Phenotypic immune characterization of gastric and esophageal adenocarcinomas reveals profound immune suppression in esophageal tumor locations.

Background: Tumors in the distal esophagus (EAC), gastro-esophageal junction including cardia (GEJAC), and stomach (GAC) develop in close proximity and show strong similarities on a molecular and cellular level. However, recent clinical data showed that the effectiveness of chemo-immunotherapy is limited to a subset of GEAC patients and that EACs and GEJACs generally benefit less from checkpoint inhibition compared to GACs. As the composition of the tumor immune microenvironment drives response to (immuno)therapy we here performed a detailed immune analysis of a large series of GEACs to facilitate the development of a more individualized immunomodulatory strategy. Methods: Extensive immunophenotyping was performed by 14-color flow cytometry in a prospective study to detail the immune composition of untreated gastro-esophageal cancers (n=104) using fresh tumor biopsies of 35 EACs, 38 GEJACs and 31 GACs. The immune cell composition of GEACs was characterized and correlated with clinicopathologic features such as tumor location, MSI and HER2 status. The spatial immune architecture of a subset of tumors (n=30) was evaluated using multiplex immunohistochemistry (mIHC) which allowed us to determine the tumor infiltration status of CD3+, CD8+, FoxP3+, CD163+ and Ki67+ cells. Results: Immunophenotyping revealed that the tumor immune microenvironment of GEACs is heterogeneous and that immune suppressive cell populations such as monocytic myeloid-derived suppressor cells (mMDSC) are more abundant in EACs compared to GACs (p<0.001). In contrast, GACs indicated a proinflammatory microenvironment with elevated frequencies of proliferating (Ki67+) CD4 Th cells (p<0.001), Ki67+ CD8 T cells (p=0.002), and CD8 effector memory-T cells (p=0.024). Differences between EACs and GACs were confirmed by mIHC analyses showing lower densities of tumor- and stroma-infiltrating Ki67+ CD8 T cells in EAC compared to GAC (both p=0.021). Discussions: This comprehensive immune phenotype study of a large series of untreated GEACs, identified that tumors with an esophageal tumor location have more immune suppressive features compared to tumors in the gastro-esophageal junction or stomach which might explain the location-specific responses to checkpoint inhibitors in this disease. These findings provide an important rationale for stratification according to tumor location in clinical studies and the development of location-dependent immunomodulatory treatment approaches.

Interferon- and STING-independent induction of type I interferon stimulated genes during fractionated irradiation.

BACKGROUND: Improvement of radiotherapy efficacy requires better insight in the dynamic responses that occur during irradiation. Here, we aimed to identify the molecular responses that are triggered during clinically applied fractionated irradiation. METHODS: Gene expression analysis was performed by RNAseq or microarray analysis of cancer cells or xenograft tumors, respectively, subjected to 3-5 weeks of 5 × 2 Gy/week. Validation of altered gene expression was performed by qPCR and/or ELISA in multiple cancer cell lines as well as in pre- and on-treatment biopsies from esophageal cancer patients ( NCT02072720 ). Targeted protein inhibition and CRISPR/Cas-induced gene knockout was used to analyze the role of type I interferons and cGAS/STING signaling pathway in the molecular and cellular response to fractionated irradiation. RESULTS: Gene expression analysis identified type I interferon signaling as the most significantly enriched biological process induced during fractionated irradiation. The commonality of this response was confirmed in all irradiated cell lines, the xenograft tumors and in biopsies from esophageal cancer patients. Time-course analyses demonstrated a peak in interferon-stimulated gene (ISG) expression within 2-3 weeks of treatment. The response was accompanied by a variable induction of predominantly interferon-beta and/or -lambda, but blocking these interferons did not affect ISG expression induction. The same was true for targeted inhibition of the upstream regulatory STING protein while knockout of STING expression only delayed the ISG expression induction. CONCLUSIONS: Collectively, the presented data show that clinically applied fractionated low-dose irradiation can induce a delayed type I interferon response that occurs independently of interferon expression or STING signaling. These findings have implications for current efforts that aim to target the type I interferon response for cancer treatment.

Molecular profiles of response to neoadjuvant chemoradiotherapy in oesophageal cancers to develop personalized treatment strategies.

Identification of molecular predictive markers of response to neoadjuvant chemoradiation could aid clinical decision-making in patients with localized oesophageal cancer. Therefore, we subjected pretreatment biopsies of 75 adenocarcinoma (OAC) and 16 squamous cell carcinoma (OSCC) patients to targeted next-generation DNA sequencing, as well as biopsies of 85 OAC and 20 OSCC patients to promoter methylation analysis of eight GI-specific genes, and subsequently searched for associations with histopathological response and disease-free (DFS) and overall survival (OS). Thereby, we found that in OAC, CSMD1 deletion (8%) and ETV4 amplification (5%) were associated with a favourable histopathological response, whereas SMURF1 amplification (5%) and SMARCA4 mutation (7%) were associated with an unfavourable histopathological response. KRAS (15%) and GATA4 (7%) amplification were associated with shorter OS. In OSCC, TP63 amplification (25%) and TFPI2 (10%) gene promoter methylation were associated with an unfavourable histopathological response and shorter DFS (TP63) and OS (TFPI2), whereas CDKN2A deletion (38%) was associated with prolonged OS. In conclusion, this study identified candidate genetic biomarkers associated with response to neoadjuvant chemoradiotherapy in patients with localized oesophageal cancer.

A Phase I Open-Label Clinical Trial Evaluating the Therapeutic Vaccine hVEGF26-104/RFASE in Patients with Advanced Solid Malignancies.

LESSONS LEARNED: The novel therapeutic vaccine hVEGF26-104 /RFASE was found to be safe and well tolerated in patients with cancer. hVEGF26-104 /RFASE failed to induce seroconversion against native hVEGF165 and, accordingly, neither a decrease in circulating vascular endothelial growth factor (VEGF) levels nor clinical benefit was observed. Remarkably, hVEGF26-104 /RFASE induced VEGF165 -neutralizing antibodies in a nonhuman primate model. The absence of seroconversion in human calls for caution in the interpretation of efficacy of human vaccines in nonhuman primates. BACKGROUND: Targeting vascular endothelial growth factor-A (VEGF) is a well-established anticancer therapy. We designed a first-in-human clinical trial to investigate the safety and immunogenicity of the novel vaccine hVEGF26-104 /RFASE. METHODS: Patients with advanced solid malignancies with no standard treatment options available were eligible for this phase I study with a 3+3 dose-escalation design. On days 0, 14, and 28, patients received intramuscular hVEGF26-104 , a truncated synthetic three-dimensional (3D)-structured peptide mimic covering the amino acids 26-104 of the human VEGF165 isoform, emulsified in the novel adjuvant Raffinose Fatty Acid Sulphate Ester (RFASE), a sulpholipopolysaccharide. Objectives were to determine safety, induction of VEGF-neutralizing antibodies, and the maximum tolerated dose. Blood was sampled to measure VEGF levels and antibody titers. RESULTS: Eighteen of 27 enrolled patients received three immunizations in six different dose-levels up to 1,000 µg hVEGF26-104 and 40 mg RFASE. No dose-limiting toxicity was observed. Although in four patients an antibody titer against hVEGF26-104 was induced (highest titer: 2.77 10 log), neither a reduction in VEGF levels nor neutralizing antibodies against native VEGF165 were detected. CONCLUSION: Despite having an attractive safety profile, hVEGF26-104 /RFASE was not able to elicit seroconversions against native VEGF165 and, consequently, did not decrease circulating VEGF levels. Deficient RFASE adjuvant activity, as well as dominant immunoreactivity toward neoepitopes, may have impeded hVEGF26-104 /RFASE's efficacy in humans.

Development of transient radioresistance during fractionated irradiation in vitro.

BACKGROUND AND PURPOSE: Effective combination treatments with fractionated radiotherapy rely on a proper understanding of the dynamic responses that occur during treatment. We explored the effect of clinical fractionated radiotherapy on the development and timing of radioresistance in tumor cells. METHODS AND MATERIALS: Different colon (HT29/HCT116/COLO320/SW480/RKO) and high-grade astrocytoma (D384/U-251MG) cancer cell lines were treated for 6 weeks with daily fractions of 2 Gy, 5 days per week. Clonogenic survival was determined throughout the treatment period. In addition, the radiosensitivity of irradiated and non-irradiated was compared. Finally, the effect of different dose fractions on the development of radioresistance was determined. RESULTS: All cell lines developed radioresistance within 2-3 weeks during fractionated radiotherapy. This was characterized by the occurrence of a steady state phase of clonogenic survival. In U-251MG cells this was accompanied by increased cell senescence and stemness. After recovering from six weeks of treatment, the radiosensitivity of fractionally irradiated and non-irradiated cells was similar. Including transient radioresistance, described as (α/ß)-(d+1), as a factor in the classic LQ model resulted in a perfect fit with the experimental data observed during fractionated radiotherapy. This was confirmed when different dose fractions were applied. CONCLUSIONS: Fractionated irradiation of cancer cells in vitro following clinical radiation schedules induces a reversible radioresistance response. This adaptive response can be included in the LQ model as a function of the dose fraction and the alpha/beta-ratio of a given cell line. These findings warrant further investigation of the mechanisms and clinical relevance of adaptive radioresistance.

Combining Radiation Therapy With Interferons: Back to the Future.

Radiation therapy has been linked to the induction of an intratumoral type I interferon (IFN) response, which positively affects the response to treatment. This has spiked the interest to combine radiation therapy with IFN-based treatment. Interestingly, this combination treatment has been considered previously, since preclinical studies demonstrated a radiosensitizing effect of interferons. As a result, multiple clinical trials have been performed combining radiation therapy with interferons in different tumor types. Although potential benefit has been suggested, the outcomes of the trials are diverse and challenging to interpret. In addition, increased grade ≥3 toxicity frequently resulted in a negative recommendation regarding the combination therapy. The latter appears premature because many studies were small and several aspects of the combination treatment have not yet been sufficiently explored to justify such a definite conclusion. This review summarizes the available literature on this combination therapy, with a focus on IFN-α and IFN-ß. Based on preclinical studies and clinical trials, we evaluated the potential opportunities and describe the current challenges. In addition, we identify several issues that should be addressed to fully exploit the potential benefit of this combinatorial treatment approach.

[Non-metastatic oesophageal cancer: diagnosis and treatment]. / Niet-gemetastaseerde slokdarmkanker.

The incidence of oesophageal cancer is on the rise, particularly due to an increase in the number of adenocarcinomas of the distal oesophagus. Adenomas and squamous cell carcinomas are the most common histological subtypes; each should be considered as a different entity. The diagnosis 'oesophageal cancer' is confirmed on the basis of histopathological investigation of biopsies, whereas tumour staging is conducted through transoesophageal endoscopic ultrasound and FDG-PET/CT diagnostics. There are various options to treat patients with oesophageal cancer, such as endoscopic resection, multimodal therapy or definitive chemoradiotherapy. Since 2012, neoadjuvant chemoradiotherapy followed by surgery is the standard treatment for oesophageal cancer, except with regard to patients with a T1 or M1 tumour. In the Netherlands, most surgical procedures are now minimally invasive procedures. Despite improved treatment options, mortality rates associated with oesophageal cancer remain high.

Combining Radiotherapy With Anti-angiogenic Therapy and Immunotherapy; A Therapeutic Triad for Cancer?

Radiotherapy has been used for the treatment of cancer for over a century. Throughout this period, the therapeutic benefit of radiotherapy has continuously progressed due to technical developments and increased insight in the biological mechanisms underlying the cellular responses to irradiation. In order to further improve radiotherapy efficacy, there is a mounting interest in combining radiotherapy with other forms of therapy such as anti-angiogenic therapy or immunotherapy. These strategies provide different opportunities and challenges, especially with regard to dose scheduling and timing. Addressing these issues requires insight in the interaction between the different treatment modalities. In the current review, we describe the basic principles of the effects of radiotherapy on tumor vascularization and tumor immunity and vice versa. We discuss the main strategies to combine these treatment modalities and the hurdles that have to be overcome in order to maximize therapeutic effectivity. Finally, we evaluate the outstanding questions and present future prospects of a therapeutic triad for cancer.

Hysteroscopic sterilization using a virtual reality simulator: assessment of learning curve.

STUDY OBJECTIVE: To assess the learning curve using a virtual reality simulator for hysteroscopic sterilization with the Essure method. DESIGN: Prospective multicenter study (Canadian Task Force classification II-2). SETTING: University and teaching hospital in the Netherlands. PARTICIPANTS: Thirty novices (medical students) and five experts (gynecologists who had performed >150 Essure sterilization procedures). INTERVENTIONS: All participants performed nine repetitions of bilateral Essure placement on the simulator. Novices returned after 2 weeks and performed a second series of five repetitions to assess retention of skills. Structured observations on performance using the Global Rating Scale and parameters derived from the simulator provided measurements for analysis. MEASUREMENTS AND MAIN RESULTS: The learning curve is represented by improvement per procedure. Two-way repeated-measures analysis of variance was used to analyze learning curves. Effect size (ES) was calculated to express the practical significance of the results (ES ≥ 0.50 indicates a large learning effect). For all parameters, significant improvements were found in novice performance within nine repetitions. Large learning effects were established for six of eight parameters (p < .001; ES, 0.50-0.96). Novices approached expert level within 9 to 14 repetitions. CONCLUSION: The learning curve established in this study endorses future implementation of the simulator in curricula on hysteroscopic skill acquisition for clinicians who are interested in learning this sterilization technique.