A total of 128 primary mammary tumors (66 of them malignant) occurred in 35 female beagles injected with226 Ra at eight dose levels ranging from 0.2 to 440 kBq/kg body mass as young adults, while a total of 156 mammary tumors (57 of them malignant) were seen in 46 female control beagles not given any radioactivity. Sixty-three of 65 control dogs and 59 of 61 dogs given226 Ra survived the minimum age for diagnosis of mammary tumors of 3.75 years. Based on the observed age-dependent tumor incidence rates in the controls and on the corresponding number of dog-years at risk, the total number of observed malignant tumors in the radium group was statistically greater than the number of expected malignant tumors (66 observed vs 34 expected, P < 0.005). There was no such difference for the benign tumors. Cox regression analysis indicated no increased risk for the first tumor occurrence in irradiated dogs. Cox regression analysis of the multivariate risk sets showed no significantly increased risk for the occurrence of benign tumors but a statistically higher risk of 1.66 with a confidence interval of 1.15-2.40 for the occurrence of malignant tumors. The increased risk was dependent on dose, but a dependence on the frequency of previous occurrence of mammary tumors could not be confirmed. Censoring ovariectomized dogs at time of surgery decreased the relative risks slightly but did not alter the significance. Exposure to diagnostic X rays with cumulative exposures below 0.2 Gy had no effect on tumor formation. It is unknown whether the increased risk for malignant mammary tumors was due to some initial deposition of radium in sensitive tissue, a possible irradiation of fatty mammary tissue from transient radon→polonium deposition, or a general effect of the overall radium deposition on the immune system of the dogs that lowered their resistance to formation of mammary tumors. Results of this study are potentially useful in understanding risks of radium-induced breast cancers in humans.
Skip Nav Destination
Research Article| June 01 1994
Occurrence of Mammary Tumors in Beagles Given Radium-226
F. W. Bruenger ;
S. C. Miller ;
G. N. Taylor ;
Radiat Res (1994) 138 (3): 423–434.
- Views Icon Views
- Share Icon Share
- Search Site
F. W. Bruenger, R. D. Lloyd, S. C. Miller, G. N. Taylor, W. Angus, D. A. Huth; Occurrence of Mammary Tumors in Beagles Given Radium-226. Radiat Res 1 June 1994; 138 (3): 423–434. doi: https://doi.org/10.2307/3578692
Download citation file:
Citing articles via
Commonalities Between COVID-19 and Radiation Injury
Carmen I. Rios, David R. Cassatt, Brynn A. Hollingsworth, Merriline M. Satyamitra, Yeabsera S. Tadesse, Lanyn P. Taliaferro, Thomas A. Winters, Andrea L. DiCarlo
Low-Dose Radiation Therapy (LDRT) for COVID-19: Benefits or Risks?
Pataje G. Prasanna, Gayle E. Woloschak, Andrea L. DiCarlo, Jeffrey C. Buchsbaum, Dörthe Schaue, Arnab Chakravarti, Francis A. Cucinotta, Silvia C. Formenti, Chandan Guha, Dale J. Hu, Mohammad K. Khan, David G. Kirsch, Sunil Krishnan, Wolfgang W. Leitner, Brian Marples, William McBride, Minesh P. Mehta, Shahin Rafii, Elad Sharon, Julie M. Sullivan, Ralph R. Weichselbaum, Mansoor M. Ahmed, Bhadrasain Vikram, C. Norman Coleman, Kathryn D. Held
Photon GRID Radiation Therapy: A Physics and Dosimetry White Paper from the Radiosurgery Society (RSS) GRID/LATTICE, Microbeam and FLASH Radiotherapy Working Group
Hualin Zhang, Xiaodong Wu, Xin Zhang, Sha X. Chang, Ali Megooni, Eric D. Donnelly, Mansoor M. Ahmed, Robert J. Griffin, James S. Welsh, Charles B. Simone, II, Nina A. Mayr
Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light
Manuela Buonanno, Brian Ponnaiya, David Welch, Milda Stanislauskas, Gerhard Randers-Pehrson, Lubomir Smilenov, Franklin D. Lowy, David M. Owens, David J. Brenner