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PubMed2026

Risk of Relapse and Efficacy of Adjuvant Chemotherapy in Localized Appendiceal Adenocarcinoma.

IMPORTANCE: Relapse risk and benefit of adjuvant chemotherapy after resection of appendiceal adenocarcinoma (AA) are uncertain. OBJECTIVE: To identify clinicopathologic and genomic factors associated with relapse and assess efficacy of adjuvant chemotherapy in localized AA. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study (January 2000 through February 2024; median follow-up, 62.6 months) used Kaplan-Meier and Cox proportional hazards modeling. It took place at the University of Texas MD (UT MD) Anderson Cancer Center with validation from Memorial Sloan Kettering Cancer Center (MSKCC). Participants included a complete localized cohort of 439 patients with stage I to III AA from UT MD Anderson, of whom 202 underwent surgery at UT MD Anderson and also included a validation cohort of 128 patients with stage II AA from MSKCC. EXPOSURES: Surgical resection with or without adjuvant chemotherapy. MAIN OUTCOMES AND MEASURES: Rate of recurrence, recurrence-free survival (RFS), and overall survival (OS). RESULTS: There were 439 patients with localized AA (median age, 56.5 [IQR, 22.2-83.7] years; 50% female and 50% male) managed at MD Anderson between January 2000 and February 2024. Of 202 MDA surgical patients, 19 (9.4%) had a relapse including 9 (6%) patients with stage II and 8 (19.5%) of patients stage III disease. Five-year OS was 95.7% without vs 77.2% with relapse (hazard ratio [HR], 5.50; 95% CI, 3.07-9.83; P < .001). Relative to goblet cell tumors, mucinous (HR, 5.60; 95% CI, 2.1-15; P < .001) and enteric-type (HR, 6.60; 95% CI, 2.9-15; P < .001) histologies were independently associated with relapse, as was pathologic T4 (HR, 3.30; 95% CI, 1.9-5.7; P < .001). Importantly, poor differentiation, perforation, lymphovascular invasion, and perineural invasion, known risk factors in colorectal cancer, were not significantly associated with relapse. For the complete localized cohort, adjuvant chemotherapy was not associated with improved RFS (univariate HR, 2.06; 95% CI, 1.36-3.13; P = .001 and multivariable HR, 0.98; 95% CI, 0.43-2.28; P = .90) or OS (univariate HR, 1.80; 95% CI, 1.0-3.2; P = .04 and multivariable HR, 0.71; 95% CI, 0.24-2.1; P = .53). TP53 mutation in goblet cell tumors (HR, 6.93; 95% CI, 1.50-31.00; P = .01) and GNAS mutation in nongoblet tumors (HR, 17.0; 95% CI, 3.09-93.3; P = .001) were associated with greater risk of relapse. CONCLUSIONS AND RELEVANCE: These results demonstrate that relapse after resection of localized AA is uncommon. Molecular profiling and histopathologic subtype refine risk. Adjuvant chemotherapy were not associated with benefit.

Journal Article↗

PubMed2026

Isolation of folate-producing probiotic candidates and their effects on homocysteine metabolism and gut microbiota composition.

BACKGROUND: Folate deficiency is a global nutritional problem associated with multiple adverse health outcomes, including impaired one-carbon metabolism and elevated homocysteine levels (hyperhomocysteinemia). Gut microbiota-mediated folate biosynthesis has emerged as a promising strategy for improving the host's folate status. This study aimed to isolate folate-producing probiotic strains, clarify their folate synthesis mechanisms, and evaluate their regulatory effects on folate metabolism and gut microbiota. METHODS: High-throughput cultivation and screening were performed to isolate folate-producing candidate probiotics. Whole-genome sequencing analysis, pathway reconstruction, and metabolite profiling in fermented milk were performed to explore folate biosynthesis pathways and microbial cross-feeding interactions. A folate-deficient mouse model was established to evaluate the effects of a candidate probiotic cocktail on serum folate, homocysteine (Hcy) levels, and gut microbiota composition using quantitative PCR (qPCR) and 16S rRNA gene sequencing. RESULTS: High-throughput screening identified 8 high-folate-producing candidate probiotic strains, including Lactiplantibacillus plantarum and Heyndrickxia coagulans, from over 1,000 isolates. Genomic analysis revealed that most commonly used probiotics lacked para-aminobenzoic acid (pABA) biosynthesis genes but retained downstream modules, suggesting a reliance on cross-feeding with pABA-producing gut commensals such as Bacteroides. Metabolite profiling of fermented milk demonstrated that selected strains significantly increased bioactive 5-methyltetrahydrofolate (5-MeTHF) and tetrahydrofolate levels. In vivo, only a high-dose candidate probiotic cocktail significantly elevated serum folate (p < 0.05) and reduced homocysteine levels (p < 0.05) in deficient mice. Fecal qPCR confirmed dose-dependent transient persistence of the administered bacterial species. Consistent with the qPCR data, 16S rRNA gene sequences demonstrated significant enrichment of these administered species observed in the high-dose group. Furthermore, beta-diversity analysis found that high-dose candidate probiotic supplementation promoted a shift in the gut microbiota composition toward a normal profile, partially mitigating the dysbiosis induced by the folate-deficient diet. This effect was accompanied by a significant enrichment of potential short-chain fatty acid producers (e.g., Lachnospiraceae and Oscillospiraceae) and the depletion of potential opportunistic pathogens. CONCLUSION: This study screened high-folate-producing candidate probiotic strains and demonstrated their ability to synthesize the active form of 5-MeTHF. Moreover, folate-producing candidate probiotic cocktail treatment significantly improved folate status and Hcy metabolism and modulated the gut microbiota by enriching potential beneficial bacterial taxa. These findings suggested that folate-producing probiotics may serve as a promising microbiota-based strategy to improve folate availability and homocysteine metabolism.

B vitamin↗