Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest solid tumors and is resistant to immunotherapy. B cells play an essential role in PDAC progression and immune responses, both... Show morePancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest solid tumors and is resistant to immunotherapy. B cells play an essential role in PDAC progression and immune responses, both locally and systemically. Moreover, increasing evidence suggests that microbial compositions inside the tumor, as well as in the oral cavity and the gut, are important factors in shaping the PDAC immune landscape. However, the gut-associated lymphoid tissue (GALT) has not previously been explored in PDAC patients. In this study, we analyzed healthy vermiform appendix (VA) from 20 patients with PDAC and 32 patients with colon diseases by gene expression immune profiling, flow cytometry analysis, and microbiome sequencing. We show that the VA GALT of PDAC patients exhibits markers of increased inflammation and cytotoxic cell activity. In contrast, B cell function is decreased in PDAC VA GALT based on gene expression profiling; B cells express significantly fewer MHC class II surface receptors, whereas plasma cells express the immune checkpoint molecule HLA-G. Additionally, the vermiform appendix microbiome of PDAC patients is enriched with Klebsiella pneumoniae, Bifidobacterium animalis, and Adlercreutzia equolifaciens, while certain commensals are depleted. Our findings may suggest impaired B cell function within the GALT of PDAC patients, which could potentially be linked to microbial dysbiosis. Additional investigations are imperative to validate our observations and explore these potential targets of future therapies. Show less
va't Land, F.R.; Latifi, D.; Moskie, M.; Homs, M.Y.V.; Bosscha, K.; Bonsing, B.A.; ... ; South West Pancreatic Canc Care SW 2023
Background and purpose: In this phase I/II trial, non-progressive locally advanced pancreatic cancer (LAPC) patients after (modified)FOLFIRINOX therapy were treated with stereotactic body... Show moreBackground and purpose: In this phase I/II trial, non-progressive locally advanced pancreatic cancer (LAPC) patients after (modified)FOLFIRINOX therapy were treated with stereotactic body radiotherapy (SBRT) combined with heat-killed mycobacterium (IMM-101) vaccinations. We aimed to assess safety, feasibility, and efficacy of this treatment approach.Materials and methods: On five consecutive days, patients received a total of 40 Gray (Gy) of SBRT with a dose of 8 Gy per fraction. Starting two weeks prior to SBRT, they in addition received six bi-weekly intradermal vaccinations with one milligram of IMM-101. The primary outcomes were the number of grade 4 or higher adverse events and the one-year progression free-survival (PFS) rate. Results: Thirty-eight patients were included and started study treatment. Median follow-up was 28.4 months (95 %CI 24.3 - 32.6). We observed one grade 5, no grade 4 and thirteen grade 3 adverse events, none related to IMM-101. The one-year PFS rate was 47 %, the median PFS was 11.7 months (95 %CI 11.0 - 12.5) and the median overall survival was 19.0 months (95 %CI 16.2 - 21.9). Eight (21 %) tumors were resected, of which 6 (75 %) were R0 resections. Outcomes were comparable with the outcomes of the patients from the previous LAPC-1 trial, in which LAPC patients were treated with SBRT, without IMM-101.Conclusion: Combination treatment with IMM-101 and SBRT was safe and feasible for non-progressive locally advanced pancreatic cancer patients after (modified)FOLFIRINOX. No improvement in the progression-free survival could be demonstrated by adding IMM-101 to SBRT.(c) 2023 Published by Elsevier B.V. Radiotherapy and Oncology 183 (2023) 109541 Show less
