In patients with localized Ewing sarcoma, chemotherapy administered every two weeks is more effective than chemotherapy administered every three weeks, with no increase in toxicity, according to the results of a study published in the Journal of Clinical Oncology.
Ewing sarcoma is a type of cancer that forms in bone or soft tissue. Ewing sarcoma can occur in any bone of the body, although the most frequent sites are the pelvis, thigh, lower leg, upper arm, and ribs. Ewing sarcoma may also arise in the soft tissues of the body.
Localized Ewing’s sarcoma affects only the bone in which it developed and the tissues next to the bone, such as muscle and tendon. There is no detectable spread of the cancer to other areas of the body. The standard treatment approach for localized Ewing sarcoma includes chemotherapy with cycles that alternate between vincristine/doxorubicin/cyclophosphamide and ifosfamide/etoposide as well as primary tumor treatment with surgery and/or radiation therapy.
To evaluate whether shortening the intervals between chemotherapy cycles could improve outcomes, researchers conducted a prospective, controlled clinical trial that included 568 patients younger than 50 years old with newly diagnosed localized extradural Ewing sarcoma. Patients were randomly assigned to standard chemotherapy treatment every 21 days or intensified chemotherapy treatment every 14 days.
Patients received alternating chemotherapy treatment (vincristine/doxorubicin/cyclophosphamide and ifosfamide/etoposide) for 14 cycles and primary tumor treatment (surgery and/or radiation) was slated to begin at week 13, which was after four chemotherapy cycles in the standard treatment arm and six cycles in the intensified arm.
The primary endpoint of the study was event-free survival (EFS), which after five years, was 73 percent in the intensified treatment group versus 65 percent in the standard treatment group. The toxicity was similar between the two groups.
The researchers concluded that for localized Ewing sarcoma, chemotherapy administered every two weeks is more effective than chemotherapy administered every three weeks, with no increase in toxicity.
Womer RB, West DC, Krailo MD, et al. Randomized controlled trial of interval-compressed chemotherapy for the treatment of localized Ewing Sarcoma: A report from the Children’s Oncology Group. Journal of Clinical Oncology. Published early online October 22, 2012. doi: 10.1200/JCO.2011.41.5703