The potential link regarding the bovine leukemia virus breast cancer relationship remains a subject of significant scientific investigation. Researchers recently conducted a cross-sectional study at Ankara Etlik City Hospital to evaluate BLV IgG seroprevalence in women. Specifically, the study included 124 participants to compare those with malignant breast cancer against a control group with benign breast lesions. While BLV is a zoonotic retrovirus primarily affecting cattle, its presence in human samples suggests potential cross-species transmission routes that require careful monitoring.

Evaluating Bovine Leukemia Virus Breast Cancer Risk

During the study, clinical teams analyzed serum samples from 82 women with confirmed breast cancer and 42 women with benign lesions. Notably, the overall BLV IgG seroprevalence among all participants was 12.9%. Within the malignant group, the seropositivity rate was 13.4%, whereas the benign group showed a rate of 11.9%. Statistical analysis revealed no significant difference between these two groups. However, researchers observed that seropositive patients in the malignant group were significantly older than their seronegative counterparts. This finding indicates that exposure risk might accumulate over time or vary with age-related factors.

Furthermore, international literature presents varying data on this zoonotic threat. Some meta-analyses suggest a higher prevalence of BLV DNA in cancerous breast tissues compared to healthy samples. Moreover, experts identify the consumption of unpasteurized dairy and undercooked meat as primary transmission sources. Nevertheless, the results of this specific Turkish cohort do not support a direct association between BLV seropositivity and malignancy. Consequently, clinicians should consider regional dietary habits and viral prevalence in local cattle when assessing potential risks. Therefore, while the virus is detectable in the human population, its definitive role in carcinogenesis continues to be debated globally.

How can humans be exposed to BLV?

Humans typically encounter the bovine leukemia virus through the consumption of raw, unpasteurized milk or undercooked meat products derived from infected cattle. Additionally, researchers are investigating other potential environmental and direct contact routes.

Does a positive BLV antibody test mean I have breast cancer?

No, a positive BLV IgG antibody test only indicates that an individual has been exposed to the virus at some point. Currently, evidence does not confirm that this exposure leads directly to the development of breast cancer.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or a professional diagnosis. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

1. Kürkçü MF et al. Bovine Leukemia Virus Prevalence in Women with Breast Cancer and Premalignant Breast Lesions. Viral Immunol. 2026 Apr 23. doi: 10.1177/08828245261445779. PMID: 42024437.
2. Blanco R et al. Bovine Leukemia Virus and Human Breast Cancer: A Review of Clinical and Molecular Evidence. Viruses. 2025 Feb 26;17(3):324.
3. Saeedi-Moghaddam S et al. Bovine leukemia virus (BLV) and risk of breast cancer; a systematic review and meta-analysis. Infect Agent Cancer. 2024 Dec 03;19(1):45.