Microbiome and Association With Implant Infections

Sponsor

University of California, San Francisco (Other)

Overall Status

Recruiting

CT.gov ID

NCT05020574

Collaborator

The Plastic Surgery Foundation (Other)

Enrollment

Location

Arms

16.1

Anticipated Duration (Months)

2.5

Patients Per Site Per Month

Study Details

Study Description

Brief 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 patients 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.

Condition or Disease	Intervention/Treatment	Phase
Breast Cancer Breast Cancer Female Genetic Predisposition to Disease	Drug: Cephalexin	Phase 2

Detailed Description

PRIMARY OBJECTIVE:

To determine the feasibility of breast microbiome sampling using the study techniques

SECONDARY OBJECTIVES:

To define the differences in the gut and breast microbiomes between patients undergoing mastectomy with implant-based reconstruction who develop post-operative implant infection and those who do not.
To determine the effects of post-operative antibiotics on the gut and breast microbiomes after mastectomy with implant-based reconstruction.

Patients are followed-up for 90 days after undergoing implant-based reconstruction.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

40 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Supportive Care

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

Actual Study Start Date :

Sep 28, 2021

Anticipated Primary Completion Date :

Jan 31, 2023

Anticipated Study Completion Date :

Jan 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Cohort A: Standard antibiotics Receive standard pre-incision antibiotics and 24-hour perioperative antibiotics - Prescribed standard postoperative antibiotics to take for at least 7 days post-operatively	Drug: Cephalexin Given orally (PO) Other Names: Keflex
No Intervention: Cohort B: No antibiotics Receive standard pre-incision antibiotics and 24-hour perioperative antibiotics - No antibiotics post-operatively, unless patient develops clinical evidence of infection

Arm

Intervention/Treatment

Experimental: Cohort A: Standard antibiotics

Receive standard pre-incision antibiotics and 24-hour perioperative antibiotics - Prescribed standard postoperative antibiotics to take for at least 7 days post-operatively

Drug: Cephalexin

Given orally (PO)

Other Names:

Keflex

No Intervention: Cohort B: No antibiotics

Receive standard pre-incision antibiotics and 24-hour perioperative antibiotics - No antibiotics post-operatively, unless patient develops clinical evidence of infection

Outcome Measures

Primary Outcome Measures

Proportion of tissue samples obtained successfully over time [90 days]
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.
Proportion of aspirate samples obtained successfully overall [90 days]
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.
Proportion of tissue samples successfully producing microbiome data [90 days]
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.
Proportion of aspirate samples successfully producing microbiome data [90 days]
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.
Proportion of any samples successfully producing microbiome data [90 days]
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.
Correlation of the change in breast microbiome over time with total duration of antibiotics (Cohort A only) [90 days]
We 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.

Secondary Outcome Measures

Proportion of participants with post-operative infection [90 days]
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.
Shannon Diversity Index Score for species of microbiome [90 days]
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.
Number of overall identified microbes [90 days]
We will evaluate microbial composition by grouping identified microbes into operational taxonomic units at the species, genera and phyla levels. We will compare the relative abundances of these microbes between groups at the species, gene

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

Female

Accepts Healthy Volunteers:

Inclusion Criteria:

Patients must have histologically confirmed breast malignancy OR genetic predisposition to breast cancer.
Age >= 18 years
Scheduled to undergo mastectomy with the immediate placement of tissue expanders
Ability to understand a written informed consent document, and the willingness to sign it
At least 4 weeks post-completion of chemotherapy or radiation therapy.

Exclusion Criteria:

Any significant medical condition or laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study
Pregnant or breastfeeding
Patients who have taken antibiotics within 90 days of the consent date
Patients who have taken probiotics within 90 days of the consent date
Patients who have a documented or reported allergic reaction to the outlined antibiotics to be used in this study
Male patients