Tamoxifen modulates the expression of Ki67, apoptosis, and microvessel density in cervical cancer.

ABSTRACT

PURPOSE: The aim of the study was to investigate if a short-term administration of high-dose Tamoxifen (Tam) could affect the expression of biologically relevant biochemical parameters in cervical cancer tissue. EXPERIMENTAL DESIGN: The study was conducted in 24 patients with histologically confirmed cervical tumors. Biopsies were obtained by colposcopy on day 0 in all patients, who then received either 80 mg/die or 160 mg/die for 5 consecutive days until the second biopsy was obtained. Immunohistochemistry was performed with antiestrogen receptor (ER), anti-Ki67, anticaspase cleavage product of keratin 18 (M30), and anti-CD31 monoclonal antibodies. RESULTS: Eleven (45.8%) of 24 cervical tumors were ER positive. The percentage of Ki67-positive tumor cells in pre-Tam biopsies was significantly higher than the percentage in the corresponding posttreatment biopsies (z = 4.29, P = 0.0001). No difference in the pretreatment percentage of Ki67-positive cells according to ER status was found. The percentage of M30 positivity was higher in post-Tam than in pre-Tam biopsies. Microvessel density values in pre-Tam biopsies were significantly higher than corresponding values in posttreatment tissues (z = -3.72, P = 0.0002). The reduction in the percentage of Ki67-positive tumors was significantly (z = 3.58, P = 0.0003) higher in ER-positive than in ER-negative tumors, whereas no difference in Tam-induced reduction of microvessel density values according to ER status (z = -0.18, P = 0.85) was found. Tam treatment did not induce any change of M30 positivity in ER-positive tumors, whereas in ER-negative tumors, it produced a significant (P = 0.015) increase in the percentage of M30-positive cells in post-Tam versus pre-Tam biopsies. CONCLUSIONS: A short-term treatment with Tam at doses 4-8-fold higher than those in conventional schemes is associated with modifications of biological parameters associated with tumor cell proliferation, apoptosis, and neoangiogenesis in cervical cancer.