hCGβ expression by cervical squamous carcinoma: in vivo histological association with tumour invasion and apoptosis

Aims: To investigate the correlation of β-subunit of human chorionic gonadotrophin (hCGβ) expression by cervical carcinomas with measures of tumour apoptosis. Methods and results: Eighty-nine cervical carcinoma patients’ samples were subject to hCGβ immunohistochemistry and scored with respect to intensity of immunopositivity and percentage of positive cells. Apoptosis was evaluated by three independent parameters: morphological characteristics [haematoxylin and eosin (H&E)], terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL) and poly (ADP-ribose) polymerase (PARP) immunopositivity. Of the 12 adenocarcinomas, only one (8%) was hCGβ+. However, 87% (61/70) of the squamous cell and 100% (7/7) of adenosquamous cell carcinomas were hCGβ+. hCGβ reactivity and intensity was predominantly confined to peripheral tumour cells at the stromal–epithelial interface. Correlation analysis showed that H&E and PARP apoptotic immunopositivity negatively correlated with hCGβ expression (P < 0.001 and P = 0.028 respectively), whereas TUNEL did not (P = 0.12). However, immunopositivity for apoptotic cells by TUNEL was significantly less in tumours where hCGβ expression was greater (scoring ≥ 6) and vice versa. hCGβ immunopositivity was also observed in newly formed blood vessels, as well as tumour cells within lymphatic vessels. When tumour vascularization was taken into account, samples with noted vascularization positively correlated with hCGβ scoring. Conclusions: hCGβ expression correlates with reduced tumour cell apoptosis and may be involved in tumour vascularization and dissemination