Researchers have discovered a method of blocking an enzyme that is used by the disease to spread to the bones and is being described as "important progress" in the prevention of one of the most common and deadly second stages of the disease.
Some breast cancers spread to the bones by using an enzyme to drill holes in the bones to plant new tumors, research has shown. The enzyme oxidase is released from the primary tumor in the breast and scientists have found that it produces holes in bone giving tumors fertile ground to use to spread cancer cells.
But the process can be blocked, at least in mice, with bisphosphonate drugs that are already used to prevent bone loss and are used to treat osteoporosis. These drugs are already being prescribed to men with advanced prostate cancer that has spread to the bones in order to prevent pain and fractures.
The new discovery could lead to treatments designed to prevent secondary breast cancers in patients with non-hormone sensitive disease.
"This is important progress in the fight against breast cancer metastasis and these findings could lead to new treatments to stop secondary breast tumors growing in the bone, increasing the chances of survival for thousands of patients," said Dr. Alison Gartland, from the University of Sheffield, who led the research. "We are really excited about our results that show breast cancer tumors send out signals to destroy the bone before cancer cells get there in order to prepare the bone for the cancer cells' arrival."
"The next step is to find out exactly how the tumor secreted Lox interacts with bone cells to be able to develop new drugs to stop the formation of the bone lesions and cancer metastasis. This could also have implications for how we treat other bone diseases too."
While most breast cancers are hormone sensitive, researchers found it was the non-estrogen sensitive cancers that most often spread to the bones. Secondary breast cancer that has spread to the bones or liver is the primary cause of death to women suffering from breast cancer and an estimated 85 percent involve bone metastasis.
Study co-author Dr. Janine Erler, from the University of Copenhagen, said, "Once cancer spreads to the bone it is very difficult to treat. Our research has shed light on the way breast cancer cells prime the bone so it is ready for their arrival."
"If we were able to block this process and translate our work to the clinic, we could stop breast cancer in its tracks thereby extending patients' lives."
Katherine Woods, from Breast Cancer Campaign and Breakthrough Breast Cancer, said, "The reality of living with secondary breast cancer in the bone is a stark one, which leaves many women with bone pain and fractures that need extensive surgery just when they need to be making the most of the time they have left with friends and family."
