Intestinal Microbiota in Postmenopausal Breast Cancer Patients and Controls

Background: Previous preclinical and clinical research has investigated the role of intestinal microbiota in carcinogenesis. Growing evidence exists that intestinal microbiota can influence breast cancer carcinogenesis. However, the role of intestinal microbiota in breast cancer needs to be further investigated. This study aimed to identify the microbiota differences between postmenopausal breast cancer patients and controls. Patients and methods: This prospective cohort study compared the intestinal microbiota richness, diversity, and composition in postmenopausal histologically proven ER+/HER2- breast cancer patients and postmenopausal controls. Patients scheduled for (neo)adjuvant adriamycin, cyclophosphamide (AC), and docetaxel (D), or endocrine therapy (tamoxifen) were prospectively enrolled in a multicentre cohort study in the Netherlands. Patients collected a faecal sample and completed a questionnaire before starting systemic cancer treatment. Controls, enrolled from the National Dutch Breast Cancer Screening Programme, also collected a faecal sample and completed a questionnaire. Intestinal microbiota was analysed by amplicon sequencing of the 16S rRNA V4 gene region. Results: In total, 81 postmenopausal ER+/HER2- breast cancer patients and 67 postmenopausal controls were included, resulting in 148 faecal samples. Observed species richness, Shannon index, and overall microbial community structure were not significantly different between breast cancer patients and controls. There was a significant difference in overall microbial community structure between breast cancer patients scheduled for adjuvant treatment, neoadjuvant treatment, and controls at the phylum (p = 0.042) and genus levels (p = 0.015). Dialister (p = 0.001) and its corresponding family Veillonellaceae (p = 0.001) were higher in patients scheduled for adjuvant treatment, compared to patients scheduled for neoadjuvant treatment. Additional sensitivity analysis to correct for the potential confounding effect of prophylactic antibiotic use, indicated no differences in microbial community structure between patients scheduled for neoadjuvant systemic treatment, adjuvant systemic treatment, and controls at the phylum (p = 0.471) and genus levels (p = 0.124). Conclusions: Intestinal microbiota richness, diversity, and composition are not different between postmenopausal breast cancer patients and controls. The increased relative abundance of Dialister and Veillonellaceae was observed in breast cancer patients scheduled for adjuvant treatment, which might be caused by a relative decrease in other bacteria due to prophylactic antibiotic administration rather than an absolute increase.

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Adjuvant treatment of early-stage HER2+ elderly breast cancer patients: A retrospective, multicenter French study.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.15_suppl.636 ◽

2012 ◽

Vol 30 (15_suppl) ◽

pp. 636-636

Author(s):

Philippe Barthelemy ◽

Karine Bassot ◽

Florence Joly ◽

Isabelle Ray Coquard ◽

Gilles Freyer ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Adjuvant Treatment ◽

Early Stage ◽

Single Agent ◽

Her2 Status ◽

Routine Practice ◽

Breast Cancer Patients ◽

Her2 Breast Cancer

636 Background: Trastuzumab (T) is the standard of care for the adjuvant treatment of early stage, HER2+ breast cancer (BC). However, few data are available for elderly HER2+ breast cancer patients in this setting. In this current study, the patterns of care for elderly HER2+ early stage BC in 7 French cancer centres was evaluated. Methods: Medical records of all consecutive early stage HER2+ BC patients over 70 years old treated between 2006 and 2011 among participating centres were retrospectively reviewed. Specific factors such as age, comorbidities, tumor stage, grade, ER/PR and HER2 status, treatment characteristics, follow-up and cardiotoxicity data were analysed. Results: One hundred and two patients were identified, median age 75.4 (range 70-95). Elderly patients presented mostly (57%) large tumors (pT ≥2), and positive lymph node involvement (n=61). Trastuzumab-based adjuvant treatment was administered in 62% of patients (n=63). 54% of patients (n=55) received adjuvant chemotherapy whereas five patients received neoadjuvant chemotherapy. Chemotherapy without T was administered in 2 additional patients. Anthracyclines (A)-Taxanes (Ta) combination-based chemotherapy was given in 27% of patients (n=16), whereas 38% received a Ta-based chemotherapy (n=23), 35% (n=19) an A-based chemotherapy. Five patients received single-agent T. Treatment delays for T were required in 37% of patients (n=23) among whom 15 and 8 permanently or temporarily stopped T, respectively. The most frequent reason for interrupting or delaying therapy was cardiotoxicity (n=12) as well as patients refusal (n=7). A ≥ 10% decrease in LVEF was observed in 18/63 (29%) of patients, among whom T was stopped in 12. After a median 33 months follow-up, the median progression-free survival was not reached in patients receiving T-based therapy. The 2 and 3-year PFS rate were 94 and 89.5%, respectively. Conclusions: In routine practice only 62% of elderly early stage HER2+ BC patients are treated with a neoadjuvant or adjuvant T-based regimen. However, less than 50% of all patients completed their therapy. A-based chemotherapy was administered in around 60% of treated patients, and could explain cardiotoxicity in this setting.

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