A rapid histological score for the semiquantitative assessment of bone metastases in experimental models of breast cancer.
BACKGROUND
Using a nude rat model of site-specific metastatic bone disease (MBD), we developed a semiquantitative histological score for rapid assessment of lytic lesions in bone. This provides additional information to conventional histological measurement by clarifying the extent and location of metastatic infiltration and the tumor growth pattern. The score can also be used to assess the action of bisphosphonates on bone metastases.


METHODS
Male nude rats (n = 12 per group) were inoculated with the human breast cancer cell line MDA-MB-231 via the femoral artery. Following appearance of radiographically visible osteolytic lesions on day 18, the animals received phosphate-buffered saline (PBS; controls) or ibandronate (IBN, 10 microg P/kg) daily until day 30. Whole body radiographs were obtained on days 18 and 30, and osteolytic areas (OA) were determined by radiographic computer-based analysis (CBA). On day 30, MBD was assessed in both tibias using conventional histological CBA and the new scoring system.


RESULTS
Metastatic tumor area correlated with the total sum of the new score in both PBS- (r = 0.762) and IBN-treated animals (r = 0.951; p < 0.001). OA correlated well with the total sum in both groups (r = 0.845 and 0.854, respectively; p < 0.001).


CONCLUSIONS
Significant reduction of bone marrow and cortical infiltration of tumor cells with IBN suggested local control of metastases.
Department of Medicine, University of Heidelberg, Heidelberg, Germany.
Marcus
M
Neudert
Christian
C
Fischer
Burkhard
B
Krempien
Markus J
MJ
Seibel
Frieder
F
Bauss
D000818:Animals; D001859:Bone Neoplasms / Q000473:pathology* / Q000556:secondary*; D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D051381:Rats; D011923:Rats, Nude; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity