Ovarian cancer is often limited to the peritoneal cavity in the form of peritoneal carcinomatosis. Peritoneal spreading offers the opportunity for locoregional delivery of combinations of immuno- therapy agents, maximizing bioavailability while potentially reduc-ing systemic exposure and side effects.

Neutrophil extracellular traps (NETs) are webs of extracellular nuclear DNA extruded by dying neutrophils infiltrating tissue. NETs constitute a defence mechanism to entrap and kill fungi and bacteria. Tumours induce the formation of NETs to the advantage of the malignancy via a variety of mechanisms shown in mouse models. Here, we investigated the presence of NETs in a variety of human solid tumours and their association with IL-8 (CXCL8) protein expression and CD8(+) T-cell density in the tumour microenvironment. Multiplex immunofluorescence panels were developed to identify NETs in human cancer tissues by co-staining with the granulocyte marker CD15, the neutrophil marker myeloperoxidase and citrullinated histone H3 (H3Cit), as well as IL-8 protein and CD8(+) T cells. Three ELISA methods to detect and quantify circulating NETs in serum were optimised and utilised. Whole tumour sections and tissue microarrays from patients with non-small cell lung cancer (NSCLC; n = 14), bladder cancer (n = 14), melanoma (n = 11), breast cancer (n = 31), colorectal cancer (n = 20) and mesothelioma (n = 61) were studied. Also, serum samples collected retrospectively from patients with metastatic melanoma (n = 12) and NSCLC (n = 34) were ELISA assayed to quantify circulating NETs and IL-8. NETs were detected in six different human cancer types with wide individual variation in terms of tissue density and distribution. At least in NSCLC, bladder cancer and metastatic melanoma, NET density positively correlated with IL-8 protein expression and inversely correlated with CD8(+) T-cell densities. In a series of serum samples from melanoma and NSCLC patients, a positive correlation between circulating NETs and IL-8 was found. In conclusion, NETs are detectable in formalin-fixed human biopsy samples from solid tumours and in the circulation of cancer patients with a considerable degree of individual variation. NETs show a positive association with IL-8 and a trend towards a negative association with CD8(+) tumour-infiltrating lymphocytes. (c) 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

It has been reported that a group of patients with advanced non- small cell lung cancer showed circulating T cells with a senescent phenotype, and an abundance of such cells is associated with worse clinical response to immune checkpoint inhibitors. This study encourages further analysis of the role of senescent T cells in resistance to lung cancer immunotherapy.

Harnessing the immune system by blocking the programmed cell death protein 1 (PD-1) pathway has been a major breakthrough in non-small-cell lung cancer treatment. Nonetheless, many patients fail to respond to PD-1 inhibition. Using three syngeneic models, we demonstrate that short-term starvation synergizes with PD-1 blockade to inhibit lung cancer progression and metastasis. This antitumor activity was linked to a reduction in circulating insulin-like growth factor 1 (IGF-1) and a downregulation of IGF-1 receptor (IGF-1R) signaling in tumor cells. A combined inhibition of IGF-1R and PD-1 synergistically reduced tumor growth in mice. This effect required CD8 cells, boosted the intratumoral CD8/Treg ratio and led to the development of tumor-specific immunity. In patients with non-small-cell lung cancer, high plasma levels of IGF-1 or high IGF-1R expression in tumors was associated with resistance to anti-PD-1¿programmed death-ligand 1 immunotherapy. In conclusion, our data strongly support the clinical evaluation of IGF-1 modulators in combination with PD-1 blockade.

BACKGROUND: The differential diagnosis between multiple primary lung cancer (MPLC) and advanced lung cancer has traditionally relied on conventional radiology and pathology. However, the outcomes of traditional diagnostic workup are often limited, and staging is uncertain. Increasing evidence suggests that next-generation sequencing (NGS) techniques offer the possibility of comparing multiple tumors on a genomic level. OBJECTIVES: The objective of this study is to assess the clinical impact utility of targeted sequencing in patients presenting with multiple synchronous or metachronous lung tumors. MATERIALS AND METHODS: We describe the diagnostic workup conducted in a patient with three lung tumors, where we used a targeted 50-gene DNA sequencing panel (Ion AmpliSeq TM Cancer Hotspot Panel v2) to assess clonality and establish an accurate lung adenocarcinoma stage. Positive results were confirmed by pyrosequencing or Sanger sequencing. RESULTS: Three surgically resected lung tumors were submitted for targeted sequencing. The tumor from the upper right lobe was positive for a TP53 c.659A¿>¿G mutation and native for KRAS. The tumor from the upper left lobe was positive for TP53 c.725G¿>¿T and KRAS c.35G¿>¿T mutations. The tumor from the lower left lobe was positive for TP53 c.1024C¿>¿T and KRAS C.34G¿>¿T mutations. Results and reviewed literature in the field support the diagnosis of MPLC instead of a single advanced lung cancer. CONCLUSION: Targeted DNA sequencing significantly increases diagnostic accuracy in patients with multiple lung tumors. NGS panels should be available for patients presenting with multiple lung tumors.