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

Therapeutic effect of haploidentical peripheral blood stem cell treatment on relapsed/refractory ovarian cancer

The traditional immunotherapy is limited on relapsed/refractory metastatic ovarian cancer because tumors cause immunosuppression. Since new therapeutic strategies to improve clinical outcomes for patients with relapsed/refractory metastatic ovarian carcinoma are needed, the aim of this study was to evaluate the therapeutic effect of haploidentical peripheral blood stem cells (haplo-PBSCs) adoptive treatment on relapsed/refractory ovarian cancer. Thirteen patients with advanced stage of ovarian cancer and refractory history after surgery and chemotherapy were treated with interleukin-2 activated haplo-PBSCs donated by their parents or children. Clinical outcomes including therapeutic response by measuring tumor size changes using CT scanning, CA-125 levels and survival times were evaluated. T and NK cell population in patients before and after treatment was detected by flow cytometry analysis. The median follow-up time after haplo-PBSCs adoptive treatment was 14 months. At the time of the last follow-up, the median overall survival after haplo-PBSCs adoptive treatment was 9.1 months. Ten patients (76.9%) achieved a relief of symptoms, including abdominal distention, ache, fatigue, and poor appetite. During the first 2 months after treatment, CA125 levels decreased in 10 patients (76.9%). Five patients (38.5%) had a stable disease and 1 patient (8%) had partial response. T cell population (CD3⁺CD4⁺ and CD3⁺CD8⁺) and CD3^-CD16⁺CD56⁺ NK cells were increased in patients after haplo-PBSCs adoptive treatment. Our study reveals that haplo-PBSCs adoptive treatment is associated with an anti-tumor effect and increasing immune responses in patients with relapsed/refractory ovarian cancer.

Inflammation Control and Immunotherapeutic Strategies in Comprehensive Cancer Treatment

Tumor growth and expansion are determined by the immunological tumor microenvironment (TME). Typically, early tumorigenic stages are characterized by the immune system not responding or weakly responding to the tumor. However, subsequent tumorigenic stages witness the tumor promoting its growth and metastasis by stimulating tumor-protective (pro-tumor) inflammation to suppress anti-tumor immune responses. Here, we propose the pivotal role of inflammation control in a successful anti-cancer immunotherapy strategy, implying that available and novel immunotherapeutic modalities such as inflammation modulation, antibody (Ab)-based immunostimulation, drug-mediated immunomodulation, cancer vaccination as well as adoptive cell immunotherapy and donor leucocyte transfusion could be applied in cancer patients in a synergistic manner to amplify each other's clinical effects and achieve robust anti-tumor immune reactivity. In addition, the anti-tumor effects of immunotherapy could be enhanced by thermal and/or oxygen therapy. Herein, combined immune-based therapy could prove to be beneficial for patients with advanced cancers, as aiming to provide long-term tumor cell/mass dormancy by restraining compensatory proliferation of surviving cancer cells observed after traditional anti-cancer interventions such as surgery, radiotherapy, and metronomic (low-dose) chemotherapy. We propose the Inflammatory Prognostic Score based on the blood levels of C-reactive protein and lactate dehydrogenase as well as the neutrophil-to-lymphocyte ratio to effectively monitor the effectiveness of comprehensive anti-cancer treatment.

Clinically feasible and prospective immunotherapeutic interventions in multidirectional comprehensive treatment of cancer

INTRODUCTION

The immune system is able to exert both tumor-destructive and tumor-protective functions. Immunotherapeutic technologies aim to enhance immune-based anti-tumor activity and (or) weaken tumor-protective immunity.

AREAS COVERED

Cancer vaccination, antibody (Ab)-mediated cytotoxicity, Ab-based checkpoint molecule inhibition, Ab-based immunostimulation, cytokine therapy, oncoviral therapy, drug-mediated immunostimulation, exovesicular therapy, anti-inflammatory therapy, neurohormonal immunorehabilitation, metabolic therapy, as well as adoptive cell immunotherapy, could be coherently used to synergize and amplify each other in achieving robust anti-cancer responses in cancer patients. Tumor-specific immunotherapy applied at early stages is capable of eliminating remaining tumor cells after surgery, thus preventing the development of minimal residual disease. Patients with advanced disease stages could benefit from combined immunotherapy, which would be aimed at providing tumor cell/mass dormancy. Traditional therapeutic anti-cancer interventions (chemoradiotherapy, hyperthermia, anti-hormonal therapy) could significantly enhance tumor sensitivity to anti-cancer immunotherapy. It is important that lower-dose (metronomic) chemotherapy regimens, which are well-tolerated by normal cells, could advance immune-mediated control over tumor growth.

EXPERT OPINION

We envisage that combined immunotherapy regimens in the context of traditional treatment could become the mainstream modality for treating cancers in all phases of the tumorigenesis. The effectiveness of the anti-cancer treatment could be monitored by the following blood parameters: C-reactive protein, lactate dehydrogenase, and neutrophil-to-lymphocyte ratio.