Abstract
1. The average number of cases of osteogenic sarcoma found in the years 1946-58 inclusive in the northern division of the South-west Hospital region of England was 6·7 for each year, varying from three to ten. 2. The annual incidence of this sarcoma in this area was one tumour per 230,000 population. 3. These figures were compared with similar figures from Norway which indicate a rather similar tumour incidence among juveniles, but a very much smaller number of tumours in elderly persons. 4. Among the eighty-seven sarcomata collected in the specified area in thirteen years twenty-Six were associated with Paget's disease. 5. It is estimated that among the population of the specified area there were probably 26,000 persons at any time with Paget's disease, of whom one in 650 (0·15 per cent) would eventually develop sarcoma. 6. This study suggests that Paget's disease increases the risk of sarcoma about thirty-fold in persons over forty years of age. 7. It is tentatively suggested that the incidence of Paget's disease is influenced more by heredity than environment.