Effect of a half dose of tamoxifen on proliferative activity in normal breast tissue.

OBJECTIVES: To investigate the proliferative activity of the mammary gland epithelium and plasma levels of progesterone, estradiol, prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and sex hormone-binding globulin (SHBG) in premenopausal women treated with 10 and 20 mg of tamoxifen (TAM) for 22 days. PATIENTS AND METHODS: A randomized double-blind study was performed with 43 premenopausal women with a diagnosis of fibroadenoma of the breast. The patients were divided into three groups: A (n = 15, placebo); B (n = 15, TAM 10 mg/day) and C (n = 13, TAM 20 mg/day). They started taking an oral dose of TAM or placebo on the very first day of the menstrual cycle. Lumpectomy was performed on the 22nd day of therapy. Normal breast tissue samples were collected during surgery, immediately immersed in 10% buffered formalin, processed for routine histology and immunohistochemistry for proliferating cell nuclear antigen (PCNA) detection. Two peripheral blood samples were collected, both on the 22nd day of the menstrual cycle, in order to evaluate the hormone levels. PCNA expressing epithelial cells were quantified by using a digital program Kontron Image System KS-300 in 1000 cells (400 x ). RESULTS: The percentage of cells expressing PCNA was significantly higher in the group receiving placebo (group A, 50.3%) when compared to groups receiving TAM 10 or 20 mg/day (group B, 24.1%; and group C, 23.2%, respectively) (P < 0.001). Differences between groups B and C were not significant. Levels of progesterone, estradiol and SHBG were significantly higher in B and C groups compared to group A. Increasing concentrations of FSH (P < 0.0045) and lower levels of prolactin (P < 0.0055) were only found in the group receiving 20 mg/day of TAM (group C). CONCLUSIONS: A 22-day TAM therapy, either with 10 or 20 mg/day, significantly reduced the PCNA expression and therefore the proliferative activity of the normal human breast tissue. Increasing levels of estradiol, progesterone and SHBG were associated with TAM therapy at 10 or 20 mg/day. However, a significant change of the level of FSH and prolactin was reached only with a 20-mg/day dose.

Use of acrylic of low polymerization after heminandibulectomy.

Two cases of mandibular reconstruction are presented in which a premolded prosthesis of acrylic of low polymerization covered by silicone rubber was used. We believe that the good results obtained were not only due to the material used, but also because the periosteum and meniscus were preserved in the joint space.

The effect of tamoxifen on PCNA expression in fibroadenomas.

For almost three decades, tamoxifen has been used in the adjuvant treatment of breast cancer. It has also proven effective in the chemoprophylaxis of this disease and in the treatment of cyclic mastalgia. Since a fibroadenoma is a benign hormone-dependent neoplasm which contains estrogen receptor (ER) levels higher than in the mammary lobule, an evaluation of the effect of this drug on the proliferative activity of both the epithelium and the stroma of fibroadenomas in premenopausal women following the administration of 10 or 20 mg/day over 22 days was proposed. Forty women with fibroadenoma were selected for a randomized double-blind trial. They had regular menstrual cycles and had received neither hormones nor become pregnant 12 months prior to this study. Patients were divided into three groups: A (n = 14; placebo), B (n = 13; tamoxifen 10 mg/day), and C (n = 13; tamoxifen 20 mg/day). The treatment was initiated on the first day of their menstrual cycle and the surgeries were performed on the 22nd day. Estradiol, progesterone, and steroid hormone binding globulin (SHBG) were measured twice. The first measurement was performed on the 22nd day of the previous menstrual cycle and the second one was performed on the day of surgery. The fibroadenoma was fixed in 10% formaldehyde solution and stained with hematoxylin and eosin and then processed through immunohistochemical reaction (PC-10, DAKO code number M879, Denmark A/S). The immunoexpression of the proliferative cell nuclear antigen (PCNA) of at least 500 epithelial and 500 stromal cells was evaluated. Such cells were interactively counted using the Kontron Imaging System KS-300 computerized analysis system, with x 400 magnification. As to PCNA expression in the fibroadenomas' epithelium, the average percentage of stained nuclei in groups A, B, and C was 25.2, 19.3, and 18.0, respectively. However, no significant difference was found in the variance analysis of these data (p = 0.168). As to the study of the fibroadenomas' stroma, the average percentage of stained nuclei found in groups A, B, and C was 32.4, 23.2, and 18.4, respectively. The variance analysis (p = 0.031) and Fisher's multiple comparison test (1.39; 26.67 confidence interval [CI]) confirmed that the number of PCNA-expressing nuclei in the stroma was significantly lower in group C (20 mg/day) compared to group A (control). However, there was no significant difference between group B (10 mg/day) and group C (20 mg/day). It was found that tamoxifen reduced the expression of PCNA in the epithelium and the stroma of the fibroadenoma. However, the effect was only statistically significant in the stroma when a 20 mg/day dose was administered.