Bone Sarcoma Characteristics and Distribution in Beagles Fed Strontium-90

Abstract

A total of 66 primary bone sarcomas were diagnosed in 47 beagles; 43 of these dogs were part of the 403 beagles fed 90Sr and 4 were part of the 162 controls. Multiple primary bone sarcomas were found in 15 of the 47 beagles (32%). The incidence of multiple primary bone sarcoma was restricted to the two highest dose groups, except for a single control dog which developed two bone sarcomas. A threshold-like radiation dose response was observed; no sarcomas were observed in the lowest three dose groups, but the number of primary bone sarcomas increased rapidly in the higher dose groups. Of the 66 primary sarcomas, 49 were osteosarcomas (74%). As the dose increased, the proportion of osteosarcomas increased sharply, 4/10 (40%), 26/29 (90%), and 16/18 (89%), in the three highest dose groups. Thirteen of the bone sarcomas of other types occurred in males, and 4 in females, whereas 21 osteosarcomas occurred in males, and 28 in females. The ratio of bone sarcomas of the appendicular skeleton to those in the axial skeleton was 40:26, with osteosarcomas occurring more often in the appendicular than the axial skeleton (32:17), whereas nonosteogenic tumors showed no predilection (8:9). A statistical study of the distribution of bone sarcomas among 16 separate bone groups showed a correlation only with the distribution of cancellous bone volume-to-surface ratio and not with either skeletal mass distribution or dose distribution. The highest occurrence of sarcomas was in the humeri, femora, and mandible, and no occurrence in the coccygeal vertebrae, paws, or sternum. It is postulated that the distribution of bone sarcomas reflects a critical combination of the osteosarcoma precursor cell population, their cell division rate, and the radiation dose absorbed by these cells.

Immune System Modifications Induced in a Mouse Model of Chronic Exposure to90Sr

“…Because of disruption of these processes, cartilage and fibrous marrow were sometimes incorporated into cortical bone, resulting in weakness or fracture. For all species studied, a long-term effect of 90 Sr incorporation in young animals or in utero was a higher incidence of bone-associated cancers compared to animals exposed as adults Finkel et al 1960;White et al 1993). Size differences may contribute to the possible higher vulnerability of children to bone marrow effects from retained radiostrontium.…”

“…In the main study, groups of pregnant beagles were fed 0.002-3.6 µCi 90 Sr/kg/day (0.074-133.2 kBq/kg/day) from gestational day 21 through lactation to postnatal day 44, and the pups were fed the same doses from weaning at day 42 through day 540 (Raabe et al 1983;White et al 1993). Survival of the pups was reduced by 18, 64, and 85% at the three highest levels (0.4, 1.2, and 3.6 µCi/kg/day or 14.…”

“…Groups of pregnant beagles were fed 0.002-3.6 µCi 90 Sr/kg/day (0.074-133.2 kBq/kg/day) from gestational day 21 through lactation to PND 44, and the pups were fed the same doses from weaning at day 42 through day 540 (Raabe et al 1983;White et al 1993). Ten years from the start of the study, dose-related skeletal effects included mild trabecular osteopenia, endosteal and periosteal cortical changes (sclerosis and thickening), and mottling or focal osteolytic lesions (Momeni et al 1976).…”

“…In the dog study, groups of pregnant beagles were fed between 0.002 and 3.6 µCi 90 Sr/kg/day (0.074 and 133.2 kBq/kg/day) from day 21 of gestation to postnatal day 42 (White et al 1993). The pups were weaned and then fed a diet containing the same 90 Sr/calcium ratio as the dam until day 540.…”

“…Chronic oral administration of radioactive strontium was shown to increase the incidence of boneassociated cancer in animals (Book et al 1982;Finkel et al 1960;White et al 1993;Zapol'skaya et al 1974). No chronic inhalation or dermal studies were located.…”