In a study reported in the Journal of Clinical Oncology, Kelley et al found that pathologic fracture was associated with poorer overall survival among adult—but not pediatric—patients with primary central high-grade osteosarcoma of the extremities.
The study involved retrospective analysis of data from 2,847 patients in the Consecutive Cooperative Osteosarcoma Study Group database (including 208 institutions in Germany, Austria, Switzerland, Czechoslovakia, and Hungary) treated between 1980 and 2010. Intended treatment included pre- and postoperative chemotherapy and surgery.
A total of 2,193 patients (77%) were aged ≤ 18 years at diagnosis. Overall, the median age was 15.3 years (range = 2–71 years). The median ages were 24.5 years in the adult group and 14.2 years in the pediatric group.
A total of 321 patients (11.3%) presented with pathologic fracture or developed fracture prior to or during neoadjuvant therapy. Fracture rates were highest in patients aged 0 to 10 years (22% of cases) and in those aged > 40 years (eg, 23% of cases in those aged 41–50 years).
Among all patients, presence of fracture was significantly associated with tumor site, histologic subtype, relative tumor size, and primary metastases, but not with body mass index or local surgical remission.
In univariate analysis, 5-year overall survival of patients with vs without fracture was 63% vs 71% (P = .007) and 5-year event-free survival was 51% vs 58% (P = .026). In pediatric patients, no significant difference in overall or event-free survival was observed for fracture vs no fracture. In adult patients, 5-year overall survival was 46% vs 69% (P < .001) and 5-year event-free survival was 36% vs 56% (P < .001).
In multivariate analysis, pathologic fracture was not significantly associated with overall survival or event-free survival for the entire population or among pediatric patients. In adults, it remained a significant predictor of poorer overall survival (hazard ratio [HR] = 1.893, P = .013) but not event-free survival (HR = 1.312, P = .263).
The investigators concluded, “In this largest study to date [of] extremity osteosarcomas, we observed the occurrence of [pathologic fracture] to correlate with inferior [overall survival] expectancies in adult but not in pediatric patients.”
Irene von Lüttichau, MD, of Kinderklinik München Schwabing, StKM GmbH und Klinikum Rechts der Isar der Technischen Universität München, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.