Low-intensity conditioning and hematopoietic stem cell transplantation in patients with renal and colon carcinoma

Graft-Versus-Solid-Tumor Effect: From Hematopoietic Stem Cell Transplantation to Adoptive Cell Therapies

After allogeneic hematopoietic stem cell transplantation (HSCT), donor lymphocytes may contribute to the regression of hematological malignancies and select solid tumors, a phenomenon referred to as the graft-versus-tumor effect (GVT). However, this immunologic reaction is frequently limited by either poor specificity resulting in graft-versus-host disease or the frequency of tumor-specific T cells being too low to induce a complete and sustained anti-tumor response. Over the past 2 decades, it has become clear that the driver of GVT following allogeneic HSCT is T-cell-mediated recognition of antigens presented on tumor cells. With that regard, even though the excitement for using HSCT in solid tumors has declined, clinical trials of HSCT in solid tumors provided proof of concept and valuable insights leading to the discovery of tumor antigens and the development of targeted adoptive cell therapies for cancer. In this article, we review the results of clinical trials of allogeneic HSCT in solid tumors. We focus on lessons learned from correlative studies of these trials that hold the potential for the creation of tumor-specific immunotherapies with greater efficacy and safety for the treatment of malignancies.

Graft-versus-cancereffect and innovative approaches in thetreatment of refractory solid tumors

Background/aim

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been used for the treatment of various refractory solid tumors during the last two decades. After the demonstration of graft-versus-leukemia (GvL) effect in a leukemic murine model following allo-HSCT from other strains of mice, graft-versus-tumor (GvT) effect in a solid tumor after allo-HSCT has also been reported in a murine model in 1984. Several trials have reported the presence of a GvT effect in patients with various refractory solid tumors, including renal, ovarian and colon cancers, as well as soft tissue sarcomas [1]. The growing data on haploidentical transplants also indicate GvT effect in some pediatric refractory solid tumors. Novel immunotherapy-based treatment modalities aim at inducing an allo-reactivity against the metastatic solid tumor via a GvT effect. Recipient derived immune effector cells (RDICs) in the antitumor reactivity following allo-HSCT have also been considered as an emerging therapy for advanced refractory solid tumors.

Conclusion

This review summarizes the background, rationale, and clinical results of immune-based strategies using GvT effect for the treatment of various metastatic and refractory solid tumors, as well as innovative approaches such as haploidentical HSCT, CAR-T cell therapies and tumor infiltrating lymphocytes (TIL).

Immune precision medicine for cancer: a novel insight based on the efficiency of immune effector cells

Cancer cell growth is associated with immune surveillance failure. Nowadays, restoring the desired immune response against cancer cells remains a major therapeutic strategy. Due to the recent advances in biological knowledge, efficient therapeutic tools have been developed to support the best bio-clinical approaches for immune precision therapy. One of the most important successes in immune therapy is represented by the applicational use of monoclonal antibodies, particularly the use of rituximab for B-cell lymphoproliferative disorders. More recently, other monoclonal antibodies have been developed, to inhibit immune checkpoints within the tumor microenvironment that limit immune suppression, or to enhance some immune functions with immune adjuvants through different targets such as Toll-receptor agonists. The aim is to inhibit cancer proliferation by the diminishing/elimination of cancer residual cells and clinically improving the response duration with no or few adverse effects. This effect is supported by enhancing the number, functions, and activity of the immune effector cells, including the natural killer (NK) lymphocytes, NKT-lymphocytes, γδ T-lymphocytes, cytotoxic T-lymphocytes, directly or indirectly through vaccines particularly with neoantigens, and by lowering the functions of the immune suppressive cells. Beyond these new therapeutics and their personalized usage, new considerations have to be taken into account, such as epigenetic regulation particularly from microbiota, evaluation of transversal functions, particularly cellular metabolism, and consideration to the clinical consequences at the body level. The aim of this review is to discuss some practical aspects of immune therapy, giving to clinicians the concept of immune effector cells balancing between control and tolerance. Immunological precision medicine is a combination of modern biological knowledge and clinical therapeutic decisions in a global vision of the patient.

Placenta-Derived Decidua Stromal Cells for Hemorrhagic Cystitis after Stem Cell Transplantation

BACKGROUND/AIMS

Hemorrhagic cystitis (HC) is a serious complication after hematopoietic stem cell transplantation (HSCT). Stromal cells have been tested as therapy for HC. Decidua stromal cells (DSCs) protect the fetus from the mother's immune system.

METHODS

Eleven patients with HC of grades 3-4 were treated with DSCs after HSCT. The median age was 33 years (range 8-50), and the median dose of DSCs was 1.5 × 106/kg (range 0.7-2.5). The patients were given 1 dose (1-4).

RESULTS

In 5 patients, HC disappeared within 5 days after DSC infusion. Patients who received DSCs within 3 days after the start of HC had a duration of HC of 5 days and a shorter duration of pain than patients who were given DSCs later (p = 0.02). Three patients received DSCs prepared in albumin instead of AB-plasma and tended to have a shorter duration of pain (p = 0.07). There was no infusion toxicity. Adverse events were those often seen after HSCT. Nine of the 11 patients (82%) were alive 1 year after HSCT.

CONCLUSIONS

Based on this pilot study, we started a randomized, placebo-controlled double-blind study using 2 doses of 1 × 106 DSCs/kg suspended in albumin for treatment of early HC.

Cancer vaccines and immunotherapeutic approaches in hepatobiliary and pancreatic cancers

Hepatobiliary and pancreatic cancers along with other gastrointestinal malignancies remain the leading cause of cancer-related deaths worldwide. Strategies developed in the recent years on immunotherapy and cancer vaccines in the setting of primary liver cancer as well as in pancreatic cancer are the scope of this review. Significance of orthotopic and autochthonous animal models which mimic and/or closely reflect human malignancies allowing for a prompt and trustworthy analysis of new therapeutics is underlined. Combinational approaches that on one hand, specifically target a defined cancer-driving pathway, and on the other hand, restore the functions of immune cells, which effector functions are often suppressed by a tumor milieu, are shown to have the strongest perspectives and future directions. Among combinational immunotherapeutic approaches a personalized- and individual cancer case-based therapy is of special importance.

A Preliminary Report: Radical Surgery and Stem Cell Transplantation for the Treatment of Patients With Pancreatic Cancer

We examined the immunologic effects of allogeneic hematopoietic stem cell transplantation (HSCT) in the treatment of pancreatic ductal adenocarcinoma, a deadly disease with a median survival of 24 months for resected tumors and a 5-year survival rate of 6%. After adjuvant chemotherapy, 2 patients with resected pancreatic ductal adenocarcinoma underwent HSCT with HLA-identical sibling donors. Comparable patients who underwent radical surgery, but did not have a donor, served as controls (n=6). Both patients developed humoral and cellular (ie, HLA-A*01:01-restricted) immune responses directed against 2 novel tumor-associated antigens (TAAs), INO80E and UCLH3 after HSCT. Both TAAs were highly expressed in the original tumor tissue suggesting that HSCT promoted a clinically relevant, long-lasting cellular immune response. In contrast to untreated controls, who succumbed to progressive disease, both patients are tumor-free 9 years after diagnosis. Radical surgery combined with HSCT may cure pancreatic adenocarcinoma and change the cellular immune repertoire capable of responding to clinically and biologically relevant TAAs.

Risk Factors for Subsequent Central Nervous System Tumors in Pediatric Allogeneic Hematopoietic Cell Transplant: A Study from the Center for International Blood and Marrow Transplant Research (CIBMTR)

Survivors of hematopoietic cell transplantation (HCT) are at risk of subsequent solid tumors, including central nervous system (CNS) tumors. The risk of CNS tumors after HCT in pediatric HCT recipients is not known. We evaluated the incidence and risk factors for CNS tumors in pediatric recipients of allogeneic HCT reported to the Center for International Blood and Marrow Transplant Research between 1976 and 2008. A case control design was used. There were no CNS tumors in the nonmalignant cohort (n = 4543) or in those undergoing HCT for solid tumors (n = 26). There were 59 CNS tumors in 8720 patients transplanted for hematologic malignancies. In comparison with the general population, pediatric HCT recipients with hematologic malignancies had a 33 times higher than expected rate of CNS tumors (95% confidence interval, 22.98 to 45.77; P < .0001). The cumulative incidence of subsequent CNS tumors was 1.29% (95% confidence interval .87 to 1.87) at 20 years after HCT. Significant risk factors in the entire cohort were having an unrelated donor (HR, 3.35; P = .0002) and CNS disease before HCT for both acute lymphoblastic leukemia (HR, 8.21; P = .0003) and acute myeloid leukemia (HR, 6.21; P = .0174). Analysis of the matched cohort showed having an unrelated donor transplant (HR, 4.79; P = .0037), CNS disease before HCT (HR, 7.67; P = .0064), and radiotherapy exposure before conditioning (HR, 3.7; P = .0234) to be significant risk factors. Chronic graft-versus-host disease was associated with a lower risk (HR, .29; P = .0143). Survivors of HCT for nonmalignant diseases did not show an increased incidence of CNS tumors, whereas survivors of hematologic malignancies have a markedly increased incidence of CNS tumors that warrants lifelong surveillance.

Review of allogeneic hematopoietic stem cell transplantation with reduced intensity conditioning in solid tumors excluding breast cancer

Solid tumors in adults constitute a heterogeneous group of malignancy originating from various organ systems. Solid tumors are not completely curable by chemotherapy, even though some subgroups are very chemo-sensitive. Recently, oncologists have focused on the use of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with reduced intensity conditioning (RIC) for the treatment of some refractory solid tumors. After the demonstration of allogeneic graft-versus-leukemia effect in patients with hematological malignancies who received allo-HSCT, investigators evaluated this effect in patients with refractory metastatic solid tumors. According to data from experimental animal models and preliminary clinical trials, a graft-versus-tumor (GvT) effect may also be observed in the treatment of some solid tumors (e.g., renal cell cancer, colorectal cancer, etc.) after allo-HSCT with RIC. The use of RIC regimens offers an opportunity of achieving full-donor engraftment with GvT effect, as well as, a reduced transplant-related mortality. Current literature suggests that allo-HSCT with RIC might become a choice for elderly and medically fragile patients with refractory metastatic solid tumors.

Long-Term Follow-Up of Allogeneic Hematopoietic Stem Cell Transplantation for Solid Cancer

We wanted to determine whether allogeneic hematopoietic stem cell transplantation (HSCT) may result in long-term survival in patients with solid cancer. HSCT was performed in 61 patients with solid cancer: metastatic renal carcinoma (n = 22), cholangiocarcinoma (n = 17), colon carcinoma (n = 15), prostate cancer (n = 3), pancreatic adenocarcinoma (n = 3), or breast cancer (n = 1). Liver transplantation was performed for tumor debulking in 18 patients. Median age was 56 years (range, 28 to 77). Donors were either HLA-identical siblings (n = 29) or unrelated (n = 32). Conditioning was nonmyeloablative (n = 23), reduced (n = 36), or myeloablative (n = 2). Graft failure occurred in 13 patients (21%). The cumulative incidence of acute graft-versus-host disease (GVHD) of grades II to IV was 47%, and that of chronic GVHD was 32%. Treatment-related mortality was 21%. At 5 years cancer-related mortality was 63%. Currently, 6 patients are alive, 2 with renal cell carcinoma, 1 with cholangiocarcinoma, and 3 with pancreatic carcinoma. Eight-year survival was 12%. Risk factors for mortality were nonmyeloablative conditioning (HR, 2.95; P < .001), absence of chronic GVHD (HR, 3.57; P < .001), acute GVHD of grades II to IV (HR, 2.90; P = .002), and HLA-identical transplant (HR, 5.00; P = .03). With none of these risk factors, survival at 6 years was 50% (n = 6). Long-term survival can be achieved in some patients with solid cancer after HSCT.

Immunotherapy of Metastatic Colorectal Cancer: Prevailing Challenges and New Perspectives

Patients with recurring or metastatic colorectal cancer (mCRC) have strikingly low long-term survival, while conventional treatments such as chemotherapeutic intervention and radiation therapy marginally improve longevity. Although, many factors involving immunosurveillance and immunosuppression were recently validated as important for patient prognosis and care, a multitude of experimental immunotherapies designed to combat unresectable mCRC have, in few cases, successfully mobilized antitumor immune cells against malignancies, nor conclusively or consistently granted protection, complete remission, and/or stable disease from immunotherapy - of which benefit less than 10% of those receiving therapy. After decades of progress, however, new insights into the mechanisms of immunosuppression, tolerance, and mutation profiling established novel therapies that circumvent these immunological barriers. This review underlines the most exciting methods to date that manipulate immune cells to curb mCRC, including adoptive cell therapy, dendritic cell vaccines, and checkpoint inhibitor antibodies - of which hint at effective and enduring protection against disease progression and undetected micrometastases.

TCR+CD4-CD8- T cells in antigen-specific MHC class I-restricted T-cell responses after allogeneic hematopoietic stem cell transplantation

Human TCRαβ(+) CD4(-)CD8(-) double-negative (DN) T cells represent a minor subset in peripheral blood, yet are important in infectious diseases and autoimmune responses. We examined the frequency of DN T cells in 17 patients after allogeneic hematopoietic stem cell transplantation (aHSCT) at 1, 2, 3, 6, and 12 months post-aHSCT and show that these cells increase early after aHSCT and decrease with time after aHSCT. DN T cells reside in the terminally differentiated effector (CD45RA(+)CCR7(-)) T-cell population and are polyclonal, determined by T-cell receptor Vβ CDR3 analysis. Gene expression analysis of ex vivo sorted DN T cells showed a distinct set of gene expression, including interleukin-8, as compared with CD4(+) or CD8(+) T cells. DN T cells contributed to MHC class I-restricted EBV-directed immune responses, defined by antigen-specific cytokine production and by detection of HLA-A*02:01-restricted EBV BMLF-1 (GLCTLVAML), LMP-2A (CLGGLLTMV), and HLA-A*24:02-restricted EBV BRLF-1 (DYCNVLNKEF) and EBNA3 (RYSIFFDY)-specific T cells. We created retroviral-transfected Jurkat cell lines with a Melan-A/MART-1-specific TCR(+) and the CD8α chain to study TCR(+) DN T cells in response to their nominal MHC class I/peptide ligand. We show that DN T cells exhibit increased TCRζ chain phosphorylation as compared with the TCR(+)CD8(+) transgenic T-cell line. DN T cells contribute to antigen-specific T-cell responses and represent an effector T-cell population that may be explored in immunotherapeutic approaches against viral infections or transformed cells.

Stem cell Transplantation for Eradication of Minimal PAncreatic Cancer persisting after surgical Excision (STEM PACE Trial, ISRCTN47877138): study protocol for a phase II study

Background

Pancreatic cancer is the third most common cancer related cause of death. Even in the 15% of patients who are eligible for surgical resection the outlook is dismal with less than 10% of patients surviving after 5 years. Allogeneic hematopoietic (allo-HSCT) stem cell transplantation is an established treatment capable of to providing cure in a variety of hematopoietic malignancies. Best results are achieved when the underlying neoplasm has been turned into a stage of minimal disease by chemotherapy. Allo-HSCT in advanced solid tumors including pancreatic cancer have been of limited success, however studies of allo-HSCT in solid tumors in minimal disease situations have never been performed. The aim of this trial is to provide evidence for the clinical value of allo-HSCT in pancreatic cancer put into a minimal disease status by effective surgical resection and standard adjuvant chemotherapy.

Methods/Design

The STEM PACE trial is a single center, phase II study to evaluate adjuvant allogeneic hematopoietic stem cell transplantation in pancreatic cancer after surgical resection. The study will evaluate as primary endpoint 2 year progression free survival and will generate first time state-of-the-art scientific clinical evidence if allo-HSCT is feasible and if it can provide long term disease control in patients with effectively resected pancreatic cancer. Screened eligible patients after surgical resection and standard adjuvant chemotherapy with HLA matched related stem cell donor can participate. Patients without a matched donor will be used as a historical control. Study patients will undergo standard conditioning for allo-HSCT followed by transplantation of allogeneic unmanipulated peripheral blood stem cells. The follow up of the patients will continue for 2 years. Secondary endpoints will be evaluated on 7 postintervention visits.

Discussion

The principal question addressed in this trial is whether allo-HSCT can change the unfavourable natural course of this disease. The underlying hypothesis is that allo-HSCT has the capacity to provide long-term disease control to an extent otherwise not possible in pancreatic cancer, thereby substantially improving survival of affected patients.

Trial registration

This trial has been registered: ISRCTN47877138

Immunotherapy options in metastatic renal cell cancer: where we are and where we are going

The treatment of renal cell carcinoma is rapidly changing as a result of recent evidence concerning the efficacy of biological drugs, antiangiogenetic agents and signal-transduction inhibitors. This paper will provide a critical overview of the use of immunotherapy in renal cell carcinoma and review the available data concerning the efficacy of interferons, interleukin-2 and other forms of immunological treatment, particularly allogenic transplantation and vaccines. Moreover, it will focus on the new mechanisms of regulation of the immune system with a better understanding of the interaction between host and tumor, the role of T regulatory cells, heat-shock proteins and vaccines. The mechanism of action and the results obtained in renal cell carcinoma using the new molecular targeted drugs will be examined, along with the possibility of using immunotherapy combined with the new biological agents. Future research will not only need to make every effort to optimize the use of the new molecules and to define their efficacy precisely, but also to consider how to integrate these drugs with the traditional immunotherapy.

Allogeneic stem cell transplantation for patients with metastatic renal cell carcinoma

Allogeneic stem cell transplantation and donor lymphocyte infusions are currently under clinical investigation as an innovative therapeutic option for patients with metastatic renal cell carcinoma. A variety of trials have proven the clinical efficacy of allogeneic stem cell transplantation using reduced-intensity conditioning protocols and donor lymphocyte infusions, as demonstrated by the induction of objective remissions in metastatic renal cell carcinoma patients. However, despite clinical remissions, reduced-intensity conditioning protocols and donor lymphocyte infusions were associated with a high treatment-related mortality rate of approximately 17%. The disproportion between clinical efficacy and treatment-related mortality may mainly be caused by the selection of patients that had often been heavily pretreated, with a large tumor burden and rapidly progressing tumors. The improvement of efficacy with the preservation of a powerful graft-versus-tumor effect while reducing the toxicity, is the major experimental and clinical challenge of allogeneic stem cell transplantation in the treatment of metastatic renal cancer and other solid tumors. Recently, there has been a revolutionary development of molecular-targeted agents in metastatic renal cancer. These inhibitors of angiogenesis and signal-transduction pathways have demonstrated clinical efficacy and significant survival prolongation in the first- and second-line settings, while causing moderate toxicity. Some of these agents have already been approved by the US FDA and will probably replace standard cytokines, such as interferon-alpha2 and interleukin-2, in metastatic renal cancer. In the context of these innovative clinical developments, allogeneic stem cell transplantation clearly has to be regarded an investigational clinical treatment approach. Therefore, patients should only be treated at centers that are experienced in clinical trials, and patient selection remains a critical factor for a successful transplant procedure.

Analysis of donor and recipient ABO incompatibility and antibody-associated complications after allogeneic stem cell transplantation with reduced-intensity conditioning

Allogeneic hematopoietic stem cell transplantation (HSCT) can be performed across the ABO blood group barrier. The impact of ABO incompatibility on clinical outcome is controversial. A retrospective analysis of 310 patients who underwent HSCT with reduced-intensity conditioning between 1998 and 2011 was performed to investigate the frequency and clinical implications of anti-RBC antibodies in passenger lymphocyte syndrome (PLS) after minor ABO mismatch (mm), persistent or recurring recipient type ABO antibodies (PRABO) after major ABO mm HSCT, and autoimmune hemolytic anemia (AIHA). Transplantation characteristics and clinical outcome were analyzed by univariate and multivariate analysis for groups with or without anti-RBC antibodies. ABO blood group incompatibility did not affect clinical outcome despite an increased requirement of blood transfusion. Twelve patients with AIHA, 6 patients with PLS, and 12 patients with PRABO post-HSCT were identified. AIHA did not affect overall survival (OS) or transplant-related mortality (TRM), but patients with AIHA had a lower incidence of grades II to IV acute graft-versus-host disease (P = .05). OS in the PLS group was 0% compared with 61% in the whole group receiving minor ABO mm transplants (P < .001). Comparing PRABO patients with those receiving a major ABO mm HSCT, the OS was 17% versus 73% (P = .002) and TRM was 50% versus 21% (P = .03). At our center, PLS after minor ABO mm and PRABO antibodies after major ABO mm HSCT are significant risk factors for decreased OS and TRM. Our results suggest that occurrence of unexpected ABO antibodies after HSCT warrant a wider investigation individual to find the underlying cause.

Achieving graft-versus-tumor effect in brain tumor patients: from autologous progenitor cell transplant to active immunotherapy

Success in treating aggressive brain tumors like glioblastoma multiforme and medulloblastoma remains challenging, in part because these malignancies overcome CNS immune surveillance. New insights into brain tumor immunology have led to a rational development of immunotherapeutic strategies, including cytotoxic Tlymphocyte therapies and dendritic cell vaccines. However, these therapies are most effective when applied in a setting of minimal residual disease, so require prior use of standard cytotoxic therapies or cytoreduction by surgery. Myeloablative chemotherapy with autologous hematopoietic cell transplantation (autoHCT) can offer a platform upon which different cellular therapies can be effectively instituted. Specifically, this approach provides an inherent 'chemical debulking' through high-dose chemotherapy and a graft-versus-tumor effect through an autologous T-cell replete graft. Furthermore, autoHCT may be beneficial in 'resetting' the body's immune system, potentially 'breaking' tumor tolerance, and in providing a 'boost' of immune effector cells (NK cells or cytotoxic T lymphocytes), which could augment desired anti-tumor effects. As literature on the use of autoHCT in brain tumors is scarce, aspects of immunotherapies applied in non-CNS malignancies are reviewed as potential therapies that could be used in conjunction with autoHCT to eradicate brain tumors.

Graft failure in the modern era of allogeneic hematopoietic SCT

Graft failure may contribute to increased morbidity and mortality after allogeneic hematopoietic SCT (allo-HSCT). Here, we present risk factors for graft failure in all first allo-HSCTs performed at our center from 1995 to mid-2010 (n=967). Graft failure was defined as >95% recipient cells any time after engraftment with no signs of relapse, or re-transplantation because of primary or secondary neutropenia (<0.5 × 10(9)/L) and/or thrombocytopenia (<30 × 10(9)/L). Fifty-four patients (5.6%) experienced graft failure. The majority were because of autologous reconstitution (n=43), and only a few patients underwent re-transplantation because of primary (n=6) or secondary (n=5) graft failures. In non-malignant disorders, graft failure had no effect on survival, whereas in malignant disease graft failure was associated with reduced 5-year survival (22 vs 53%, P<0.01). In multivariate analysis, ex vivo T-cell depletion (relative risk (RR) 8.82, P<0.001), HLA-mismatched grafts (RR 7.64, P<0.001), non-malignant disorders (RR 3.32, P<0.01) and reduced-intensity conditioning (RR 2.58, P<0.01) increased the risk for graft failure, whereas graft failures were prevented by total nucleated cell doses of ≥ 2.5 × 10(8)/kg (RR 0.36, P<0.01). In conclusion, graft failure was only associated with inferior survival in malignant disease. Non-malignant disorders, HLA match, conditioning intensity, immunosuppression regimen and cell dose all influenced graft failure risk.

Stem cell factor-displaying simian immunodeficiency viral vectors together with a low conditioning regimen allow for long-term engraftment of gene-marked autologous hematopoietic stem cells in macaques

Although clinical benefits have been reported in several human hematopoietic gene therapy trials, a remaining important goal is the transition to nonmyeloablative pretransplantation conditioning to decrease toxicity. Previous attempts at reduced intensity conditioning in nonhuman primates have resulted in only temporary vector marking of autologous blood cells or their persistence at low levels, well below the thresholds for clinical efficacy. In addition, we reasoned that lentiviral vector particles displaying cytokines at their surface have the potential to preserve stem cell fitness better than current ex vivo transduction protocols, which involve exposure to cytokine overstimulation. Here we show that the classically nonmyeloablative agent fludarabine (30 mg/m(2)/day for 3 days) together with low-level total body irradiation (2 Gy) and the use of a stem cell factor-displaying simian immunodeficiency virus-based vector, resulted in sustained, single-copy vector marking of autologous blood cells in two macaques over 3 years posttransplantation at levels averaging 1% of all lineages. This percentage is within the range of anticipated efficacy levels for hemophilia and related diseases and forms a basis for further improvement.

Cytokine expression in tumors treated with donor lymphocyte infusions after allogeneic hematopoietic stem cell transplantation

AIMS

Risk factors for disease relapse are remaining tumor or leukemic cells or mixed chimerism (MC) following allogeneic hematopoietic stem cell transplantation. Donor lymphocyte infusion (DLI) after stem cell transplantation can contribute to complete donor chimerism and graft-versus-tumor/leukemia effect. We evaluate cytokine secretion at the single-cell level using ELISpot in relation to DLI effect on disease response.

PATIENTS & METHODS

Blood samples were collected from four patients with solid tumors and four with hematological malignancies before DLI, and 1 and 3 weeks after DLI. Tumor response was evaluated according to the international Response Evaluation Criteria In Solid Tumors (RECIST) method. Indications for DLI were stable disease or MC and/or progressive disease in solid tumors, and molecular or early relapse, or MC in hematological malignancies. ELISpot was performed for TNF-α, IFN-γ, IL-12, IL-4, IL-10 and IL-13 cytokines.

RESULTS

Depending on the disease response, patients were divided into two groups: responders and nonresponders. Responders were patients who achieved partial response (one renal cell cancer) or stable disease (one prostate cancer) or clinical remission (two acute myeloid leukemia). Patients who relapsed, progressed or rejected the graft were the nonresponders. DLI rescued the renal cell cancer patient, who has partial response, and two acute myeloid leukemia patients, who are in clinical remission. Patients who responded tended to have a higher expression of TNF-α, IFN-γ, IL-12 and IL-10 than those who did not respond.

CONCLUSIONS

DLI can act when the patients' mononuclear cells have normal or increased capacity to produce TNF-α, IFN-γ, IL-12 and IL-10. Assessment of these cytokines may be useful to predict those patients who will respond to DLI therapy.

Immunotherapy for metastatic colorectal cancer: present status and new options

Although no immunotherapeutic treatment is approved for colorectal cancer (CRC) patients, promising results from clinical trials suggest that several immunotherapeutic strategies may prove efficacious and applicable to this group of patients. This review describes the immunogenicity of CRC and presents the most interesting strategies investigated so far: cancer vaccination including antigen-defined vaccination and dendritic cell vaccination, chemo-immunotherapy, and adoptive cell transfer. Future treatment options as well as the possibility of combining existing therapies will be discussed along with the challenges presented by tumor escape mechanisms.

Allogeneic stem cell transplantation for renal cell carcinoma

Allogeneic hematopoietic stem cell transplantation from a compatible donor has been utilized as adoptive immunotherapy in metastatic, cytokine-refractory renal cell carcinoma (RCC). Since the year 2000, several investigators have established that RCC is susceptible to a graft-versus-tumor effect: they reported that patients with renal cancer may have partial or complete disease responses, in the 20-40% range, after allogeneic transplantation following a reduced-intensity regimen. However, transplant-related mortality is still high in the 10-20% range, and responses are rarely durable. Experimental evidence suggests that donor-derived T cells and natural killer cells are the main mediators of the graft-versus-RCC effect upon allogeneic hematopoietic stem-cell transplantation. Isolation of CD8(+) cytotoxic T lymphocyte clones recognizing several target antigens of graft-versus-RCC effect (minor histocompatibility antigens on RCC cells; a peptide epitope derived from human endogenous retrovirus type E; the tumor-associated antigen encoded by the Wilms' tumor 1 gene) has increased our knowledge of the disease and has opened up the possibility of antigen-specific adoptive cell therapy. The introduction in the clinic of molecularly targeted agents that interfere with neoangiogenesis, both monoclonal antibodies and small tyrosine-kinase inhibitor molecules (e.g., sunitinib, sorafenib and bevacizumab), has decreased the use of allogeneic transplantation. Although not curative, novel targeted agents may be combined with allogeneic transplantation or with adoptive cell therapy in order to maximize the chances of cure.

A novel BMT technique for treatment of various currently intractable diseases

A recently-developed BMT method combines a "Perfusion Method" (PM) for collecting bone marrow cells (BMCs) with the Intra-Bone Marrow (IBM) injection of BMCs (IBM-BMT). As distinct from the conventional aspiration method (AM), the PM allows rapid (within 1 h) collection of BMCs without T cell contamination (T cells < 10%). Therefore, no GvHD occurs. Moreover, the burden on donors, such as back pain, bleeding and infection, can be reduced. Full chimerism can be achieved even with only mild conditioning regimens if IBM-BMT is carried out, since IBM-BMT replaces not only the recipient's hemopoietic stem cells (HSCs) but also mesenchymal stem cells (MSCs) with donor-derived HSCs and MSCs. Using this method, we show that most currently intractable diseases are HSC or MSC disorders, and that this novel strategy (PM + IBM-BMT) can be used to treat various otherwise intractable diseases (including autoimmune diseases and age-associated diseases). We believe that the development of this technique will herald a revolution in the field of BMT, regeneration medicine and also organ transplantation.

Improved survival after allogeneic hematopoietic stem cell transplantation in recent years. A single-center study

We analyzed the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) over the past 2 decades. Between 1992 and 2009, 953 patients were treated with HSCT, mainly for a hematologic malignancy. They were divided according to 4 different time periods of treatment: 1992 to 1995, 1996 to 2000, 2001 to 2005, and 2006 to 2009. Over the years, many factors have changed considerably regarding patient age, diagnosis, disease stage, type of donor, stem cell source, genomic HLA typing, cell dose, type of conditioning, treatment of infections, use of granulocyte-colony stimulating factor (G-CSF), use of mesenchymal stem cells, use of cytotoxic T cells, and home care. When we compared the last period (2006-2009) with earlier periods, we found slower neutrophil engraftment, a higher incidence of acute graft-versus-host disease (aGVHD) of grades II-IV, and less chronic GVHD (cGHVD). The incidence of relapse was unchanged over the 4 periods (22%-25%). Overall survival (OS) and transplant-related mortality (TRM) improved significantly in the more recent periods, with the best results during the last period (2006-2009) and a 100-day TRM of 5.5%. This improvement was also apparent in a multivariate analysis. When correcting for differences between the 4 groups, the hazard ratio for mortality in the last period was 0.59 (95% confidence interval [CI]: 0.44-0.79; P < .001) and for TRM it was 0.63 (CI: 0.43-0.92; P = .02). This study shows that the combined efforts to improve outcome after HSCT have been very effective. Even though we now treat older patients with more advanced disease and use more alternative HLA nonidentical donors, OS and TRM have improved. The problem of relapse still has to be remedied. Thus, several different developments together have resulted in significantly lower TRM and improved survival after HSCT over the last few years.

Allogeneic hematopoietic cell transplantation for renal cell carcinoma: ten years after

INTRODUCTION

The first series of patients with metastatic renal cell carcinoma (RCC) treated by non-myeloablative allogeneic hematopoietic cell transplantation (HCT) was reported in 2000 and demonstrated an allogeneic graft-versus-tumor (GVT) effect that encouraged further investigation of this approach. However, the past 10 years have also witnessed profound changes in the medical management of metastatic RCC with the introduction of targeted therapies directed against VEGF or mammalian target of rapamycin (mTOR) signaling pathways creating uncertainty about a continued role for allogeneic HCT in the treatment of RCC.

AREAS COVERED

A total of 21 published reports describing clinical outcomes for 398 patients with metastatic RCC treated by allogeneic HCT compiled herein provide a composite overview of the world wide experience for key efficacy and toxicity outcomes. Review of correlative studies that identify donor-derived T cells as mediators of RCC-specific GVT effects offers insight into both the potential as well as the technical barriers to the delivery of antigen-specific post-transplant cellular therapy or vaccination designed to augment the allogeneic GVT effect.

EXPERT OPINION

The future development of non-myeloablative allogeneic HCT for metastatic RCC will require novel treatment protocols designed to augment and sustain post-transplant GVT effects against RCC to generate renewed enthusiasm for this approach.

Immunotherapy in renal cell carcinoma

Treatment of metastatic renal cell cancer is still challenging due to its resistance to conventional therapies, such as radiotherapy or chemotherapy. Immunotherapeutic approaches with IL-2 and/or IFN-alpha have become standard regimens in treating metastatic renal cell cancer. Furthermore, molecularly targeted therapies, such as VEGF-pathway inhibition or use of mammalian target of rapamycin inhibitors, have demonstrated promising results and might become even more important in the following years. Finally, vaccination therapies have gained increasing interest and have been tested in multiple clinical trials. There is a vast choice of different application and production types of these vaccines, ranging from dendritic cell-based principals to the application of naked RNA. The development of new immune-enhancing strategies led to the option of interesting, potent combination regimes. This review has a focus on vaccination therapies in renal cell cancer, especially dendritic cell-based principals, and aims to give an overview of this rapidly changing field of investigation.

Granulocyte colony-stimulating factor induced acute and chronic graft-versus-host disease

BACKGROUND

A recent experimental study in mice shed new light on the controversy as to whether granulocyte colony-stimulating factor (G-CSF) increases graft-versus-host disease (GVHD). Total body irradiation and bone marrow were found to be prerequisites for acute GVHD. This study encouraged us to perform a retrospective clinical study.

METHODS

We compared 260 patients given G-CSF prophylaxis after allogeneic hematopoietic stem-cell transplantation with 205 controls transplanted between 1993 and 2003.

RESULTS

G-CSF hastened the engraftment of neutrophils, but that of platelets was delayed (P<0.0001). The proportion of acute GVHD of grades II to IV was 29% in the G-CSF group and 19% in the controls (P<0.01) and that of chronic GVHD was 54% and 43%, respectively (P=0.019). G-CSF increased acute and chronic GVHD in patients preferentially conditioned with chemotherapy. Unexpectedly, it exacerbated acute GVHD in recipients of peripheral blood stem cells and enhanced chronic GVHD in bone marrow recipients. A multivariable analysis showed that acute GVHD (hazards ratio=1.52, P=0.03) and chronic GVHD (hazards ratio=1.51, P=0.004) were associated with G-CSF. There was no significant difference between study groups regarding nonrelapse mortality, relapse, or survival.

CONCLUSION

G-CSF increased acute and chronic GVHD in patients treated with chemotherapy but did not affect relapse or survival.

Immunotherapy by allogeneic stem cell transplantation

During the past three decades, allogeneic stem cell transplantation (ASCT) has developed from being an experimental therapy in patients with endstage leukemia into a well-established therapy in patients with a range of disorders of the immunohematopoietic system. Graft-versus-host disease (GVHD), acute or chronic, attacking host tissue is a major threat. However, donor immunocompetent T cells have a potent graft-versus-leukemia effect. A combination of calcineurin inhibitors and methotrexate is the standard therapy to prevent GVHD. Modulation of the immunosuppressive regimen may induce mild acute and mild chronic GVHD, reduce the risk of relapse, and improve long-term survival. Natural killer cells also play a role in this context. Killer cell immunoglobulin-like receptor incompatibility between recipient and donor may reduce the risk of relapse in patients with myeloid leukemia. Relapse of leukemia is a major cause of death after ASCT. Minimal residual disease and recipient leukemia lineage-specific chimerism are sensitive techniques for early detection of leukemic relapse. Donor lymphocyte infusions can enhance the antitumor effect, especially for patients with molecular relapse. The allogeneic graft-versus-cancer effect has been demonstrated in patients with metastatic breast, renal, colorectal, ovarian, prostatic, and pancreatic carcinoma. Mesenchymal stem cells have immunomodulatory properties and may be used for immunomodulation of GVHD and tissue repair. All things considered, the future looks promising for ASCT.

Nonmyeloablative allogeneic hematopoietic stem cell transplantation as immunotherapy for pancreatic cancer

OBJECTIVE

Advanced unresectable pancreatic cancer has an extremely poor prognosis despite intensive chemotherapy. As a new therapeutic modality, we investigated nonmyeloablative allogeneic hematopoietic stem cell transplantation from a related donor.

METHODS

Five patients with chemotherapy-resistant pancreatic cancer received allogeneic peripheral blood stem cell transplantation after a conditioning regimen consisting of low-dose total body irradiation and fludarabine. The prophylaxis for graft-versus-host disease consisted of mycophenolate mofetil and cyclosporine.

RESULTS

The median age of the 5 patients was 54 years, and the median duration from diagnosis to nonmyeloablative allogeneic hematopoietic stem cell transplantation was 10 months. Three of the 5 patients achieved complete donor chimerism of peripheral T cells, at a median time of day 42. Acute graft-versus-host disease developed in 3 patients: grade 2 in 2 patients and grade 1 in 1. Tumor reduction was observed in 2 patients: 1 patient showed disappearance of the pancreatic tumor, and the other patient showed approximately 20% reduction of the tumor. Marked elevation of tumor necrosis factor alpha was observed as the tumor regressed.

CONCLUSIONS

Although advanced pancreatic cancer progresses rapidly, some graft-versus-tumor effects and pivotal role of tumor necrosis factor alpha were suggested. To obtain the durable response, patient selection and new strategies become important.

The allogeneic graft-versus-cancer effect

Allogeneic haematological stem cell transplantation (HSCT) has developed into immunotherapy. Donor CD4+, CD8+ and natural killer (NK) cells have been reported to mediate graft-versus-leukaemia (GVL) effects, using Fas-dependent killing and perforin degranulation to eradicate malignant cells. Cytokines, such as interleukin-2, interferon-gamma and tumour necrosis factor-alpha potentiate the GVL effect. Post-transplant adoptive therapy of cytotoxic T-cells (CTL) against leukaemia-specific antigens, minor histocompatibility antigens, or T-cell receptor genes may constitute successful approaches to induce anti-tumour effects. Clinically, a significant GVL effect is induced by chronic rather than acute graft-versus-host disease (GVHD). An anti-tumour effect has also been reported for myeloma, lymphoma and solid tumours. Reduced intensity conditioning enables HSCT in older and disabled patients and relies on the graft-versus-tumour effect. Donor lymphocyte infusions promote the GVL effect and can be given as escalating doses with response monitored by minimal residual disease. A high CD34+ cell dose of peripheral blood stem cells increases GVL. There is a balance between effective immunosuppression, low incidence of GVHD and relapse. For instance, T-cell depletion of the graft increases the risk of relapse. This paper reviews the current knowledge in graft-versus-cancer effects. Future directions, such as immunotherapy using leukaemia-specific CTLs, allo-depleted T-cells and suicide gene manipulated T-cells, are presented.

Reduced-intensity allogeneic hematopoietic stem cell transplantation in metastatic colorectal cancer as a novel adoptive cell therapy approach. The European group for blood and marrow transplantation experience

Reduced-intensity conditioning (RIC) regimens for allogeneic hematopoietic stem cell transplantation (HCT) allowed the existence of an allogeneic cell-mediated antitumor effect in metastatic colorectal cancer (mCRC) to be explored. We report on 39 patients with progressing mCRC treated with different RIC regimens in a multicenter clinical trial of the European Bone Marrow Transplantation Group. Disease status at transplant was progressive disease (PD) in 31 patients (80%), stable disease (SD) in 6 (15%), and partial response (PR) in 2 (5%). All patients engrafted (median donor T cell chimerism of 90% at day +60). Transplant-related morbidities were limited. Grades II-IV acute graft-versus-host disease (aGVHD) occurred in 14 patients (35%) and chronic GVHD (cGVHD) in 9 patients (23%). Transplant-related mortality occurred in 4 patients (10%). The best tumor responses were: 1 complete response (CR) (2%), 7 PR (18 %), and 10 SD (26%), giving an overall disease control in 18 of 39 patients (46%). Allogeneic HCT after RIC is feasible; the collected results compared favorably in terms of tumor response with those observed using conventional approaches beyond second-line therapies. The study of an allogeneic cell based therapy in less advanced patients is warranted.

Decreasing mortality rate in early pneumonia following hematopoietic stem cell transplantation

Pulmonary complications after allogeneic hematopoietic stem-cell transplantation (HSCT) remain 1 of the most important causes of morbidity and mortality. This study evaluates the change over time of incidence, aetiology and risk factors for death related to pneumonia within 3 months after HSCT. 997 patients who underwent HSCT were studied retrospectively. Most patients (83%) had a haematological malignancy. The majority (89%) had an HLA-A, -B, and -DR matched related or unrelated donor. Conditioning consisted of cyclophosphamide and total-body irradiation or busulfan and graft-versus-host disease prophylaxis of cyclosporin and methotrexate in most cases. Death related to pneumonia occurred in 56 (5.6%) patients. Cytomegalovirus (37%) was the main pathogen involved, especially during the first 2 decades studied. In the multivariate risk factor analysis, we found that death from pneumonia was significantly associated with receiving a T-cell depleted graft (p<0.001), bacteraemia (p=0.001), and y of transplantation (p<0.001). In patients receiving a transplant during the last decade, the incidence of death related to pneumonia was 2.8% compared to 8.9% during the first decade. We conclude that the rate of mortality related to pneumonia has decreased over time, possibly as a result of improved diagnostic, prophylactic and therapeutic methods and treatment.

Donor CD4 T cells are critical in allogeneic stem cell transplantation against murine solid tumor

Nonmyeloablative allogeneic stem cell transplantation (SCT) has been used for various malignancies, although detailed mechanisms of antitumor effects remain unclear. We showed that a nonmyeloablative allogeneic SCT regimen, which consists of mixed chimerism induced by an injection of donor spleen and bone marrow cells followed by cyclophosphamide treatment and a donor lymphocyte infusion (DLI), exerted antitumor effects on established murine bladder tumor, MBT-2. An expansion of donor CD4 T cells accompanied by transient but vigorous IFN-gamma production was detected shortly after DLI. In vivo neutralization of IFN-gamma or depletion of CD4 T cells from DLI abolished the antitumor effects, indicating an indispensable role of donor CD4 T cells producing IFN-gamma. Donor as well as host CD8 T cells accumulated in the tumor region with time. Importantly, depletion of CD8 T cells from DLI did not reverse the suppression of tumor growth, indicating that CD4 T cells play a more essential role in mediating early antitumor effects. Furthermore, tumor-specific response of host CD8 T cells was suggested. These results not only provide the first evidence of nonmyeloablative allogeneic SCT for the treatment of bladder tumor but also elucidate detailed mechanisms of antitumor effects provoked by DLI.

Allogeneic cell therapy from immunized donors with tumor antigen peptide enhances the antitumor effect after cyclophosphamide-using non-myeloablative allogeneic hematopoietic cell transplantation

Non-myeloablative allogeneic stem cell transplantation is an option for the treatment of hematological malignancies as well as solid tumors. We recently proposed a cyclophosphamide-using non-myeloablative cell therapy in which donor lymphocytes infusion (DLI) was carried out after tolerance induction to donor cells. In this study, we tested the possibility that the cyclophosphamide-using cell therapy could be augmented by pre-immunization of donors before DLI. We initially assessed whether or not the cyclophosphamide-using cell therapy could also show antitumor effect against subcutaneously established colon 26 carcinoma. As a tumor antigen-derived peptide for colon 26, we used AH1, an immunodominant H-2Ld-binding peptide derived from the envelope protein (gp70) of an endogenous murine leukemia virus. The cyclophosphamide-using cell therapy with the DLI from donors which were pre-immunized with the AH1 peptide was compared with that from non-immunized mice. The cyclophosphamide-using cell therapy significantly suppressed subcutaneously established colon 26 carcinoma, and the tumor-rejected mice acquired the tumor-specific protective immunity. When combined with the DLI from donors that were immunized with AH1, antitumor effect of the cyclophosphamide-using cell therapy was significantly augmented. The DLI from tumor peptide-immunized donors showed no influence on donor chimerism and bodyweight of the treated mice, indicating no increased risk of graft-versus-host disease. Tumor-specific cytotoxic T lymphocytes could be generated from tumor-rejected mice. Our results indicate that the cyclophosphamide-using non-myeloablative cell therapy with the DLI from tumor peptide-immunized donors is a useful protocol to augment graft-versus-tumor effect without exacerbation of graft-versus-host disease.

C19orf48 encodes a minor histocompatibility antigen recognized by CD8+ cytotoxic T cells from renal cell carcinoma patients

PURPOSE

Tumor regression has been observed in some patients with metastatic renal cell carcinoma (RCC) after nonmyeloablative allogeneic hematopoietic cell transplantation (HCT). Cellular and molecular characterization of antigens recognized by tumor-reactive T cells isolated from responding patients could potentially provide insight into the mechanisms of tumor regression.

EXPERIMENTAL DESIGN

CD8+ CTL clones that recognized a novel RCC-associated minor histocompatibility (H) antigen presented by HLA-A*0201 were isolated from two patients with metastatic RCC who experienced tumor regression or stable disease following nonmyeloablative allogeneic HCT. These clones were used to screen a cDNA library and isolate the unique cDNA encoding the antigen.

RESULTS

An alternative open reading frame in the C19orf48 gene located on chromosome 19q13 encodes the HLA-A*0201-restricted minor H antigen recognized by the RCC-reactive T cells. The differential T-cell recognition of donor- and recipient-derived target cells is attributable to a nonsynonymous single-nucleotide polymorphism within the nucleotide interval that encodes the antigenic peptide. Assays for gene expression and CTL recognition showed that the C19orf48-encoded peptide is widely expressed in renal tumors and solid tumors of other histologies. The antigenic peptide can be processed for CTL recognition via both TAP-dependent and TAP-independent pathways.

CONCLUSIONS

Donor T-cell responses against the HLA-A*0201-restricted minor H antigen encoded by C19orf48 may contribute to RCC regression after MHC-matched allogeneic HCT.

Adoptive transfer of allogeneic tumor-specific T cells mediates effective regression of large tumors across major histocompatibility barriers

Graft-versus-tumor effects can be achieved after allogeneic bone marrow transplantation in patients with malignancies of the kidney or hematopoietic system but are often accompanied by severe graft-versus-host-disease (GVHD). We sought to maximize graft-versus-tumor while minimizing GVHD using tumor-specific allogeneic effector T cells rather than open-repertoire T cells. We transferred allogeneic CD8(+) pmel-1 or CD4(+) TRP-1 T cells specific for the melanoma-associated antigens, glycoprotein 100 (gp100) and tyrosinase-related protein-1 (TRP-1), respectively, into B16-melanoma-bearing mice. Mice receiving a preparative regimen of nonmyeloablating (5 Gy) total body irradiation experienced the rapid rejection of tumor-specific allogeneic lymphocytes with no impact on tumor growth. However, when mice were given more intense total body irradiation conditioning regimens combined with autologous bone marrow transplantation, adoptively transferred allogeneic tumor-specific T lymphocytes persisted at detectable levels for several weeks and mediated significant regression of large, vascularized tumors. We found that the risk of GVHD was low when tumor-specific T cells were transferred and significant toxicity was observed only when substantial numbers of open repertoire allogeneic naive T cells were mixed with the tumor-specific lymphocytes. Taken together, these data indicate that the use of tumor-specific allogeneic CD8(+) T cells or CD4(+) can result in significant antitumor effects in the absence of measurable GVHD.

Case-control comparison of at-home and hospital care for allogeneic hematopoietic stem-cell transplantation: the role of oral nutrition

BACKGROUND

Acute graft-versus-host disease (GVHD) was reduced using home care compared with hospital care after allogeneic hematopoietic stem-cell transplantation (ASCT).

METHODS

Between March 1998 and December 2006, 601 patients underwent ASCT at our unit. Requirements for at-home ASCT were fulfilled by 76 patients. A control group of 76 patients treated in the hospital were matched for age, sex, diagnosis, stage of disease, conditioning, stem-cell source, type of donor, and immunosuppression. Oral nutrition was determined as median kcal/kg/day for the first 21 days after ASCT.

RESULTS

The home-care patients received more oral nutrition per day than hospital controls (P<0.05). Number of days at home correlated with oral nutrition (P=0.004). In multivariate analysis, acute GVHD of grades II to IV was associated with poor oral nutrition (P=0.003) and hospital care (P=0.06). Transplant-related mortality was associated with acute GVHD grades II to IV (P<0.0001) and bacteremia (P=0.004). In addition to acute GVHD and bacteremia, death was associated with absence of chronic GVHD (P=0.012). Five-year survival was 65% in patients treated at home, when compared with 47% in the controls (P=0.04).

CONCLUSION

Better oral nutrition may be one reason for the reduced probability of acute GVHD and better survival with at-home care than with hospital care.

[Stem cell transplantation in the treatment of gastrointestinal diseases]

The stem cells with self-renewal ability are capable to form one or more cell types. They will be in the target of cell and gene therapy because of their multipotency and easy retrieval. Application of adult mesenchymal, neuronal, epidermal and haematopoietic stem cell can be favourable in the treatment of cardiac (myocardial infarction), bone (osteoarthritis), neurological (Parkinson's, Alzheimer's) and hematological (hemophilia, thrombocytopenia) disorders. Authors summarize the knowledge in connection with their application in the therapy of gastrointestinal diseases. Haematopoietic stem cell transplantation has been successful for the treatment of refractory Crohn's disease, as well as in selected group of celiac patients. Mesenchymal stem cell transplantation has been proved beneficial in the prevention of liver fibrotic process. It will gain more grounds in the treatment of autoimmune liver diseases: autoimmune hepatitis, primary biliary cirrhosis and primary sclerosing cholangitis in the future. Well-designed, multicentric, prospective studies are needed to confirm the results of case reports and clinical studies with small group of patients.

Graft-versus-tumor effect after reduced-intensity allogeneic hematopoietic stem cell transplantation in a patient with advanced colon cancer

A 27-year-old man with advanced colon cancer that was resistant to conventional chemoradiotherapies was treated with reduced-intensity allogeneic peripheral blood stem cell transplantation (PBSCT). After obtaining complete donor-type chimerism, there was an apparent graft-versus-tumor effect accompanied by severe hepatic graft-versus-host disease (GVHD) showing hyperbilirubinemia, resulting in a stable disease condition that lasted for 18 months, which had not been seen previously in his previous disease history. The antitumor effect observed in this patient was insufficient for the patient to achieve complete remission, because the disease was at an already widespread and treatment-resistant stage. He finally died of hepatic failure due to extensive liver GVHD 65 months after the diagnosis of the advanced colon cancer and 29 months after the allogeneic PBSCT. Prospective studies are necessary to achieve better clinical results in patients with advanced colon cancer.