| Abstract: | Evaluation of tumor cell proliferation status belongs to the basic prognostic indicators in a routine biopsy report. In cutaneous
basal cell carcinoma (BCC), however, there are discrepancies about a true prognostic significance of this histopathological
parameter. The aim of this study was to assess a proliferative activity (Ki-67 index) in BCCs of the skin. Biopsy specimens
from 80 cutaneous BCCs (63 primary, 17 recurrent) of different histological types from 75 subjects (34 men, 41 women) were
enrolled into this study. All samples were immunohistochemically stained by antibody against Ki-67 antigen (DAKO, clone MIB-1,
dilution 1:100). For the statistical analysis, χ
2 test was employed. We found a striking percentage variability of nuclear Ki-67 expression in individual tumors (range 2–70%).
Mean value of Ki-67 index was 27.4% (in primary tumors 28.1 %, in recurrent lesions 25.6%). The highest Ki-67 expression occurred
in infiltrative BCCs (average 38.1%), morpheaform BCCs (average 37.0%), and superficial BCCs (average 35.7%), the lowest expression
was recorded in nodular BCCs (average 21.7%) and BCCs with adnexal (trichoepithelial) differentiation (18.6%). There were
not persuasive and statistically significant quantitative differences in proliferation activity of tumor cells between the
individual histological BCC types, as well as between primary and recurrent lesions. A distribution of Ki-67 positive cells
in tumor nests was mostly irregular and areas with a high number of Ki-67 labeled cells often occurred adjacent to areas with
a lower number of cells expressing this marker. Because of a marked Ki-67 staining variability, we can conclude that the simple
quantification of BCC proliferation activity alone may not be sufficient for the prediction of further biological behavior,
evolution and clinical outcome of this malignancy. |
