Impact of breast cancer neoadjuvant chemotherapy on plasma and urine amino acid profile, plasma proteins and nitrogen metabolism

Abstract

Neoadjuvant chemotherapy (NAC) is the preferred treatment option in locally advanced breast cancer (BC). The administration of NAC is associated with a wide range of adverse effects. This pilot observational prospective study examined the effect of NAC using anthracycline + cyclophosphamide (AC) followed by paclitaxel (PTx) on a portfolio of 22 plasma and urinary amino acids, plasma proteins (albumin, prealbumin, transferrin), and products of nitrogen metabolism (urea, creatinine, uric acid) in plasma and urine. Plasma and 24-h urine samples were obtained from ten patients with early breast cancer (N1-3 N0-2 M0), at the following time points: before the start of NAC and during the AC/PTx treatment period (a total of 8 measurements at three-weekly intervals). Amino acids were analyzed using ion exchange chromatography. There were no significant differences in the measured parameters in plasma and urine between pre-NAC and during AC- and PTx-treatment. No trend was detected. A significant difference in the portfolio of plasma and urinary amino acids was found only in the pre-treatment period compared to the control group. Levels of eight plasma amino acids (8/22) were significantly reduced and those of nine urine amino acids were increased (9/22). Nitrogenous catabolites in plasma and urine were not indicative of increased protein catabolism during the anthracycline and taxane treatment periods. A slightly positive nitrogen balance was accompanied by an average weight gain of 3.3 kg (range 0–6 kg). The AC/PTx treatment regimen did not cause significant changes in the monitored laboratory parameters.

Keywords:

• Neoadjuvant chemotherapy
• breast cancer
• amino acids
• plasma proteins
• nitrogen metabolism

Author contributions

MH and ZČ participated in the conceptualization, methodology, investigation, data curation, reviewing, and editing; AM and JG participated in the methodology, investigation, data curation and statistic; MD participated in the conceptualization, methodology, investigation, data curation, writing of the original draft, reviewing, and editing. All authors provided final approval of the submitted manuscript.

Compliance with ethical standards

The study was approved by the local Ethical Committee of the Masaryk Memorial Cancer Institute. All participants provided written informed consent to participate in the study.

Disclosure statement

No potential conflict of interest was reported by the author(s)

Data availability statement

The data used to support the findings of this study are included within the article

Additional information

Funding

This work is supported by Ministry of Health of the Czech Republic – DRO (MMCI 00209805). Ministerstvo Zdravotnictví České Republiky;