Bovine Leukemia Virus Prevalence in Women with Breast Cancer and Premalignant Breast Lesions

Abstract

The potential role of bovine leukemia virus (BLV), a zoonotic deltaretrovirus, in human breast carcinogenesis remains controversial, and evidence from seroepidemiological studies is limited. This study aimed to evaluate BLV IgG seroprevalence in women with malignant breast cancer and benign breast lesions and to explore the possible association between BLV exposure and breast cancer development. In this cross-sectional comparative study, a total of 124 women aged ≥18 years who presented to Ankara Etlik City Hospital between May and July 2024 were included. The malignant group comprised 82 women with histopathologically confirmed breast cancer, while the control group included 42 women with benign breast lesions. Serum samples were analyzed for BLV-specific IgG antibodies using a commercial enzyme-linked immunosorbent assay kit. Overall BLV IgG seroprevalence was 12.9% (16/124), with rates of 13.4% in the malignant group and 11.9% in the benign group, showing no statistically significant difference (p = 0.812). In the malignant group, BLV IgG seropositive patients were significantly older than seronegative patients, and seropositivity increased with age (p < 0.01). Although higher BLV IgG seropositivity were observed in invasive mucinous carcinoma cases, this association did not reach statistical significance in logistic regression analysis. Hematological parameters were evaluated to investigate potential systemic immune or inflammatory responses associated with BLV exposure; however, no significant associations were identified between BLV IgG seropositivity and these parameters. These findings suggest that BLV exposure, as reflected by humoral immune response, is not directly associated with breast cancer development but may represent cumulative or long-term exposure. Further large-scale, multicenter studies integrating molecular and serological approaches are warranted to clarify the potential role of BLV in human breast cancer etiology.