Real-world genome profiling in Japanese patients with pancreatic ductal adenocarcinoma focusing on HRD implications.

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges due to its high mortality, making it a critical area of research. This retrospective observational study aimed to analyze real-world data from comprehensive genome profiling (CGP) of Japanese patients with PDAC, mainly focusing on differences in gene detection rates among panels and the implications for homologous recombination deficiency (HRD) status. This study enrolled 2568 patients with PDAC who had undergone CGP between June 2019 and December 2021 using data from the nationwide Center for Cancer Genomics and Advanced Therapeutics database. Two types of CGP assays (tissue and liquid biopsies) were compared and a higher detection rate of genetic abnormalities in tissue specimens was revealed. HRD-related gene alterations were detected in 23% of patients, with BRCA1/2 mutations accounting for 0.9% and 2.9% of patients, respectively. Treatment outcome analysis indicated that patients with BRCA1/2 mutations had a longer time to treatment discontinuation with FOLFIRINOX than gemcitabine plus nab-paclitaxel as first-line therapy (9.3 vs. 5.6 months, p = 0.028). However, no significant differences were observed in the treatment response among the other HRD-related genes. Logistic regression analysis identified younger age and family history of breast, prostate, and ovarian cancers as predictive factors for HRD-related gene alterations. Despite the lack of progression-free survival data and the inability to discriminate between germline and somatic mutations, this study provides valuable insights into the clinical implications of CGP in Japanese patients with PDAC. Further research is warranted to optimize panel selection and elucidate the efficacy of platinum-based therapies depending on the HRD status.

Water-soluble dietary fiber alleviates cancer-induced muscle wasting through changes in gut microenvironment in mice.

Cancer cachexia and the associated skeletal muscle wasting are considered poor prognostic factors, although effective treatment has not yet been established. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. In this study, we evaluated the possible effects of modifying the gut microenvironment with partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, on cancer-related muscle wasting and its mechanism using a colon-26 murine cachexia model. Compared with a fiber-free (FF) diet, PHGG contained fiber-rich (FR) diet-attenuated skeletal muscle loss in cachectic mice by suppressing the elevation of the major muscle-specific ubiquitin ligases Atrogin-1 and MuRF1, as well as the autophagy markers LC3 and Bnip3. Although tight-junction markers were partially reduced in both FR and FF diet-fed cachectic mice, the abundance of Bifidobacterium, Akkermansia, and unclassified S24-7 family increased by FR diet, contributing to the retention of the colonic mucus layer. The reinforcement of the gut barrier function resulted in the controlled entry of pathogens into the host system and reduced circulating levels of lipopolysaccharide-binding protein (LBP) and IL-6, which in turn led to the suppression of proteolysis by downregulating the ubiquitin-proteasome system and autophagy pathway. These results suggest that dietary fiber may have the potential to alleviate skeletal muscle loss in cancer cachexia, providing new insights for developing effective strategies in the future.

Treatment with broad-spectrum antibiotics upregulates Sglt1 and induces small intestinal villous hyperplasia in mice.

Although extensive evidence indicates that the gut microbiota plays a crucial role in regulating glucose homeostasis, the exact regulatory mechanism remains unclear. This study aimed to investigate the effect of broad-spectrum antibiotics on the expression of glucose transporters, histomorphology of the small intestine, and glucose metabolism in mice. C57BL/6 mice were administered drinking water with or without a broad-spectrum antibiotic combination for 4 weeks. Thereafter, an oral glucose tolerance test was performed. Body weight, small intestine histopathology, mRNA levels of glucose transporters (SGLT1 and GLUT2) and intestinal transcription factors (CDX1 and CDX2) were evaluated. SGLT1 and CDX1 were upregulated in the small intestine upon antibiotic administration compared with that in the control group. The height and surface area of the jejunal villi were significantly higher upon antibiotic administration than in the control group. Fasting glucose levels were significantly higher upon antibiotic administration than in the control group. The present results indicate that treatment with broad-spectrum antibiotics upregulates SGLT1 and CDX1 and induces hyperplasia in the small intestine, thus increasing fasting blood glucose levels. Our results further the current understanding of the effects of broad-spectrum antibiotics on the gut microbiota and glucose homeostasis that may have future clinical implications.

Underwater endoscopic papillectomy for a small neuroendocrine tumor of the ampulla of Vater.

Neuroendocrine tumors (NETs) of the ampulla of Vater are rare. Therefore, there is a lack of comprehensive information regarding their pathogenesis. We herein present the case of a patient with a 5-mm ampullary NET who demonstrated the presence of lymphatic invasion after undergoing endoscopic papillectomy. A 44-year-old woman was referred to our hospital for treatment of a grade 1 NET in the ampulla of Vater. Endoscopic ultrasonography revealed a hypoechoic mass within the submucosal layer without obvious infiltration into the common bile duct or the main pancreatic duct. We performed underwater endoscopic papillectomy (UEP) to remove the tumor with a negative margin. Pathological evaluation of the resected specimen showed a grade 1 NET with a negative margin. However, pancreaticoduodenectomy was subsequently performed because of the risk of lymph node metastasis, which was expected due to the significant number of NET cells infiltrating the endothelium of the lymphatic vessels. No lymph node metastasis or recurrence was observed during the 26-month follow-up period. UEP is a useful method to achieve complete resection for diagnostic and therapeutic purposes. UEP may be a novel option for endoscopic treatment of ampullary NET.

Genomic profile and clinical features of MSI-H and TMB-high pancreatic cancers: real-world data from C-CAT database.

BACKGROUND: Microsatellite instability high (MSI-H) and tumor mutational burden high (TMB-high) pancreatic cancer are rare, and information is lacking. Based on the C-CAT database, we analyzed the clinical and genomic characteristics of patients with these subtypes. METHODS: We retrospectively reviewed data on 2206 patients with unresectable pancreatic adenocarcinoma enrolled in C-CAT between July 2019 and January 2022. The clinical features, proportion of genomic variants classified as oncogenic/pathogenic in C-CAT, overall response rate (ORR), disease control rate (DCR), and time to treatment failure (TTF) of chemotherapy as first-line treatment were evaluated. RESULTS: Numbers of patients with MSI-H and TMB-high were 7 (0.3%) and 39 (1.8%), respectively. All MSI-H patients were TMB-high. MSI-H and TMB-high patients harbored more mismatch repair genes, such as MSH2, homologous recombination-related genes, such as ATR and BRCA2, and other genes including BRAF, KMT2D, and SMARCA4. None of the 6 MSI-H patients who received chemotherapy achieved a clinical response, including 4 patients treated with gemcitabine plus nab-paclitaxel (GnP) therapy, whose DCR was significantly lower than that of microsatellite stable (MSS) patients (0 vs. 67.0%, respectively, p = 0.01). Among the TMB-high and TMB-low groups, no significant differences were shown in ORR, DCR (17.1 vs. 23.1% and 57.1 vs. 63.1%, respectively), or median TTF (25.9 vs. 28.0 weeks, respectively) of overall first-line chemotherapy. CONCLUSIONS: MSI-H and TMB-high pancreatic cancers showed some distinct genomic and clinical features from our real-world data. These results suggest the importance of adapting optimal treatment strategies according to the genomic alterations.

Trifluridine/tipiracil with and without ramucirumab for advanced gastric cancer: a comparative observational study.

The combination of trifluridine/tipiracil hydrochloride (FTD/TPI) plus ramucirumab has demonstrated clinical activity in patients with advanced gastric cancer (AGC). We evaluated the efficacy and safety of this combination compared with those of FTD/TPI monotherapy in patients with AGC. We retrospectively reviewed data of patients with AGC who received FTD/TPI plus ramucirumab or FTD/TPI monotherapy as third- or later-line treatment. This study included 36 patients treated with FTD/TPI plus ramucirumab and 70 patients receiving FTD/TPI monotherapy. The objective response rate (ORR) and disease control rate (DCR) were 25.8% and 58.1%, respectively, in the FTD/TPI plus ramucirumab group and 5.0% and 38.3%, respectively, in the FTD/TPI group (ORR, P = 0.007; DCR, P = 0.081). The median progression-free survival (PFS) was significantly longer in the FTD/TPI plus ramucirumab group (median PFS, 2.9 vs. 1.8 months; hazard ratio [HR]: 0.52; P = 0.001). A numerical survival benefit was also observed (median overall survival, 7.9 months vs. 5.0 months; HR: 0.68, P = 0.089). In the multivariate analysis, PFS was significantly longer in the FTD/TPI plus ramucirumab group than in the FTD/TPI monotherapy group (HR: 0.61, P = 0.030). The incidence of febrile neutropenia was higher in the FTD/TPI plus ramucirumab group than in the FTD/TPI group (13.8% vs. 2.9%); however, no new safety signals were identified. Compared with FTD/TPI monotherapy, FTD/TPI plus ramucirumab offers clinical benefits with acceptable toxicity in heavily pretreated patients with AGC. Further investigation via randomized trials is warranted to confirm these findings.

Genomic landscape and clinical features of rare subtypes of pancreatic cancer: analysis with the national database of Japan.

BACKGROUND: Special subtypes of pancreatic cancer, such as acinar cell carcinoma (ACC), adenosquamous carcinoma (ASC), and anaplastic carcinoma of the pancreas (ACP), are rare, and so data on them are limited. Using the C-CAT database, we analyzed clinical and genomic characteristics of patients with these and evaluated differences on comparison with pancreatic ductal adenocarcinoma (PDAC) patients. METHODS: We retrospectively reviewed data on 2691 patients with unresectable pancreatic cancer: ACC, ASC, ACP, and PDAC, entered into C-CAT from June 2019 to December 2021. The clinical features, MSI/TMB status, genomic alterations, overall response rate (ORR), disease control rate (DCR), and time to treatment failure (TTF) on receiving FOLFIRINOX (FFX) or GEM + nab-PTX (GnP) therapy as first-line treatment were evaluated. RESULTS: Numbers of patients with ACC, ASC, ACP, and PDAC were 44 (1.6%), 54 (2.0%), 25 (0.9%), and 2,568 (95.4%), respectively. KRAS and TP53 mutations were prevalent in ASC, ACP, and PDAC (90.7/85.2, 76.0/68.0, and 85.1/69.1%, respectively), while their rates were both significantly lower in ACC (13.6/15.9%, respectively). Conversely, the rate of homologous recombination-related (HRR) genes, including ATM and BRCA1/2, was significantly higher in ACC (11.4/15.9%) than PDAC (2.5/3.7%). In ASC and ACP, no significant differences in ORR, DCR, or TTF between FFX and GnP were noted, while ACC patients showed a trend toward higher ORR with FFX than GnP (61.5 vs. 23.5%, p = 0.06) and significantly more favorable TTF (median 42.3 vs. 21.0 weeks, respectively, p = 0.004). CONCLUSIONS: ACC clearly harbors different genomics compared with PDAC, possibly accounting for differences in treatment efficacy.

Proton Pump Inhibitors Enhance the Antitumor Effect of Chemotherapy for Esophageal Squamous Cell Carcinoma.

BACKGROUND: Vacuolar ATPase (V-ATPase) is involved in cancer development. The use of proton pump inhibitors (PPIs) as V-ATPase inhibitors has been reported to enhance the effectiveness of chemotherapy in certain cancers. This study aimed to evaluate the effect of PPIs on chemotherapy for esophageal cancer. METHODS: To investigate the effects of PPIs on esophageal cancer cells, human KYSE50 and 70 cells were plated and 3 PPIs (lansoprazole, esomeprazole, vonoprazan) were added at various concentrations with 5-Fluorouracil (5-FU) to the corresponding cells for a cell viability assay. To investigate the effects of PPI treatment on patients undergoing 5-FU-based therapy in the clinical setting, we retrospectively analyzed the clinical outcomes and chemotherapy-related adverse events in 40 esophageal cancer patients who received 5-FU chemotherapy in our hospital between May 2013 and April 2017. RESULTS: In the viability assays, all PPIs significantly enhanced the cytotoxic effect of 5-FU on the two esophageal cancer cell lines. In the clinical study, PPI-treated patients showed better overall survival (OS) than patients managed without PPI treatment. A multivariate analysis revealed that PPI treatment was independently associated with OS (p = 0.009, HR, 0.33; 95% CI, 0.12-0.76). CONCLUSIONS: PPI treatment may safely enhance chemosensitivity in esophageal cancer patients.

Effect of concomitant use of G-CSF and myelosuppressive chemotherapy on bone marrow and peripheral granulocytes in a mouse model.

Granulocyte-colony stimulating factor (G-CSF) stimulates bone marrow progenitor cell proliferation and enhances neutrophil production. Exogenous G-CSF administration is indicated for chemotherapy-induced neutropenia management. However, there is a paucity of basic research examining the effects of the concomitant use of G-CSF and chemotherapy on myeloid cells in vivo. Whether concomitant G-CSF and chemotherapy adversely affect myeloid cell proliferation have not been determined. Herein, we examined the effects of the concomitant use of pegfilgrastim and 5-fluorouracil on myeloid cells and peripheral blood cells in mouse models. Balb/c mice were treated intraperitoneally with 5-fluorouracil (20 µg/g b.w.) or a vehicle as a control for 5 days, and pegfilgrastim was administered subcutaneously at 1 µg/g b.w. on day 3. As a result, we demonstrated that the concomitant use of pegfilgrastim suppressed the 5-fluorouracil-induced decrease of granulocytic cells in both bone marrow and peripheral blood in mice. To assess the clinical efficacy of early administration of pegfilgrastim during docetaxel, cisplatin, and 5-fluorouracil therapy in patients with esophageal cancer, we retrospectively identified 42 consecutive patients treated with this regimen. The incidence of both febrile neutropenia and grade 4 neutropenia was significantly lower in patients who received pegfilgrastim than in those who did not receive it (P = 0.002 and P = 0.002, respectively). These results suggest that the concomitant use of pegfilgrastim and chemotherapy, consisting of continuous infusions of 5-fluorouracil, improved chemotherapy-induced neutropenia without detrimental effects on proliferating myeloid granulocytic cells.

Safety and tolerability of PD-1/PD-L1 inhibitors in elderly and frail patients with advanced malignancies.

The number of elderly patients with cancer has increased due to aging of the population. However, safety of programmed cell death-1 (PD-1) or programed cell death ligand 1 (PD-L1) inhibitors in elderly patients remains controversial, and limited information exists in frail patients. The present study retrospectively identified 197 patients treated with nivolumab, pembrolizumab or atezolizumab for unresectable advanced cancer between September 2014 and December 2018. Patients were divided into the elderly (age, ≥75 years) and non-elderly (age, <75 years) groups. The detailed immune-related adverse events (irAE) profile and development of critical complications were evaluated. To assess tolerability, the proportion of patients who continued PD-1/PD-L1 inhibitor for >6 months was analyzed. In the two groups, a three-element frailty score, including performance status, Charlson Comorbidity Index and neutrophil-lymphocyte ratio, was estimated, and patients were divided into the low-, intermediate- and high-frailty subgroups. Safety and tolerability were evaluated using the aforementioned items. A total of 58 patients (29.4%) were aged ≥75 years. No significant difference was found in the development of irAEs, hospitalization and treatment discontinuation due to irAEs between the two groups. However, the occurrence of unexpected critical complications was significantly higher in the elderly group (P=0.03). Among the elderly patients with high frailty, more critical complications and fatal irAE (hepatitis) were observed. In this population, 33.3% were able to continue treatment for >6 months without disease progression. The present analysis based on real world data showed similar safety and tolerability of PD-1/PD-L1 inhibitors in elderly patients with advanced malignancies. However, the impact of irAE in elderly patients, especially those with frailty, was occasionally greater compared with that in younger and fit patients.

Clinical features of immune-related thyroid dysfunction and its association with outcomes in patients with advanced malignancies treated by PD-1 blockade.

Programmed cell death protein-1 (PD-1) blockade therapy has improved outcomes in the treatment of advanced cancers. The therapy is well-tolerated, although it occasionally causes immune-related adverse events (irAEs). Thyroid dysfunction is one of the most common irAEs seen. Our aim was to clarify the clinical characteristics of thyroid dysfunction induced by PD-1 blockade and its association with the therapeutic effect of the treatment in advanced cancers. A total of 174 patients who received nivolumab or pembrolizumab for metastatic or unresectable advanced cancers were included in this retrospective study. The patients were divided into two groups: The thyroid dysfunction group and the euthyroid group. In the present study, the clinical characteristics, the association with anti-thyroid antibodies, as well as the progression-free survival (PFS) and overall survival (OS) were estimated. An adjusted Cox proportional hazard regression model was used to evaluate prognostic factors for OS and PFS. This study showed that 25 out of 150 patients (16.7%) developed immune-related thyroid dysfunction. Hypothyroidism occurred in the early stage of the clinical course (median: 12 weeks); subsequently, 9 of the 25 patients underwent a transient period of hyperthyroidism, all with mild symptoms. The presence of positive anti-thyroid antibodies at baseline was significantly higher in the thyroid dysfunction group (13/22) than in the euthyroid group (18/100, P=0.0002). Moreover, PFS (median: 66 vs. 27 weeks, hazard ratio (HR): 0.50, 95% CI: 0.26-0.89, P=0.02) and OS (median 156 vs. 59 weeks, HR: 0.34, 95% CI: 0.13-0.75, P=0.01) were significantly longer in the thyroid dysfunction group than in the euthyroid group. Multivariable analysis also revealed that thyroid dysfunction was an independent prognostic factor for OS (HR: 0.42, 95% CI: 0.16-0.97, P=0.04). These findings may enable the early recognition and appropriate management of thyroid dysfunction, and help in maximizing the therapeutic effect of PD-1 blockade.

A Bile Duct Stone Formation around a Fish Bone as a Nidus after Pancreatoduodenectomy.

We report a rare case of bile duct stone formation around an ingested fish bone as a nidus after pancreatoduodenectomy. A 78-year-old woman was admitted to our department for fever and epigastric pain. Abdominal computed tomography revealed an elongated bile duct stone containing a linearly shaped foreign body of bone density. Enteroscopic lithotomy was performed using single balloon enteroscopy to safely remove the stone and foreign body from the bile duct. The foreign body was determined to be a fish bone by pathological examination and component analysis.

Late-onset severe biliary bleeding after endoscopic pigtail plastic stent insertion.

Here, we report our experience with a case of severe biliary bleeding due to a hepatic arterial pseudoaneurysm that had developed 1 year after endoscopic biliary plastic stent insertion. The patient, a 78-year-old woman, presented with hematemesis and obstructive jaundice. Ruptured hepatic arterial pseudoaneurysm was diagnosed, which was suspected to have been caused by long-term placement of an endoscopic retrograde biliary drainage (ERBD) stent. This episode of biliary bleeding was successfully treated by transarterial embolization (TAE). Pseudoaneurysm leading to hemobilia is a rare but potentially fatal complication in patients with long-term placement of ERBD. TAE is a minimally invasive procedure that offers effective treatment for biliary bleeding.