Conversely, proliferative activity, as expressed by Ki-67 index, was strongly related to polysomic status ([chi square] test: P = .
Among 174 evaluable polysomic cases (3 of 177 polysomic tumors were not available for HER2/neu immunocytochemical evaluation and were discarded), 18 (10.
The results of this study highlight 2 main aspects: firstly, the high disagreement between overexpression as detected by immunohistochemistry and amplification as detected by FISH in aneusomic (polysomic in its usual sense) cases; secondly, the significantly higher proliferative index in the polysomic tumors.
Therefore, in our opinion, it is possible that the difference in agreement--consisting of the absence of amplification in the presence of strong overexpression (score 3+)--could be related to the polysomic status of the cancer cells.
27 Also, in their analysis, these authors as well as Dal Lago et al,29 did not find increased HER2/neu mRNA expression by quantitative real-time polymerase chain reaction in Chr17 polysomic tumors, demonstrating that HER2/neu gene amplification is independent from Cep17 alteration.
27) In fact, no statistically significant correlation was found between chromosome 17 polysomic status and pathologic variables such as tumor grade, nodal status, and estrogen receptor and progesterone receptor expression.
Still, our data suggest that the clinicopathologic impact of Cep17 alteration is not as strong as that of HER2/neu gene amplification and show that polysomic unamplified tumors possess pathologic features more similar to HER2/ neu-negative than to HER2/ neu-positive tumors.
A high number of polysomic cases were associated with overexpression but not amplification; therefore, polysomy could be a cause of disagreement between HER2/ neu protein expression and HER2/neu gene amplification status, which needs to be considered.
002) is significantly higher in polysomic than eusomic cancer.
Biopathologic Features of the "Polysomic" Cases (n = 177) and Eusomic Cases (n = 470) [chi square] Test Polysomic (P Value) Evaluable Eusomic Polysomic Cases, Evaluable Versus No.