Larger core size has superior technical and analytical accuracy in bladder tissue microarray.

Area of Science:

• Oncology
• Pathology
• Biotechnology

Background:

• Tissue microarrays (TMAs) enable simultaneous analysis of multiple patient specimens.
• Accurate TMA construction requires precise capture of histologic areas (technical accuracy) and concordance with tissue origin (analytical accuracy).
• Small histologic features and intratumor heterogeneity pose challenges for TMA accuracy, particularly in bladder cancer.

Purpose of the Study:

• To evaluate the impact of core size (0.6 mm vs 1.0 mm) on the technical and analytical accuracy of TMAs.
• To determine optimal TMA core size for accurately representing bladder cancer heterogeneity and small histologic features.

Main Methods:

• Construction of TMAs using 0.6 mm and 1.0 mm cores from paraffin-embedded bladder tissues.
• Assessment of technical accuracy by evaluating the capture of normal urothelium, tumor, and carcinoma in situ (CIS).
• Quantitative image analysis of proliferation (Ki67+ and mitotic counts) to assess analytical accuracy.

Main Results:

• The 1.0 mm core size demonstrated significantly higher technical accuracy for normal (80.9%), tumor (94.2%), and CIS (71.4%) tissues compared to 0.6 mm cores.
• While 0.6 mm cores could compensate with more replicates, 1.0 mm cores showed superior analytical accuracy in proliferation assessments (P=0.004 and 0.035).
• The 1.0 mm core size provided better representation of tissue heterogeneity and small features.

Conclusions:

• Utilizing two or more 1.0 mm cores in TMA construction significantly enhances both technical and analytical accuracy.
• Larger core sizes are particularly beneficial for tissues with small histologic features or substantial intratumor heterogeneity.
• Optimized TMA core selection is crucial for reliable analysis of complex tissue samples in cancer research.