Osteosarcoma of the Pelvis

The cases of 40 patients with osteosarcoma of the pelvis treated between 1977 and 1994 were reviewed. The location of the tumor was ilium in 30 patients, ischium in four, pubis in one, and sacrum in five. Most (58%) of the tumors were of the chondroblastic subtype. Thirty patients had surgical excision of the tumors: 10 with hemipelvectomies and 20 with limb sparing procedures. A wide margin was achieved in 16 of 30 (53%) patients, including 12 of 14 who had no sacral tumor involvement. Positive margins occurred at the sacrum in 11 patients, lumbar vertebra in one, perirectal space in one, and contralateral pubic body in one. Macroscopic tumor emboli within the regional large vessels were found in seven patients. The incidence of local recurrence was 32%: 13% in wide excisions, 38% in marginal excisions, and 80% in intralesional excisions. The 1- and 5-year overall patient survivals were 73% and 34%, respectively. Patients who had a surgical excision of the primary tumor had a significantly better survival than did those treated without surgery (5-year survival; 41% and 10%, respectively). Tumor size, surgical excision of the primary tumor, surgical margin, and type of surgical procedure were the prognostic factors for patients with Stage IIB tumors.