Changing metastatic patterns of osteosarcoma.

The clinical courses of 111 patients with osteosarcoma treated at UCLA between 1971 and 1982 were reviewed to ascertain the evolution of the natural history of this disease. Only patients with classic high-grade intraosseous osteosarcoma of the extremity, scapula, or pelvis were considered. Patients with low-grade parosteal osteosarcomas; primary osteosarcomas of the face, skull, vertebra, or ribs; and osteosarcomas arising in Paget's disease or previously irradiated bones were not included. Fifty-nine patients developed clinically evident distant metastases. Of these, 36 developed pulmonary metastases alone as the initial site of recurrence. Eighteen of 19 (94.7%) patients treated between 1971 and 1974 by amputation alone developed pulmonary relapse as the initial site of recurrence, whereas only 18 of 40 patients (45%) treated after 1974 with surgery and adjuvant chemotherapy developed pulmonary metastases alone as the initial site of recurrence. Although no patients in the early group developed an extrapulmonary metastasis as the initial site of recurrence, 11 of 40 patients (27.5%) treated with adjuvant chemotherapy developed an extrapulmonary metastasis as the initial site of recurrent disease, and 11 patients developed simultaneous pulmonary and extrapulmonary metastases. Although it is impossible to attribute this alteration in metastatic pattern to adjuvant chemotherapy alone, it is apparent that nonpulmonary metastases are becoming more common among patients currently treated for osteosarcoma.