Is the frequency of mitoses and PCNA positive cells in tissues affected by delay in fixation? Lessons for accurate tumor grading.
Using uniform systematic random sampling, we tested whether a drop in mitoses and PCNA (proliferation cell nuclear antigen) positive cells following a delay in tissue fixation of up to five hours, would be unequivocally discernible at the well perfused periphery from 11 aggressive rat adenocarcinomas. No statistically significant difference (0.05 < P < 0.10; 95% Cl (-13.3, 1.3)) was found. We attributed this finding to the high proliferative heterogeneity of rapidly growing solid tumors because: (1) vascular perfusion is heterogeneous as rapidly proliferating epithelial tumors tend to outgrow their blood supply; (2) the ratio of perfused/ non-perfused tumor volumes may change as a solid tumor grows, altering to the same extent the ratio of proliferative vs. non proliferative regions in the tumor; and (3) the duration of mitoses is not constant. The consequences for accurate tumor grading are discussed.
Laroye
G J
GJ
Department of Anatomical Pathology, Sabah Hospital, Kuwait.
D000230:Adenocarcinoma / Q000737:chemistry; D000818:Animals; D005260:Female; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000737:chemistry; D008938:Mitosis; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis*; D051381:Rats; D011915:Rats, Inbred BUF; D013997:Time Factors; D016707:Tissue Fixation / Q000379:methods*
D018809:Proliferating Cell Nuclear Antigen