Microbiome and Association With Implant Infections

Breast Cancer Clinical Trial

Official title:

Microbiome and Association With Implant Infections: Investigating the Impact of Antibiotics on the Gut and Breast Microbiomes Post-mastectomy With Implant-based Breast Reconstruction

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05020574
• Other study ID #: 217510
• Secondary ID: NCI-2021-08985
• Status: Recruiting
• Phase: Phase 2
• Start date: September 28, 2021
• Est. completion date: December 31, 2025

Study information

• Verified date: November 2023
• Source: University of California, San Francisco
• Contact: Laura Barnes, MD
• Phone: (415) 502-1259
• Email: Laura.Barnes[@]ucsf.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The most common tissue expander-related infections are from Staphylococcus and Pseudomonas species. In addition, from breast tissue microbiome studies, Staphylococcus and Pseudomonas show variable abundance across samples. The investigator hypothesizes that participants undergoing mastectomy with high initial abundance of Staphylococcus and/or Pseudomonas are more likely to develop subsequent tissue expander-related infections from these respective organisms.

Description:

PRIMARY OBJECTIVE: I. To determine the feasibility of breast microbiome sampling using the study techniques SECONDARY OBJECTIVES: I. To define the differences in the gut and breast microbiomes between participants undergoing mastectomy with implant-based reconstruction who develop post-operative implant infection and those who do not. II. To determine the effects of post-operative antibiotics on the gut and breast microbiomes after mastectomy with implant-based reconstruction. OUTLINE: Participants are randomized to 1 of 2 cohorts. COHORT A: Participants receive postoperative antibiotics to take for at least 7 days post-operatively. COHORT B: Participants receive no antibiotics post-operatively in the absence of clinical evidence of infection. Participants are followed up for 90 days.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 200
• Est. completion date: December 31, 2025
• Est. primary completion date: December 31, 2025
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

1. Patients must have histologically confirmed breast malignancy OR genetic predisposition to breast cancer.

2. Age >= 18 years

3. Scheduled to undergo mastectomy with the immediate placement of tissue expanders or implant placement

4. Ability to understand a written informed consent document, and the willingness to sign it

5. At least 4 weeks post-completion of chemotherapy or radiation therapy.

Exclusion Criteria:

1. Any significant medical condition or laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study

2. Pregnant or breastfeeding

3. Patients who have taken antibiotics within 90 days of the consent date

4. Patients who have taken probiotics within 90 days of the consent date

5. Patients who have a documented or reported allergic reaction to the outlined antibiotics to be used in this study

6. Male patients

Related Conditions & MeSH terms

• Breast Cancer
• Breast Cancer Female
• Breast Neoplasms
• Genetic Predisposition to Disease
• Infections

Intervention

Drug:
• Cephalexin
Given orally (PO)

Locations

Country	Name	City	State
United States	University of California, San Francisco	San Francisco	California

Sponsors (2)

Lead Sponsor	Collaborator
University of California, San Francisco	The Plastic Surgery Foundation

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Proportion of tissue samples obtained successfully over time	The feasibility of success in obtaining samples from breast tissue will be measured as a binary outcome (successful or not successful) over time (intra-operatively, week 1, week 2, week 3, and week 4). The investigators will assess and document success in obtaining a tissue sample immediately at the time of sampling of each participant.	90 days
Primary	Proportion of aspirate samples obtained successfully overall	The feasibility of success in obtaining samples from the tissue expander aspiration ports will be measured as a binary outcome (successful or not successful) over time (intra-operatively, week 1, week 2, week 3, and week 4). The investigators will assess and document success in obtaining a aspirate sample immediately at the time of sampling of each participant.	90 days
Primary	Proportion of tissue samples successfully producing microbiome data	Feasibility based off of the success rates in producing microbiome data from tissue samples in each patient will be measured as a binary outcome (successful or not successful) and will be reported.	90 days
Primary	Proportion of aspirate samples successfully producing microbiome data	Feasibility based off of the success rates in producing microbiome data from tissue samples in each patient will be measured as a binary outcome (successful or not successful) and will be reported.	90 days
Primary	Proportion of any samples successfully producing microbiome data	Feasibility based off of the success rates in producing microbiome data from tissue or aspirate samples in each patient will be measured as a binary outcome (successful or not successful) and will be reported.	90 days
Primary	Correlation of the change in breast microbiome over time with total duration of antibiotics (Cohort A only)	The investigators will analyze the microbiomes between groups, between microbiome environments (gut v. breast, inter-individual). The correlate of change in breast microbiome over time will be compared to the total duration of antibiotics for Cohort A only. The measure of association ranges from +1 to -1, with a value of zero equal to no association.	90 days
Secondary	Proportion of participants with post-operative infection	Safety will be assessed by clinically assessing for signs of post-operative infection in each patient at each clinic visit. A post-operative infection is defined by clinical assessment of findings of surgical site erythema, tenderness, edema, and/or purulent drainage +/- fever. Proportion of participants with clinically diagnosed infection will be reported for each group and final diagnosis for analyses will be binary; a participant will either have a post-operative infection in the 90 day post-operative period or not have a post-operative infection in the 90 day post-operative period.	90 days
Secondary	Shannon Diversity Index Score for species of microbiome	Alpha diversity will be evaluated for species richness by number of operational taxonomic units and for evenness using the Shannon Index. The Shannon diversity index (H) is an index that is commonly used to characterize species diversity in a community and accounts for both abundance and evenness of the species present. The proportion of species (i) relative to the total number of species (pi) is calculated, and then multiplied by the natural logarithm of this proportion (lnpi). The resulting product is summed across species, and multiplied by -1. Shannon's equitability (EH) can be calculated by dividing H by Hmax (here Hmax = lnS). Equitability assumes a value between 0 and 1 with 1 being complete evenness and the overall index score is represented by a percentage of the species.	90 days
Secondary	Number of overall identified microbes	The investigators will evaluate microbial composition by grouping identified microbes into operational taxonomic units at the species, genera and phyla levels and will compare the relative abundances of these microbes between groups at the species, gene	90 days