Pediatric extraskeletal osteosarcoma

Abstract

Sir, Beall et al. [1] are to be commended for reminding clinicians and radiologists about the entity of extraskeletal osteosarcoma, which is rare in adults and exceedingly rare in children. However, their final conclusion that “treatment is often palliative but can improve survival greatly in children and may even be curative in low-grade cancers” requires clarification and comment. With appropriate multidisciplinary care consisting of surgery with wide, uncontaminated margins as well as intensive, multidrug chemotherapy, there is a reasonable likelihood of achieving long-term, recurrence-free survival not only in low-grade cancers, but in high-grade tumors as well, in children as well as in adults. Using such a combined modality approach, for example, our Cooperative Osteosarcoma Study (COSS) group has achieved an event-free survival estimate of 56% at 5 years for 17 patients (including four in the pediatric age group) with high-grade extraskeletal osteosarcoma who received treatment as for conventional osteosarcoma of bone. The corresponding percentage for those 14 patients among the 17 who achieved a complete surgical remission as part of combined modality therapy was 69% [2]. Also, Ahmad et al. [3] have reported a 5-year disease-specific survival of 46% in a group of 38 patients with localized disease, of whom 24 had some form of chemotherapy [3]. Therefore, curative treatment attempts should not be limited to patients with low-grade variants of extraskeletal osteosarcoma, which are much rarer even than their very rare high-grade counterparts, but should be offered to most affected patients!