A five-day antibiotic course is not beneficial compared to a single-day regimen for patients recovering from lower-limb sarcoma cancer surgery, says a McMaster University-led study.

The study, published in JAMA Oncology, enrolled 604 surgery patients undergoing treatment in 55 specialized centres from Canada and 11 other countries.

They were randomized to either a one-day or a five-day post-operative course of intravenous antibiotics. The worldwide study ran from January 2013 to October 2019 and all patients were undergoing treatment for sarcomas, or cancers of the bones and connective tissues, or for metastatic bone disease.

The study showed that prolonging the use of post-operative antibiotics beyond one day does not reduce the rate of surgical site infections, but can significantly increase the risk of antibiotic-related complications.

“Bone tumours of the limbs were historically managed with amputation. Today, the current standard is limb-salvage surgery where orthopedic oncologists remove the tumour and reconstruct the limb with a large metal bone replacement called a ‘tumour prosthesis’,” said first study author Michelle Ghert, a professor in McMaster’s Department of Surgery.

“However, these surgeries have a high risk of devastating surgical site infections. The most effective antibiotic regimen to prevent infections after these surgeries has been unknown and surgeons do not agree on how much antibiotics to prescribe.”

She said a large-scale worldwide trial was vital for gaining reliable results, as bone and connective tissue cancers are relatively rare and only a small number of patients are treated at a given specialist centre in any given year.