How do you incorporate denosumab into the surgical management of giant cell tumor of bone?

Does the degree of resectability affect your management?

2 Answers

Mednet MemberInvited Expert

Medical Oncology · Emory University

Answered on

Denosumab forever.

Giant cell tumors of bone have a clonal cancer component and then osteoclasts that are hypnotized by the cancer. Denosumab works on the osteoclasts so they quit listening to the cancer and then the whole thing turns to bone. Denosumab does not kill anything and the cancer cells are still in there. I have a patient who we thought was in remission have her giant cell tumor (in the cervical spine) wake up after some years off treatment.

There are retrospectives reporting higher rate of recurrence for GCT treated with denosumab before surgery vs surgery alone. It makes sense - if the tumor turns to bone it will be harder to curette it out and harder to see where it ends. It also likely has selection bias - if the surgeon could easily remove the tumor then the med onc would never have heard about it, so these denosumab pretreated tumors will be the ones that were tricky in the first place and the surgeon wanted help.

In my patients on denosumab, I start monthly. Then after 1 or 2 good scans and clinical benefit, I stretch to every 6 weeks, then later to every 2 months then to every 3 months. Not to 6 months which is not often enough. I recently inherited a young man from the pediatricians - he had been giving denosumab to himself at home which I did not know could happen. It sounds a lot better than going to the infusion center!

I would not radiate the giant cell tumor. Again, lore-based but supposedly radiation can turn giant cell tumors into sarcoma. I think any tumor that grows through denosumab has one leg over that fence already and from now on, I am going to re-biopsy any tumor that breaks through denosumab.

Mednet MemberInvited Expert

Medical Oncology · University of Texas MD Anderson Cancer Center

Answered on

The primary treatment of choice remains surgery (resection or curettage and packing per Ortho Onc). If not feasible or accompanied by significant associated morbidity, a trial of Denosumab would be very appropriate. Optimal duration of therapy is unknown, but reasonable to continue until maximum response/tolerance and revisit consolidative local therapy.