New Clinical Trial Shows Repurposed Drugs Can Prevent Breast-Cancer Recurrence By Eliminating Hidden Cells

A recent clinical trial has shown that it is possible to detect and eliminate dormant cancer cells in breast cancer survivors, potentially preventing the disease from returning. The breakthrough could transform the way doctors approach long-term breast cancer treatment, according to a Science Daily report.

The research, led by the Abramson Cancer Centre and the Perelman School of Medicine at the University of Pennsylvania, marks the first time that dormant tumour cells have been successfully targeted using existing medicines. These so-called ‘sleeper cells,’ or minimal residual disease, often linger undetected after treatment and can re-emerge years or even decades later, causing incurable relapse in breast cancer survivors.

While survival rates for breast cancer have steadily improved, recurrence remains a major obstacle. According to Science Daily, around 30% of patients eventually face relapse, and once the cancer returns, treatment becomes indefinite and rarely curative.

In the phase II trial, 51 breast cancer survivors were screened for dormant cells. Those with MRD were treated with repurposed FDA-approved drugs, either alone or in combination. The results were striking. Dormant tumour cells were cleared in 80% of patients. After more than three years of follow-up, survival without recurrence stood above 90% for single-drug therapy and reached 100% among those who received both drugs.

"The lingering fear of cancer returning is something that hangs over many breast cancer survivors after they celebrate the end of treatment," said principal investigator Angela DeMichele, the Science Daily report mentioned. “Our study shows that preventing recurrence by monitoring and targeting dormant tumour cells is a strategy that holds real promise, and I hope it ignites more research in this area.”

Senior author Lewis Chodosh added that the dormant phase offers “a window of opportunity” to eradicate hidden cells before they transform into metastatic disease.

The findings build on earlier preclinical studies, which showed that targeting autophagy and mTOR signalling pathways could flush out MRD in mice. Encouraged by these results, Penn Medicine researchers are now enrolling patients in larger clinical trials.

As reported by Science Daily, the work has been supported by the US National Cancer Institute, Department of Defense and several philanthropic organisations. If confirmed in larger populations, this approach could provide survivors with something they have long sought, which is not just treatment after relapse, but the chance to prevent breast cancer altogether.