Muriel Brackstone

Microbiota of Human Breast Tissue

ABSTRACT In recent years, a greater appreciation for the microbes inhabiting human body sites has emerged. In the female mammary gland, milk has been shown to contain bacterial species, ostensibly reaching the ducts from the skin. We decided to investigate whether there is a microbiome within the mammary tissue. Using 16S rRNA sequencing and culture, we analyzed breast tissue from 81 women with and without cancer in Canada and Ireland. A diverse population of bacteria was detected within tissue collected from sites all around the breast in women aged 18 to 90, not all of whom had a history of lactation. The principal phylum was Proteobacteria. The most abundant taxa in the Canadian samples were Bacillus (11.4%), Acinetobacter (10.0%), Enterobacteriaceae (8.3%), Pseudomonas (6.5%), Staphylococcus (6.5%), Propionibacterium (5.8%), Comamonadaceae (5.7%), Gammaproteobacteria (5.0%), and Prevotella (5.0%). In the Irish samples the most abundant taxa were Enterobacteriaceae (30.8%), Staphylococcus (12.7%), Listeria welshimeri (12.1%), Propionibacterium (10.1%), and Pseudomonas (5.3%). None of the subjects had signs or symptoms of infection, but the presence of viable bacteria was confirmed in some samples by culture. The extent to which these organisms play a role in health or disease remains to be determined.

The Microbiota of Breast Tissue and Its Association with Breast Cancer

ABSTRACT In the United States, 1 in 8 women will be diagnosed with breast cancer in her lifetime. Along with genetics, the environment contributes to disease development, but what these exact environmental factors are remains unknown. We have previously shown that breast tissue is not sterile but contains a diverse population of bacteria. We thus believe that the hosts local microbiome could be modulating the risk of breast cancer development. Using 16S rRNA amplicon sequencing, we show that bacterial profiles differ between normal adjacent tissue from women with breast cancer and tissue from healthy controls. Women with breast cancer had higher relative abundances of Bacillus, Enterobacteriaceae and Staphylococcus. Escherichia coli (a member of the Enterobacteriaceae family) and Staphylococcus epidermidis, isolated from breast cancer patients, were shown to induce DNA double-stranded breaks in HeLa cells using the histone-2AX (H2AX) phosphorylation (γ-H2AX) assay. We also found that microbial profiles are similar between normal adjacent tissue and tissue sampled directly from the tumor. This study raises important questions as to what role the breast microbiome plays in disease development or progression and how we can manipulate this for possible therapeutics or prevention. IMPORTANCE This study shows that different bacterial profiles in breast tissue exist between healthy women and those with breast cancer. Higher relative abundances of bacteria that had the ability to cause DNA damage in vitro were detected in breast cancer patients, as was a decrease in some lactic acid bacteria, known for their beneficial health effects, including anticarcinogenic properties. This study raises important questions as to the role of the mammary microbiome in modulating the risk of breast cancer development.

Enhancing accrual to chemotherapy trials for patients with early stage triple-negative breast cancer: a survey of physicians and patients

PurposeThe optimal chemotherapy regimen for patients with early stage triple-negative breast cancer (TNBC) remains unknown. The purpose of the study is to survey physicians and breast cancer patients about preferred chemotherapy regimens for early stage TNBC and clinical trial strategies.MethodsA standardised online questionnaire was developed and circulated to medical oncologists known to treat breast cancer. A separate questionnaire was given to patients who had received chemotherapy for breast cancer.ResultsThe questionnaire was completed by 41/84 medical oncologists (48.8% response rate) and 74 patients. The most commonly used neoadjuvant and adjuvant chemotherapy regimens for TNBC were dose-dense doxorubicin and cyclophosphamide (AC)–paclitaxel (P), dose-dense AC followed by weekly P and fluorouracil, epirubicin, cyclophosphamide–docetaxel (FEC-D). The majority of medical oncologists (80%) would be willing to enrol patients in trials evaluating the most effective chemotherapy regimen for TNBC. Oncologists favoured a three arm trial design comparing currently available standard of care treatments (36%) and trials of novel or non-standard of care agents 22% (9/41). Sixty percent (41/74) of patients indicated that they would be willing to be enrolled in trials evaluating various adjuvant regimens for TNBC. Both oncologists and patients were interested in novel consent approaches such as using the integrated consent model.ConclusionOptimisation of chemotherapy for TNBC is an important and unmet clinical need. It is apparent that various chemotherapy regimens are used for patients with early stage TNBC. The majority of medical oncologists and patients are interested in entering trials to optimise chemotherapy choices.

A Canadian national expert consensus on neoadjuvant therapy for breast cancer: linking practice to evidence and beyond

BACKGROUND Use of the neoadjuvant approach to treat breast cancer patients has increased since the early 2000s, but the overall pathway of care for such patients can be highly variable. The aim of our project was to establish a multidisciplinary consensus among clinicians with expertise in neoadjuvant therapy (nat) for breast cancer and to determine if that consensus reflects published methods used in randomized controlled trials (rcts) in this area. METHODS A modified Delphi protocol, which used iterative surveys administered to 85 experts across Canada, was established to obtain expert consensus concerning all aspects of the care pathway for patients undergoing nat for breast cancer. All rcts published between January 1, 1967, and December 1, 2012, were systematically reviewed. Data extracted from the rcts were analyzed to determine if the methods used matched the expert consensus for specific areas of nat management. A scoring system determined the strength of the agreement between the literature and the expert consensus. RESULTS Consensus was achieved for all areas of the pathway of care for patients undergoing nat for breast cancer, with the exception of the role of magnetic resonance imaging in the pre-treatment or preoperative setting. The levels of agreement between the consensus statements and the published rcts varied, primarily because specific aspects of the pathway of care were not well described in the reviewed literature. CONCLUSIONS A true consensus of expert opinion concerning the pathway of care appropriate for patients receiving nat for breast cancer has been achieved. A review of the literature illuminated gaps in the evidence about some elements of nat management. Where evidence is available, agreement with expert opinion is strong overall. Our study is unique in its approach to establishing consensus among medical experts in this field and has established a pathway of care that can be applied in practice for patients receiving nat.

The effect of surgery type on survival and recurrence in very young women with breast cancer

The impact of surgical treatment on outcomes in breast cacner in very young women remains unclear. We sought to determine the effect of surgery type on risk of recurrence and survival in a population‐based cohort.

Physician “out of office” alert: does it work?

We have presented a collection of prospectively collected data pertaining to the nature of e-mail messages received in modern clinical oncology practice. Despite all the limitations of the study, some useful information emerged. Use of ooo appears to reduce the number of e-mail messages a physician receives. If you use ooo so that people sending you messages of importance recognize that they won’t be receiving a reply, then there is value in using it. Further, physicians could have some peace of mind that senders are aware not to expect a response as quickly as they might otherwise anticipate. Perhaps a notification saying “your e-mail message will be deleted; if it is important that I see it, please resend upon my return” might ultimately be the optimal way to manage an inbox during an absence from work?