Study links NKR antagonists to reduced breast cancer spread

Neurokinin receptor (NKR) antagonists, currently a standard nonhormone treatment for menopausal hot flashes, may offer additional benefits for breast cancer patients. A new study indicates these drugs could restrict the spread of cancer cells and help prevent recurring diagnoses. The results are scheduled for presentation at the 2026 Annual Meeting of The Menopause Society in San Diego from October 20-24, 2026.

Mechanism behind hot flash relief

During menopause, falling estrogen levels disrupt the hypothalamus, the brain's temperature control center. This hormonal drop causes KNDy neurons to become hyperactive, overproducing a peptide known as neurokinin B (NKB). Excessive NKB signaling tricks the body into feeling overheated, resulting in sudden sweating and flushing. NKR antagonists block these receptors, calming the overstimulated pathway and stabilizing body temperature regulation without hormones.

Exploring effects beyond the brain

Researchers investigated where else NKB receptors are expressed outside the hypothalamus, leading to an exploration of their role in breast tissue. In-silico analyses revealed that downregulating NKR signaling suppresses molecular pathways that promote invasiveness and metastatic spread. These data suggest NKR antagonists may modify breast cancer cell behavior to reduce invasiveness and spread.

Tissue expression and lab results

The team examined NKB receptor expression in human breast tissue using immunohistochemical analyses. They observed a linear increase in tissue expression of NKRs from normal to hyperplastic to cancerous breast tissue. Receptors were found to be over-expressed in cancerous tissue, indicating a relevance of NKR signaling in cancer progression. In vitro treatment of various human breast cancer cells with NKR antagonists resulted in reduced cancer cell viability and downregulated oncogenic pathways relevant to progression and therapeutic resistance.

Potential for long-term therapy

Based on these findings, researchers hypothesize that the benefits of NKR antagonists extend beyond their recognized effectiveness against hot flashes and sleep issues. Lead author Dr. Lubna Pal from Yale University stated, "These findings are indeed intriguing and suggest that long-term use of NKR antagonist drugs may hold a therapeutic potential for harnessing breast cancer progression, and even for preventing breast cancer recurrence." She noted that these hypothesized effects must first be substantiated in appropriately designed studies, adding, "We are working towards gaining this clarity, so do stay tuned."

Expert commentary on preliminary data

The study will be discussed under the presentation title "Exploring the promise of NKR antagonists – beyond the flashes, the sweats, and sleep." Dr. Stephanie Faubion, medical director for The Menopause Society, commented, "Neurokinin receptor antagonists have already transformed the treatment landscape for women seeking nonhormone therapy for vasomotor symptoms." She added that while the early findings raise intriguing questions about biologic effects beyond symptom management, the results are preliminary and derived from laboratory and tissue-based studies. According to Faubion, they provide a foundation for future research exploring the potential role of neurokinin signaling in breast health and breast cancer.