Immunohistochemical expression of “hcg-β” in colorectal carcinoma

Abstract

BACKGROUND: Tumor budding is associated with adverse histology and is a predictor of lymph node metastasis. Human chorionic gonadotropin-beta (hCG-β) expression in non-trophoblastic tumors has been associated with aggressive behavior. AIM: Evaluation of tumor budding and hCG-β immunohistochemical expression in colorectal carcinoma (CRC), and correlation of their expression with various clinicopathological parameters. MATERIALS AND METHODS: Immunohistochemical staining for hCG-β was performed on paraffin-embedded sections of 60 cases of CRC. Tumors with cytoplasmic or membranous staining of more than five epithelial cell clusters were designated hCG-β positive; otherwise, they were designated hCG-β negative. Tumor budding was assessed in hematoxylin and eosin stained slides and was classified as; low: 0–4 buds, intermediate: 5–9 buds and high: ≥10 buds; with exclusion of pure mucoid or signet ring cell morphology cases from analysis. RESULTS: Tumor budding was low in (58.8%) of the cases, intermediate in (15.7%), and high in (25.5%). There was a statistically significant correlation between tumor budding and tumor histological grade (p = 0.011), lymph node metastasis (N) (p = 0.009), overall pathologic stage group (p = 0.009), modified Dukes’ stage (p = 0.009), lymphovascular invasion (p = 0.000), and desmoplastic reaction (p = 0.004). Positive hCG-β alpha expression was detected in 12 (20%) of cases. There were statistically significant correlations between hCG-β expression and each of lymphovascular invasion (p = 0.042) and tumor budding (p = 0.000). CONCLUSION: hCG-β is a marker of aggressiveness that may have essential role in tumor invasion. Tumor budding is crucial event in tumor invasion and metastasis. Tumor budding with hCG-β expression is a novel prognostic parameter and may represent a potential therapeutic target.