Association of breast and gut microbiota dysbiosis and the risk of breast cancer: a case-control clinical study.

BACKGROUND: Breast cancer ranks first in women, and is the second cause of death in this gender. In addition to genetics, the environment contributes to the development of the disease, although the factors involved are not well known. Among the latter is the influence of microorganisms and, therefore, attention is recently being paid to the mammary microbiota. We hypothesize that the risk of breast cancer could be associated with the composition and functionality of the mammary/gut microbiota, and that exposure to environmental contaminants (endocrine disruptors, EDCs) might contribute to alter these microbiota. METHODS: We describe a case-control clinical study that will be performed in women between 25 and 70 years of age. Cases will be women diagnosed and surgically intervened of breast cancer (stages I and II). Women with antecedents of cancer or advanced tumor stage (metastasis), or who have received antibiotic treatment within a period of 3 months prior to recruitment, or any neoadjuvant therapy, will be excluded. Controls will be women surgically intervened of breast augmentation or reduction. Women with oncological, gynecological or endocrine history, and those who have received antibiotic treatment within a period of 3 months prior to recruitment will also be excluded. Blood, urine, breast tissue and stool samples will be collected. Data regarding anthropometric, sociodemographic, reproductive history, tumor features and dietary habits will be gathered. Metabolomic studies will be carried out in stool and breast tissue samples. Metagenomic studies will also be performed in stool and breast tissue samples to ascertain the viral, fungal, bacterial and archaea populations of the microbiota. Quantitation of estrogens, estrogen metabolites and EDCs in samples of serum, urine and breast tissue will also be performed. DISCUSSION: This is the first time that the contribution of bacteria, archaea, viruses and fungi together with their alteration by environmental contaminants to the risk of breast cancer will be evaluated in the same study. Results obtained could contribute to elucidate risk factors, improve the prognosis, as well as to propose novel intervention studies in this disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT03885648 , 03/25/2019. Retrospectively registered.

Validación del cuestionario FACT-B+4-MS y exploración de su capacidad predictora en mujeres intervenidas de cáncer de mama / Validation of the FACT-B+4-UL questionnaire and exploration of its predictive value in women submitted to surgery for breast cancer

Introducción y objetivo: La detección precoz de las complicaciones del miembro superior en mujeres intervenidas de cáncer de mama es importante. El cuestionario FACT-B+4-MS, variante del Functional Assessment of Cancer Therapy-Breast (FACT-B) es una escala específica de la función del miembro superior en estas pacientes. Pacientes y métodos: Se valida el FACT-B+4-MS en una cohorte prospectiva de 201 mujeres intervenidas por cáncer de mama (análisis factorial, consistencia interna, fiabilidad test-retest, validez del constructo y sensibilidad al cambio) y se explora mediante regresión logística su capacidad predictora de linfedema y otras complicaciones. Resultados: El FACT-B+4-MS es unifactorial y goza de gran consistencia interna (alfa de Cronbach: 0,87), alta fiabilidad test-retest (coeficiente de correlación intraclase: 0,98), validez de constructo (R de Pearson con el 'Quick DASH': 0,81) y sensibilidad al cambio. En los modelos de regresión, no aparece como variable explicatoria de linfedema, pero sí de otras complicaciones del miembro superior. Conclusiones: El FACT-B+4-MS es útil para medir la discapacidad del miembro superior en mujeres operadas por cáncer de mama. No predice el establecimiento de linfedema, pero sí, aunque débilmente, otras alteraciones (AU)

Introduction and objective: The early detection of upper limb complications is important in women operated on for breast cancer. The 'FACT-B+4-UL' questionnaire, a specific variant of the Functional Assessment of Cancer Therapy-Breast (FACT-B) is available among others to measure the upper limb function. Patients and methods: The Spanish version of the upper limb subscale of the FACT-B+4 was validated in a prospective cohort of 201 women operated on for breast cancer (factor analysis, internal consistency, test-retest reliability, construct validity and sensitivity to change were determined). Its predictive capacity of subsequent lymphoedema and other complications in the upper limb was explored using logistic regression. Results: This subscale is unifactorial and has a great internal consistency (Cronbach's alpha: 0.87), its test-retest reliability and construct validity are strong (intraclass correlation coefficient: 0.986; Pearson's R with 'Quick DASH': 0.81) as is its sensitivity to change. It didn’t predict the onset of lymphedema. Its predictive capacity for other upper limb complications is low. Conclusions: FACT-B+4-UL is useful in measuring upper limb disability in women surgically treated for breast cancer; but it does not predict the onset of lymphoedema and its predictive capacity for others complications in the upper limb is low (AU)

Validation of the FACT-B+4-UL questionnaire and exploration of its predictive value in women submitted to surgery for breast cancer. / Validación del cuestionario FACT-B+4-MS y exploración de su capacidad predictora en mujeres intervenidas de cáncer de mama.

INTRODUCTION AND OBJETIVE: The early detection of upper limb complications is important in women operated on for breast cancer. The "FACT-B+4-UL" questionnaire, a specific variant of the Functional Assessment of Cancer Therapy-Breast (FACT-B) is available among others to measure the upper limb function. PATIENTS AND METHODS: The Spanish version of the upper limb subscale of the FACT-B+4 was validated in a prospective cohort of 201 women operated on for breast cancer (factor analysis, internal consistency, test-retest reliability, construct validity and sensitivity to change were determined). Its predictive capacity of subsequent lymphoedema and other complications in the upper limb was explored using logistic regression. RESULTS: This subscale is unifactorial and has a great internal consistency (Cronbach's alpha: 0.87), its test-retest reliability and construct validity are strong (intraclass correlation coefficient: 0.986; Pearson's R with "Quick DASH": 0.81) as is its sensitivity to change. It didn't predict the onset of lymphedema. Its predictive capacity for other upper limb complications is low. CONCLUSIONS: FACT-B+4-UL is useful in measuring upper limb disability in women surgically treated for breast cancer; but it does not predict the onset of lymphoedema and its predictive capacity for others complications in the upper limb is low.