Knowledge as to the therapeutic value of the methods of treatment in cases of osteogenic sarcoma depends on accurate records and follow-up reports of clinician, roentgenologist, surgeon, and pathologist. The incidence of this rare malignant tumor was one in 4000 patients who presented themselves at The Mayo Clinic for treatment.

The relation of the grade of malignancy of osteogenic sarcomata to the survival of the patients was similar to that which exists in the presence of malignancy of other neoplasms of other tissues.

Patients whose tumors were of a low grade of malignancy had the highest record for five-year survival. Grade 1 was associated with a five-year survival rate of 60 per cent.; Grades 2 and 3, with an average five-year survival rate of 15.9 per cent.; and Grade 4, with a five-year survival rate of 11.1 per cent.

Of those patients treated by irradiation only, and traced for five years, 9.1 per cent. lived five years or more; of those treated by excision, with or without irradiation, 34.1 per cent. lived five years or more; and of those treated by amputation, with or without irradiation, 24.7 per cent. lived five years or more.

Excision was employed in a relatively favorable group of cases. Amputation sometimes was used with the understanding that it was only a palliative measure; it was not used at all if the malignancy was of Grade 1.

Of 158 patients treated by any method, and traced for five years, 23.4 per cent. lived five years or more after treatment.