【Key Words】 breast cancer; the PSA; diagnosis
Prostate specific antigen the (Prostate specific antigen, PSA) is the 30KD molecular weight of the single-chain glycoprotein that belongs to the serine protease, releasing enzyme (Human Glandular Kallikrein, hk) of one of the members of the gene family HKLK3 encoded by the human prostate kinin, mainly by Prostate tubular epithelial cells to synthesize. Structure when certain pathological changes in the prostate tissue destruction, PSA matrix into the blood capillaries and lymph circulation, leaving the serum PSA concentration. Since their discovery, PSA has become the most effective prostate tumor markers, and plays an important role in the diagnosis and treatment of prostate cancer . In recent years, studies have shown that PSA is not a tissue-specific or gender-specific molecules , also exist in some women organizations rely on hormonal regulation, such as breast, ovarian, adrenal gland and body fluids . This study was detected in women with breast cancer preoperative serum concentration of of T PSA and of F PSA’s, and its value in the diagnosis of breast cancer.
1 Materials and methods
1.1 The object of study
In our hospital and Guangxi Medical University Affiliated Hospital in June 2002 to 102 cases of breast cancer patients hospitalized in July 2004, aged 28 to 77 years, with an average age of 40.8 years. Including 33 cases of ductal carcinoma, lobular carcinoma in 46 cases, 23 cases unable to sub-type of breast cancer; published according to the 1997 International Union Against Cancer (UICC) TNM clinical staging criteria, 58 cases of the group stage Ⅰ + Ⅱ, Ⅲ of 25 cases, Ⅳ of 19 cases; 45 cases of benign breast disease, age 26 to 69 years, with an average age of 42.3 years (Hyperplasia 28 cases, five cases of breast cysts, milk intraductal papilloma 12 cases); these patients confirmed by pathological diagnosis. 40 cases of healthy women, aged 20 to 66 years, with an average age of 41.6 years.
Measured in patients and healthy women within a week before blood sampling to avoid urethral examination and digital rectal examination, fasting venous blood 3ml serum was separated by centrifugation, -20 ℃ save under test. Detect the T PSA and F PSA ECLIA reagents and instruments are Switzerland, Roche company’s products (Instrument model Elecsys1010), determined using receiver operating characteristic curve (Receiver operating characteristic curve, ROC curves) T PSA> 0.37 ng / ml, F PSA> 0.02 ng / ml as positive defined value. F PSA / T PSA> 50% that is the the “F PSA advantage of patients" (free PSA predominant).
1.3 statistical methods
Data statistical t-test and χ2 test with SPSS10.0 computer software, data ± s, the differences among the groups for single-factor analysis of variance.
2.1 breast cancer patients with serum of F PSA in the level of benign breast disease group and the healthy women group (P <0.05) was significantly higher than the positive rate of of of T PSA and of F PSA in the detection of breast cancer was 25.5% and 29.4%, respectively. F PSA advantage in patients, breast cancer accounted for 40.2% of benign breast disease and healthy women was only 4.4% and 2.5%, respectively, as shown in Table 1.
The 2.2 T PSA, F PSA and F PSA / T PSA> 50% level and positive rate in different histological types of breast cancer without significant difference (P> 0.05), as shown in Table 2.
The 2.3 T PSA, F PSA and F PSA / T PSA> 50% level and positive rate of the clinical stage increased the downward trend, F PSA advantage in patients with a higher incidence of early (P> 0.05). Table 3.
PSA in serum exists in two forms, and endogenous protease inhibitor α1 anti extravagant protease (α1-Antichymotrypsin, ACT) combined into a PSA ACT complex, and another small part of the non-binding type, that free PSA (F PSA). Studies have shown that prostate cancer patients with serum of F PSA in and FPSA / T PSA, significantly lower than that of normal males and benign prostatic hyperplasia patients, and FPSA / the T PSA can significantly improve the sensitivity and specificity of the diagnosis of prostate cancer .
The results of this study show that breast cancer patients with serum the T PSA levels higher than benign breast disease and healthy women, but the differences were not statistically significant, F PSA levels were significantly higher than that of the latter two (P <0.05 ). And high specificity (92.5%), there is a certain sense in differentiating benign and malignant breast lesions. The results reported in the literature  are similar. The results of this study also showed that in the serum of patients with breast cancer F PSA / T PSA significantly higher in of F PSA advantage in patients with positive rate was significantly higher than that of benign breast disease and healthy women (P <0.05) . And higher specificity (97.5%). And Black et al  is similar. In addition, with the rise of the clinical stage of breast cancer, the the T PSA and of F PSA level and positive rate downward trend, F PSA advantage in patients with early slightly higher incidence. These results suggest that preoperative clinical diagnosis and prognosis of breast cancer have a certain level of detection of breast cancer patients with serum the T PSA and F PSA.
PSA gene (HKLK3) belong to the human tissue kallikrein gene family (HKLKs) a member of the PSA gene location and structure in 1989. The In addition HKLK3 outside, HKLKs including HKLK1 and HKLK2. Studies show biological kinin activity in the traditional sense of having to to just HKLK1 coded product HKLKs family members, and the other genes, such as HKLK3, encoding a prostate specific antigen, only like HKLK1, a highly conserved genotype and protein structure, they in malignant tumors, especially sex hormone-related malignancies (prostate cancer, testicular cancer, ovarian cancer, breast cancer, etc.) occur in development, plays a role in stimulating cell growth, promote angiogenesis, degradation of cell grassroots [7, 8]. Study found that the breast tissue in the HKLKs different table in a serum the T PSA, F PSA and the the F PSA / T PSA> 50% positive rate
Constant expression . In men with prostate, PSA’s gene expression by androgens, is adjusted by a combination of testosterone and androgen receptor. PSA by the steroid hormones that regulate the same found in the female breast tissue. Breast cancer cells in vitro studies have shown that PSA gene transcription by androgens, progesterone, glucocorticoids and adrenal cortex hormones to their receptors to regulate. Although estrogen can not directly regulate the expression of the PSA gene, but can inhibit androgen on gene regulation . About HKLKs especially HKLK3 role in the pathogenesis of breast cancer rare reports pending further in-depth study.