Purpose: Tumors with high mutation load are thought to engender stronger immune responses, which in turn promote prolonged patient survival. To investigate this, we assessed tumor-infiltrating lymphocytes (TILs) and immunosuppressive factors across the 4 molecular subtypes of endometrial cancer, which have characteristic mutation rates ranging from low to ultra-high.Experimental Design: A total of 460 endometrial cancers were stratified by ProMisE (Proactive Molecular Risk Classifier in Endometrial cancer) into 4 molecular subtypes: mismatch repair-deficient (MMRd), POLE mutant (POLE), p53 abnormal (p53abn), and p53 wild-type (p53wt). Immune markers (CD3, CD8, CD79a, CD138, PD-1, PD-L1, FoxP3, IDO-1) were quantified by multiplex IHC and tested for associations with ProM-isE subtype, survival, and other clinicopathologic parameters.Results: Two major TIL patterns were observed. TIL high tumors harbored dense T-and B-lineage infiltrates and multiple immunosuppressive features and were common in molecular subtypes associated with high mutation load (MMRd and POLE); however, equally strong responses were seen in significant numbers of p53abn and p53wt tumors, which have characteristically low mutation loads. TIL low tumors were generally devoid of immunologic features and were more prevalent in p53abn and p53wt endometrial cancers, yet were also seen in MMRd and POLE subtypes. In multivariable models involving ProMisE subtype, T-cell markers, and TIL clusters, only ProMisE showed independent prognostic significance.Conclusions: Immune response correlates with endometrial cancer molecular subtype but does not carry independent prognostic significance. Profound variation in immune response is seen across and within endometrial cancer molecular subtypes, suggesting that assessment of immune response rather than molecular subtype may better predict response to immunotherapy.

BACKGROUND Endometrial cancers (ECs) with somatic mutations in DNA polymerase epsilon (POLE) are characterized by unfavorable pathological features, which prompt adjuvant treatment. Paradoxically, women with POLE‐mutated EC have outstanding clinical outcomes, and this raises concerns of overtreatment. The authors investigated whether favorable outcomes were independent of treatment. METHODS A PubMed search for POLE and endometrial was restricted to articles published between March 1, 2012, and March 1, 2018, that provided individual patient data (IPD), adjuvant treatment, and survival. Following the Preferred Reporting Items for Systematic Review and Meta‐Analysis (PRISMA) reporting guidelines for IPD, the authors used univariate and multivariate one‐stage meta‐analyses with mixed effects Cox models (random effects for study cohorts) to infer the associations of treatment, traditional prognostic factors, and outcome, which was defined as the time from first diagnosis to any adverse event (progression/recurrence or death from EC). RESULTS Three hundred fifty‐nine women with POLE‐mutated EC were identified; 294 (82%) had pathogenic mutations. Worse outcomes were demonstrated in patients with nonpathogenic POLE mutations (hazard ratio, 3.42; 95% confidence interval, 1.47‐7.58; log‐rank P < .01). Except for stage (P < .01), traditional prognosticators were not associated with progression/recurrence or death from disease. Adverse events were rare (11 progressions/recurrences and 3 disease‐specific deaths). Salvage rates in patients who experienced recurrence were high and sustained, with 8 of 11 alive without evidence of disease (range, 5.5‐14.2 years). Adjuvant treatment was not associated with outcome. CONCLUSIONS Clinical outcomes for ECs with pathogenic POLE mutations are not associated with most traditional risk parameters, and patients do not appear to benefit from adjuvant therapy. The observed low rates of recurrence/progression and the high and sustained salvage rates raise the possibility of safely de‐escalating treatment for these patients. LAY SUMMARY Ten percent of all endometrial cancers have mutations in the DNA repair gene DNA polymerase epsilon (POLE). Women who have endometrial cancers with true POLE mutations experience almost no recurrences or deaths from their cancer even when their tumors appear to have very unfavorable characteristics. Additional therapy (radiation and chemotherapy) does not appear to improve outcomes for women with POLE‐mutated endometrial cancer, and this supports the move to less therapy and less associated toxicity. Diligent classification of endometrial cancers by molecular features provides valuable information to inform prognosis and to direct treatment/no treatment.

Background New concepts for a more effective anti-cancer therapy are urgently needed. Experimental flaws represent a major counter player of this development and lead to inaccurate and unreproducible data as well as unsuccessful translation of research approaches into clinics. In a previous study we have created epithelial cell cultures from head and neck squamous cell carcinoma (HNSCC) tissue. Methods We characterize primary cell populations isolated from human papillomavirus positive HNSCC tissue for their marker expression by RT-qPCR, flow cytometry, and immunofluorescence staining. Their sensitivity to MDM2-inhibition was measured using cell viability assays. Results Primary HNSCC cell cultures showed the delayed formation of spheroids at higher passages. These spheroids mimicked the morphology and growth characteristics of other established HNSCC spheroid models. However, expression of epithelial and mesenchymal markers could not be detected in these cells despite the presence of the HNSCC stem cell marker aldehyde dehydrogenase 1 family member A1. Instead, strong expression of B- and T-lymphocytes markers was observed. Flow cytometry analysis revealed a heterogeneous mixture of CD3 + /CD25 + T-lymphocytes and CD19 + B-lymphocytes at a ratio of 4:1 at passage 5 and transformed lymphocytes at late passages (≥ passage 12) with CD45 + CD19 + CD20 + , of which around 10 to 20% were CD3 + CD25 + CD56 + . Interestingly, the whole population was FOXP3-positive indicative of regulatory B-cells (Bregs). Expression of transcripts specific for the Epstein-Barr-virus (EBV) was detected to increase in these spheroid cells along late passages, and this population was vulnerable to MDM2 inhibition. HPV + HNSCC cells but not EBV + lymphocytes were detected to engraft into immunodeficient mice. Conclusions In this study we present a primary cell culture of EBV-infected tumor-infiltrating B-lymphocytes, which could be used to study the role of these cells in tumor biology in future research projects. Moreover, by describing the detailed characteristics of these cells, we aim to caution other researchers in the HNSCC field to test for EBV-infected lymphocyte contaminations in primary cell cultures ahead of further experiments. Especially researchers who are interested in TIL-based adopted immunotherapy should exclude these cells in their primary tumor models, e.g. by MDM2-inhibitor treatment. BI-12-derived xenograft tumors represent a suitable model for in vivo targeting studies.

Three novel corynebacterial species were isolated from soil sampled at a paddock in Vilsendorf, North Rhine-Westphalia, Germany. The strains were coccoid or irregular rod-shaped, catalase-positive and pale white to yellow-orange in colour. By whole genome sequencing and comparison of the 16S rRNA genes as well as the whole genome structure, it was shown that all three strains represent novel species of the family Corynebacteriaceae , order Corynebacteriales , class Actinobacteria . This project describes the isolation, identification, sequencing, and phenotypic characterization of the three novel Corynebacterium species. We propose the names Corynebacterium kalinowskii sp. nov. (DSM 110639T=LMG 31801T), Corynebacterium comes sp. nov. (DSM 110640T=LMG 31802T), and Corynebacterium occultum sp. nov. (DSM 110642T=LMG 31803T).