An observational study in Breast Neoplasms, Hormone Receptor-Positive Breast Cancer and Abemaciclib, sponsored by Hubei Cancer Hospital. Recruiting at 1 site in China. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-04-03.
Sponsored by Hubei Cancer Hospital · Observational
Why is this study being done? Many patients with a type of breast cancer (called HR-positive) take a medicine called Abemaciclib. While this medicine is effective, a very common side effect is diarrhea, which can be severe enough to disrupt treatment and reduce quality of life. The reason why some patients get diarrhea and others do not is not well understood. This study aims to investigate whether the natural bacteria living in the gut (known as the gut microbiome) play a role in this side effect. Researchers will compare the gut bacteria of patients who develop diarrhea with those who do not.
What will happen in the study? This is an observational study, which means that patients will receive their normal cancer treatment and will not be given any new or experimental drugs as part of this initial phase.
Who can participate?
What are the potential benefits? Participants will not receive any direct medical benefit from taking part in this study. However, the information learned may help researchers better understand why diarrhea occurs and, in the future, could lead to new ways to prevent or treat this side effect for other cancer patients.
How is privacy protected? All personal information and samples collected will be de-identified using a unique code. This means that the data used for analysis cannot be directly linked back to the participant's identity. All data is stored securely according to strict ethical guidelines.
14,825 studies on the registry are indexed under Breast Neoplasms; 3,319 are open to participants now.
This study's planned enrollment of 60 is below the median of 184 across 3,235 observational studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →Hubei Cancer Hospital is the lead sponsor of 25 studies on the registry; 17 are open to participants now.
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This study will enroll a prospective cohort of female patients with hormone receptor-positive (HR⁺) breast cancer who are receiving treatment with Abemaciclib (as monotherapy or in combination) as part of their standard clinical care at Hubei Cancer Hospital. Participants will be prospectively assigned into two groups based on the presence or absence of drug-induced diarrhea, as defined by CTCAE v5.0 criteria: the Diarrhea Group and the Non-Diarrhea (Control) Group. The study involves the collection of clinical data, fecal samples, and optional blood samples for microbiome and biomarker analysis. No investigational intervention is administered in this phase of the study.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HR-positive breast cancer patients who develop diarrhea (Grade 1 or higher as per CTCAE v5.0 criteria) during treatment with Abemaciclib. This group will not receive any investigational intervention as part of the observational study. Fecal and blood samples will be collected for microbiome and biomarker analysis.
HR-positive breast cancer patients who do not develop diarrhea (Grade 0 as per CTCAE v5.0 criteria) during treatment with Abemaciclib. This group serves as the control cohort and will not receive any investigational intervention as part of the observational study. Fecal and blood samples will be collected for microbiome and biomarker analysis.
This study also gives Abemaciclib. No intervention listed here names it: that was found by reading the record.
Difference in gut microbiota beta diversity
Beta diversity of the gut microbiome (e.g., Weighted UniFrac distance) will be compared between the diarrhea group and the non-diarrhea group to assess overall microbial community structure differences.
Time frame: Through study completion, an average of 6 months.
Identification of specific bacterial species enriched in non-diarrhea group
Metagenomic sequencing data will be analyzed (e.g., using LEfSe) to identify bacterial species that are significantly enriched in the non-diarrhea group compared to the diarrhea group (LDA Score \> 2, p-value \< 0.05).
Time frame: Through study completion, an average of 6 months.
Difference in gut microbiota alpha diversity
Alpha diversity indices (Shannon, Chao1) of the gut microbiome will be compared between the diarrhea group and the non-diarrhea group.
Time frame: Through study completion, an average of 6 months.
Difference in metagenomic functional pathways
Differential abundance analysis of functional pathways (e.g., KEGG Level 2/3) derived from metagenomic sequencing data between the two groups.
Time frame: Through study completion, an average of 6 months.
Differential metabolites in serum
Differences in serum metabolomic profiles between the diarrhea and non-diarrhea groups.
Time frame: Through study completion, an average of 6 months.
Difference in systemic inflammatory cytokine levels
Levels of inflammatory cytokines (e.g., IL-6, TNF-α, CRP) in serum will be compared between the two groups.
Time frame: Through study completion, an average of 6 months.
Predictive potential of baseline gut microbiota
Exploratory analysis to assess the potential of baseline gut microbiota features for predicting the risk of developing Abemaciclib-induced diarrhea.
Time frame: Through study completion, an average of 6 months.
Plan to share: No — Individual participant data (IPD) that underlie the results reported in this study will not be shared publicly. The decision is based on the following considerations: to protect patient privacy and confidentiality, as the data contain sensitive clinical and genomic information; the informed consent obtained from participants does not include provisions for public data sharing; and the samples and data are collected under a specific ethical approval that limits their use to this research protocol. Summary results and aggregated data will be made available through publication.
No publications or documents are linked to this record.
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Hubei Cancer Hospital