Age and other factors influence osteosarcoma outcomes

Age, alkaline phosphatase level, tumor volume, and other factors influence the outcomes for osteosarcoma of the extremity treated with neoadjuvant chemotherapy, according to a report by Italian investigators published in the March 1st issue of Cancer.

“Optimal treatment is neoadjuvant chemotherapy,” Dr. Gaetano Bacci from Istituto Ortopedico Rizzoli, Bologna, told Reuters Health. “However in some cases (about 10%) with small tumor, especially if located in expendable bones (for instance, fibula), immediate surgery followed by chemotherapy could be better.”Dr. Bacci and colleagues evaluated the influence of several patient and treatment-related prognostic factors in a series of 789 patients with nonmetastatic osteosarcoma of the extremities treated with neoadjuvant chemotherapy and followed for at least 5 years.After a follow-up ranging from 5 to 22 years, more than half the patients (n=440) remained continuously event-free, the authors report. Another 313 had a recurrence, 20 developed a second neoplasm, and 10 patients died.Age of 14 years or younger, elevated serum alkaline phosphatase at presentation, tumor volume 200 mL or more, inadequate surgical margins, and poor histologic response to preoperative chemotherapy each independently predicted a high risk of recurrence, the results indicate.The first recurrences were isolated lung metastases in 243 patients (77.6%), isolated bone metastases in 26 patients (8.3%), combined lung and bone metastases in 5 patients (1.6%), and other sites in 3 patients (0.9%), the researchers note. The average time to recurrence was 24.5 months.Among 313 patients who relapsed, 171 (54.6%) were treated with surgery alone, 43 (13.7%) received surgery plus a second-line chemotherapy, 24 (7.7%) received chemotherapy only, and 6 (1.9%) received radiotherapy. Nearly two thirds of patients treated for the first recurrence entered remission.Overall, after a median of 8 years follow-up, 19.8% of patients who relapsed were alive and disease-free after the last treatment for systemic recurrence, the investigators report. Another 5 patients were alive with uncontrolled disease, and 246 relapsed patients had died.”When the surgical margins are inadequate, 30% of patients experience local recurrence in spite of chemotherapy,” Dr. Bacci said. “Local recurrence in osteosarcoma is a dramatic event because it is almost always associated with systemic relapse. The post-relapse outcome of patients who experience local recurrence is worse than the outcome of patients who relapse with only lung metastases.””For this reason, patients with osteosarcoma should be surgically treated in very selected centers with a vast experience in the treatment of bone tumors,” Dr. Bacci concluded.(Source: Cancer 2006;106:1154-1161: Reuters Health: Oncolink: March 2006.)