Prognostic factors in chondrosarcoma of bone. A clinicopathologic analysis with emphasis on histologic grading

The relationship between histopathology and tumor behavior was examined in 71 cases of chondrosarcoma. The tumors were grouped into grades I, II, and III on the basis of mitotic rate, cellularity, and nuclear size. The 5-yr survival rates of grades I, II, and III are 90%, 81%, and 43%, respectively, while the corresponding 10-yr survival rates are 83%, 64%, and 29%. None of the grade I chondrosarcomas metastasized, while metastasis was observed with 10% of the grade II tumors and 71% of the grade III tumors. No definite relationship between tumor grade and local recurrence was found. In addition, the significance of the extent of the original operative procedure was evaluated for chondrosarcoma, Grades I and II. Local recurrence which could not be controlled by additional surgery occurred in 46% of the patients treated initially by local excision, but in only 9.5% of those who were treated by amputation or resection of all or part of the involved bone. It is concluded that chrondrosarcomas range from locally aggressive non-metastasizing neoplasms to high-grade malignancies with marked metastatic potential, and that these groups may be defined and separated by the use of histopathologic criteria. The rate of local recurrence, however, is primarily dependent on the adequacy of surgical therapy rather than histologic grade.