Abstract
1. The relationship between histological grading and survival has been studied in a consecutive series of eighty-eight patients with osteogenic sarcomata. The grading has been based entirely upon the mitotic activity of these tumours.
2. There is a positive correlation ("r"=+0·59) between the two variates mitotic ratio and survival in months.
3. The frequency distributions of the mitotic ratios and survivals are similar and, from the observed range, mean and mode of mitotic ratios a more precise definition is proposed for the terms "low," "medium" and "high" malignancy.
4. Comment is made on those patients (20 per cent) in whom actual survival was very different from that expected on the basis of histological grading.
5. The five-year survival rates were: Grade I–67 per cent, Grade II–15 per cent, Grade III–nil, all–17 per cent. For the whole series the average survival period from the time of the presenting symptom was thirty-six months.
6. The five-year survival rate for forty-five tumours of the femur was 20 per cent; no further analysis by sites is attempted.
