The prognostic value of the human kallikrein gene 9 (KLK9) in breast cancer

Background. Many members of the human kallikrein gene family were found to be differentially expressed in various malignancies and some of them are useful diagnostic/prognostic markers. KLK9 is a newly discovered human kallikrein gene that is expressed in several tissues including thymus, spinal cord, testis, prostate, breast, and ovary. Like other kallikreins, the KLK9 gene was found to be regulated by steroid hormones, mainly estrogens and progestins, in cancer cell lines. Experimental design. We studied the expression of KLK9 by quantitative RT-PCR in 169 breast cancer patients of different stages, grades and histological types. We also compared the relation between KLK9 expression and other clinicopathological variables and patient survival. Results. KLK9 expression is significantly higher in patients with early stage cancers (p = 0.039) and in patients with small tumor size (<2 cm) (p = 0.028). Kaplan-Meier survival curves demonstrated that KLK9-positive patients have longer disease-free and overall survival (p = 0.015 and 0.036, respectively). Univariate and multivariate analysis also indicates that KLK9 expression is associated with increased disease-free and overall survival. When the Cox proportional hazard regression analysis was applied to subgroups of patients, KLK9 expression was found to be a significant predictor of disease-free survival in the estrogen receptor (ER) and progesterone receptor (PR) negative subgroups of patients (Hazard Ratio 'HR' = 0.28, and 0.38, respectively, and p = 0.011 and 0.028, respectively). After adjusting for other known prognostic variables, KLK9 retained its independent prognostic value in these subgroups of patients. Similar results were obtained for overall survival. Conclusions. KLK9 is a new potential independent marker of favorable prognosis in breast cancer.     

Higher expression of human kallikrein 10 in breast cancer tissue predicts tamoxifen resistance

The human tissue kallikreins are secreted serine proteases, encoded by a group of homologous genes clustered in tandem on chromosome 19q13.3-4. Human kallikrein 6 and human kallikrein 10 are two new members of this family. Recently, we developed highly sensitive and specific immunofluorometric assays for human kallikrein 6 and human kallikrein 10, which allow for their quantification in tissue extracts and biological fluids. Both human kallikrein 6 and human kallikrein 10 are found to be down-regulated in breast cancer cell lines, suggesting that they may be involved in breast cancer pathogenesis and progression. In this study, we investigated the potential value of human kallikrein 6 and human kallikrein 10 as prognostic and predictive factors in breast cancer. We quantified human kallikrein 6 and human kallikrein 10 protein levels in 749 breast tumour cytosolic extracts and correlated this data with various clinicopathological variables and patient outcomes. Human kallikrein 6 and human kallikrein 10 are positively correlated with each other. Higher human kallikrein 6 and human kallikrein 10 protein levels are associated with younger age, pre-menopausal, status and tumours which are negative for oestrogen and progesterone receptors. No correlation was found between human kallikrein 6 and human kallikrein 10 levels and tumour size, grade, and nodal status. Survival analysis showed that neither human kallikrein 6 nor human kallikrein 10 are related to the rate of relapse-free and overall survival. In the analysis with respect to response to tamoxifen therapy, although human kallikrein 6 levels were not associated with tamoxifen responsiveness, higher levels of human kallikrein 10 were significantly associated with a poor response rate. This association remained significant in the multivariate analysis. Furthermore, higher human kallikrein 10 levels were significantly related with a short progression-free and post-relapse overall survival after start of tamoxifen treatment for advanced disease. Taken together, our results suggest that although human kallikrein 6 and human kallikrein 10 are not prognostic markers for breast cancer, human kallikrein 10 is an independent predictive marker for response of tamoxifen therapy.     

Activation of AKT/PKB in breast cancer predicts a worse outcome among endocrine treated patients

Akt/PKB is a serine/threonine protein kinase that regulates cell cycle progression, apoptosis and growth factor mediated cell survival in association with tyrosine kinase receptors. The protein is a downstream effector of erbB-2 with implications in breast cancer progression and drug resistance in vitro. We aimed to examine the role of Akt-1 in breast cancer patients, by determining whether the expression (Akt-1) and/or activation (pAkt) were related to prognostic markers and survival. The expression of erbB-2, heregulin beta 1 and Bcl-2 was also assessed by flow cytometry or immunohistochemistry. This study comprised 93 patients, aged <50 who were treated with tamoxifen and/or goserelin. We found that pAkt was associated with lower S-phase fraction (P=0.001) and the presence of heregulin beta 1-expressing stromal cells (P=0.017). Neither Akt-1 nor pAkt was related with other factors. Tumour cells-derived heregulin beta 1 was found mainly in oestrogen receptor negative (P=0.026) and node negative (P=0.005) cases. Survival analysis revealed that pAkt positive patients were more prone to relapse with distant metastasis, independently of S-phase fraction and nodal status (multivariate analysis; P=0.004). The results suggest that activation of Akt may have prognostic relevance in breast cancer.     

乳腺癌中HES1的表达情况及与生存预后的相关性

目的:研究HES1在乳腺癌中的表达情况,探讨其与乳腺癌生存预后的关系。方法:采用免疫组化及Western blot检测了HES1在115例乳腺癌中的表达情况,应用Kaplan-Meier生存统计学方法分析HES1与乳腺癌生存预后的相关性。结果:在乳腺癌中,HES1阳性表达与TNM高分期（P=0.003）、淋巴结转移(P=0.043)、ER阴性(P=0.001)、PR阴性(P=0.042)及三阴性类型(P=0.001)均呈显著的相关性。此外,115例乳腺癌中HES1阳性表达组其无进展生存期（P=0.005）和总生存期（P=0.001）明显少于HES1阴性表达组。结论:HES1可能是乳腺癌的一个独立预后指标。     

Expression of human Kallikrein 14 (KLK14) in breast cancer is associated with higher tumour grades and positive nodal status

Human kallikrein 14 (KLK14) is a steroid hormone-regulated member of the tissue kallikrein family of serine proteases, for which a prognostic and diagnostic value in breast cancer has been suggested. To further characterise the value of KLK14 as a breast tumour marker, we have carefully analysed KLK14 expression in normal breast tissue and breast cancer both on the RNA level by real-time RT-PCR (n = 39), and on the protein level (n = 127) using a KLK14-specific antibody for immunohistochemistry. We correlated KLK14 protein expression data with available clinico-pathological parameters (mean follow-up time was 55 months) including patient prognosis. KLK14 RNA expression as quantified by real-time RT-PCR was significantly more abundant in breast tumours compared to normal breast tissue (P = 0.027), an issue that had not been clarified recently. Concordantly with the RNA data, cytoplasmic KLK14 protein expression was significantly higher in invasive breast carcinomas compared to normal breast tissues (P = 0.003). Furthermore, KLK14 protein expression was associated with higher tumour grade (P = 0.041) and positive nodal status (P = 0.045) but was not significantly associated with shortened disease-free or overall patient survival time in univariate analyses. We conclude that KLK14 is clearly overexpressed in breast cancer in comparison to normal breast tissues and is positively associated with conventional parameters of tumour aggressiveness, but due to a missing association with survival times, the use of KLK14 immunohistochemistry as a prognostic marker in breast cancer is questionable.     

Inverse relationship between ER-beta and SRC-1 predicts outcome in endocrine-resistant breast cancer

The oestrogen receptor (ER) interacts with coactivator proteins to modulate genes central to breast tumour progression. Oestrogen receptor is encoded for by two genes, ER-alpha and ER-beta. Although ER-alpha has been well characterized, the role of ER-beta as a prognostic indicator remains unresolved. To determine isoform-specific expression of ER and coexpression with activator proteins, we examined the expression and localisation of ER-alpha, ER-beta and the coactivator protein steroid receptor coactivator 1 (SRC-1) by immunohistochemistry and immunofluorescence in a cohort of human breast cancer patients (n=150). Relative levels of SRC-1 in primary breast cultures derived from patient tumours in the presence of beta-oestradiol and tamoxifen was assessed using Western blotting (n=14). Oestrogen receptor-beta protein expression was associated with disease-free survival (DFS) and inversely associated with the expression of HER2 (P=0.0008 and P<0.0001, respectively), whereas SRC-1 was negatively associated with DFS and positively correlated with HER2 (P<0.0001 and P<0.0001, respectively). Steroid receptor coactivator 1 protein expression was regulated in response to beta-oestradiol or tamoxifen in 57% of the primary tumour cell cultures. Protein expression of ER-beta and SRC-1 was inversely associated (P=0.0001). The association of ER-beta protein expression with increased DFS and its inverse relationship with SRC-1 suggests a role for these proteins in predicting outcome in breast cancer.     

Prognostic factors in primary breast cancer

A review and update of published studies on oestrogen receptor and progesterone receptor as prognostic factors in breast cancer supports the following conclusions. In stage I breast cancer the lack of oestrogen receptor seems to be the most important factor for predicting earlier recurrence and poorer survival. In stage II breast cancer, measurement of progesterone receptor appears to be better than measurement of oestrogen receptor for predicting disease-free survival, and is as important as the oestrogen receptor in predicting overall survival. The benefits of adjuvant endocrine therapy are better predicted by the presence or absence of progesterone receptor rather than by oestrogen receptor. Measurement of proliferative activity (DNA S-phase) by thymidine labelling or flow cytometry, and of aneuploidy by flow cytometry, also provides prognostic information. The strong correlations between tumour receptor content, per cent S-phase and aneuploidy suggest that these measurements in concert might identify a subset of stage I breast cancer patients at increased risk for recurrence, who would thus be potential candidates for adjuvant therapy.     

C-myc amplification in breast cancer: a meta-analysis of its occurrence and prognostic relevance

Data from basic research suggests that amplification of the proto-oncogene c-myc is important in breast cancer pathogenesis, but its frequency of amplification and prognostic relevance in human studies have been inconsistent. In an effort to clarify the clinical significance of c-myc amplification in breast cancer, we conducted a comprehensive literature search and a meta-analysis in which 29 studies were evaluated. The weighted average frequency of c-myc amplification in breast tumours was 15.7% (95% CI = 12.5-18.8%), although estimates in individual studies exhibited significant heterogeneity, P<0.0001. C-myc amplification exhibited significant but weak associations with tumour grade (RR = 1.61), lymph-node metastasis (RR = 1.24), negative progesterone receptor status (RR = 1.27), and postmenopausal status (RR = 0.82). Amplification was significantly associated with risk of relapse and death, with pooled estimates RR = 2.05 (95% CI = 1.51-2.78) and RR = 1.74 (95% CI = 1.27-2.39), respectively. This effect did not appear to be merely a surrogate for other prognostic factors. These results suggest that c-myc amplification is relatively common in breast cancer and may provide independent prognostic information. More rigorous studies with consistent methodology are required to validate this association, and to investigate its potential as a molecular predictor of specific therapy response.     

In ovarian cancer the prognostic influence of HER2/neu is not dependent on the CXCR4/SDF-1 signalling pathway

HER2/neu overexpression is a driving force in the carcinogenesis of several human cancers. In breast cancer the prognostic influence of HER2/neu was shown to be at least partly based on increased metastatic potential mediated by the chemokine-chemokine receptor pair SDF-1(CXCL12)/CXCR4. We wanted to evaluate the influence of HER2/neu on ovarian cancer prognosis and to investigate whether compromised survival would correlate with CXCR4 expression and/or SDF-1 abundance. Therefore, we analysed HER2/neu, CXCR4, and SDF-1 in 148 ovarian tumour samples by means of immunohistochemistry on tissue microarrays. Overexpression of HER2/neu was found in 27.6% of ovarian cancer tissues and in 15% of ovarian borderline tumours. In ovarian cancer patients, overexpression of HER2/neu correlated closely with overall survival (univariate hazard ratio (HR) 2.59, P=0.005; multiple corrected HR 1.92, P=0.074). In contrast, CXCR4 expression and SDF-1 abundance had no impact on overall survival, and both parameters were not correlated with HER2/neu expression. As expected, cytoplasmic CXCR4 expression and SDF-1 abundance correlated closely (P<0.0001). Our results confirm a univariate influence of HER2/neu expression on overall survival, which was completely independent of the expression of CXCR4 and the abundance of SDF-1, implying significant differences between the HER2/neu downstream pathways in ovarian cancer compared with breast cancer.     

Reduced expression of BAX is associated with poor prognosis in patients with epithelial ovarian cancer: a multifactorial analysis of TP53, p21, BAX and BCL-2.

Traditional clinicopathological features do not predict which patients will develop chemotherapy resistance. The TP53 gene is frequently altered in ovarian cancer but its prognostic implications are controversial. Little is known on the impact of TP53-downstream genes on prognosis. Using molecular and immunohistochemical analyses we examined TP53 and its downstream genes p21, BAX and BCL-2 in ovarian tumour tissues and have evaluated the results in relation to clinico-pathological parameters, clinical outcome and response to platinum-based chemotherapy. Associations of tested factors and patient and tumour characteristics were studied by Spearman rank correlation and Pearsons chi2 test. The Cox proportional hazard model was used for univariate and multivariate analysis. The associations of tested factors with response was tested using logistic regression analysis. TP53 mutation, p21 and BCL-2 expression were not associated with increased rates of progression and death. Expression of TP53 was associated with a shorter overall survival only (relative hazard rate [RHR] 2.01, P = 0.03). Interestingly, when combining TP53 mutation and expression data, this resulted in an increased association with overall survival (P = 0.008). BAX expression was found to be associated with both progression-free (RHR 0.44, P = 0.05) and overall survival (RHR 0.42, P = 0.03). Those patients who simultaneously expressed BAX and BCL-2 had a longer progression-free and overall survival compared to patients whose tumours did not express BCL-2 (P = 0.05 and 0.015 respectively). No relations were observed between tested factors and response to platinum-based chemotherapy. We conclude that BAX expression may represent a prognostic indicator for patients with ovarian cancer and that the combined evaluation of BAX and BCL-2 may provide additional prognostic significance.     

Season of tumour detection influences factors predicting survival of patients with breast cancer

Summary The rate of initial detection of breast tumours varies during the year in a seasonal fashion, more tumours being discovered in late spring/early summer than at other times of the year. This phenomenon is particularly pronounced in young women (< 50 years) with progesterone receptor positive tumours. The present study investigates whether season of tumour detection influences the predictive capacity of several recognised prognostic and risk factors in patients with breast cancer. Axillary nodal status, tumour progesterone receptor status, and season of tumour detection significantly influenced survival in both older (> 50 yrs) and younger (< 50 yrs) patients. Parity, lactational history, body mass index, tumour oestrogen receptor status, and patient age also influenced survival, but these effects were significant only in age groups < 50 or > 50 yrs. Season of detection of tumour did not affect the prognostic significance of axillary nodal status. However, the effect of oestrogen receptor status on survival was more significant in patients who detected their tumours in the spring/summer compared with winter (odds ratio 0.52 and 0.73 respectively). Negative progesterone receptor status was associated with significantly poorer survival only in patients with tumours found in the winter. There was a significant survival disadvantage for nulliparous compared with parous women with breast cancer who were 50 years at diagnosis, and for women who had never lactated compared with those who had lactated, but this disadvantage was restricted to those who found their tumours in the summer. An increased body mass index ( 28) was associated with decreased survival, but this was significant only for those detecting tumours in winter. The increased incidence of detection of breast cancer in spring/summer may reflect cyclic influences on tumour growth. Such influences may be hormonal in nature and may underlie the effect of season of tumour detection on the prognostic influence of lactation, parity, body mass index, and oestrogen and progesterone receptor status in patients with breast cancer.