Survival after metastasis in osteosarcoma

We analyzed survival patterns of 106 patients with metastatic osteosarcoma treated at the M. D. Anderson Hospital from 1954 to 1975. All were 20 years of age or less, had a confirmed diagnosis of medullary osteosarcoma (excluding mandibular and radiogenic osteosarcoma), and had developed evidence of metastasis at diagnosis or during treatment. Clinical characteristics evaluated statistically as possible prognostic factors in postmetastatic survival were: age at diagnosis, sex, race, site or primary, site of first metastasis, year of diagnosis, and time from diagnosis to metastasis. Two factors, year of diagnosis and time to metastasis, showed statistically significant association with postmetastastic survival. Those patients treated in 1971 or later (62) had significantly longer postmetastatic survival times than those (44) treated in 1970 or earlier (P = 0.002). Also, 14 patients who developed metastasis 1 year or more after diagnosis had significantly longer postmetastatic survival times than the 19 with metastasis at diagnosis (P = 0.002) or the 73 who developed metastasis during the 1st year after diagnosis (P = 0.005). Analysis also indicated a statistically significant interaction effect between the two factors (P = 0.093) that suggested the time to metastasis had a greater influence on postmetastatic survival time in those diagnosed in 1971 or later than in those diagnosed earlier.