Phase Angle Is Related to Oxidative Stress and Antioxidant Biomarkers in Breast Cancer Patients Undergoing Chemotherapy

Bruna R. da Silva ,Sarah Rufato , Mirele S. Mialich, Loris P. Cruz, Thais Gozzo, Alceu A. Jordão


The study aimed to analyze the influence of chemotherapy on health biomarkers and examine the relationship between phase angle (PhA) and oxidative stress.


Breast cancer is the most common cancer in women (2.3 million new cases in 2021) and the second among all populations worldwide [1]. Nearly 30% of all new diagnoses will progress and become metastatic diseases [2]. Oxidative stress is a condition promoted by an imbalance between oxidants and antioxidants, with increased reactive oxygen species (ROS) levels [3]. This condition has been shown to play an essential role in the pathogenesis of cancer, which can be related to the development, proliferation, and progression of metastatic cancer cells [4].

Materials and methods

During the clinical orientation of chemotherapy, a responsible nurse informed the patient about the study, those who were interested know more about it were forwarded to talk with the study researcher. All women who met the following inclusion criteria were enrolled in the study: age ≥18 years and <65 years; a histologically confirmed diagnosis of early breast cancer (range of stage I–III); and very first chemotherapy treatment course. Smokers, patients metabolic syndrome; worse blood pressure control, which means the use of two or more antihypertensive drugs; lipid disorders, which means values above the normal range for triglycerides, total cholesterol and low dense cholesterol, according to the criteria of the National Cholesterol Education Program’s Adult Treatment Panel III (NCEP-ATP III) [43] and, the Brazilian nation recommendations [44]; diabetes type I or II or with a more recent glucose test above 125 mg/dl according to the results available on the electronic clinical records; pregnant women; who previously has already received or started chemotherapy in any other moment of life; those fitted with a defibrillator, cardiac pacemaker, metal implants or those with a local infection/wound preventing the use BIA pads, those unable to use a handheld dynamometer due to a neuromuscular disorder were all excluded.


For the control group, 61 women were recruited. However, three did not attend the data collection visit. Therefore, the final sample included was 58 women. Control and breast cancer patients, both groups presented overweight according to BMI. We did not find statistically significant alteration in body weight, BMI, FM, or GSH levels during the follow-up period, but FFM (p < 0.001) and TBW (p = 0.01) were statistically significant. Chemotherapy also impacted PhA, EW, EW ratio, AL, CRP and HB (p<0.05). MDA and DPPH improved, and alpha-tocopherol increased after one month of chemotherapy treatment (p<0.05) (Table 1).


Recently, our research group identified that despite fewer studies have evaluated the relationship between PhA and markers of oxidative stress, available data suggest that PhA has potential to be used as an indicator (for screening) of oxidative damage [61]. Zouridakis et al. in 2016 reported a positive correlation between PhA and total antioxidant capacity (TAC) [27], and Venâncio et al. in 2021 found a negative correlation with advanced oxidation protein products [28]. In addition, another Brazilian group described a positive correlation between PhA and catalase, total radical-trapping antioxidant potential and a negative correlation with ferrous oxidation-xylenol orange (FOX) and AOPP [25, 26]. Our results only found the association between PhA and oxidant, antioxidant, CRP, and AL in the breast cancer group.


Our results suggest that breast cancer patients have worse nutritional status, food consumption, biochemical blood markers and oxidative stress biomarkers than a control group with similar age and body composition. Chemotherapy promoted a deterioration in PhA, increased inflammation by PCR and a higher mobilization of antioxidant regulatory mechanisms. PhA was statistically correlated to oxidative stress parameters regardless of age and BMI. Thus, PhA might be a potential inexpensive alternative to monitor oxidative stress in breast cancer patients. In-depth studies are needed to confirm these findings.


We thank all of the research group on Nutrition and Breast Cancer of the University of São Paulo, especially the students who assisted in all phases of the study.

Citation: da Silva BR, Rufato S, Mialich MS, Cruz LP, Gozzo T, Jordão AA (2023) Phase angle is related to oxidative stress and antioxidant biomarkers in breast cancer patients undergoing chemotherapy. PLoS ONE 18(6): e0283235.

Editor: Alvaro Reischak-Oliveira, Universidade Federal do Rio Grande do Sul, BRAZIL

Received: June 9, 2022; Accepted: March 6, 2023; Published: June 8, 2023

Copyright: © 2023 da Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper.

Funding: RS was founded by São Paulo Research Foundation (FAPESP). Scholarship number: 2017/07963-0 and FAPESP scholarship number: 2019/09877-9. The funders had no role in study design, data collection and analysis, the decision to publish, or the preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

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