Pharmacologic modulation of 5-fluorouracil by folinic acid and high-dose pyridoxine for treatment of patients with digestive tract carcinomas

Supplementation of cancer cells exposed to 5-fluorouracil (FUra) and folinic acid (FA) with high concentration pyridoxal 5′-phosphate, the cofactor of vitamin B6, potentiates the cytotoxicity of FUra in a synergistic interaction mode. We report a pilot study in 13 patients with previously untreated advanced carcinoma of the digestive tract to assess the impact of high-dose pyridoxine (PN) on the antitumor activity of regimens comprising FUra and FA. Five patients had colorectal adenocarcinoma (CRC); 5 had pancreas adenocarcinoma (PC); and 3 had squamous cell carcinoma of the esophagus (EC). Patients with CRC and with PC received oxaliplatin, irinotecan, FUra and FA, and patients with EC had paclitaxel, carboplatin, FUra and FA. PN iv from 1000 to 3000 mg/day preceded each administration of FA and FUra. Eleven patients responded. Two patients with CRC attained CRs and 3 had PRs with reduction rates ≥ 78%. Two patients with PC attained CRs, and 2 had PRs with reduction rates ≥ 79%. Responders experienced disappearance of most metastases. Of 3 patients with EC, 2 attained CRs. Median time to attain a response was 3 months. Unexpected toxicity did not occur. Results suggest that high-dose vitamin B6 enhances antitumor potency of regimens comprising FUra and FA.

The role of the microbiome in ovarian cancer: mechanistic insights into oncobiosis and to bacterial metabolite signaling

Ovarian cancer is characterized by dysbiosis, referred to as oncobiosis in neoplastic diseases. In ovarian cancer, oncobiosis was identified in numerous compartments, including the tumor tissue itself, the upper and lower female genital tract, serum, peritoneum, and the intestines. Colonization was linked to Gram-negative bacteria with high inflammatory potential. Local inflammation probably participates in the initiation and continuation of carcinogenesis. Furthermore, local bacterial colonies in the peritoneum may facilitate metastasis formation in ovarian cancer. Vaginal infections (e.g. Neisseria gonorrhoeae or Chlamydia trachomatis) increase the risk of developing ovarian cancer. Bacterial metabolites, produced by the healthy eubiome or the oncobiome, may exert autocrine, paracrine, and hormone-like effects, as was evidenced in breast cancer or pancreas adenocarcinoma. We discuss the possible involvement of lipopolysaccharides, lysophosphatides and tryptophan metabolites, as well as, short-chain fatty acids, secondary bile acids and polyamines in the carcinogenesis of ovarian cancer. We discuss the applicability of nutrients, antibiotics, and probiotics to harness the microbiome and support ovarian cancer therapy. The oncobiome and the most likely bacterial metabolites play vital roles in mediating the effectiveness of chemotherapy. Finally, we discuss the potential of oncobiotic changes as biomarkers for the diagnosis of ovarian cancer and microbial metabolites as possible adjuvant agents in therapy.

Adenocarcinoma of ectopic pancreas

Ectopic pancreas adenocarcinoma is a very rare form of aberrant pancreas. It is part of differential diagnosis of submucosal tumors. The final diagnosis is based on the histological analysis. Surgery is the standard treatment for those tumours. This case illustrates this pathology.

Chemo4MetPanc: A phase II study with combination chemotherapy (gemcitabine and nab-paclitaxel), chemokine (C-X-C) motif receptor 4 inhibitor (motixafortide), and immune checkpoint blockade (cemiplimab) in metastatic treatment naïve pancreas adenocarcinoma (PDAC).

TPS454 Background: Pancreas adenocarcinoma (PDAC) is an aggressive cancer projected to be the second leading cause of cancer-related death in the United States by 2030 for which improved treatment options are desperately needed. Immune checkpoint blockade (ICB) for PDAC has failed as monotherapy in early phase clinical trials likely due to a highly immunosuppressive tumor microenvironment. The CXCR4/CXCL12 axis is a key immune evasion mechanism thought to deter CD8+ T-cells (CTLs) from infiltrating the tumor. We performed a large seven arm survival and biopsy/necropsy study in KPC mice (KrasLSL.G12D/+;p53R172H/+;Pdx1Cretg/+) where we demonstrate that addition of gemcitabine to CXCR4 inhibition in combination with ICB, enhanced tumor stabilization and neoplastic cell death, and improved survival by 50 percent. Multiplex immunofluorescence indicated an increased CTL to regulatory T-cell ratio and clustering of CTLs around neoplastic cells. Presented here is a trial-in progress that will evaluate combination of a CXCR4 inhibitor, ICB, and chemotherapy in treatment naïve patients with PDAC. Methods: This is a multicenter, single arm, open-label phase 2 study of combination motixafortide 1.25mg/kg SC monotherapy for 5 days during priming followed by twice weekly, cemiplimab 350mg IV once every 21 days, gemcitabine 1000mg/m2 IV with nab-paclitaxel 125mg/m2 IV on days 1, 8, and 15 every 28 days. Patients with histologically confirmed metastatic PDAC who have not received prior therapy will be enrolled. The primary endpoint is overall response rate by 16 weeks. A response rate greater than 45% by 16 weeks is considered promising, whereas a response rate of less than 23% is considered not promising. We will use a Simon optimal 2-stage design, where we will enroll 10 patients in the first stage. If 3 or more patients meet the endpoint in the first stage, the study will be expanded to a total of 40 patients. If a total of 14 or more patients achieve CR or PR by 16 weeks, the agent will be considered promising and worthy of further study. Secondary endpoints include safety, mPFS, disease control rate (DCR), and mOS. Correlative aims include analyses of pre- and on-treatment biopsies with quantitative multiplex immunofluorescence, RNA-sequencing, and generation of patient derived organoids for association with clinical benefit and to determine mechanisms of action/resistance. An interim analysis will be performed at the conclusion of the stage I portion of the study. Clinical trial information: NCT04543071.