The Expression of Stem Cell Marker LGR5 and Its Coexpression with Β-Catenin in Sporadic Colorectal Carcinoma and Adenoma: A Comparative Immunohistochemical Study.

Background: LGR5 is one of the most important stem cell markers for colorectal cancer (CRC), as it potentiates Wnt/Β-catenin signaling. The well-characterized deregulation of Wnt/Β-catenin signaling that occurs during adenoma/carcinoma sequence in CRC renders LGR5 a hopeful therapeutic target. We assessed the immunohistochemical expression of LGR5 and Β-catenin in normal colonic and tumorous lesions with a clinicopathological correlation. Methods: Tissue blocks and clinical data of 50 selected cases were included: 8 from normal mucosa, 12 cases of adenoma, and 30 cases of CRC, where sections were cut and re-examined and the immunohistochemical technique was conducted using anti-LGR5 and anti-Β-catenin to measure the staining density. Results: There was no expression of LGR5 in normal mucosa compared to samples of adenoma and CRC samples. The association analysis showed that CRC specimens were more likely to have strong LGR5 and Β-catenin expressions than the other two groups (p = 0.048 and p < 0.001, respectively). Specimens with high-grade dysplastic adenoma were more likely to express moderate-to-strong expression of LGR5 and Β-catenin (p = 0.013 and p = 0.036, respectively). In contrast, there were no statistically significant associations between LGR5 and Β-catenin expression with grade and stage. Conclusion: These results suggest and support the possible role of LGR5 as a potential marker of cancer stem cells in sporadic colorectal carcinogenesis in addition to a prognostic value for LGR5 and Β-catenin in adenomatous lesions according to immunohistochemical expression density. A potential therapeutic role of LGR5 in CRC is suggested for future studies based on its role in pathogenesis.

HER2/neu expression status of post BCG recurrent non-muscle-invasive bladder urothelial carcinomas in relation to their primary ones.

BACKGROUND: Transurethral resection (TUR) followed by adjuvant therapy is still the treatment of choice of Non-Muscle-Invasive Bladder Urothelial Carcinoma (NMIBUC). However, recurrence is one of the most troublesome features of these lesions. Early second resection and adjuvant BCG therapy has been shown to improve the outcome. OBJECTIVE: To evaluate the prognostic value of C-erbB-2 (HER2/neu) expression status in Non-Muscle-Invasive Bladder Urothelial Carcinoma cases, before and after intravesical Bacillus Calmette Guerin (BCG immunotherapy). MATERIALS AND METHODS: HER2/neu expression was studied in 120 (Ta-T1) Non-Muscle-Invasive Urothelial Carcinoma cases. The expression was evaluated and compared to the expression after Bacillus Calmette Guerin (BCG) immunotherapy. RESULTS: HER2/neu expression in low and high grade of the Non- Muscle-Invasive Urothelial Carcinoma was (38%) and (83%) respectively. The difference of the expression rates by tumor grade was statistically significant. In recurring lesions post BCG therapy, C-erbB-2 expression was markedly decreased (31.6%) when compared to its expression before therapy (65%). CONCLUSIONS: The HER2/neu expression increased as the tumor grade rose. The reduction in expression following BCG treatment in Non-Invasive transitional cell carcinoma cases could reflect a reduction of the potential malignancy of the tumor.