According to a study by researchers at the University of Texas MD Anderson Cancer Center, resistant Ewing sarcoma may be treated with a combination therapy. Ewing sarcoma is a rare type of cancer affecting the bone or the soft tissue. The most common locations are the femur, humerus, ribs, clavicle and pelvis.
According to The Bone Cancer Research Trust, the most characteristic symptom is localized pain, which is usually a severe bone pain. Ewing sarcoma usually affects teenagers and young adults. Prognosis depends on the presence of metastases. 5-year survival rate in patients without metastases and treated with chemotherapy is 70-80%. Instead, for those with metastases the long-term survival rate is less than 10%. Treatment usually consists of chemotherapy and radiotherapy. In some cases the affected limb needs amputation.
According to researchers, 5 of 17 patients responded to combination therapy cixutumumab-temsirolimus. Moreover, two of them reached complete remission. Both drugs inhibit tumor cell growth and proliferation and vascular growth. The first is a monoclonal antibody that inhibits the insulin growth factor receptor 1 (IGF-1R), and the second inhibits mTOR, or “mammalian target of rapamycin”. Lead researcher Aung Naing, MD, assistant professor in MD Anderson’s Department of Investigation Cancer Therapeutics, said that after a cycle of 4 weeks of combination therapy, the tumors of 7 of the 20 patients had stoped growing and 5 presented a tumor reduction of more than 20%. The study was a Phase 1 clinical trial and the duration of response to treatment was 8 to 27 luni.It is important to remember that of the 20 patients, 17 were patients with Ewing sarcoma and 3 with desmoplastic small round cell- tumors (DSRCT). Also, patients enrolled in the study were previously treated with other therapies but without success.
Problems that occur frequently when treating these cancers are resistance to treatment and relapse. Therefore, the findings are promising and represent a new hope for patients with treatment resistant tumors. Used separately, the two drugs had different results. So researchers have thought that a good way to avoid the appearance of resistance to treatment and relapse would be to combine them.
Another important issue is the ability to control chemotherapy side effects. Dr. Naing said the medical team managed to control the toxicity of treatment. The common side effects were bone marrow suppression (thrombocytopenia, neutropenia), hypercholesterolemia, hypertriglyceridemia, hyperglycemia and mucositis. Reactions such as fatigue, rash, elevated creatinine and urea, weight loss, anorexia, vomiting were also present. Dr Naing underlined that it is extremely important to maintain the health of the patient as close to normal in order to be able to undergo chemotherapy.