Analysis of immune status after iodine-125 permanent brachytherapy in prostate cancer

The roles of essential trace elements in T cell biology

T cells are crucial for adaptive immunity to regulate proper immune response and immune homeostasis. T cell development occurs in the thymus and mainly differentiates into CD4+ and CD8+ T cell subsets. Upon stimulation, naive T cells differentiate into distinct CD4+ helper and CD8+ cytotoxic T cells, which mediate immunity homeostasis and defend against pathogens or tumours. Trace elements are minimal yet essential components of human body that cannot be overlooked, and they participate in enzyme activation, DNA synthesis, antioxidant defence, hormone production, etc. Moreover, trace elements are particularly involved in immune regulations. Here, we have summarized the roles of eight essential trace elements (iron, zinc, selenium, copper, iodine, chromium, molybdenum, cobalt) in T cell development, activation and differentiation, and immune response, which provides significant insights into developing novel approaches to modulate immunoregulation and immunotherapy.

Brachytherapy for high grade prostate cancer induces distinct changes in circulating CD4 and CD8 T cells - Implications for systemic control

This exploratory study is a follow up to our previous investigation of immune response in the circulation of high-grade Gleason 9 prostate cancer patients treated with EBRT + BT compared to EBRT alone. Notably, EBRT + BT demonstrates the potential to elicit an effect on CD4/CD8 ratio which may have attributed to improved clinical response to therapy. Our findings show promise for leveraging circulating immune cells as predictive biomarkers for radiotherapy response.

A "scoping" review of prostate brachytherapy and immune responses

PURPOSE

Whether prostate brachytherapy (BT) results in opportunistic biological changes that can improve clinical outcomes is not well studied. We sought to investigate the impact of prostate BT on the immune system.

MATERIALS AND METHODS

A scoping review was performed using PubMed/Scopus for papers published between 2011-2021. Search terms were "brachytherapy" AND "immune" AND "prostate". A total of 81 records were identified and 6 were selected for further review.

RESULTS

2 low-dose-rate BT papers (n=68) evaluated changes in the peripheral blood following I-125 monotherapy. Both showed significant increases in peripheral CD3+ and CD4+ T cells post-BT. One also demonstrated significant increases in Treg subsets up to 150 days post-BT. 4 high-dose-rate (HDR) studies (n=37) were identified, and all were done in combination with EBRT. The largest study (n=24) showed a single 10 Gy fraction of HDR converted 80% of "cold" tumors into an "intermediate" or "hot" state, based on a tumor inflammation signature when comparing a pre-BT biopsy to one prior to a second HDR fraction.

CONCLUSION

Prostate BT can invoke an immune activating phenotype; however, changes in immunosuppressive cells are also seen. Additional data is needed to understand how to promote synergy between BT and the immune system.

Traditional Chinese medicine CFF-1 exerts a potent anti-tumor immunity to hinder tumor growth and metastasis in prostate cancer through EGFR/JAK1/STAT3 pathway to inhibit PD-1/PD-L1 checkpoint signaling

BACKGROUND

Traditional Chinese Medicine (TCM) CFF-1 has been used in clinic for prostate cancer therapy in China. We reported before CFF-1 induced cell apoptosis via suppressing EGFR-related pathways, reminding us its potential role associated with antitumor immunity.

PURPOSE

The study was aimed to investigate the regulatory mechanism of CFF-1 on PD-L1/PD-1-mediated tumor immune escape.

METHODS

Prostate-specific antigen (PSA) test and the functional assessment of cancer therapy-prostate (FACT-P) and karnosky performance status (KPS) questionnaires were carried out to evaluate patient' condition before and after therapy. Flow cytometry (FCM) was used for analyzing cell apoptosis, T lymphocyte subsets and cell cycle. Western blotting and Immunohistochemistry (IHC) were performed to measure protein expressions. The synergy of drug combination was assessed by calculating combination index (CI).

RESULTS

CFF-1 obviously decreased PSA and improved the quality of life in patients with advanced prostate cancer. PD-L1 was highly expressed in prostate cancer cells including LNCaP, 22Rv1, PC-3, DU145 and RM-1. PD-1/PD-L1 was upregulated in tumorigenesis and tumor progression of subcutaneous homograft mouse model with immune response, where CD3+ T cell subsets were declined. CFF-1 inhibited PD-L1 expression in prostate cancer cells in a time/dose-dependent manner and blocked tumor growth by suppressing PD-1/PD-L1 upregulation to promote the recovery of CD3+ T lymphocytes, especially CD4+ T cell subset, accompanied by the downregulation of CD4+ FOXP3+ T cell subset. CFF-1 also prolonged the survival and inhibited lung metastasis in tail vein prostate cancer mouse model while repressing PD-1/PD-L1. CFF-1 in combination with docetaxol (DTX) produced a synergistic effects by sensitizing the inhibitory effect of DTX on JAK1/STAT3 pathway targeting PD-L1 blockade.

CONCLUSION

CFF-1 inhibited tumor growth and lung metastasis by blocking PD-1/PD-L1 to ameliorate T lymphocyte immune response through EGFR/JAK1/STAT3 pathway, suggesting that CFF-1 might be a promising treatment to resist tumor immunosuppression for prostate cancer patients.

Radioactive Iodine-125 in Tumor Therapy: Advances and Future Directions

Radioactive iodine-125 (I-125) is the most widely used radioactive sealed source for interstitial permanent brachytherapy (BT). BT has the exceptional ability to deliver extremely high doses that external beam radiotherapy (EBRT) could never achieve within treated lesions, with the added benefit that doses drop off rapidly outside the target lesion by minimizing the exposure of uninvolved surrounding normal tissue. Spurred by multiple biological and technological advances, BT application has experienced substantial alteration over the past few decades. The procedure of I-125 radioactive seed implantation evolved from ultrasound guidance to computed tomography guidance. Compellingly, the creative introduction of 3D-printed individual templates, BT treatment planning systems, and artificial intelligence navigator systems remarkably increased the accuracy of I-125 BT and individualized I-125 ablative radiotherapy. Of note, utilizing I-125 to treat carcinoma in hollow cavity organs was enabled by the utility of self-expandable metal stents (SEMSs). Initially, I-125 BT was only used in the treatment of rare tumors. However, an increasing number of clinical trials upheld the efficacy and safety of I-125 BT in almost all tumors. Therefore, this study aims to summarize the recent advances of I-125 BT in cancer therapy, which cover experimental research to clinical investigations, including the development of novel techniques. This review also raises unanswered questions that may prompt future clinical trials and experimental work.

Interventional Treatment for Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common type of primary liver malignancy. The latest classification includes intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma, with the latter one further categorized into perihilar and distal cholangiocarcinoma. Although surgical resection is the preferred treatment for CCA, less than half of the patients are actually eligible for radical surgical resection. Interventional treatment, such as intra-arterial therapies, ablation, and brachytherapy (iodine-125 seed implantation), has become an acceptable palliative treatment for patients with unresectable CCA. For these patients, interventional treatment is helpful for locoregional control, symptom relief, and improving quality of life. Herein, in a timely and topical manner, we will review these advances and highlight future directions of research in this article.

125I Seed Brachytherapy Combined with Single-Agent Chemotherapy in the Treatment of Non-Small-Cell Lung Cancer in the Elderly: A Valuable Solution

Purpose

The aim of this study was to compare the effectiveness and safety of CT-guided ¹²⁵I seed brachytherapy combined with single-agent chemotherapy versus combined chemotherapy in the treatment of elderly NSCLC.

Materials and Methods

We retrospectively analyzed 110 patients (64 men and 46 women; mean age=71.25±7.14 years) who were diagnosed with NSCLC without distant metastases between January 2015 and May 2020. A total of 50 patients received ¹²⁵I brachytherapy combined with single-agent chemotherapy (group A), whereas 60 patients received combined chemotherapy (group B). The response to therapy and adverse effect were compared between groups. The local response rate was evaluated by CT. Progression-free survival (PFS) and overall survival (OS) data were obtained through clinical follow-up.

Results

All patients had been treated and were followed-up for 3-60 months. The median OS and PFS were 23.71±1.41 months (95% CI=20.95-26.47) vs 16.12±0.93 months (95% CI=14.31-17.93) (P<0.05) and 15.08±0.85 months (95% CI=13.42-16.74) vs 10.03±0.53 months (95% CI=9.01-11.06) (P<0.05) in group A and group B, respectively. The local response rate and clinical symptoms of patients in group A were significantly relieved when compared with group B. Severe complications were not observed in either group.

Conclusion

CT-guided ¹²⁵I seed brachytherapy combined with single-agent chemotherapy is an effective and safe therapy and shows promising results compared to combined chemotherapy alone for NSCLC in the elderly. A randomized study will be needed to assess the superiority of this combined modality treatment.

A Clinician's Guide to Cancer-Derived Exosomes: Immune Interactions and Therapeutic Implications

Understanding of the role of immunity in the regulation of cancer growth continues to rapidly increase. This is fuelled by the impressive results yielded in recent years by immune checkpoint inhibitors, which block regulatory pathways to increase immune-mediated cancer destruction. Exosomes are cell-secreted membranous nanoscale vesicles that play important roles in regulating physiological and pathophysiological processes. Cancer-derived exosomes (CDEXs) and their biologically-active cargos have been proven to have varied effects in malignant progression, including the promotion of angiogenesis, metastasis, and favorable microenvironment modification. More recently, there is an increasing appreciation of their role in immune evasion. In addition to CDEXs, there are immune-derived exosomes that facilitate communication between immune cells in the non-malignant setting. Investigation of cancer-mediated mechanisms behind interruption or modification of these normal exosomal pathways may provide further understanding of how malignant immune evasion is accomplished. Accumulating evidence indicates that immune-active CDEXs also have the potential to impact clinical oncological management. Whilst immune checkpoint inhibitors have well-established pharmacologically-targeted pathways involving the immune system, other widely used treatments such as radiation and cytotoxic chemotherapies do not. Thus, investigating exosomes in immunotherapy is important for the development of next-generation combination therapies. In this article, we review the ways in which CDEXs impact individual immune cell types and how this contributes to the development of immune evasion. We discuss the relevance of lymphocytes and myeloid-lineage cells in the control of malignancy. In addition, we highlight the ways that CDEXs and their immune effects can impact current cancer therapies and the resulting clinical implications.

Biliary stenting alone versus biliary stenting combined with 125I particles intracavitary irradiation for the treatment of advanced cholangiocarcinoma

We aimed to compare the efficacy of percutaneous transhepatic biliary stenting (PTBS) and PTBS combined with ¹²⁵I particles implantation in the treatment of advanced extrahepatic cholangiocarcinoma (EHC). A total of 184 advanced EHC patients, who received PTBS (PTBS group) or PTBS combined with ¹²⁵I particles implantation (PTBS + ¹²⁵I group) from January 2012 to April 2017 in our department, were retrospectively reviewed. The improvement of jaundice and liver function was observed in both groups. The postoperative complications, risk of biliary re-obstruction, and overall survival (OS) were compared between the two groups. Amongst, 71 cases received PTBS and 113 had the additional implantation of ¹²⁵I particles. The jaundice and liver function were significantly improved in all patients, especially in PTBS + ¹²⁵I group. There was no significant difference in the risk of postoperative complications between the two groups. However, the risk of biliary re-obstruction significantly reduced in PTBS + ¹²⁵I group (19.5% vs. 35.2%, p = 0.017). Kaplan Meier analysis showed that patients in PTBS + ¹²⁵I group had a significantly better OS, both for hilar and distal cholangiocarcinoma. Univariate analysis demonstrated that preoperative levels of carbohydrate antigen 19-9 (CA19-9), total bilirubin, neutrophil count, lymphocyte count, and different therapeutic method were significant factors affecting OS. Multivariate analysis further identified the treatment of PTBS combined with ¹²⁵I particles implantation as an independent protective prognostic factor (HR = 0.26, 95% CI: 0.17–0.39, p < 0.001). In conclusion, for patients with advanced EHC, PTBS combined with ¹²⁵I particles implantation is superior to PTBS alone in improving liver function, inhibiting biliary re-obstruction, and prolonging survival time.

Inflammation-based prognostic scores in patients with extrahepatic bile duct lesions treated by percutaneous transhepatic biliary stenting combined with 125I seeds intracavitary irradiation

PURPOSE

This study aimed at investigating the efficacy of percutaneous transhepatic biliary stenting (PTBS) combined with ¹²⁵I seeds intracavitary irradiation in the treatment of extrahepatic cholangiocarcinoma (EHC) and to preliminarily explore the prognostic values of inflammation-based scores in these patients.

METHODS

A total of 113 clinically/pathologically diagnosed cases of EHC who received PTBS combined with ¹²⁵I seeds implantation were retrospectively analyzed. The postoperative changes of clinical symptoms and serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total serum bilirubin (TBIL), direct bilirubin (DBIL), and albumin (ALB) were observed. Preoperative clinical data were extracted to calculate inflammation-based scores, including systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelets-to-lymphocyte ratio (PLR). Kaplan-Meier survival curves and Cox regression analyses were used to evaluate the prognostic significance of inflammation-based scores.

RESULTS

After operation, clinical symptoms such as jaundice and fever significantly improved in all patients. At 1 month and 3 months postoperatively, serum levels of ALT, AST, ALP, TBIL, and DBIL significantly reduced, and ALB significantly increased, compared with preoperative values. The median survival time of the patients was 12 months and the 1-year survival rate was 56.8%. Univariate analysis revealed that factors related to overall survival were CA19-9, TBIL, ALB, SII, and NLR. Multivariate analysis further identified SII and NLR as independent prognostic models.

CONCLUSION

The combination of PTBS and ¹²⁵I seeds intracavitary irradiation is an effective palliative treatment for advanced EHC. Elevated SII and NLR can be used to predict poor survival.