Tissue microarray technique in evaluation of proliferative activity in invasive ductal breast cancer.

AIM

Investigation of the relationship between expression of Ki-67 antigen and minichromosome maintenance 2 (MCM-2) protein by using an immunohistochemical study on whole sections (WS) and sections of invasive ductal breast cancer (IDC) obtained in the tissue microarray (TMA) technique.

MATERIALS AND METHODS

Material consisted of 51 archival paraffin blocks of IDC. Tissue microarrays were composed of 0.6 mm core punches. Reactions were performed using specific antibodies (anti-Ki-67 and anti-MCM-2). Intensity of the marker expression was evaluated using computer-assisted image analysis. For statistical purposes, three different tests were used.

RESULTS

Spearman rank correlation revealed a strong positive correlation between expression of tested markers: Ki-67 (TMA) vs. Ki-67 (WS) (r=0.91, p<0.05) and MCM-2 (TMA) vs. MCM-2 (WS) (r=0.87, p<0.05). Mann Whitney U-test showed no significant differences between the two markers in both analysed techniques. Moreover, the Bland-Altman plot demonstrated a low level of bias between the analysed methods.

CONCLUSION

This study shows that TMA could have a great potential in evaluation of proliferative activity in IDC and that MCM-2 protein might be a specific and sensitive marker of cell proliferation.