Expression of proliferation-associated antigens in cervical carcinoma: correlations among indexes

Monoclonal antibodies recognizing proliferation-associated antigens can be employed in formalin-fixed, paraffin-embedded sections. The MIB1, PC10, 19A2, cytoplasmic p105 indexes, and mitotic index in hematoxylin and eosin stained preparations represent the growth, S-phase and mitotic fractions, respectively. The specimens consecutively taken from 194 patients with stage III cervical carcinoma were investigated immunohistochemically. Cancer cells that were positive for MIB1, PC10 and 19A2 showed a nuclear staining pattern. Mitotic cancer cells were strongly positive for p105 in their cytoplasm and also showed chromosomal p105 positivity. The mean indexes for MIB1, PC10, 19A2 and cytoplasmic p105 and the mitotic index in hematoxylin and eosin preparations were 43% (range, 18-74%), 26% (5-60%), 15% (0-60%), 2% (0-11%) and 0.6% (0-6.3%), respectively. The linear regression analysis showed only a very weak or no correlations between the MIB1, PC10, 19A2 and cytoplasmic p105 indexes among the patients (linear regression correlation coefficient r = 0.10 to 0.32). We conclude that (1) the MIB1 growth fraction, PC10 or 19A2 S-phase fraction, and the mitotic fraction show wide variations among patients with cervical carcinoma and (2) the PC10 or 19A2-positive S-phase fraction and the mitotic fraction of cervical carcinoma should not be used instead of the MIB1 growth fraction as equivalent to cycling cancer cell population.