplantation setting. Previous reports have documented a significant loss of progenitor cells by any manipulation other than cryopreservation. We have evaluated the feasibility of fractionating and cryopreserving CB samples with minimal loss of progenitor cells. We have compared various separation procedures based on different density gradients in the attempt to obtain the highest depletion of red blood cells (RBC) while maintaining the highest recovery of progenitor cells. We compared three different densities of Percoll (1.069 g/ml, 1.077 g/ml, 1.084 g/ml), sedimentation over poligeline (Emagel ) and sedimentation over poligeline followed by separation over Ficoll/Hypaque (F/H). Separated samples (n = 25) were analyzed for recovery of CD34+ cells and progenitor cells (CFU-GEMM, BFU-E, CFU-GM). Separation by sedimentation over poligeline followed by F/H allowed the highest depletion of RBC (hematocrit of the final cellular suspension 0.4 +/- 0.1%) while maintaining high recovery of CD34+ cells (85.3 +/- 5.6%) and total recovery for CFU-GEMM, BFU-E and CFU-GM. After cryopreservation, recovery of clonogenic progenitors was 82% for CFU-GEMM, 94% for BFU-E, 82% for CFU-GM and 90% for colony-forming units (CFUs) after five weeks of long-term culture (LTC). We further evaluated the effect of stem cell factor (SCF) on the in vitro growth of hemopoietic progenitors and on replating efficiency.(ABSTRACT TRUNCATED AT 250 WORDS)