The role of interleukin‑7 serum level as biological marker in breast cancer: a cross‑sectional, observational, and analytical study

Abstract

Background The important role that the immune system plays in malignant diseases is well known. The action of interleukin-7 (IL-7) as a cytokine has been observed in many cellular processes, both in normal cells of the immune system and in some cancer cells. The aim of this study has been to explore whether there is any elevation of interleukin-7 serum levels in early invasive breast cancer (EIBC) patients in comparison with healthy controls. In addition, the correlation between the IL-7 serum level and the histopathological characteristics of the tumor has been evaluated. Methods This cross-sectional, observational, and analytical study included 213 consecutive patients with EIBC (113 from Croatia and 100 from Kosovo) and 62 healthy participants as the control group (30 from Croatia and 32 from Kosovo). Blood samples have been taken from patients confirmed with breast cancer (BC) by biopsy, prior to surgical intervention and other oncological treatments, as well as from healthy participants. A serum IL-7 level has been measured, using the “Sandwich” ELISA Immunoenzyme test. In addition, after the surgical intervention, histopathological specimen examinations and immunohistochemistry have been performed and analyzed. The differences in the distribution of the numerical variables have been analyzed with the Mann–Whitney U test and Kruskal–Wallis ANOVA test. Correlations have been tested with Pearson coefficients. A P-value < 0.05 has been accepted as statistically significant. Results The serum level of IL-7 in EIBC patients was significantly higher than in control cases (P 0.001). Patients with invasive lobular carcinoma (ILC) seem to have a lower IL-7 serum level compared to other histological subtypes, and the difference has been significant (P = 0.043). There has been no correlation between IL-7 serum level and histopathological characteristics of the tumor, with neither age nor menopausal status of the patients. Conclusions Noting the significant increase in the IL-7 serum level in the EIBC patients as compared to the healthy control group, the use of IL-7 as a potential diagnostic indicator for BC, as well as in the follow-up of the patients after treatment, can be assumed. The lack of correlation with tumor size, lymph node metastasis, and all other histopathological characteristics of the tumor questions its use as a prognostic indicator.

Circulating Proteins as Diagnostic Biomarkers in Breast Cancer

“…In a study conducted on 213 BC patients, researchers discovered that EBC patients had significantly higher IL-7 serum levels than healthy control cases (p < 0.001). IL-7 serum levels, on the other hand, have not been linked to tumor size, lymph node metastasis, or tumor progression regardless of age or menopausal status of the patients [12] -8-Iso-prostaglandin F2α (8-iso-PGF2α): Increased lipid peroxidation and the absence of antioxidants, combined with oxidative stress, have been related to breast tumorigenesis in BC studies [26,27]. Lipid peroxidation is the most well researched free radical-inducing process linked to cancer, assisting in the creation of numerous relatively stable breakdown products, such as isoprostanes, which serve as indirect cellular prooxidant indicators in bodily fluids [28][29][30][31].…”

Immune Profiling of Secreted Factors from Human Vestibular Schwannoma Cells and Tumor‐associated Macrophages

“…Similarly, an IL‐7 variant (IL‐7δ5) has pivotal roles in AKT‐mediated cell proliferation, apoptosis, angiogenesis, and metastasis in breast cancer, 60 all of which may increase tumor size. However, a recent (2022) observational study in breast cancer found no significant correlation between tumor size and IL‐7 serum concentrations, 61 thus the effect of IL‐7 may depend on the type of tumor or could be limited to the tumor microenvironment.…”

Breast Cancer Immune Landscape: Interplay Between Systemic and Local Immunity

“…[123,124] that may result from an intensive secretion of IL-7 by the tumor as IL-7 facilitates B-cell maturation. [125,126] Plasma cells mediate Ab-dependent cytotoxicity, Abdependent cellular phagocytosis, and complement-dependent cytotoxicity. [127] The antibodies secreted by plasma cells are categorized into different classes, with immunoglobulin G (IgG) antibodies providing the major antitumor cytotoxicity.…”

“…[ 123,124 ] that may result from an intensive secretion of IL‐7 by the tumor as IL‐7 facilitates B‐cell maturation. [ 125,126 ]…”