Background/Aim: Cancer immune therapy by immune checkpoint inhibitors (ICIs) is a promising therapeutic strategy for various cancer types. Among ICIs, anti-programmed cell death protein-1 (PD1) and antiprogrammed death-ligand 1 (PD-L1) antibodies have shown a remarkable clinical benefit. The present study aimed to address the functional and clinical significance of serum levels of soluble PD-L1 (sPD-L1) in patients. Materials and Methods: A total of 21 patients, 11 with NSCLC, nine with gastric cancer and one with bladder cancer, who underwent anti-PD-1 therapy were evaluated for sPD-L1 concentration by ELISA analyses at diagnosis and after treatment. Results: Pretreatment levels of sPD-L1 in patients who received ICIs were not remarkably correlated with the overall survival of these patients (r=0.3394, p=0.1323). Reduction of plasma sPD-L1 level was significantly correlated with tumor regression in patients administered four cycles of treatment (p<0.05). Conclusion: sPD-L1 might be derived and secreted from tumors and might be useful to identify primary responders to ICIs at a relatively early treatment timepoint.Programmed death protein (PD1) and its ligand PD-L1 are central components in immune suppression, comprising the so-called 'immune checkpoint' (1, 2). Accumulating evidence revealed that the PD1/PD-L1 pathway is closely involved in resistance to antitumor immunity in multiple cancer types. Therefore, targeting immune checkpoints using immune checkpoint inhibitors (ICIs), such as those against PD1/PD-L1, has contributed to recent advances in cancer therapeutics (3, 4). However, many patients failed to respond or developed resistance after an initial response to ICIs. Predictive biomarkers for identifying potential responders to ICIs are currently under debate (5). Notably, several lines of evidence suggest a correlation between tumor PD-L1 expression and response to ICIs in variable malignancies including lung adenocarcinoma, melanoma, refractory Hodgkin's lymphoma, and other solid tumor types (6-10). Intriguingly, such correlation was reported for the expression level of membrane-bound PD-L1 (mPD-L1) on tumor tissues and plasma level of soluble PD-L1 (sPD-L1) in the blood of patients with cancer, highlighting the importance of their prognostic value. Several studies showed that high expression of sPD-L1 was associated with a poor prognosis in multiple types of malignant tumor. This suggests that sPD-L1 might be a predictive marker for low treatment responses to conventional chemotherapy and patients with high expression of sPD-L1 might be suitable for ICI therapy (11)(12)(13)(14)(15)(16)(17)(18)(19)(20). However, it remains unclear whether the plasma sPD-L1 level is derived from malignant tumors pre-existing in patients and reflects a potential response to ICIs. Here, we measured the plasma level of sPD-L1 collected from patients with non-small cell lung cancer (NSCLC) and those with gastric cancer who underwent anti-PD1 therapy and analyzed 5195

Pancreatic cancer has an extremely poor prognosis, and identification of novel predictors of therapeutic efficacy and prognosis is urgently needed. Chemoresistance-related molecules are correlated with poor prognosis and may be effective targets for cancer treatment. Here, we aimed to identify novel molecules correlated with chemoresistance and poor prognosis in pancreatic cancer. We established 10 patient-derived xenograft (PDX) lines from patients with pancreatic cancer and performed next-generation sequencing (NGS) of tumor tissues from PDXs after treatment with standard drugs. We established a gene-transferred tumor cell line to express chemoresistance-related molecules and analyzed the chemoresistance of the established cell line against standard drugs. Finally, we performed immunohistochemical (IHC) analysis of chemoresistance-related molecules using 80 pancreatic cancer tissues. From NGS analysis, we identified olfactomedin-4 (OLFM4) as having high expression in the PDX group treated with anticancer drugs. In IHC analysis, OLFM4 expression was also high in PDXs administered anticancer drugs compared with that in untreated PDXs. Chemoresistance was observed by in vitro analysis of tumor cell lines with forced expression of OLFM4. In an assessment of tissue specimens from 80 patients with pancreatic cancer, Kaplan-Meier analysis showed that patients in the low OLFM4 expression group had a better survival rate than patients in the high OLFM4 expression group. Additionally, multivariate analysis showed that high expression of OLFM4 was an independent prognostic factor

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Background/Aim: There is an increasing use of immunotherapy for non-small cell lung cancer (NSCLC) patients. The present study analysed the effect of antibiotic use on the outcome of NSCLC patients undergoing treatment with anti-programmed cell death-1 (anti-PD-1) immunotherapy. Patients and Methods: This was a retrospective study of 69 NSCLC patients. Eighteen out of 69 patients received antibiotics within 21 days before or within 21 days after start of anti-PD-1 therapy. Results: Patients treated with anti-PD-1 antibodies receiving antibiotics had greatly decreased objective response rate (ORR), overall survival (OS) and progression-free survival (PFS) compared to those who did not use antibiotics. Multivariate analysis showed that antibiotic treatment of patients on anti-PD-1 antibody therapy was an independent negative predictive factor of PFS; however, it was not a significant independent predictive factor of OS. Conclusion: Use of antibiotics within 21 days before and after anti-PD-1 treatment initiation in patients with NSCLC strongly reduced OS and PFS, suggesting the two treatments should not be combined.Immunotherapy with anti-programmed cell death-1 (anti-PD-1) antibody has been only modestly successful in non-small cell lung cancer (NSCLC) (1). Thus, there is a critical need to identify more effective treatment strategies for anti PD-1 treatment of NSCLC.Specific intestinal bacteria have been reported to affect the immune system and therapeutic outcome of anti-PD-1 immunotherapy in NSCLC, melanoma, renal cell carcinoma (RCC) and urothelial carcinoma (UC) (2-5). Additionally, the diversity of bacterial flora may also affect the therapeutic outcome of anti-PD-1 immunotherapy (6).

IntroductionImmune checkpoint inhibitors have had a major impact on cancer treatment. Gut microbiota plays a major role in the cancer microenvironment, affecting treatment response. The gut microbiota is highly individual, and varies with factors, such as age and race. Gut microbiota composition in Japanese cancer patients and the efficacy of immunotherapy remain unknown. MethodsWe investigated the gut microbiota of 26 patients with solid tumors prior to immune checkpoint inhibitor monotherapy to identify bacteria involved in the efficacy of these drugs and immune-related adverse events (irAEs).ResultsThe genera Prevotella and Parabacteroides were relatively common in the group showing efficacy towards the anti-PD-1 antibody treatment (effective group). The proportions of Catenibacterium (P = 0.022) and Turicibacter (P = 0.049) were significantly higher in the effective group than in the ineffective group. In addition, the proportion of Desulfovibrion (P = 0.033) was significantly higher in the ineffective group. Next, they were divided into irAE and non-irAE groups. The proportions of Turicibacter (P = 0.001) and Acidaminococcus (P = 0.001) were significantly higher in the group with irAEs than in those without, while the proportions of Blautia (P = 0.013) and the unclassified Clostridiales (P = 0.027) were significantly higher in the group without irAEs than those with. Furthermore, within the Effective group, Acidaminococcus and Turicibacter (both P = 0.001) were more abundant in the subgroup with irAEs than in those without them. In contrast, Blautia (P = 0.021) and Bilophila (P= 0.033) were statistically significantly more common in those without irAEs.DiscussionOur Study suggests that the analysis of the gut microbiota may provide future predictive markers for the efficacy of cancer immunotherapy or the selection of candidates for fecal transplantation for cancer immunotherapy.