Estrogen Receptor

Prostate-specific antigen (PSA) is thought to be produced exclusively by prostatic epithelial cells and is currently used as a tumor marker of prostatic adenocarcinoma. We recently found that 30% of breast cancers contain PSA immunoreactivity (IR-PSA). To examine the prognostic value of PSA in female breast cancer, we measured IR-PSA in tumor cytosols of 174 breast cancer patients and classified the breast cancers as either PSA positive or PSA negative based on an IR-PSA cutoff level of 0.03 ng/mg. IR-PSA was present in 27% of the patients. IR-PSA presence was associated with early disease stage, small tumors, and estrogen receptor-positive tumors. We used the Cox proportional hazards regression model to analyze survival of patients in association with PSA status and found that patients with IR-PSA-positive tumors had a reduced risk for relapse and death in univariate analysis (P = 0.02 and 0.06, respectively) and a reduced risk for relapse in multivariate analysis (P = 0.03). Furth...

KLK5 is a newly discovered human kallikrein gene. Many kallikrein genes have been found to be differentially expressed in various malignancies, and prostate-specific antigen (PSA; encoded by the KLK3 gene) is the best tumor marker for prostate cancer. Like the genes that encode PSA and other kallikreins, the KLK5 gene was found to be regulated by steroid hormones in the BT-474 breast cancer cell line. We studied KLK5 expression in 179 patients with different stages and grades of epithelial breast carcinoma by quantitative reverse transcription-PCR (RT-PCR), using LightCycler((R)) technology. An optimal cutoff point equal to the detection limit (65th percentile) was used. KLK5 values were then compared with other established prognostic factors in terms of disease-free (DFS) and overall survival (OS). High KLK5 expression was found more frequently in pre-/perimenopausal (P = 0.026), node-positive (P = 0.029), and estrogen receptor-negative (P = 0.038) patients. In univariate analysis,...

Purpose: To compare the efficacy of chemotherapy versus that of tamoxifen plus ovarian suppression in pre-/perimenopausal estrogen receptor-positive pa- tients with early breast cancer. Patients and Methods: Patients were randomly as- signed to receive either six cycles of a standard regimen of cyclophosphamide 100 mg/m2 orally days 1 to 14, methotrexate 40 mg/m2 intravenously (IV) days 1 and 8, and