Dedifferentiated chondrosarcoma: current standards of care

Lay abstract Dedifferentiated chondrosarcomas are rare cancers composed of two components: a high-grade component and a low-grade component, with one abruptly blending into another. These rare tumors affect middle-aged individuals and present with pain and swelling in the affected site. X-rays and other scans often show tumor within the soft tissue with bony destruction. Although the precise treatment protocol is not well defined, surgery remains the standard of care for those where the tumor has not spread elsewhere. Once the disease spreads to other parts of the body, the outcome is very poor. The role of certain drugs targeting the tumor (chemotherapeutic agents) is controversial. This review briefly describes the genetic basis, treatment modalities involved and newer agents being developed for this lethal cancer. Dedifferentiated chondrosarcomas are aggressive variants of chondrosarcoma, associated with poor outcomes. Tumor biphasism is the norm. The majority of these tumors are symptomatic at presentation. Radiologically, large soft tissue masses with bony destruction predominate. Treatment protocols of these tumors are not well defined. Surgical resection forms the standard of care for localized disease. (Neo)adjuvant therapies remain controversial as the results from multiple (mainly retrospective) studies remain conflicting. Age at presentation, stage and ability to obtain negative resection margins are important prognostic factors. The overall prognosis is dismal. Newer and novel therapies targeting the complex genetic makeup of these tumors have renewed interest in the adjuvant setting that could hold promise in the near future.