TY - JOUR
T1 - The effect of tumor size on necrosis and polarographically measured pO2
AU - Milross, Christopher G.
AU - Tucker, Susan L.
AU - Mason, Kathy A.
AU - Hunter, Nancy R.
AU - Peters, Lester J.
AU - Milas, Luka
N1 - Funding Information:
We are grateful to Lane Watkins and his staff for supply and care of the mice used in this study. Animals were maintained in facilities approved by the American Association for Accreditation of Laboratory Animal Care and in accordance with current regulations and standards of The United States Department of Agriculture and Department of Health and Human Services. This work was financially supported by NIH Program Project Grant Ca-06294.
PY - 1997
Y1 - 1997
N2 - Tumor necrosis and oxygen status were investigated as a function of tumor size in three syngeneic murine carcinomas, MCa-4, OCa-I, and SCC-VII, in C3Hf/Kam mice. Tumor necrosis was estimated histologically, and tumor oxygenation determined by direct polarographic histography. As tumor volume increased necrosis increased significantly in all three tumor types (p < 0.001). Similarly, as tumor volume increased from 200 to 1 400 mm3, hypoxia, defined as the percentage of measured pO2 values ≤ 5.0 mm Hg, increased from 55.1% to 95.9%; 70.3% to 81.4%, and 56.8% to 98.5% in MCa-4, OCa-I, and SCC-VII tumors respectively (p < 0.001). Correcting pO2 for necrosis reduced the tumor size dependence of measured tumor hypoxia in all three tumor types but in no case was the reduction significant. The main effect of correction was to shift the fitted curves of percent pO2 values ≤ 5.0 mm Hg down toward lower percentages for all tumors. This change was significant for MCa-4 and OCa-I tumors (p < 0.001), but not for SCC-VII (p = 0.054). Defining the influence of variables such as necrosis that affect polarographic assessment of tumor oxygenation is important to enhance the technique's reliability and prospect as an investigative and predictive tool.
AB - Tumor necrosis and oxygen status were investigated as a function of tumor size in three syngeneic murine carcinomas, MCa-4, OCa-I, and SCC-VII, in C3Hf/Kam mice. Tumor necrosis was estimated histologically, and tumor oxygenation determined by direct polarographic histography. As tumor volume increased necrosis increased significantly in all three tumor types (p < 0.001). Similarly, as tumor volume increased from 200 to 1 400 mm3, hypoxia, defined as the percentage of measured pO2 values ≤ 5.0 mm Hg, increased from 55.1% to 95.9%; 70.3% to 81.4%, and 56.8% to 98.5% in MCa-4, OCa-I, and SCC-VII tumors respectively (p < 0.001). Correcting pO2 for necrosis reduced the tumor size dependence of measured tumor hypoxia in all three tumor types but in no case was the reduction significant. The main effect of correction was to shift the fitted curves of percent pO2 values ≤ 5.0 mm Hg down toward lower percentages for all tumors. This change was significant for MCa-4 and OCa-I tumors (p < 0.001), but not for SCC-VII (p = 0.054). Defining the influence of variables such as necrosis that affect polarographic assessment of tumor oxygenation is important to enhance the technique's reliability and prospect as an investigative and predictive tool.
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U2 - 10.3109/02841869709109228
DO - 10.3109/02841869709109228
M3 - Article
C2 - 9140436
AN - SCOPUS:0030963568
SN - 0284-186X
VL - 36
SP - 183
EP - 189
JO - Acta Oncologica
JF - Acta Oncologica
IS - 2
ER -