Background: Pyrotinib is an effective targeted drug for HER2-positive breast cancer, but it very frequently causes diarrhea, which can be severe enough to disrupt treatment and reduce patients' quality of life. The reason why some patients develop diarrhea while others do not is not well understood. Recent research suggests that the community of bacteria in the gut (gut microbiota) may play a key role in this side effect. What is the purpose of this study? This is an observational study (Phase 1) that aims to understand the relationship between pyrotinib treatment, changes in gut bacteria, and the occurrence of diarrhea. The main goal is to compare the gut bacteria of patients who develop diarrhea while taking pyrotinib with those who do not. Researchers hope to identify specific bacteria that might protect against diarrhea, which could lead to new ways to prevent or treat this side effect in the future. What will happen in the study? Patients with HER2-positive breast cancer who are being treated with pyrotinib will be invited to participate. They will be divided into two groups: those who experience diarrhea and those who do not. Participants will provide stool samples at specific time points (e.g., 2 and 4 weeks after starting pyrotinib). They will also allow researchers to collect information from their medical records about their clinical condition and diarrhea symptoms. No experimental intervention will be administered in this phase of the study; all patients will receive standard medical care. Potential Benefits: Participants will not receive any direct benefit from this observational phase of the study. However, the information gathered may help scientists better understand pyrotinib-induced diarrhea and develop future strategies to help other breast cancer patients manage this side effect more effectively.
Study Type
OBSERVATIONAL
Enrollment
60
Hubei Cancer Hospital
Wuhan, Hubei, China
Difference in gut microbiota β-diversity between the Diarrhea group and the Non-diarrhea group.
Beta diversity (e.g., using UniFrac distance) of the gut microbiota will be compared between the two groups based on metagenomic sequencing data. A statistically significant difference (P \< 0.05) is expected.
Time frame: Through study completion, an average of 6 months.
Identification of specific bacterial species enriched in the Non-diarrhea group.
Metagenomic sequencing data will be analyzed to identify bacterial species that are significantly more abundant in the Non-diarrhea group compared to the Diarrhea group, using statistical methods such as LEfSe (Linear Discriminant Analysis Effect Size) with a threshold of LDA Score \> 2 and P \< 0.05.
Time frame: Through study completion, an average of 6 months.
Difference in gut microbiota α-diversity between groups.
Alpha diversity indices (e.g., Shannon index, Chao1 index) of the gut microbiota will be compared between the Diarrhea and Non-diarrhea groups.
Time frame: Through study completion, an average of 6 months.
Differences in metagenomic functional pathways between groups.
Metagenomic sequencing data will be annotated using databases like KEGG. The abundance of functional pathways (e.g., KEGG Level 2 or 3) will be compared between the two groups to identify differentially abundant metabolic or functional modules.
Time frame: Through study completion, an average of 6 months.
Differences in serum inflammatory cytokine levels between groups.
Levels of systemic inflammatory cytokines (e.g., IL-6, TNF-α, CRP) measured in serum samples by ELISA or other assays will be compared between the Diarrhea and Non-diarrhea groups.
Time frame: Through study completion, an average of 6 months.
Differences in serum metabolomic profiles between groups.
Metabolomic profiling of serum samples will be performed (e.g., by mass spectrometry). The metabolic profiles will be compared between the two groups to identify differentially abundant metabolites.
Time frame: Through study completion, an average of 6 months.
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