CAR-T Cells in the Treatment of Ovarian Cancer: A Promising Cell Therapy

Ovarian cancer (OC) is among the most common gynecologic malignancies with a poor prognosis and a high mortality rate. Most patients are diagnosed at an advanced stage (stage III or IV), with 5-year survival rates ranging from 25% to 47% worldwide. Surgical resection and first-line chemotherapy are the main treatment modalities for OC. However, patients usually relapse within a few years of initial treatment due to resistance to chemotherapy. Cell-based therapies, particularly adoptive T-cell therapy and chimeric antigen receptor T (CAR-T) cell therapy, represent an alternative immunotherapy approach with great potential for hematologic malignancies. However, the use of CAR-T-cell therapy for the treatment of OC is still associated with several difficulties. In this review, we comprehensively discuss recent innovations in CAR-T-cell engineering to improve clinical efficacy, as well as strategies to overcome the limitations of CAR-T-cell therapy in OC.

Priming the tumor immune microenvironment with chemo(radio)therapy: A systematic review across tumor types

BACKGROUND

Chemotherapy (CT), radiotherapy (RT), and chemoradiotherapy (CRT) are able to alter the composition of the tumor immune microenvironment (TIME). Understanding the effect of these modalities on the TIME could aid in the development of improved treatment strategies. Our aim was to systematically review studies investigating the influence of CT, RT or CRT on different TIME markers.

METHODS

The EMBASE (Ovid) and PubMed databases were searched until January 2019 for prospective or retrospective studies investigating the dynamics of the local TIME in cancer patients (pts) treated with CT, RT or CRT, with or without targeted agents. Studies could either compare baseline and follow-up specimens - before and after treatment - or a treated versus an untreated cohort. Studies were included if they used immunohistochemistry and/or flow cytometry to assess the TIME.

RESULTS

In total we included 110 studies (n = 8850 pts), of which n = 89 (n = 6295 pts) compared pre-treatment to post-treatment specimens and n = 25 (n = 2555 pts) a treated versus an untreated cohort (4 studies conducted both comparisons). For several tumor types (among others; breast, cervical, esophageal, ovarian, rectal, lung mesothelioma and pancreatic cancer) remodeling of the TIME was observed, leading to a potentially more immunologically active microenvironment, including one or more of the following: an increase in CD3 or CD8 lymphocytes, a decrease in FOXP3 Tregs and increased PD-L1 expression. Both CT and CRT were able to immunologically alter the TIME.

CONCLUSION

The TIME of several tumor types is significantly altered after conventional therapy creating opportunities for concurrent or sequential immunotherapy.

Combination therapy: A feasibility strategy for CAR-T cell therapy in the treatment of solid tumors

Chimeric antigen receptor (CAR) T-cell therapies have been demonstrated to have durable and potentially curative therapeutic efficacies in patients with hematological malignancies. Currently, multiple clinical trials in CAR-T cell therapy have been evaluated for the treatment of patients with solid malignancies, but have had less marked therapeutic effects when the agents are used as monotherapies. When summarizing relevant studies, the present study found that combination therapy strategies for solid tumors based on CAR-T cell therapies might be more effective. This review will focus on various aspects of treating solid tumors with CAR-T cell therapy: i) The therapeutic efficacy of CAR-T cell monotherapy, ii) the feasibility of the CAR-T cell therapy in conjunction with chemotherapy, iii) the feasibility of CAR-T cell therapy with radiotherapy, iv) the feasibility of CAR-T cell therapy with chemoradiotherapy, and v) the feasibility of the combination of CAR-T cell therapy with other strategies.

MZB1 in borderline resectable pancreatic cancer resected after neoadjuvant chemoradiotherapy

BACKGROUND

A high accumulation of CD8⁺ tumor-infiltrating lymphocytes (TILs) induced by neoadjuvant chemoradiotherapy (NACRT) is associated with a favorable prognosis in patients with pancreatic ductal adenocarcinoma (PDAC). However, the correlation between a high accumulation of CD8⁺ TILs and a favorable prognosis has yet to be fully clarified. The aim of this study was to determine predictive markers of a high accumulation of CD8⁺ TILs, with a favorable prognosis, using proteomic analysis.

MATERIALS AND METHODS

We studied 72 resected borderline resectable PDAC patients treated with NACRT between April 2009 and March 2014. Three matched pairs of high CD8⁺ TIL patients with a favorable prognosis and low CD8⁺ TIL patients with a poor prognosis were selected. Shotgun proteomics of the stroma and cancerous lesion was performed using formalin-fixed, paraffin-embedded tissue. Validation of the identified proteins was performed using immunohistochemical staining. Relationships between the identified proteins and TILs and clinical outcomes were assessed.

RESULTS

Marginal zone B- and B1-cell-specific protein (MZB1) was detected in the tumor stroma. MZB1 expression was positively correlated with a high accumulation of CD8⁺ TILs. High stromal MZB1 expression also correlated with disease-free and overall survival. In a subgroup analysis of CD8⁺ expression, there was a significant association between stromal MZB1 expression and disease-free and overall survival in the high CD8⁺ TIL group.

CONCLUSIONS

MZB1 is a potential marker of a high accumulation of CD8⁺ TILs in borderline resectable PDACs resected after NACRT. Combination of CD8⁺ TILs with MZB1 may be a new biomarker of resected cases after NACRT.