leptin and Carcinoma-in-Situ

Obesity increases the risk of breast cancer. It is established that adipocyte secretions, i.e. adipokines, may play a role in mammary carcinogenesis. We have shown that two major adipokines, leptin and adiponectin, were expressed in mammary adenocarcinoma.. Here, we evaluated zinc-alpha2-glycoprotein (ZAG) expression in tumor (n=55) and healthy (n=6) breast tissue by immunohistochemistry and examined whether it was correlated with that of major adipokines, usual tumor biomarkers (sex steroids receptors, i.e. estrogen (ER) and progesterone; Ki-67; cErb2), or apoptosis markers (Bcl2 and Bax).. ZAG expression was detected in ductal carcinoma and normal epithelial adjacent tissue but not in normal tissue of healthy women. In cancer tissue, its expression was correlated positively to leptin receptor and negatively to adiponectin receptor and ER.. These preliminary results suggest both a relationship between ZAG expression and pathways involving adipokines or estrogen and that ZAG may be a potential breast cancer biomarker.

Topics: Adipokines; Adiponectin; Adult; Aged; Aged, 80 and over; Apoptosis; bcl-2-Associated X Protein; Biomarkers, Tumor; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Carrier Proteins; Case-Control Studies; Female; Glycoproteins; Humans; Immunohistochemistry; Leptin; Middle Aged; Proto-Oncogene Proteins c-bcl-2

Mammary adipose tissue is an important source of paracrine mitogens and anti-mitogens, including insulin-like growth factor, transforming growth factors, and cytokines (especially, TNFalpha and IL-1beta). Nevertheless, it is also an important source of the adipocytokine, leptin. Recently, leptin was reported to stimulate the proliferation of various cell types (pancreatic beta cells, prostate, colorectal, lung, etc.) as a new growth factor. It was also shown to stimulate the proliferation of breast cancer cell lines. In this study, we conducted an immunohistochemical analysis of leptin expression in normal tissue and benign and malignant ductal breast cell, representing the different states of the invasion process. We determined for the first time that leptin is expressed both by ductal breast tumors and by benign lesions as atypical hyperplasia. This suggests that leptin may be taken up or synthesized by all modified ductal breast cells, and may prove a proliferative factor. Moreover, leptin is unexpressed by normal tissue in the healthy breast but is exhibited by the normal tissue in near vicinity of the malignant ductal breast lesions. We also postulated that leptin may be a prognostic or diagnostic factor for ductal breast cancer. These putative hypotheses require further study.

Topics: Adult; Aged; Aged, 80 and over; Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Female; Humans; Leptin; Middle Aged

To investigate the effects of total abdominal hysterectomy on circulating leptin levels, 16 pre- and 8 postmenopausal patients with uterine leiomyoma or carcinoma in situ of the uterine cervix were enrolled. Serum levels of leptin and fasting blood sugar (FBS) were determined before (day -7) and after surgery (day +1 and +7). Body mass index (BMI) was recorded at day -7 and +7. Anesthesia duration, surgical duration, hematology, and blood loss during surgery were recorded. Relations of these variables to serum leptin levels were investigated. Serum leptin levels rose from 7.3+/-4.7 ng/mL to 9.3+/-5.8 ng/mL at day +1 (P < 0.01), then decreased to 4.9+/-3.0 ng/mL at day +7 (P < 0.05 vs. values at day -7 and +1). FBS levels also rose from 89.4+/-7.5 mg/dL to 119.3+/-24.0 mg/dL (P < 0.01), then returned to normal at day +7 (96.2+/-9.0 mg/dL). However, there was no significant correlation observed between FBS and leptin levels at each time point (r < or = 0.22). BMI decreased from 22.7+/-3.0 kg/m2 to 21.7+/-2.9 kg/m2 at day +7 (P < 0.001). At day -7 and +7, leptin levels were positively correlatd with BMI (r = 0.79, P < 0.001 and r = 0.71, P < 0.001, respectively). Circulating leptin levels were increased on day one after total abdominal hysterectomy.

Topics: Adult; Blood Glucose; Body Mass Index; Carcinoma in Situ; Female; Humans; Hysterectomy; Leiomyoma; Leptin; Middle Aged; Postmenopause; Premenopause; Uterine Cervical Neoplasms; Uterine Neoplasms

Leptin reflects the amount of energy stores, regulates energy balance and is associated with circulating levels of reproductive hormones and insulin-like growth factor-I (IGF-I). Breast cancer has also been associated with obesity, reproductive hormones and circulating IGF-I levels. To determine whether leptin is involved in the etiology of breast cancer, we compared serum leptin levels in 83 cases of pre-menopausal carcinoma in situ of the breast and 69 healthy controls recruited in Massachusetts. Serum leptin levels were 13.69 + 1.3 ng/ml in cases and 16.03 + 1.7 ng/ml in controls. Data were also analyzed using multiple logistic regression with adjustment for known risk factors for the development of breast cancer as well as anthropometric, demographic and hormonal variables, including estradiol, prolactin, IGF-I and IGF-binding protein-3. Odds ratios were 1.75 (95% CI, 0.73-4.21) for the second control-defined tertile and 1.54 (0.46-5.16) for the third control-defined tertile relative to the first. Thus, leptin does not appear to increase the risk of pre-menopausal breast cancer in situ substantially.

Topics: Adult; Biomarkers; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Case-Control Studies; Estradiol; Female; Humans; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor I; Leptin; Middle Aged; Premenopause; Prolactin; Proteins