Correlation Of PEDF Expression With Breast Diseases And The Ultrasound Features Of Breast Cancer

Breast cancer is the most common malignancy in women, and its incidence is increasing every year. The best way to reduce the mortality of breast cancer and to improve the prognosis of patients with breast cancer is owing to early detection, early diagnosis and early treatment. At present, the early diagnosis of breast cancer is mainly dependent on the medical imaging methods, just like mammography, ultrasound. The differences in the imaging equipment and diagnostic doctor individual level, restricted the improvement of the overall level of early diagnosis. Investigate the pathogenesis of tumors, looking for a strong sensitivity, specificity biomarkers for diagnosis and prognosis, and thus leads to new therapeutic targets for breast cancer is one of research focus in recent years.Pigment epithelium-derived factor (PEDF), a50-kDa secreted glycoprotein, was first identified and isolated from the conditioned media of primary human fetal retinal pigment epithelial cells. It is a noninhibitory member of the serine protease inhibitor superfamily, and its gene is highly conserved through evolution and resides on human chromosome17p13.3. It is well known that PEDF is widely expressed in the adult and fetal tissues, including the adult brain, spinal cord, plasma, liver, bone, eyes, heart and lung tissues. In recent years, the multiple biological effects of PEDF have being gradually clear, such as neuroprotective, neurotrophic, anti-angiogenesis and induce tumor cell apoptosis. It is the anti-tumor effect of PEDF that has brought it much recent attention.In recent years, studies have shown that there is a close correlation between the decreased levels of PEDF expression and tumor occurrence and development. At present, PEDF exert its anti-tumor effect through the following three paths:1) antiangiogenesis2) apoptosis mediated tumor suppression3) promote tumor cell differentiation and maturation.Intraductal proliferative lesions (IDPL) is a group of proliferative lesions with cytology and histology diversity, the typical ones are locating in the terminal duct lobular units (TDLU). According to their architectural and cytologic characteristics, this group of lesions can be divided into four major types, usual ductal hyperplasia (UDH), flat epithelial atypia (FEA), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS). The relevance between these lesions and invasive breast cancer are different. The reason of our studying of such lesions is to recognize these lesions essentially, and then to reveal its relationship with invasive breast cancer, as well as its role in the incidence and progression of breast cancer, in order to take appropriate measures to curb this kind of lesions developing into invasive cancer.Resent researches of the relationship between PEDF and breast cancer are as follows:First, in one study the PEDF expression in breast cancer tissues and normal breast tissues are quantitative detected, the results showed that there is a significant reduction in the expression of PEDF in breast cancer tissues. It suggested that the lack of expression of PEDF is an important factor in breast cancer tumor growth and angiogenesis. The first part of this study, we selected several key steps in the development of the ductal hyperplasia lesions, in order to study the relationship between PEDF levels and breast disease progression.Secondly, in a variety of malignant tumors, the antiangiogenic action of PEDF is reflected in the reduction of tumor microvessel density (MVD). Whether the anti-tumor neovascularization effect of PEDF is visible by the unaided eyes, it is still unknown. In the second part of our study, a quantitative analysis of breast cancer ultrasonography was given to explore the correlation between the level of expression of PEDF and breast ultrasound characteristics.Thirdly, in the study of the correlation between the PEDF expression level of breast cancer lesions and clinical prognostic indicates that the low expression of PEDF is a sign of poor prognosis. In this regard, in the present study, we will do a further exploration, and then we will discuss the feasibility of PEDF as a bridge between the preoperative medical imaging and the clinical prognosis.Finally, in the study of PEDF and ovarian cancer, we can learn that estrogen is an important upstream regulator of PEDF in human ovarian surface epithelium. The rise of E2, will lead to the down-regulation of the PEDF in both mRNA and protein levels, its role is mediated through the estrogen receptor (ER). This reminds us that breast cancer as a kind of disease which is closely related to the endocrine, too, there might be a correlation between the expression of ER and the PEDF level. However, the current study has not yet confirmed this. It will be a direction of our future research, and will give us more information about the mechanism of endocrine therapy of breast cancer, and will help us to choose the sensitive populations of endocrine therapy more accurately.PART Ⅰ PEDF Expression in Breast Ductal Hyperplasia Lesions and Invasive Ductal CarcinomaObjective 1. To study the relationship between PEDF expression levels and breast disease progression, and then analyze the possibility of PEDF as a biomarker for early of breast cancer.2. To study the relationship between PEDF expression levels and the prognostic index in breast cancer tissue, and then assess the value of PEDF as a predictor of tumor biological behavior and prognosis.3. To study the relationship between PEDF expression levels and breast cancer angiogenesis, and then analyze the possibility of PEDF as a new therapeutic target for breast cancer.Materials and MethodsCollected124cases from Shenzhen Maternal and Child Health Hospital, South Medical University, all of the cases had got a clear pathologically diagnosis during January2010to June2011. In the124cases,26cases are usual ductal hyperplasia,31cases are atypical ductal hyperplasia,15cases are ductal carcinoma in situ, and52cases are invasive ductal carcinoma. All the clinical and pathological data, including age, menopausal status, tumor size, grade and stage, hormone receptor situation were got. The expression of PEDF were measured by immunohistochemical method. The chi-square test or Mann-Whitney U test were used in the statistical analysis, Statistic significance was defined as P<0.05.Result1. In72cases with intraductal proliferative lesions,41cases are positive, the positive rate is56.9%. In52cases of invasive ductal breast cancer,14cases are positive, the positive rate is26.9%. The difference was statistically significant (P=0.001), that means the expression levels of invasive ductal breast cancer was significantly lower than ductal epithelial hyperplasia lesions.2. The positive rate of PEDF protein expression in usual ductal hyperplasia, atypical ductal hyperplasia and ductal carcinoma in situ lesions are65.4%,51.6%,53.3%, there is no statistically significant during the three groups (P=0.550), that means the expression of PEDF protein was no significant difference among various stages of breast ductal hyperplasia lesions.3.52cases of invasive ductal carcinoma were divided into two groups based on tumor size≤2.0cm and>2.0cm, the positive rates of the two groups were57.1%and6.5%, the difference was statistically significant (P<0.001), that means tumors with a diameter>2.0cm having a significantly lower positive rate of PEDF protein expression. In the groups with lymph node metastasis negative or positive, the positive rate were40%and9.1%, the difference is significant, that means in the lymph node metastasis positive group, PEDF protein expression positive rate was significantly reduced. Similarly, in the groups of different stages, which is closely related to tumor size and lymph node metastasis, the PEDF protein expression in the group of patients with early breast cancer (stage I, n=18) and in the group with advanced breast cancer (stageⅡ-Ⅳ, n=34) also significantly different (P<0.001). In patients with advanced breast cancer, the positive rate was significantly reduced. In groups divide based on the patient’s age, menstrual status, and histological grade, ER, PR expression, the difference was not statistically significant(P values are0.724,1.000,1.000,0.789,0.211).4. We use NPI to assess the prognosis of patients with breast cancer. based on NPI<3.4,3.4-5.4and>5.4, patients were divided in to1,2,3grads.14patients in grad1are having a better prognosis, the positive rate of PEDF protein expression is64.3%,16patients in grad3are having a poor prognosis, the positive rate of PEDF protein expression is6.3%,22patients in grad2are in the median, the positive rate is18.2%. The difference among the three groups is significant (P=0.001), in NPI score higher group, PEDF protein expression positive rate was significantly lower.5. In52cases of invasive ductal breast cancer, the expression of VEGF was positive in30cases, and negative in22cases. The positive rate of PEDF expression in VEGF-positive cases was13.3%, the positive rate of PEDF expression in VEGF-negative cases was45.5%, the difference was statistically significant (P=0.026), PEDF expression was significantly reduced in patients with VEGF positive. The contingency coefficient C=-0.308, that means there is a negative association between the two factors.Conclusion1. PEDF protein expression level in invasive ductal breast cancer is significantly reduced than intraductal proliferative lesions, suggesting that PEDF protein play a role in breast cancer development.2. The lower or absence of PEDF protein expression in breast cancer tissues is associated with tumor size, lymph node metastasis and clinical stage, suggested the value of PEDF protein in predicting breast cancer prognosis.3. The negative association between PEDF protein and VEGF protein expression in invasive ductal breast cancer, suggested that PEDF may be a new target for anti-angiogenic treatment of breast cancer.PART II Correlation of PEDF Expression and the Ultrasound Features of Breast CancerObjective1. To study the relationship between PEDF expression levels and breast ultrasound blood flow signals, and then analyze whether there is a macroeconomic performance of the antiangiogenic effect of PEDF in breast cancer. 2. To study the relationship between PEDF expression levels and the breast ultrasound signs of malignant, in order to assess the feasibility of PEDF as a bridge between the preoperative medical imaging and the clinical prognosis.Materials and MethodsSelect cases with pathological diagnosis of breast cancer from January2010to June2011.62cases were included in our study,52cases of which are invasive ductal carcinoma,6cases are invasive lobular carcinoma,3cases are mucinous carcinoma, and one case is invasive cribriform carcinoma.High-frequency ultrasound and color Doppler flow imaging were performed in all patients, and the characters of the tumor were record, such as tumor size, shape, border, posterior echo, internal calcification, aspect ratio, color Doppler flow imaging were used to detect tumor blooa flow, and the flow were classified according to the Alder classification method. Considering all the information above, all cases were graded according to the Breast Imaging Reporting and Data System (BI-RADS)(4th Edition) from American College of Radiology. Ultrasound images and pathological information were record completely. The expression of PEDF in all specimen were measured by immunohistochemical method. The chi-square test, Fisher’s exact test or Mann-Whitney U test were used in the statistical analysis, Statistic significance was defined as P<0.05.Result1.62cases of breast cancer were divided into four groups according to the color Doppler flow imaging, grade0including19cases, grade I including13cases, grade II including16cases, and grade III including13cases. The positive rates of PEDF protein expression were47.4%(9/19),30.8%(4/13),31.3%(5/16) and7.1%(1/14). After statistical analysis, the difference was significant (P=0.021). That means in masses of grade III with the rich blood flow, the positive rate of PEDF is much lower in breast cancer tissues. In contrast, in masses of grade0 with no blood flow signals, the positive rate is higher.2.62cases with different types of breast cancer, includ52cases of invasive ductal carcinoma, the positive rate of PEDF protein expression was26.9%(14/52). In6cases with invasive lobular carcinoma, the positive rate was50%(3/6), and in4cases of invasive cancer with a good prognosis (mucinous carcinoma and invasive cribriform carcinoma), the positive rate was50%(2/4). The difference among these groups was not statistically significant (P=0.330).3. The analysis about the correlation between PEDF expression and ultrasound image features of the62cases with invasive breast cancer showed that only in the groups divided by tumor size, the difference was significant (P=0.002). In groups with tumor size≤2.0cm and>2.0cm, the positive rate were44.4%and7.7%respectively. PEDF protein expression positive rate was significantly lower in patients with tumor diameter>2.0cm. In addition, in groups based on shape, borders, posterior echo, aspect ratio, internal calcification, there was no significant difference.Conclusion1. The antiangiogenesis effect of PEDF in breast cancer is not only showed in the MVD, but also has a macroeconomic performance, and can be detected by ultrasound.2. The ultrasound features of breast cancer may reflect the level of PEDF expression. It is valuable for the assessment of biological behavior and prognosis of breast cancer.