Katherine Weilbaecher

A new treatment designed to limit the spread of cancerous tumors is using medications that attack healthy cells. Washington University researcher Katherine Weilbaecher says this unusual strategy has improved survival in tumorous mice.

She studied mice that are genetically susceptible to a type of blood cancer that also results in tumors that can spread into the bone. Weilbaecher was looking for a way to keep cancer from spreading so she treated the mice with osteoporosis drugs that inhibit osteoclasts, the cells that normally break down the bone.

"If we gave a medicine that blocks the normal cells that chew and resorb bone," she says, "the cancer cells didn't like that. We had fewer tumors in the bone. We also affected the tumors that developed elsewhere." In other words, inhibiting normal, healthy osteoclasts also somehow limited the formation of tumors, not just in the bone, but elsewhere in the mice too.

Weilbaecher says it is already known that some cancer patients who receive these osteoporosis drugs have less pain, fewer tumors in the bone and fewer fractures. "What we didn't know - and what we're finding in this model - is that if you started treating mice with these bone-strengtheners before they even got the tumor, you not only prevented them from getting tumors in their bone, but you also increased their survival, and they got less tumors in other places."

Dr. Weilbaecher says the finding means it might be appropriate to begin studying these bone strengthening drugs in humans, both as a way to protect bone and to inhibit certain types of cancer.