A commentary has been posted on this article:
Response: Commentary: Human gut, breast, and oral microbiome in breast cancer: A systematic review and meta-analysis
Guilherme Gamba1
Antonio José Grande2
Tamy Colonetti1
Maria Laura Rodrigues Uggioni1
Leonardo Roever3,4
Maria Inês da Rosa1*- 1Laboratory of Translational Biomedicine, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
- 2Laboratory of evidence-based practice, Universidade Estadual de Mato Grosso do Sul, Campo Grande, MS, Brazil
- 3Department of Clinical Research, Federal University of Uberlândia, Uberlândia, Brazil
- 4Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beiruta, Lebanon
A Commentary on
Human gut, breast, and oral microbiome in breast cancer: A systematic review and meta-analysis
by Thu MS, Chotirosniramit K, Nopsopon T, Hirankarn N and Pongpirul K (2023). Front. Oncol. 13:1144021. doi: 10.3389/fonc.2023.1144021
1 Introduction
This text is intended as a “letter to the editor” in order to contribute to the reflection of a recent systematic review performed by Thu et al. (1). The review suggested that the fecal, tumor, and oral microbiome profiles of breast cancer patients differ in microbiota abundance by menopausal status, menarche, cancer stages, and the change in the microbial pattern before and after chemotherapy.
2 Commentary and discussion
However, we have observed a few inconsistencies concerning this synthesis, which we would like to point out, namely: (1) In the Introduction, there is a misconception on the definition of subtypes of breast cancer: the definition of luminal A and luminal B disease by the AJCC 8th edn; Amin et al. (2) do not include HER2-positive disease but HER2-negative disease instead. The reference they use for this concept in the systematic review is Loibl et al. (3); however, when we double-checked the original article, the concept was correct, so there was a misinterpretation of the information contained in the study of Loibl et al. (3). (2) In Table 5, the description in the study of Uzan-Ulzari et al. (4) is inaccurate because they described five patients with benign cancers when, in fact, what is described in the original study are five patients with gynecological cancer. (3) In Tables 3–5, the authors use Illumina Sequencing in the description of the microbiota detection methods, but this is a platform that performs several genomic tests, so it would be important to describe the specific test because, in the way presented, we have a false impression that all studies used the same test, which is false as Zhu (5) used a metagenomic sequencing test and most other studies used 16S rRNA sequencing. (4) The study by Goedert (6) uses standard error, and the study by Byrd (7) uses standard deviation. When using both in the forest plot, we observed that SE was not converted to SD in the analysis. According to the study of Kadlec et al. (8), using standard error instead of standard deviation can overstate values, producing large effect sizes and overly narrow confidence intervals. The standard deviation can be estimated from reported standard errors of the mean by multiplying by the square root of n, it may play an aggravating factor since the heterogeneity found was I2 = 87%. According to the Cochrane Handbook (9), it is not recommended to conduct a meta-analysis because heterogeneity can affect the validity and interpretability of the meta-analysis results. There are only a small number of studies available or if the studies have limited sample sizes, it may not be appropriate to conduct a meta-analysis. In such cases, it is better to rely on the results of individual studies or consider other forms of evidence synthesis.
Meta-analysis is a powerful statistical approach that combines data from multiple individual studies to examine specific research questions or hypotheses. However, it is important to be aware of potential sources of error that can impact the accuracy and reliability of the calculated results. These errors can ultimately lead to flawed conclusions if not properly addressed and accounted for in the analysis. Therefore, appropriate statistical methods are necessary to minimize the risk of statistical errors and ensure the validity of the meta-analysis findings.
Author contributions
GG: Conceptualization, Investigation, Writing – original draft. AG: Conceptualization, Methodology, Writing – original draft. TC: Conceptualization, Methodology, Writing – original draft. MU: Conceptualization, Visualization, Writing – review & editing. LR-D: Conceptualization, Resources, Writing – review & editing. MR: Conceptualization, Project administration, Supervision, Writing – original draft.
Funding
The authors declare that no financial support was received for the research, authorship, and/or publication of this article.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
Publisher’s note
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References
1. Thu MS, Chotirosniramit K, Nopsopon T, HIrankarn N, Pongpirul K. Human gut, breast, and oral microbiome in breast cancer: A systematic review and meta-analysis. Front Oncol (2023) 13:1144021. doi: 10.3389/fonc.2023.1144021
2. Amin MB, Greene FL, Edge SB, Compton CC, Gershenwald JE, Brookland RK, et al. The Eighth Edition AJCC Cancer Staging Manual: Continuing to build a bridge from a population-based to a more "personalized" approach to cancer staging. CA Cancer J Clin. (2017) 67(2), 93–99. doi: 10.3322/caac.21388
3. Loibl S, Poortmans P, Morrow M, Denkert C, Curigliano G. Breast cancer. Lancet (2021) 397(10286):1750–69. doi: 10.1016/S0140-6736(20)32381-3
4. Uzan-Yulzari A, Morr M, Tareef-Nabwani H, Ziv O, Magid-Neriya D, Armoni R. The intestinal microbiome, weight, and metabolic changes in women treated by adjuvant chemotherapy for breast and gynecological Malignancies. BMC Med (2020) 18:281. doi: 10.1186/s12916-020-01751-2
5. Zhu J, Liao M, Yao Z, Liang W, Li Q, Liu J, et al. Breast cancer in postmenopausal women is associated with an altered gut metagenome. Microbiome (2018) 6:1–13. doi: 10.1186/s40168-018-0515-3
6. Goedert JJ, Jones G, Hua X, Xu X, Yu G, Flores R. Investigation of the association between the fecal microbiota and breast cancer in postmenopausal women: a population-based case-control pilot study. J Natl Cancer Institute (2015) 107(8):djv147. doi: 10.1093/jnci/djv147
7. Byrd DA, Vogtmann E, Wu Z, Han W, Wan Y, Clegg-Lamptey JN. Associations of fecal microbial profiles with breast cancer and nonMalignant breast disease in the Ghana Breast Health Study. Int J Cancer (2021) 148(11):2712–23. doi: 10.1002/ijc.33473
8. Kadlec D, Sainani KL, Nimphius S. With great power comes great responsibility: common errors in meta-analyses and meta-regressions in strength & Conditioning research. Sports Med (2023) 53:313–25. doi: 10.1007/s40279-022-01766-0
9. Deeks JJ, Higgins JPT, Altman DG. Chapter 10: Analysing data and undertaking meta-analyses. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA, editors. Cochrane Handbook for Systematic Reviews of Interventions version 6.3. Cochrane (2022). Available at: www.training.cochrane.org/handbook.
Keywords: microbiota, breast cancer, systematic review, meta-analysis, breast
Citation: Gamba G, Grande AJ, Colonetti T, Uggioni MLR, Roever L and da Rosa MI (2023) Commentary: Human gut, breast, and oral microbiome in breast cancer: a systematic review and meta-analysis. Front. Oncol. 13:1253435. doi: 10.3389/fonc.2023.1253435
Received: 05 July 2023; Accepted: 14 August 2023;
Published: 19 September 2023.
Edited by:
George Grant, University of Aberdeen, United KingdomReviewed by:
Peter Bai, University of Debrecen, HungaryCopyright © 2023 Gamba, Grande, Colonetti, Uggioni, Roever and da Rosa. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Maria Inês da Rosa, mir@unesc.net