A joint research team from the University of Pisa in Italy and the UK’s University of Salford have reported positive results from a pilot clinical trial that investigated the antitumour action of doxycycline antibiotic to treat breast cancer.

Doxycycline is part of the tetracyclines antibiotic family and is primarily used for the treatment of acne.

A University of Pisa statement said: “In fact, as well as eradicating bacteria, the antibiotics also have a destructive effect on mitochondria, the ‘power stations’ of cells, which abound in neoplastic stem cells.

“These cells are responsible for the origins of tumours, local tumour recurrence, resistance to treatment and the dreaded distant metastases.”

University of Pisa department of translational research and new technologies in medicine professor Antonio Giuseppe Naccarato and anatomical pathologist Dr Cristian Scatena led the research group that conducted the trial.

“These cells are responsible for the origins of tumours, local tumour recurrence, resistance to treatment and the dreaded distant metastases.”

Researchers from the University of Salford and the Pisa Science Foundation were also involved in the trial, among others.

The trial included 15 female patients with early breast cancer and demonstrated a reduction of around 40% in the number of neoplastic stem cells after 14 days of treatment.

University of Salford researchers have examined this effect in tumour models ‘in vitro’ to find that doxycycline was able to eradicate the neoplastic stem cells in eight different types of tumours including breast cancer.

Based on the results of these studies, researchers conducted the first clinical trials of doxycycline in early breast cancer patients destined for surgical treatment.

The trial was performed at the AOUP Breast Unit under the direction of professor Manuela Roncella.

Of the 15 patients enrolled in the trial, nine were treated with 200mg daily dose of doxycycline for 14 days before surgery and six were observed as controls before undergoing surgery directly.

Researchers analysed several biomarkers in patients, such as stemness, mitochondria, cell proliferation, and others.