Objective: Programmed cell death protein 1 (PD-1) checkpoint inhibition and adoptive cellular therapy have had limited success in patients with microsatellite stable colorectal cancer liver metastases (CRLM). We sought to evaluate the effect of interleukin 10 (IL-10) blockade on endogenous T cell and chimeric antigen receptor T (CAR-T) cell antitumour function in CRLM slice cultures. Design: We created organotypic slice cultures from human CRLM (n=38 patients’ tumours) and tested the antitumour effects of a neutralising antibody against IL-10 (αIL-10) both alone as treatment and in combination with exogenously administered carcinoembryonic antigen (CEA)-specific CAR-T cells. We evaluated slice cultures with single and multiplex immunohistochemistry, in situ hybridisation, single-cell RNA sequencing, reverse-phase protein arrays and time-lapse fluorescent microscopy. Results: αIL-10 generated a 1.8-fold increase in T cell-mediated carcinoma cell death in human CRLM slice cultures. αIL-10 significantly increased proportions of CD8 ⁺ T cells without exhaustion transcription changes, and increased human leukocyte antigen - DR isotype (HLA-DR) expression of macrophages. The antitumour effects of αIL-10 were reversed by major histocompatibility complex class I or II (MHC-I or MHC-II) blockade, confirming the essential role of antigen presenting cells. Interrupting IL-10 signalling also rescued murine CAR-T cell proliferation and cytotoxicity from myeloid cell-mediated immunosuppression. In human CRLM slices, αIL-10 increased CEA-specific CAR-T cell activation and CAR-T cell-mediated cytotoxicity, with nearly 70% carcinoma cell apoptosis across multiple human tumours. Pretreatment with an IL-10 receptor blocking antibody also potentiated CAR-T function. Conclusion: Neutralising the effects of IL-10 in human CRLM has therapeutic potential as a stand-alone treatment and to augment the function of adoptively transferred CAR-T cells.

The impact of systemic therapy on the tumor microenvironment has been difficult to study in human solid tumors. Our protocol describes steps for establishing slice cultures to investigate response to chemotherapies, immunotherapies, or adoptive cell therapies. Endpoints include changes in viability, histology, live-cell imaging, and multi-omics analyses. The protocol has been applied to a broad array of gastrointestinal malignancies. Culture conditions and treatment parameters can be modified for specific experiments. The platform is highly flexible and easy to manipulate.

PURPOSE: Nearly half of all Medicare beneficiaries are enrolled in privatized Medicare insurance plans (Medicare Advantage [MA]). Little comparative information is available about access, outcomes, and cost of inpatient cancer surgery between MA and Traditional Medicare (TM) beneficiaries. We set out to assess and compare access, postoperative outcomes, and estimated cost of inpatient cancer surgery among MA and TM beneficiaries.METHODS: Retrospective cohort analysis of MA or TM beneficiaries undergoing elective inpatient cancer surgery (for cancers located in lung, esophagus, stomach, pancreas, liver, colon, or rectum) was performed using the Office of Statewide Health Planning Inpatient Database linked to California Cancer Registry from 2000 to 2020. For each cancer site, risk-standardized access to high-volume hospitals, postoperative 30-day mortality, complications, failure to rescue, and surgery-specific estimated costs were compared between MA and TM beneficiaries.RESULTS: This analysis of 76,655 Medicare beneficiaries (median age 74 years, 51% female, 39% MA) included 31,913 colectomies, 10,358 proctectomies, 4,604 hepatectomies, 2,895 pancreatectomies, 3,639 gastrectomies, 1,555 esophagectomies, and 21,691 lung resections. Except for colon surgery, MA beneficiaries were less likely to receive care at a high-volume hospital. Mortality was significantly higher among MA beneficiaries ( v TM) for gastrectomy (adjusted risk difference [ARD], 1.5%; 95% CI, 0.01 to 2.9; P = .036), pancreatectomy (ARD, 2.0%; CI, 0.80 to 3.3; P = .002), and hepatectomy (ARD, 1.4%; 95% CI, 0.1 to 2.9; P = .04). By contrast, compared with TM, MA beneficiaries incurred lower estimated hospital costs.CONCLUSION: Enrollment in MA plan is associated with lower estimated hospital costs. However, compared with TM, MA beneficiaries had lower access to high-volume hospitals and increased 30-day mortality for stomach, pancreas, or liver surgery.

Metastatic colorectal cancer (CRC) is a major cause of cancer-related death, and incidence is rising in younger populations (younger than 50 years). Current chemotherapies can achieve response rates above 50%, but immunotherapies have limited value for patients with microsatellite-stable (MSS) cancers. The present study investigates the impact of chemotherapy on the tumor immune microenvironment. We treat human liver metastases slices with 5-fluorouracil (5-FU) plus either irinotecan or oxaliplatin, then perform single-cell transcriptome analyses. Results from eight cases reveal two cellular subtypes with divergent responses to chemotherapy. Susceptible tumors are characterized by a stemness signature, an activated interferon pathway, and suppression of PD-1 ligands in response to 5-FU+irinotecan. Conversely, immune checkpoint TIM-3 ligands are maintained or upregulated by chemotherapy in CRC with an enterocyte-like signature, and combining chemotherapy with TIM-3 blockade leads to synergistic tumor killing. Our analyses highlight chemomodulation of the immune microenvironment and provide a framework for combined chemo-immunotherapies.

A spectrum of immune states resulting from tumor resident macrophages and T-lymphocytes in the solid tumor microenvironment correlates with patient outcomes. We hypothesized that in gastric cancer (GC), macrophages in a polarized immunosuppressive transcriptional state would be prognostic of poor survival. We derived transcriptomic signatures for M2 (M2_TS, MRC1; MS4A4A; CD36; CCL13; CCL18; CCL23; SLC38A6; FGL2; FN1; MAF) and M1 (M1_TS, CCR7; IL2RA; CXCL11; CCL19; CXCL10; PLA1A; PTX3) macrophages, and cytolytic T-lymphocytes (CTL_TS, GZMA; GZMB; GZMH; GZMM; PRF1). Primary GC in a TCGA stomach cancer dataset was evaluated for signature expressions, and a log-rank test determined overall survival (OS) and the disease-free interval (DFI). In 341 TCGA GC entries, high M2_TS expression was associated with histological types and later stages. Low M2_TS expression was associated with significantly better 5-year OS and DFI. We validated M2_TS in prospectively collected peritoneal fluid of a GC patient cohort (n = 28). Single-cell RNA sequencing was used for signature expression in CD68⁺CD163⁺ cells and the log-rank test compared OS. GC patients with high M2_TS in CD68⁺CD163⁺ cells in their peritoneal fluid had significantly worse OS than those with low expression. Multivariate analyses confirmed M2_TS was significantly and independently associated with survival. As an independent predictor of poor survival, M2_TS may be prognostic in primary tumors and peritoneal fluid of GC patients.

With the widespread adoption of molecular profiling in clinical oncology practice, many physicians are faced with making therapeutic decisions based upon isolated genomic alterations. For example, epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) are effective in EGFR-mutant non-small cell lung cancers (NSCLC) while anti-EGFR monoclonal antibodies are ineffective in Ras-mutant colorectal cancers. The matching of mutations with drugs aimed at their respective gene products represents the current state of “precision” oncology. Despite the great expectations of this approach, only a fraction of cancers responds to ‘targeted’ interventions, and many early responders will ultimately develop resistance to these agents. The underwhelming success of mutation-driven therapies across all cancer types is not due to an inability to detect genetic changes in tumors; rather a deficit in functional insight into the genomic alterations that give rise to each cancer. The Achilles heel of precision oncology thus remains the lack of a robust functional understanding of an individual cancer genome that then allows prediction of the best therapy and resultant outcome for that patient. Current practice focuses on one ‘actionable’ mutation at a time, while solid cancers typically possess many mutations that involve different cellular sub-populations within a tumor. No method or platform currently exists to guide the interpretation of these complex data, nor to accurately predict response to treatment. This problem is particularly germane to primary liver cancers (PLC), for which only a handful of targeted therapies have been introduced. Here, we will review strategies aimed at overcoming some of these challenges in precision oncology, using liver cancer as an example.