Working night shifts and suffering from chronic sleep disruption may not only increase the risk of breast cancer but also make existing tumors significantly more aggressive and prone to metastasis. This crucial conclusion was reached by scientists from Texas A&M University, who published their detailed findings in the journal *Oncogene*.
Circadian Rhythms and Malignancy
In experimental settings, researchers demonstrated that the disruption of circadian rhythms—the body`s internal biological “clock”—accelerates the onset of tumors and enhances their malignant properties. In models where the light-dark cycle was intentionally disturbed, cancer developed earlier than usual and more frequently spread to the lungs. This spread (metastasis to the lungs) is a recognized sign of a poor prognosis.
The Role of the LILRB4 Receptor
Beyond the direct impact on existing tumors, circadian disruption also altered the structure of healthy breast tissue, rendering it more vulnerable to malignant transformation. According to the study authors, a key player in this destructive process is the immune receptor LILRB4. LILRB4 acts as an “off switch” for the immune response; when biological rhythms are disturbed, this receptor begins to excessively suppress the body`s essential protective reactions.
Crucially, blocking this specific receptor allowed researchers to partially restore anti-tumor immunity, even in subjects with severely disrupted biorhythms. This breakthrough suggests a potentially novel and targeted approach for treating aggressive forms of breast cancer.
The authors emphasize that these results are particularly important for individuals who regularly work night shifts or experience chronic jet lag. The study confirms that sleep disruption is not merely an inconvenience or a source of discomfort, but a serious and quantifiable threat to long-term health, particularly concerning oncological risk.
In related research, scientists previously discovered that an aqueous extract of oregano is capable of suppressing the growth of breast cancer cells.
