Combined vaccine-immune-checkpoint inhibition constitutes a promising strategy for treatment of dMMR tumors.

BACKGROUND: Mlh1-knock-out-driven mismatch-repair-deficient (dMMR) tumors can be targeted immunologically. By applying therapeutic tumor vaccination, tumor growth is delayed but escape mechanisms evolve, including upregulation of immune-checkpoint molecules (LAG-3, PD-L1). To counteract immune escape, we investigated the therapeutic activity of a combined tumor vaccine-immune-checkpoint inhibitor therapy using α-PD-L1. DESIGN: In this trial, Mlh1-knock-out mice with established gastrointestinal tumors received single or thrice injections of α-PD-L1 monoclonal antibody clone 6E11 (2.5 mg/kg bw, q2w, i.v.) either alone or in combination with the vaccine. Longitudinal flow cytometry and PET/CT imaging studies were followed by ex vivo functional immunological and gene expression assays. RESULTS: 6E11 monotherapy slightly increased median overall survival (mOS: 6.0 weeks vs. control 4.0 weeks). Increasing the number of injections (n = 3) improved therapy outcome (mOS: 9.2 weeks) and was significantly boosted by combining 6E11 with the vaccine (mOS: 19.4 weeks vs. 10.2 weeks vaccine monotherapy). Accompanying PET/CT imaging confirmed treatment-induced tumor growth control, with the strongest inhibition in the combination group. Three mice (30%) achieved a complete remission and showed long-term survival. Decreased levels of circulating splenic and intratumoral myeloid-derived suppressor cells (MDSC) and decreased numbers of immune-checkpoint-expressing splenic T cells (LAG-3, CTLA-4) accompanied therapeutic effects. Gene expression and protein analysis of residual tumors revealed downregulation of PI3K/Akt/Wnt-and TGF-signaling, leading to T cell infiltration, reduced numbers of macrophages, neutrophils and MDSC. CONCLUSIONS: By successful uncoupling of the PD-1/PD-L1 axis, we provide further evidence for the safe and successful application of immunotherapies to combat dMMR-driven malignancies that warrants further investigation.

Soluble Triggering Receptor Expressed on Myeloid Cells 1 in lung cancer.

Soluble Triggering Receptor Expressed on Myeloid Cells 1 (sTREM-1) can be found in the sera of patients with infectious, autoimmune and malignant diseases. The primary objective of this study was to investigate the prognostic significance of sTREM-1 in lung cancer patients. We analyzed the sera of 164 patients with lung cancer of all histologies and all stages at the time of diagnosis. We employed an ELISA using the anti-TREM-1 clone 6B1.1G12 mAb and recombinant human TREM-1. Patient data was collected retrospectively by chart review. In ROC-analysis, a sTREM-1 serum level of 163.1 pg/ml showed the highest Youden-Index. At this cut-off value sTREM-1 was a marker of short survival in patients with NSCLC (median survival 8.5 vs. 13.3 months, p = 0.04). A Cox regression model showed stage (p < 0.001) and sTREM-1 (p = 0.011) to indicate short survival. There were no differences in sTREM-1 serum values among patients with or without infection, pleural effusion or COPD. sTREM-1 was not associated with metastasis at the time of diagnosis and was not a predictor of subsequent metastasis. In SCLC patients sTREM-1 levels were lower than in NSCLC patients (p = 0.001) and did not predict survival. sTREM-1 did not correlate with CRP or the number of neutrophils. In non-small cell lung cancer patients, sTREM-1 in serum has prognostic significance.

Thoracic Malignancies and Pulmonary Nodules in Patients under Evaluation for Transcatheter Aortic Valve Implantation (TAVI): Incidence, Follow Up and Possible Impact on Treatment Decision.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has become the treatment of choice in patients with severe aortic valve stenosis who are not eligible for operative replacement and an alternative for those with high surgical risk. Due to high age and smoking history in a high proportion of TAVI patients, suspicious findings are frequently observed in pre-procedural chest computer tomography (CCT). METHODS: CCT scans of 484 consecutive patients undergoing TAVI were evaluated for incidentally discovered solitary pulmonary nodules (SPN). RESULTS: In the entire study population, SPN ≥ 5 mm were found in 87 patients (18%). These patients were compared to 150 patients who were incidentally collected from the 397 patients without SPN or with SPN < 5 mm (control group). After a median follow-up of 455 days, lung cancer was diagnosed in only two patients. Neither SPN ≥ 5 mm (p = 0.579) nor SPN > 8 mm (p = 0.328) were significant predictors of overall survival. CONCLUSIONS: Despite the high prevalence of SPNs in this single center TAVI cohort lung cancer incidence at midterm follow-up seems to be low. Thus, aggressive diagnostic approaches for incidentally discovered SPN during TAVI evaluation should not delay the treatment of aortic stenosis. Unless advanced thoracic malignancy is obvious, the well documented reduction of morbidity and mortality by TAVI outweighs potentially harmful delays regarding further diagnostics. Standard guideline-approved procedure for SPN can be safely performed after TAVI.

Humoral immune responses of lung cancer patients against the Transmembrane Phosphatase with TEnsin homology (TPTE).

OBJECTIVE: The cancer/testis (C/T) antigen Transmembrane Phosphatase with TEnsin homology (TPTE) is aberrantly expressed in many tumors including lung cancer. In the present study, we analyzed TPTE-auto-antibodies in lung cancer patients. METHODS: Using a crude-lysate ELISA, we analyzed a large cohort of 307 sera from lung cancer patients and 47 healthy donors for TPTE-specific autoantibodies. Sero-reactivity was correlated with clinical parameters and patients' survival. RESULTS: TPTE-specific antibodies were detected in 41 of 307 (13.4%) sera from lung cancer patients. Based on an optimal cut-off value calculated by ROC curve analysis sensitivity for diagnosing lung cancer was 52% and specificity was 72%. TPTE sero-positivity was not associated with tumor stage, tumor histology, gender or age. Multivariate analysis indicated that TPTE sero-positivity is associated with prolonged survival in patients with lung cancer, but established prognostic factors for survival prediction such as stage and histology remain indispensable. CONCLUSION: Autoantibodies against TPTE occur spontaneously in lung cancer patients. TPTE sero-reactivity has moderate sensitivity and specificity for diagnosing lung cancer and is a positive prognostic marker.

TA-MUC1 epitope in non-small cell lung cancer.

MUC1 (CD227), an established tumor marker, is expressed on glandular epithelia and on epithelial tumors. Tumor MUC1 differs from normal MUC1 by modified glycan side chains. Recently, a novel carbohydrate-induced conformational tumor-associated MUC1 epitope (TA-MUC1) was described, whose clinical relevance in lung cancer is not known. Eighty-five paraffin embedded tissue sections of non-small cell lung cancer (NSCLC) patients (73% male; mean age 64+/-9 years) were stained with the monoclonal antibody PankoMab (against TA-MUC1) and compared with the established antibodies E29 and 214D4 regarding prognostic relevance. TA-MUC1 is virtually absent in bronchial epithelium. As shown by multivariate analysis, only staining with PankoMab, but not with E29 or 214D4, was correlated with patients' survival (p=0.029). Moreover, when regarding interactions of MUC1 antibody staining results and clinico-pathological parameters, patients with lymph node metastasis lacking PankoMab staining were attributed the highest risk by far (Hazard ratio=4.6, 95% CI: 2.1-9.7, p=0.000). In summary, the presence of TA-MUC1 is a favorable prognostic factor in this cohort of NSCLC patients, in particular if lymph node metastases are present. This is in contrast to the results for E29 and 214D4, which recognize less or not glycosylation dependent epitopes. As this is the first report on a well-defined MUC1 epitope associated with improved survival in NSCLC, a more differentiated view on MUC1 may be mandatory.

The prognostic impact of blood group-related antigen Lewis Y and the ABH blood groups in resected non-small cell lung cancer.

The blood group antigen Lewis Y is expressed on epithelial tumors of the respiratory, digestive and reproductive system. Despite being regarded as an attractive target for immunotherapy, its function is still not well defined and its prognostic value remains a subject of discussion. Eighty-three paraffin-embedded tissue sections of non-small cell lung cancer (NSCLC) patients in stage I-IIIa, who underwent surgical resection of the primary tumor (73% male; 43% adenocarcinoma), were stained with a new, highly specific monoclonal antibody against Lewis Y (clone A70-C/C8). A positive Lewis Y expression was observed in 51% of patients; adenocarcinomas were favorably stained (67%). Multivariate analysis identified stage I, blood group A or AB and Lewis Y expression on tumor cells to be independent markers for improved survival after tumor resection (p = 0.024, 0.043, 0.003, respectively). In summary, unlike in several previous studies the presence of Lewis Y on tumor cells is a favorable prognostic factor in this cohort of resected NSCLC patients. Coexisting blood group antigen A may be of additional positive prognostic impact. We hypothesize that related blood group antigens both on tumor cells and in peripheral blood may have an underestimated function for progression in resected NSCLC.