Prognostic role of p27Kip1 and apoptosis in human breast cancer

Immunoexpression of HER2 pathway related markers in HER2 invasive breast carcinomas treated with trastuzumab

PURPOSE

We evaluated the immunoexpression of potential markers involved in the HER2 pathway in invasive breast carcinoma with HER2 amplification treated with trastuzumab.

METHODS

Samples of ninety patients diagnosed and treated at two public Brazilian hospitals with overexpressed invasive carcinoma between 2009 and 2018 were included. Several markers (Bcl-2, CDK4, cyclin D1, EGFR, IGF1, IGF-1R, MDM2, MUC4, p16, p21, p27, p53, PTEN, RA, TNFα, and VEGF) were immune analyzed in the tumor by immunohistochemistry and then correlated with clinicopathological variables.

RESULTS

Tumor sample expression results determined potential markers of good prognosis with statistically significant values: cyclin D1 with a nuclear grade, and recurrence; IGF-1 with tumor size, and death; p16 with a response after treatment; PTEN with a response after treatment, and death. Markers of poor prognosis: p53 with histological, and nuclear grade; IGF-1R with a compromised lymph node. The treatment resistance rate after trastuzumab was 40%; the overall survival was 4.13 years (95% CI 5.1-12.5) and the disease-free survival was 3.6 years (95% CI 5.1-13.1).

CONCLUSIONS

The tumor samples profile demonstrated that cyclin D1, IGF-1, p16, and PTEN presented the potential for a good prognosis and p53 and IGF-1R for worse.

Immunoexpression of proliferation and apoptosis markers in oral vascular anomalies

The biological behavior of lesions is highly dependent on the imbalance between their proliferative and apoptotic capacity. This study evaluated a correlation between the proliferative and apoptotic rates of different oral vascular anomalies (VAs) by analyzing the immunoexpression of proliferation (Ki-67) and apoptosis (Bcl-2 and Bax) markers in endothelial cells of 20 cases of GLUT-1 positive infantile hemangiomas (IHs), 20 cases of pyogenic granulomas (PGs) and 20 cases of vascular malformations (VMs). Immunoexpression analysis of Ki-67, Bcl-2 and Bax revealed a lower median percentage of positive cells in VMs cases compared to IHs and PGs cases (P <0.001). The Wilcoxon signed-rank test showed significantly higher percentages of immunostaining for Bax than for Bcl-2 in IHs (P = 0.048). In the group of PGs, a positive correlation was observed between the immunoexpressions of Ki-67 and Bax (r = 0.476; P = 0.034). Although oral IHs, PGs and VMs present similar clinical and histopathological features, each of these lesions has its etiopathogenic particularities. The results of this study suggest that different biological behaviors of VAs may be related to differences in the proliferative and apoptotic profiles of their endothelial cells.

MicroRNA-182-5p targets a network of genes involved in DNA repair

MicroRNAs are noncoding regulators of gene expression, which act by repressing protein translation and/or degrading mRNA. Many have been shown to drive tumorigenesis in cancer, but functional studies to understand their mode of action are typically limited to single-target genes. In this study, we use synthetic biotinylated miRNA to pull down endogenous targets of miR-182-5p. We identified more than 1000 genes as potential targets of miR-182-5p, most of which have a known function in pathways underlying tumor biology. Specifically, functional enrichment analysis identified components of both the DNA damage response pathway and cell cycle to be highly represented in this target cohort. Experimental validation confirmed that miR-182-5p-mediated disruption of the homologous recombination (HR) pathway is a consequence of its ability to target multiple components in that pathway. Although there is a strong enrichment for the cell cycle ontology, we do not see primary proliferative defects as a consequence of miR-182-5p overexpression. We highlight targets that could be responsible for miR-182-5p-mediated disruption of other biological processes attributed in the literature so far. Finally, we show that miR-182-5p is highly expressed in a panel of human breast cancer samples, highlighting its role as a potential oncomir in breast cancer.

Association between the nuclear to cytoplasmic ratio of p27 and the efficacy of adjuvant polychemotherapy in early breast cancer

BACKGROUND

The purpose of this study was to evaluate the prognostic and predictive value of p27 expression in patients with early breast cancer.

PATIENTS AND METHODS

Quantitative immunofluorescence assays for p27 were done on a tissue microarray that included 823 samples from patients randomized between anthracycline-based chemotherapy and no chemotherapy. Quantification of p27 was done using the AQUA® system (HistoRx, Inc., Branford, CT). Both p27 nuclear expression and the nuclear to cytoplasmic ratio were assessed.

RESULTS

Nuclear p27 expression was not predictive for the efficacy of anthracycline-based chemotherapy [adjusted P=0.18 for disease-free survival (DFS)] nor prognostic [95% confidence interval (CI) 0.99-1.01, P=0.49]. However, p27 nuclear/cytoplasmic ratio was predictive for the efficacy of adjuvant chemotherapy (adjusted P=0.016 DFS). The adjusted hazard ratio (HR) for relapse associated with adjuvant chemotherapy was 0.56 (95% CI 0.37-0.84, P=0.005) and 1.06 (95% CI 0.76-1.47, P=0.74) for patients with high and low nuclear/cytoplasmic ratio, respectively. p27 N/C ratio was prognostic in patients treated with chemotherapy (HR for relapse or death for a 1 unit increase in p27 N/C ratio was 0.30, 95% CI 0.12-0.77) but not in the untreated arm (HR for relapse or death was 1.27, 95% CI 0.58-2.8).

CONCLUSIONS

This study did not confirm the role of p27 nuclear expression as a prognostic parameter. However, the p27 nuclear/cytoplasmic ratio was predictive in patients treated with anthracycline-based chemotherapy.

Cyclin-dependent kinase inhibitor p27 as a prognostic biomarker and potential cancer therapeutic target

The prognosis and clinical management of patients with cancer is commonly determined by traditional clinical and pathological factors. Nevertheless, patients may present with significantly different clinical outcomes despite similar clinicopathological features. This has prompted intense research to find biological markers that may closely reflect tumor biology and thereby clinical outcome. This article presents the current knowledge on the prognostic significance of p27 expression in cancer and its potential role as a target for future therapy.

p27: a barometer of signaling deregulation and potential predictor of response to targeted therapies

Phosphorylation of the cyclin-dependent kinase inhibitor p27 by upstream mitogenic signaling pathways regulates its stability, localization, and biological function. In human cancers, loss of the antiproliferative action of p27 can arise through reduced protein levels and/or cytoplasmic mislocalization, leading to increased cell proliferation and/or cell migration, respectively. Reduced p27 expression levels and p27 mislocalization have potential prognostic and therapeutic implications in various types of human cancers. This review highlights mechanisms of functional deregulation of p27 by oncogenic signaling that provide an important molecular rationale for pathway targeting in cancer treatment.

p27(Kip1) as a prognostic factor in breast cancer: a systematic review and meta-analysis

The aim of this study was to comprehensively evaluate via a meta-analysis the association between p27 expression and clinical outcome in breast cancer patients. We conducted a meta-analysis of 20 studies (n= 6463 patients) that evaluated the correlation between p27 expression and indicators of breast cancer clinical outcome, including overall survival (OS), disease-free survival (DFS) and relapse-free survival (RFS). Data pooling was performed by RevMan 4.2. A total of 60% (9 of 15) of the studies showed a significant association between p27 high expression and OS, whereas 25% (2 of 8) and 60% (3 of 5) studies demonstrated a correlation between p27 high expression and DFS and RFS, respectively. The relative risks (RRs) were 1.34 (1.26–1.42) for OS (P < 0.00001), 1.27 (1.10–1.47) for DFS (P= 0.001) and 1.49 (0.92–2.42) for RFS (P= 0.10). In lymph node-negative breast cancer patients, the RRs for OS and RFS were 1.84 (1.30–2.59; P= 0.0005) and 1.30 (0.20–8.50; P= 0.78), respectively. In lymph node-positive breast cancer patients, the RRs for OS and RFS were 2.99 (1.77–5.07; P < 0.0001) and 1.49 (0.80–2.77; P= 0.21), respectively. This meta-analysis indicates that reduced p27 is an independent prognostic factor for poor overall and disease-free cancer survival.

Low p27 expression predicts early relapse and death in postmenopausal hormone receptor-positive breast cancer patients receiving adjuvant tamoxifen therapy

PURPOSE

Previously, we have shown that p27 may be a potential predictive biomarker for the selection of premenopausal women with early-stage hormone-responsive breast cancer for adjuvant endocrine therapy. The purpose of the present study was to assess the clinical relevance of p27 expression in postmenopausal hormone receptor-positive breast cancer patients who were treated with adjuvant tamoxifen therapy.

EXPERIMENTAL DESIGN

We determined the expression of p27 by immunohistochemistry in the surgical specimens of breast carcinoma patients who had been enrolled in Austrian Breast and Colorectal Cancer Study Group Trial 06 and received tamoxifen for 5 years. Early relapse and death within the first 5 years of follow-up were analyzed using Cox models adjusted for clinical and pathologic factors.

RESULTS

p27 expression was high (>70% p27-positive tumor cells) in 252 of 483 (52%) tumor specimens and was associated with favorable outcome of the patients. Women with high p27 expression had a significantly longer disease-free survival (adjusted hazard ratio for relapse, 0.22; 95% confidence interval, 0.11-0.42; P < 0.001) and overall survival (adjusted hazard ratio for death, 0.39; 95% confidence interval, 0.21-0.72; P = 0.002) as compared with women with low p27 expression.

CONCLUSION

Low p27 expression independently predicts early relapse and death in postmenopausal women with early-stage, hormone receptor-positive breast cancer who received adjuvant tamoxifen for 5 years.

Cyclin D1 and p27 expression as prognostic factor in papillary carcinoma of thyroid: association with clinicopathological parameters

AIM

To determine the prognostic value of cell cycle regulators cyclin D1 and p27 for papillary thyroid carcinomas.

METHODS

Analysis included 180 patients with papillary thyroid carcinoma who underwent surgery at Split University Hospital Center between 1999 and 2001. Clinical data were obtained from clinical charts and histopathology reports. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissue by antibody p27 and cyclin D1. Quantification was based on the intensity and distribution of nuclear staining.

RESULTS

Univariate analysis showed that sex (P=0.019) and capsular invasion (P=0.010) were significant predictors of lymph node metastases, whereas age (P=0.96), histopathological variant (P=0.075), size (P=0.556) and multifocality (P=0.131) were not. Univariate analysis also showed that overexpression of cyclin D1 (P<0.001) and underexpression of p27 (P<0.001) predicted lymph node metastases in papillary thyroid carcinomas. There was a significant correlation between cyclin D1 (P=0.024) and p27 (P=0.029) expression in two prognostic groups of low and high risk. Low risk group was cyclin D1 negative and p27 positive, while high risk group was cyclin D1 positive and p27 negative. Multivariate analysis confirmed that sex (P=0.041), capsular invasion (P=0.027), and p27 (P<0.001) were strong independent predictors of lymph node metastases in the high-risk group.

CONCLUSIONS

Immunohistochemical analysis of p27 expression may be a valuable tool for identifying risk of lymph node metastases and more aggressive behavior of papillary thyroid carcinoma.

Many forks in the path: cycling with FoxO

FoxO transcription factors are an evolutionary conserved subfamily of the forkhead transcription factors, characterized by the forkhead DNA-binding domain. FoxO factors regulate a number of cellular processes involved in cell-fate decisions in a cell-type- and environment-specific manner, including metabolism, differentiation, apoptosis and proliferation. A key mechanism by which FoxO determines cell fate is through regulation of the cell cycle machinery, and as such the cellular consequence of FoxO deregulation is often manifested through perturbation of the cell cycle. Consequently, the deregulation of FoxO factors is implicated in the development of numerous proliferative diseases, in particular cancer.

The Cdk inhibitor p27 in human cancer: prognostic potential and relevance to anticancer therapy

The cyclin-dependent kinase (Cdk) inhibitor p27 (also known as KIP1) regulates cell proliferation, cell motility and apoptosis. Interestingly, the protein can exert both positive and negative functions on these processes. Diverse post-translational modifications determine the physiological role of p27. Phosphorylation regulates p27 binding to and inhibition of cyclin-Cdk complexes, its localization and its ubiquitin-mediated proteolysis. In cancers, p27 is inactivated through impaired synthesis, accelerated degradation and by mislocalization. Moreover, studies in several tumour types indicate that p27 expression levels have both prognostic and therapeutic implications.

Aggressive breast cancer cells are dependent on activated Abl kinases for proliferation, anchorage-independent growth and survival

Mutant Abl kinases (such as BCR-Abl) drive the development of leukemia; however little is known regarding whether Abl kinases contribute to the development or progression of solid tumors. We recently demonstrated that endogenous Abl kinases (c-Abl, Arg) are activated by deregulated ErbB receptors and Src kinases, and drive invasion of aggressive breast cancer cells. In this study, we examined whether activation of endogenous Abl kinases affects transformation, proliferation and survival, which are major contributors to breast cancer development and metastatic progression. Using a pharmacological inhibitor and RNAi, we demonstrate that activation of endogenous Abl kinases dramatically promotes breast cancer cell proliferation and anchorage-independent growth in serum, as well as survival following nutrient deprivation. Activation of Abl kinases mediates phosphorylation of STAT3, and promotes proliferation by accelerating G(1) --> S progression. Moreover, we identify IGF-1R as a novel upstream activator of endogenous Abl kinases, and demonstrate that Abl kinase activation is required for IGF-1-stimulated cell cycle progression in breast cancer cells. Since activation of Abl kinases affects multiple steps of breast cancer development and progression, Abl kinase inhibitors are likely to be effective agents for the treatment of breast cancers containing highly active Abl kinases.

Semi-automated imaging system to quantitate estrogen and progesterone receptor immunoreactivity in human breast cancer

A semi-automated imaging system is described to quantitate estrogen and progesterone receptor immunoreactivity in human breast cancer. The system works for any conventional method of image acquisition using microscopic slides that have been processed for immunohistochemical analysis of the estrogen receptor and progesterone receptor. Estrogen receptor and progesterone receptor immunohistochemical staining produce colorimetric differences in nuclear staining that conventionally have been interpreted manually by pathologists and expressed as percentage of positive tumoral nuclei. The estrogen receptor and progesterone receptor status of human breast cancer represent important prognostic and predictive markers of human breast cancer that dictate therapeutic decisions but their subjective interpretation result in interobserver, intraobserver and fatigue variability. Subjective measurements are traditionally limited to a determination of percentage of tumoral nuclei that show positive immunoreactivity. To address these limitations, imaging algorithms utilizing both colorimetric (RGB) as well as intensity (gray scale) determinations were used to analyze pixels of the acquired image. Image acquisition utilized either scanner or microscope with attached digital or analogue camera capable of producing images with a resolution of 20 pixels /10 mu. Areas of each image were screened and the area of interest richest in tumour cells manually selected for image processing. Images were processed initially by JPG conversion of SVS scanned virtual slides or direct JPG photomicrograph capture. Following image acquisition, images were screened for quality, enhanced and processed. The algorithm-based values for estrogen receptor and progesterone receptor percentage nuclear positivity both strongly correlated with the subjective measurements (intraclass correlation: 0.77; 95% confidence interval: 0.59, 0.95) yet exhibited no interobserver, intraobserver or fatigue variability. In addition the algorithms provided measurements of nuclear estrogen receptor and progesterone receptor staining intensity (mean, mode and median staining intensity of positive staining nuclei), parameters that subjective review could not assess. Other semi-automated image analysis systems have been used to measure estrogen receptor and progesterone receptor immunoreactivity but these either have required proprietary hardware or have been based on luminosity differences alone. By contrast our algorithms were independent of proprietary hardware and were based on not just luminosity and colour but also many other imaging features including epithelial pattern recognition and nuclear morphology. These features provide a more accurate, versatile and robust imaging analysis platform that can be fully automated in the near future. Because of all these properties, our semi-automated imaging system 'adds value' as a means of measuring these important nuclear biomarkers of human breast cancer.

Phosphorylated HER-2 tyrosine kinase and Her-2/neu gene amplification as predictive factors of response to trastuzumab in patients with HER-2 overexpressing metastatic breast cancer (MBC)

AIM

Trastuzumab (T), a humanised monoclonal antibody against HER-2, is active in HER-2-positive MBC patients. However, nearly 60% of the patients do not benefit from T, stressing the need for additional predictive markers. The following markers could be implicated in response to T: (1) the magnitude of Her-2 gene amplification; (2) the co-expression of the other HER family receptors, possibly responsible for HER-2 trans-activation; (3) the activated status of HER-2; (4) the activated status of downstream effectors as mitogen-activated protein kinases (MAPKs), p38 and p27.

METHODS

Medical files of patients with MBC treated with T either as a single agent or in combination with chemotherapy (CT) were reviewed. HER family members (EGFR, HER-2, HER-3, HER-4), the phosphorylated forms of EGFR (p-EGFR), HER-2 (p-HER-2) and of the downstream effectors were evaluated in the archival tumours. The correlation between clinical outcome and the expression of these markers was investigated.

RESULTS

(1) Increasing values of Her-2 amplification were associated with a higher probability of achieving an objective response; (2) no statistical significant correlation between the expression of the HER family receptors was found; (3) p-HER-2 was predictive of response in patients treated with T+CT; (4) a statistically significant correlation between p-ERK 1/2, p-p38 and p-HER-2 emerged, pointing to the activated vertical pathway p-HER-2-->p-MAPKs.

CONCLUSIONS

p-HER-2 and the magnitude of Her-2 amplification were predictive of response to T and their role deserves to be analysed in larger and more homogenous T-treated populations such as those from large phase III trials.

Transforming growth factor-beta, estrogen, and progesterone converge on the regulation of p27Kip1 in the normal and malignant endometrium

Hormones and growth factors regulate endometrial cell growth. Disrupted transforming growth factor-beta (TGF-beta) signaling in primary endometrial carcinoma (ECA) cells leads to loss of TGF-beta-mediated growth inhibition, which we show herein results in lack of up-regulation of the cyclin-dependent kinase inhibitor p27(Kip1) (p27) to arrest cells in G(1) phase of the cell cycle. Conversely, in normal primary endometrial epithelial cells (EECs), TGF-beta induces a dose-dependent increase in p27 protein, with a total 3.6-fold maximal increase at 100 pmol/L TGF-beta, which was 2-fold higher in the nuclear fraction; mRNA levels were unaffected. In addition, ECA tissue lysates show a high rate of ubiquitin-mediated degradation of p27 compared with normal secretory-phase endometrial tissue (SE) such that 4% and 89% of recombinant p27 added to the lysates remains after 3 and 20 h, respectively. These results are reflected in vivo as ECA tissue lacks p27 compared with high expression of p27 in SE (P < or = 0.001). Furthermore, we show that estrogen treatment of EECs causes mitogen-activated protein kinase-driven proteasomal degradation of p27 whereas progesterone induces a marked increase in p27 in both normal EECs and ECA cells. Therefore, these data suggest that TGF-beta induces accumulation of p27 for normal growth regulation of EECs. However, in ECA, in addition to enhanced proteasomal degradation of p27, TGF-beta cannot induce p27 levels due to dysregulated TGF-beta signaling, thereby causing 17beta-estradiol-driven p27 degradation to proceed unchecked for cell cycle progression. Thus, p27 may be a central target for growth regulation of normal endometrium and in the pathogenesis of ECA.

Cytoplasmic expression of p27kip1 is associated with a favourable prognosis in colorectal cancer patients

AIM: To evaluate the prognostic significance of p27^kip1 in colorectal cancer patients.

METHODS: Cytoplasmic and nuclear p27^kip1 expression was evaluated in 418 colorectal cancers using tissue microarrays. Data were associated with known patient and tumor variables and long-term patient outcomes, providing further insight into the mechanisms by which p27^kip1 may influence tumor development.

RESULTS: Nuclear and cytoplasmic p27^Kip1 expressions were detected in 59% and 19% of tumors respectively. Cytoplasmic p27^Kip1 was almost invariably associated with positive nuclear p27^Kip1 expression. Neither case correlated with known clinical or pathological variables, including tumor stage, grade or extramural vascular invasion. Furthermore, nuclear p27^kip1 expression had no impact on survival. However, we identified a significant correlation between expression of cytoplasmic p27^kip1 and longer disease-specific survival times. On multivariate analysis, TNM stage and extramural vascular invasion were highly significant independent prognostic factors, with positive cytoplasmic p27 expression showing a trend towards improved patient survival (P = 0.059).

CONCLUSION: These findings support the recent evidence that cytoplasmic p27^kip1 has a distinct and important biological role that can influence tumor outcome.

Proliferative markers as prognostic and predictive tools in early breast cancer: where are we now?

In the last few decades, proliferative markers have been broadly evaluated as prognostic and predictive factors for early stage breast cancer patients. Several papers evaluating one or more markers have been published, often with contradictory results. As a consequence, there is still uncertainty about the role of these proliferative markers. The present paper critically reviews the current knowledge about the following markers: thymidine labeling index, S phase fraction/flow cytometry, Ki 67, thymidine kinase (TK), cyclins E, cyclin D, the cyclin inhibitors p27 and p21, and topoisomerase IIalpha. For each marker, the prognostic and predictive role was separately analyzed. Only papers published in English in peer-reviewed journals before June 2004 that include at least 100 evaluable patients were selected. In addition, the prognostic and predictive role of the proliferative markers had to be assessed through multivariate analyses. One hundred and thirty-two papers fulfilled these criteria and 159 516 patients were analyzed. Unfortunately, several methodological problems in the research to date prevent us from including any one of these proliferative markers among the standard prognostic and predictive factors. Early incorporation of translational research and new technologies with clinical trials are needed to prospectively validate biological markers and allow their use in clinical practice.

Molecular analysis of the p27/kip1 gene in breast cancer

BACKGROUND

Genetic polymorphisms and mutations of the genes involved in tumorigenesis may determine individual susceptibility for cancer. The p27/Kip1 protein belongs to the family of cyclin-dependent kinase-inhibitory proteins, which are negative regulators of cell-cycle progression. Reduced protein levels of p27/Kip1 have been reported in numerous human cancers including breast cancer.

METHODS AND RESULTS

p27 gene mutations and the codon 109 polymorphism were investigated in breast cancer patients by single strand conformation polymorphism analysis, PCR-restriction fragment length polymorphism analysis and DNA sequencing. Mutations were identified in 2 of 24 breast tumor samples. One G-->A transition resulting in a silent mutation and a single base deletion resulting in a nonsense mutation were detected in one patient. Another breast cancer sample harbored a T-->A transition at codon 159. An association between the codon 109 B allele and breast cancer was observed.

CONCLUSION

Our study indicates that mutational alterations in the p27 gene are rare in human breast cancer. The codon 109 B allele is associated with high-grade tumors.

High apoptotic index correlates to p21 and p27 expression indicating a favorable outcome of primary breast cancer patients, but lacking prognostic significance in multivariate analysis

This study was performed in order to investigate the role of the apoptotic index (AI) as a prediction parameter for the prognosis of patients with primary breast cancer. AI was determined by DNA fragmentation on 298 primary breast cancer samples and compared to clinically established breast cancer parameters. Additionally, we determined the expression of functional parameters including proliferating cell nuclear antigen, p21waf and p27kip by immunohistochemistry. The mean AI was found to be 11.9% (range, 0-90%). 189 tumors (63.4%) were negative for apoptosis, while 109 tissue samples (36.6%) were apoptotic with >5% positive cells. Using univariate analysis (chi2 test), the AI did not show any significant correlation to one of the established prognostic parameters of primary breast cancer (p > 0.05). In contrast, we found a significant positive correlation to the expression of the cell cycle inhibitors p21waf (p = 0.04) and p27kip (p = 0.024). During the clinical follow-up (median observation time for disease-free survival 87 months), several clinically established prognostic parameters including menopausal status, nodal status, tumor size, tumor grade, and hormone receptor expression could be confirmed and were analyzed with respect to the AI in the tumor. Furthermore, AI displayed a significant positive correlation to disease-free survival using Kaplan-Meier survival analysis (log-rank test, p = 0.04). However, AI lost its prognostic significance in multivariate analysis based on the Cox proportional hazard model (relative risk 0.8, confidence interval 0.52-1.33, p = 0.44). Our data indicate that high apoptotic rates in cancer tissues are indicative of a favorable patient outcome. However, the AI was not an independent factor. The study provides indirect evidence that this process may involve cell cycle inhibitors physiologically.

Prognostic molecular markers in early breast cancer

A multitude of molecules involved in breast cancer biology have been studied as potential prognostic markers. In the present review we discuss the role of established molecular markers, as well as potential applications of emerging new technologies. Those molecules used routinely to make treatment decisions in patients with early-stage breast cancer include markers of proliferation (e.g. Ki-67), hormone receptors, and the human epidermal growth factor receptor 2. Tumor markers shown to have prognostic value but not used routinely include cyclin D1 and cyclin E, urokinase-like plasminogen activator/plasminogen activator inhibitor, and cathepsin D. The level of evidence for other molecular markers is lower, in part because most studies were retrospective and not adequately powered, making their findings unsuitable for choosing treatments for individual patients. Gene microarrays have been successfully used to classify breast cancers into subtypes with specific gene expression profiles and to evaluate prognosis. RT-PCR has also been used to evaluate expression of multiple genes in archival tissue. Proteomics technologies are in development.

p27 deregulation in breast cancer: prognostic significance and implications for therapy

p27 is a key regulator of G1-to-S phase progression. It prevents premature activation of cyclin E-cdk2 in G1 and promotes the assembly and activation of D-type cyclin-cdks. While the p27 gene is rarely mutated in human cancers, the action of p27 is impaired in breast and other human cancers through accelerated p27 proteolysis, sequestration by cyclin D-cdks, and by p27 mislocalization in tumor cell cytoplasm. Reduced p27 protein is strongly associated with high histopathologic tumor grade, reflecting a lack of tumor differentiation. Loss of p27 is also an indicator of poor patient outcome in a majority of breast cancer studies, including node negative disease. The broad application of p27 in the clinical evaluation of breast cancer prognosis will require a consensus on methods of tumor fixation, staining, and scoring. This review will focus on mechanisms of p27 regulation in normal cells and how deregulation of p27 may arise in breast and other human cancers. The prognostic significance of p27 in human breast cancer and the possible therapeutic implications of these findings will also be reviewed.

High p27Kip1 expression predicts superior relapse-free and overall survival for premenopausal women with early-stage breast cancer receiving adjuvant treatment with tamoxifen plus goserelin

PURPOSE

To determine the predictive value of p27Kip1 in premenopausal women with early-stage hormone receptor-positive breast cancer.

PATIENTS AND METHODS

We retrospectively examined tumor specimens from 512 patients with breast cancer who were enrolled onto Austrian Breast and Colorectal Cancer Study Group (ABCSG) Trial 5. In this trial, premenopausal, hormone receptor-positive breast cancer patients with stage I and II disease were randomly assigned to receive either 5 years of tamoxifen plus 3 years of goserelin or six cycles of cyclophosphamide, methotrexate, and fluorouracil. p27Kip1 expression was assessed by immunohistochemistry, and its association with clinical outcome was determined. Statistical analyses were performed to test for interaction between p27Kip1 status and treatment.

RESULTS

High p27Kip1 expression (nuclear p27Kip1 staining in >/= 50% of tumor cells) independently predicted superior relapse-free survival (RFS) and overall survival (OS) in both the total study population (RFS: relative risk [RR], 0.53; 95% CI, 0.34 to 0.82; P =.004; OS: RR, 0.29; 95% CI, 0.15 to 0.58; P <.001) and patients treated with combination endocrine therapy (RFS: RR, 0.32; 95% CI, 0.16 to 0.63; P =.001; OS: RR, 0.16; 95% CI, 0.05 to 0.53; P =.003). The interaction between p27Kip1 expression and treatment was statistically significant for RFS (P =.04) but not for OS (P =.27).

CONCLUSION

High p27Kip1 expression was an independent predictor of responsiveness to hormonal therapy and thus may be useful for the selection of premenopausal women with early-stage hormone receptor-positive breast cancer for adjuvant combination endocrine therapy.

Deregulation of p27 by oncogenic signaling and its prognostic significance in breast cancer

p27 is a key regulator of progression from G1 to S phase. Although the gene encoding p27 is rarely mutated in human cancers, p27 is functionally inactivated in a majority of human cancers through accelerated p27 proteolysis, through sequestration by cyclin D-cyclin-dependent kinase complexes and by cytoplasmic mislocalization. Here we review mechanisms whereby oncogenic activation of receptor tyrosine kinase and Ras pathways lead to accelerated p27 proteolysis and p27 mislocalization in cancer cells. The prognostic significance of p27 in human breast cancer is also reviewed.

Decreased immunoreactivity for p27 protein in patients with early-stage breast carcinoma is correlated with HER-2/neu overexpression and with benefit from one course of perioperative chemotherapy in patients with negative lymph node status: results from International Breast Cancer Study Group Trial V

BACKGROUND

The objective of this study was to clarify the prognostic and predictive value of immunoreactivity for the cyclin-dependent kinase inhibitor p27(Kip1) in patients with early-stage breast carcinoma and to investigate its relation with clinicopathologic features and other markers.

METHODS

Immunoreactivity for p27 protein was analyzed on tumor slides from 461 patients who were enrolled in the International Breast Cancer Study Group (IBCSG) Trial V (median follow-up, 13 years), including 198 patients with lymph node negative disease and 263 patients with lymph node positive disease. Tumors with < 50% immunoreactive neoplastic cells were considered low expressors. Immunoreactivity for p27 was correlated with several clinicopathologic characteristics. Disease free survival (DFS) and overall survival were analyzed according to p27 immunoreactivity and treatment group.

RESULTS

In the lymph node negative population, decreased p27 immunoreactivity was associated with higher tumor grade (P = 0.001) and HER-2/neu overexpression (P = 0.04). In the lymph node positive population, low p27 expression was associated with higher tumor grade (P = 0.01), low expression of thymidylate synthase (P = 0.001), and higher Ki-67 expression (P = 0.007). DFS was not significantly different according to p27 status in either lymph node negative patients (10-year DFS: low p27 expression, 53% +/- 5%; high p27 expression, 55% +/- 5%) or in lymph node positive patients (10 year DFS: low p27 expression, 33% +/- 4%; high p27 expression, 32% +/- 4%). However, in the lymph node negative population, the benefit of one course of perioperative chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil was confined exclusively to patients with tumors that showed reduced p27 immunoreactivity (P = 0.03; test for interaction).

CONCLUSIONS

This analysis indicates that p27 immunoreactivity has little if any prognostic value in patients with early-stage breast carcinoma. However, these findings suggest that, in patients with breast carcinoma who have negative lymph node status, reduced p27 immunoreactivity is associated with HER-2/neu overexpression and may be predictive of a benefit from the early administration of adjuvant chemotherapy.

Molecular alterations in sporadic breast cancer

Breast cancer is a genetic disease. Like other human cancers, it is thought to occur as the result of progressive accumulation of genetic aberrations. These aberrations result in a deviation of the gene expression profiles from that of the normal progenitor cell. In up to 99% of cases, breast cancer is due to solely somatic genetic aberrations without germ-line ones. Considerable progress have already been made in understanding the genetic mechanisms underlying the development and progression of breast cancer. Several extensively studied genes are now well known to be involved. Unfortunately, our ability to make clinically useful interventions on the basis of these data is limited. Because of the involvement of multiple genes and complex pathways in a single cancer cell, the molecular dysfunctioning underlying breast cancer remains to be completely clarified. In a next future, studying the global gene expression of different types of tumors will allow the development of expression profiles unique for a breast cancer, its stage and prognostic category, leading to diagnostic assays and the identification of new therapeutic targets.

Molecular prognostic factors for breast cancer metastasis and survival

The biological characteristics of the tumor are used to estimate prognosis and select appropriate systemic therapy for patients with early-stage breast cancer. Well-established molecular prognostic factors include the estrogen and progesterone receptors, proliferation markers, and the HER2 gene. Novel tumor markers with potential clinical utility include molecules involved in cell transformation, invasion, and metastases. We review the available data supporting the utility of established prognostic and predictive molecular factors, and discuss challenges for integrating novel molecular markers into clinical practice.

High expression levels of p27 correlate with lymph node status in a subset of advanced invasive breast carcinomas: relation to E-cadherin alterations, proliferative activity, and ploidy of the tumors

BACKGROUND

The cyclin-dependent kinase inhibitor p27 plays a central role in cell cycle progression and is deregulated in breast carcinomas. Although its levels are inversely associated with tumor proliferation, overexpression of p27 has been reported in a subset of rapidly proliferating breast carcinoma cell lines.

METHODS

p27 levels were determined by immunohistochemistry in a series of 52 sporadic invasive breast carcinomas consisting of 47 ductal, 2 lobular, and 3 mixed; most tumors were Grade 2 or 3 (46 of 52) and Tumor Node Metastasis (TNM) Stage II-IV (46 of 52). E-cadherin expression and its gene alterations at 16q22.1 were also studied, because in vitro evidence suggests a biologic association between p27 and E-cadherin-mediated growth suppression.

RESULTS

The mean p27 labeling index (LI; percentage of p27 positive tumor cells) was 33.3% +/- 25.3% (range, 0.1-85%). High p27 levels (p27 LI, > 50%) were observed in 14 (26.9%) of 52 carcinomas and were significantly associated with metastatic disease in axillary lymph nodes (14 of 33 vs. 0 of 19; P = 0.0007 by Fisher exact test). In addition, p27 LI was higher in the group of lymph node positive vs. lymph node negative tumors (mean p27 LI, 40.9% vs. 20.1%; P = 0.008 by Mann-Whitney test). Reduced or absent E-cadherin expression was found in 27 of 45 (60%) informative cases. Allelic imbalance of the 16q22.1 locus was found in 14 (27.5%) of 51 cases by using the microsatellite markers D16S503, D16S752, and D16S512. p27 LI and E-cadherin alterations were not statistically related.

CONCLUSIONS

In summary, high p27 levels detected in a subset of advanced breast carcinomas correlate with lymph node metastasis, suggesting that other mechanisms may bypass the cell cycle inhibitory role of p27 and provide growth advantage in these tumors.

Overexpression of cyclin D1 and underexpression of p27 predict lymph node metastases in papillary thyroid carcinoma

Lymph node metastasis in papillary thyroid carcinoma increases the morbidity of treatment and the risk of local regional relapse and may also affect cure rates and survival. Factors that predict lymph node metastasis are, however, unclear. We analyzed 125 patients with papillary thyroid carcinoma for factors that predict lymph node metastasis. On univariate analysis, age, extrathyroidal extension, tumor focality, overexpression of cyclin D1, and underexpression of p27 predicted lymph node metastasis, whereas patient gender and tumor size did not. On multivariate analysis, extrathyroidal extension, overexpression of cyclin D1, and underexpression of p27 proved to be strong independent predictors of lymph node metastasis. We suggest that immunohistochemistry for cyclin D1 and p27 will prove valuable in identifying papillary thyroid carcinomas with metastatic potential.

Role of expression of cell cycle inhibitor p27 and MIB-1 in predicting lymph node metastasis in male breast carcinoma

Tumor expression of the proliferation marker (MIB-1) and the cell cycle-related protein (p27) may predict the biologic behavior of various human tumors. The purpose of this study was to evaluate the role of p27 and MIB-1 expression in predicting lymph node metastasis in male breast carcinomas (MBCs). We studied 67 patients with invasive MBC who had undergone modified radical mastectomy. Pathologic lymph node status was correlated with the p27 protein and the MIB-1 proliferation index. These factors were studied immunohistologically by standard methods. Men in this study ranged from 36 to 92 years of age (mean, 63 years); 43 (64%) were T1 lesions, and 24 (36%) were T2 lesions. Twenty-nine patients (43%) had positive nodes. p27 was expressed in 43 tumors (64%) and MIB-1 in 13 tumors (19.4%). Tumors with positive p27 showed positive lymph nodes in 10 cases (23%). In contrast, p27-negative tumors had positive lymph nodes in 18 cases (75%). Tumors positive for MIB-1 show positive lymph nodes in 11 cases (85%). However, when MIB-1 was negative, only 16 patients (30%) had positive lymph nodes. Multivariate logistic regression analysis confirmed the utility of MIB-1 overexpression in predicting lymph node metastasis ( p < 0.0006). Also, decreased p27 protein expression strongly correlates with lymph node metastasis ( p < or = 0.0001). Furthermore, when p27 was negative and MIB-1 was positive, 100% of the patients had positive lymph nodes. In contrast, when p27 was positive and MIB-1 was negative, only 12% of patients had positive lymph nodes. The reduced expression of the p27 protein and the overexpression of the MIB-1 proliferation index in this study show a significant correlation in predicting lymph nodes metastasis in MBCs.

Hormone receptors and proliferation in breast carcinomas of equivalent histologic grades in pre- and postmenopausal women

Breast cancers in younger, premenopausal women are more likely to exhibit an adverse prognostic profile (including negative steroid hormone receptors and a high rate of cellular proliferation) and poor outcome than breast cancers in postmenopausal women. It has been hypothesized that this adverse prognostic profile is a result of the higher histologic grade of breast cancers in pre- compared with post-menopausal women. To assess the association of expression of steroid hormone receptors and indicators of proliferation while controlling for histologic grade, we identified 100 infiltrating ductal carcinomas from premenopausal women 45 years of age or younger and 100 from postmenopausal women 65 years of age or older. The carcinomas were selected so that the histologic grades (low versus high) were distributed equally between the 2 groups. Estrogen receptors (ER), progesterone receptors (PR), p27(Kip1) and Ki-67 (to measure rate of proliferation) were assessed by immunohistochemistry and compared between groups. Clinical information and survival data were also analyzed. ER content was lower and proliferation was higher in carcinomas in premenopausal women (p = 0.048 and p = 0.005, respectively). By univariate analysis, p27(Kip1) and PR were not different between the groups; however, in multivariate analysis, p27(Kip1) was higher in postmenopausal women, but only in a subgroup with highly proliferative carcinomas. Overall survival was similar in the pre- and postmenopausal women. Furthermore, low p27(Kip1) and African-American ethnicity predicted a poorer overall survival in the premenopausal, but not in the postmenopausal, women in our study. After controlling for histologic grade, a lower expression of ER and a higher proliferative index were detected in breast carcinomas in premenopausal women. Therefore, some prognostic indicators, such as ER and proliferative rate, may be more closely associated with menopausal status than histologic grade. Our data also suggest that some prognostic factors are not equally effective as predictors of survival in pre- and postmenopausal women.

Distinct patterns of p27/KIP 1 gene expression in hepatoblastoma and prognostic implications with correlation before and after chemotherapy

Over the past 3 years, numerous studies have examined the diagnostic and prognostic significance of p27/Kip1 expression in various tumors. Almost all studies report decreased p27 expression in more aggressive tumors. Information about morphologic changes due to chemotherapy in hepatoblastoma (Hbs) is limited, and so is information about distinct patterns of p27 gene expression. Twenty-nine hepatoblastomas were evaluated for possible prognostic correlation between p27 expression in different histotypes of hepatoblastoma, changes during chemotherapy, and outcome. These observations should prompt prospective randomized studies designed to investigate the predictive role of p27 expression in different Hbs histotypes. Patients were treated according to the Children's Cancer Group and Pediatric Oncology Group protocols, which included initial surgery before chemotherapy wherever possible. Follow-up ranged from 1 to 133 months. The results show that primary well-differentiated fetal tumors without mitotic activity are strongly p27 positive. The embryonal pattern displays a variable p27 protein expression pattern, with focal positivity between completely negative zones; p27 is positive where the mitotic activity is low or absent and negative where the mitogenic activity is high. The vast majority of small undifferentiated cell components are p27 negative. p27 protein expression is downregulated after chemotherapy in the remaining fetal well-differentiated component of Hbs. Although this may imply selection of a more aggressive clone, all patients with this histology were cured in this series. Aggressiveness and ultimate prognosis for incompletely resected tumors after chemotherapy remain indeterminate.

p27/kip1 expression in normal epithelium, benign and neoplastic breast lesions

The development of cancer in the breast and in other sites is a complex process requiring a number of different genetic and epigenetic alterations. The accumulation of the genetic changes is thought to underlie the progression from precancerous lesions to carcinomas. The expression of p27/kip1 protein, a cyclin-dependent kinase inhibitor, was investigated by immunohistochemistry in normal epithelial specimens, benign alterations, and malignant lesions of the breast. The number of p27/kip1-positive cells ranged from none to more than 98% in the overall series. Wide ranges of p27/kip1-positive cells were consistently observed within each histological category, but the median value progressively decreased in typical hyperplasia and fibroadenoma, with an even more marked reduction in malignant lesions, compared with normal epithelium. Moreover, the percentage of cells expressing p27/kip1 in tumours was about three times lower in invasive than in in situ lesions and was inversely related to tumour size, but not to lymph node involvement. In conclusion, the degree to which p27 expression is altered in typical hyperplastic lesions and fibroadenomas indicates that the deregulation of p27 may occur very early on during breast cell transformation, but the usefulness of its determination to categorize subgroups of lesions at different risk of evolution remains somewhat doubtful.

Early de novo gene expression is required for 15-deoxy-Delta 12,14-prostaglandin J2-induced apoptosis in breast cancer cells

Cyclopentenone prostaglandin derivatives of arachidonic acid are potent inducers of apoptosis in a variety of cancer cell types. Several investigators have shown that the terminal derivative of prostaglandin J(2) (PGJ(2)) metabolism, 15-deoxy-Delta(12,14)-PGJ(2) (15dPGJ(2)), induces apoptosis in breast cancer cells and is a potent activator of the nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARgamma), but 15dPGJ(2) effects can be mediated by PPARgamma-dependent and PPARgamma-independent mechanisms. Here we report that 15dPGJ(2) regulates early gene expression critical to apoptosis. Specifically, 15dPGJ(2) induces potent and irreversible S phase arrest that is correlated with expression of genes critical to cell cycle arrest and apoptosis, including the cyclin-dependent kinase inhibitor p21(Waf1/Cip1) (p21). Inhibition of RNA or protein synthesis abrogates apoptosis induced by 15dPGJ(2) in breast cancer cells but potentiates apoptosis induced by tumor necrosis factor-alpha or CD95/Fas ligand. Additionally, 15dPGJ(2) induces caspase activation that is blocked by peptide caspase inhibitors. These data show that de novo gene transcription is necessary for 15dPGJ(2)-induced apoptosis in breast cancer cells. Critical candidate genes are likely to be revealed through analysis of differential cDNA array expression.

P27kip1 expression is associated with tumor response to preoperative chemoradiotherapy in rectal cancer

BACKGROUND

Our aim was to ascertain whether or not the response to preoperative chemoradiotherapy for rectal cancer is associated with p27kip1 and p53 protein expression.

METHODS

Thirty-eight patients (27 male, 11 female) with a mean age of 59 years (age range 33-87) and stage II-III rectal cancer received preoperative chemoradiotherapy (45-50.4 Gy; 5-FU 350 mg/m2/day and leucovorin 10 mg/m2/day). Thirty-one underwent low anterior resection; seven underwent abdominoperineal excision. Endoscopic tumor biopsies, performed before adjuvant therapy, were evaluated for: histologic type, tumor differentiation, mitotic index, and p27kip1 and p53 protein expression which were immunohistochemically determined. p53 expression was graded as: a) absent or present in < or =10% of tumor cells; b) present in 11-25%; c) present in 26-75%; and d) present in >75% of tumor cells. p27kip1 expression was assessed using both light microscopy (percent of stained cells x10 HPF) and cytometry with an image analysis workstation. Tumor response, ascertained with histology, was classified using a scale from 0 (no response) to 6 (complete pathologic response).

RESULTS

The mitotic index for the endoscopic biopsies was low in 14 cases, moderate in 17 cases, and high in 7 cases. p53 protein expression was found in 21 (a), 3 (b), 3 (c), and 11 (d) cases. The mean percentage of cells expressing the p27kip1 protein was 34 (range 0-77.14%). A close correlation was found between cytometric and light microscopy findings for p27kip1 (r2 = 0.92, P = .0001). Tumor differentiation was good in 5 cases, poor in 2 cases, and moderate in the remaining 31 cases. While the response to adjuvant therapy was good/complete in 25 (65.78%) cases, it was absent/poor in 13 (34.21%) cases. Univariate analysis associated type of adjuvant therapy (chemoradiotherapy, P = .0428) and p27kip1 protein lower expression (P = .0148) with a poor response to adjuvant treatment. Stepwise linear regression found overexpression of p53 and p27kip1 and young age to be independent variables that were linked to a good response to adjuvant therapy.

CONCLUSIONS

Lack of p27kip1 and p53 protein expression in rectal cancer is associated with a poor response to preoperative adjuvant therapy.

Quercetin inhibits the invasion and mobility of murine melanoma B16-BL6 cells through inducing apoptosis via decreasing Bcl-2 expression

Quercetin has been known to have anti-tumor and anti-oxidation activities. In the present study, we have investigated its in vitro anti-metastatic activity. Quercetin inhibited the invasion and mobility of murine melanoma B16-BL6 cells in a dose-dependent manner but did not affect their adhesion to either laminin, fibronectin, or type VI collagen. Moreover, quercetin significantly inhibited the proliferation of B16-BL6 cells only in the case of time incubation longer than 48 h. Quercetin dose-dependently decreased the cell rates in S and G2-M phases of cell cycle. The effect of quercetin to cause a remarkable apoptosis of B16-BL6 cells was also demonstrated by flow cytometric assay as well as DNA fragmentation with a typical 180-bp ladder band in agarose electrophoresis and a quantitative analysis. Furthermore, quercetin markedly inhibited the expression of anti-apoptotic protein Bcl-2 but hardly influenced Bcl-XL. These results suggest that the inhibition of quercetin on invasiveness and migration of B16-BL6 cells are closely associated with the arrest of cell cycle as well as the induction of apoptosis by decreasing the Bcl-2 expression.

Biomarker prediction of clinical outcome in operable breast cancer patients treated with tamoxifen

The predictivity of tumour size, oestrogen (ER) and progesterone (PgR) receptors, 3H-thymidine labelling index (TLI), c-erbB-2 and p27kip1 expression on clinical outcome was analysed on a consecutive series of 118 postmenopausal patients with ER-positive, node-positive tumours. All patients were treated with surgery +/- radiotherapy and adjuvant tamoxifen (30 mg/day) for at least 2 years. TLI, ER, c-erbB-2 and p27kip1 were generally unrelated to each other. PgR was directly related to ER and inversely to c-erbB-2. Tumour size was inversely related to both c-erbB-2 and p27kip1 expression. At a median follow-up of 75 months, 5-year relapse-free survival was significantly lower for patients with very rapidly proliferating (HR = 2.61, 95% CI = 1.34-5.08), PgR negative (HR = 2.76, 95% CI = 1.43-5.33) or relatively low ER content (HR = 2.20, 95% CI = 1.14-4.25) tumours than for patients with tumours expressing the opposite biological profiles. Overall survival was also significantly different as a function of TLI (HR = 3.47, 95% CI = 1.52-7.93) and PgR (HR = 2.27, 95% CI = 1.00-5.15). TLI and PgR maintained an independent relevance in multivariate analysis and together were capable of identifying subgroups of patients at significantly different risk of relapse and death.

Expression of p27Kip1 Protein in Transitional Cell Carcinoma of the Upper Urinary Tract

The expression of p27(Kip1), a negative regulator of the cell cycle, has been reported to correlate with the biological behavior and prognosis of several tumors. However, its prognostic importance in transitional cell carcinoma of the upper urinary tract (TCC-UUT) has not previously been investigated. We investigated p27(Kip1) protein expression using immunohistochemistry in 132 cases of TCC-UUT and also its relation to proliferating cell nuclear antigen (PCNA) immunoreactivity, p53 oncoprotein immunoreactivity, clinicopathologic parameters, and clinical outcome. A positive expression of p27(Kip1) protein was recognized in 94.7% of the samples and was apparent within tumor nuclei. In the normal urothelium, its expression was identified in all cell layers. A positive expression of p53 oncoprotein was recognized in 27.2% of the patients. The PCNA index was 7.4 to 93.1% (mean, 66.4%). Examination of the relationships between the expression of p27(Kip1) protein and clinicopathologic findings, PCNA index, and the expression of p53 oncoprotein revealed that the expression of p27(Kip1) protein decreased significantly with stage and grade. In a univariate analysis of disease-free and overall survival rates, no correlation was found between the expression of p27(Kip1) protein and prognosis. The expression of p27(Kip1) protein appears to be of little or no value in informing the prognosis in TCC-UUT.

Expression of p21Waf1, p27Kip1 and cyclin D1 proteins in breast ductal carcinoma in situ: Relation with clinicopathologic characteristics and with p53 expression and estrogen receptor status

p21Waf1 (p21), p27Kip1 (p27) and cyclin D1 have recently been reported as useful prognostic markers for patients with breast carcinoma. However, studies on these cell cycle regulators in ductal carcinoma in situ (DCIS) have been extremely limited. Therefore, we studied the immunohistochemical expression of p21, p27 and cyclin D1 proteins in 49 DCIS cases and compared the findings with the clinicopathologic parameters (age, tumor size, gross type, histologic type, histologic grade, necrosis and mitotic index), p53 and estrogen receptor (ER) status. A significant correlation was found between positive p21 immunoreactivity (67.3% of the cases) and well-differentiated histologic grade, non-comedo type, ER-positive and p53-negative (p53-) status. DCIS with p21+/p53- is likely to be the non-comedo type. The overexpression of cyclin D1 (59.2% of the cases) correlated positively with the ER expression (P = 0.001). The p27 protein expression (46.9% of the cases) correlated with the cyclin D1 immunopositivity (P = 0.0003) and ER expression (P = 0.005). No significant associations were seen in the p27 or cyclin D1 expression and other clinicopathologic parameters. Our results suggest that p21 might be more related to the useful biologic markers in DCIS than p27 or cyclin D1. The significant positive association between p21, p27 or cyclin D1 and ER status, and close association of p27 and cyclin D1 expression might be implicated in the tumor biology of DCIS.

Abundance of apoptotic neoplastic cells in diagnostic biopsy samples is not a prognostic factor in childhood primitive neuroectodermal tumors of the central nervous system

PURPOSE

To assess if the abundance of apoptotic tumor cells is an independent prognostic factor in primitive neuroectodermal tumors (PNET) of the central nervous system.

PATIENTS AND METHODS

Formalin-fixed paraffin-embedded tumor tissue sections from 78 clinically well-characterized children with PNET were evaluated by terminal deoxytransferase-mediated deoxyuridinie-5'-triphosphate (dUTP) nick-end labeling (TUNEL). Apoptotic indices (AI) were determined by counting TUNEL-positive tumor cells either in the highest staining region (AI hot spot) or in at least 15 randomly chosen fields (AI random). The AI hot spot and AI random were then correlated with clinical variables and survival outcome.

RESULTS

AI hot spot (median 0.56%; range 0%-6.54%) and AI random (median 0.30%; range 0%-3.21%) showed considerable intertumor variability. Moreover, 53% of the evaluated PNET showed a more than two-fold difference between AI hot spot and AI random, showing important intratumoral variability of the abundance of apoptotic cells in a subset of the evaluated PNET. No significant associations were found between AI hot spot and AI random with clinical variables or survival outcome.

CONCLUSION

The apoptotic index does not predict survival outcome and is not specifically associated with clinical variables of prognostic significance in childhood PNET.

The cyclin dependent kinase inhibitor p27 and its prognostic role in breast cancer

p27 is an inhibitor of cyclin dependent kinase involved in the regulation of the cell cycle. In this commentary we discuss the current knowledge on p27 in breast cancer and its significance in predicting the outcome. p27 protein levels are high in most cases of breast carcinomas, are correlated with the levels of cyclin D1 and estrogen receptor, and could be a useful predictor of survival, because they are low in aggressive carcinomas. Immunodetection of p27 in breast tumors could be useful in the assessment of prognosis, especially in those cases in which the commonly used parameters are insufficient, and might ultimately influence the therapy of this disease.

Germline BRCA1/2 mutations and p27(Kip1) protein levels independently predict outcome after breast cancer

PURPOSE

Decreased levels of the cyclin-dependent kinase inhibitor p27(Kip1) in breast cancer are associated with a poor outcome. The prognostic significance of BRCA1/2 mutations is less clear, and the relationship between BRCA1/2 mutation status, p27(Kip1) protein levels, and outcome has not been studied.

PATIENTS AND METHODS

Pathology blocks from 202 consecutive Ashkenazi Jewish women with primary invasive breast cancer were studied. Tumor DNA was tested for the three common BRCA1/2 founder mutations present in Ashkenazi Jews, and p27(Kip1) expression was evaluated by immunohistochemistry. The median follow-up was 6.4 years.

RESULTS

Thirty-two tumors (16%) were positive for a BRCA1/2 mutation. Low p27(Kip1) expression was seen in 110 tumors (63%) and was significantly associated with BRCA1/2 mutations (odds ratio, 4.0; 95% confidence interval [CI], 1.4 to 11.1; P =.009). BRCA1/2 mutation carriers had a significantly worse 5-year distant disease-free survival (DDFS) compared with women without BRCA1/2 mutations (58% v 82%; P =.003). Similar results were seen for women whose tumors expressed low levels of p27(Kip1), compared with those with high levels (5-year DDFS, 68% v 93%; P<.0001). In a multivariate analysis, both BRCA1/2 mutation and low p27(Kip1) expression were associated with a shorter DDFS (relative risk [RR], 2.1; 95% CI, 1.0 to 4.3; P =.05; and RR, 3.9; 95% CI, 1.4 to 11.1; P =.01, respectively).

CONCLUSION

In this study, we showed that BRCA1/2 mutations were associated with low levels of p27(Kip1) in breast cancer. Both BRCA1/2 and p27(Kip1) status were identified as independent prognostic factors.

Prognostic significance of biologic markers in node-negative breast cancer patients: a prospective study

It is generally thought that future advances in the treatment and cure of breast cancer patients will be made possible through a deeper understanding of tumor biology and an improved capability to define the prognosis of each single patient. This will lead to the formulation of new, more selective, and patient-tailored therapies. It is therefore important, when studying potential prognostic factors, to follow methodologic requirements and guidelines which involve the carrying out of prospective studies as confirmatory steps. Repeatedly or recently investigated prognostic markers (tumor size, menopausal status, ER, PgR, 3H thymidine labeling index, c-erbB-2 and p27 expression) were evaluated on a series of 286 prospectively recruited node negative breast cancer patients who underwent loco-regional treatment alone and were closely followed. The individual and relative prognostic contribution of each variable with respect to other factors, as well as their ability to identify node negative patients at risk, were assessed by univariate and multivariate analysis. At a five-year follow-up, only tumor size (p = 0.021) and TLI (p = 0.016) individually proved to be significant prognostic indicators of relapse-free survival. Conversely, p27 expression was not related to RFS and c-erbB-2 expression appeared to have only a short-term effect on patient prognosis. TLI and tumor size, tested in multivariate analysis along with ER and menopausal status, maintained their independent prognostic relevance. The study, performed on a large series of node-negative patients given loco-regional treatment alone, for the first time prospectively recruited, showed the prognostic relevance of TLI and its independence from other clinico-pathologic and biologic factors over a five-year period.

P27 in cell cycle control and cancer

In order to survive, cells need tight control of cell cycle progression. The control mechanisms are often lost in human cancer cells. The cell cycle is driven forward by cyclin-dependent kinases (CDKs). The CDK inhibitors (CKIs) are important regulators of the CDKs. As the name implies, CKIs were initially shown to negatively regulate CDK activity. However, recent data indicates that the members of the Kip/Cip family of CKIs, including p27, exert both positive and negative regulation of CDK activity at the G1/S phase transition. Mutations of Kip/Cip genes are rare, but p27 knockout mice are tumor prone when challenged with carcinogenic stimuli. Numerous studies of various human non-hematological tumors have identified low expression of p27 as a predictor of poor prognosis. In non-Hodgkin's lymphoma (NHL), we and others have also shown the independent prognostic value of p27 expression. In distinct NHL entities however, shortened survival seems to correlate with high expression of p27. For definitive assessment of the role played by p27 in lymphomagenesis, and the prognostic value of p27 in these tumors, further studies of distinct NHL entities are needed. This review addresses the function of p27 and the other Kip/Cip proteins in G1/S phase transition and their possible role in tumorigenesis with emphasis on p27 and NHL.

p27(kip1) protein expression correlates with survival in myxoid and round-cell liposarcoma

PURPOSE

The p27(kip1) protein (p27) is a cyclin-dependent kinase inhibitor that has been shown to be an independent prognostic factor in a variety of human neoplasms. Low expression of p27 tends to occur in more aggressive neoplasms. The role of p27 as an independent prognostic factor in the spectrum of myxoid and round-cell liposarcomas has not been examined.

MATERIALS AND METHODS

Forty-seven cases of myxoid and round-cell liposarcomas were examined. Clinicopathologic features and immunohistochemical expression of p27 and Ki-67 antigen were studied in all cases. Survival analysis was performed using the log-rank test and the Cox multivariate regression model.

RESULTS

The male:female ratio was 1. 4:1, and the mean age at diagnosis was 45 years. The tumors were located in the lower extremities (94%) and retroperitoneum (6%). The median tumor size was 13.5 cm. The median follow-up was 6.3 years, and the overall 5- and 10-year survival rates were 76% and 67%, respectively. Low expression of p27 was identified in 34 cases (72%) and correlated with decreased metastasis-free (P =.026) and overall survival (P =.008). In a multivariate analysis, only round-cell differentiation and low expression of p27 independently predicted decreased metastasis-free and overall survival.

CONCLUSION

p27 expression predicts the clinical behavior of myxoid and round-cell liposarcomas, even in neoplasms with few or no round-cell differentiation.

A comparison of cell cycle markers in well-differentiated lobular and ductal carcinomas

Infiltrating lobular carcinoma (ILC) and infiltrating ductal carcinoma (IDC) are similar in many respects and their histologic features occasionally overlap. Despite the many similarities, some clinical follow-up data and the patterns of metastasis suggest that ILC and IDC are biologically distinct. Unfortunately, most breast cancer research has focused almost exclusively on the ductal subtype or has not stressed the biologic or molecular genetic distinctions between breast carcinoma subtypes. Several reports have suggested the possibility that ILCs and IDCs differ with respect to expression of antigens involved in proliferation and cell cycle regulation. Therefore, we undertook an immunohistochemical evaluation of cell cycle related antigens in ILCs, including histologic variants thought to represent aggressive neoplasms, and IDCs matched for histologic grade (Modified Bloom-Richardson Grade I). We believe that different antigen expression profiles could elucidate the biological distinctiveness of breast carcinoma subtypes and possibly provide diagnostically relevant information. We studied the expression of the following antigens in 28 archived, formalin-fixed ILCs and 34 well-differentiated IDCs: estrogen receptor (ER), progesterone receptor (PR), Her 2-neu, mib-1, cyclin D1, p27, p53, mdm-2 and bcl-2. 94% of ILCs and 100% of IDCs expressed ER; 75% of ILCs and 76% of IDCs expressed PR; 4% of ILCs and 13% of IDCs expressed c cerb B-2; ILCs and IDCs both expressed mib-1 in approximately 10% of lesional cells; 82% of ILCs and 54% of IDCs expressed cyclin D1; 90% of ILCs and 83% IDCs expressed p27 strongly; 4% of ILCs and 4% of IDCs expressed p53, 25% of ILCs and 33% of IDCs expressed mdm-2; 96% of ILCs and 100% of IDCs expressed bcl-2. None of the apparent differences were statistically significant. The ILC variants demonstrated immunophenotypes that were essentially similar to ILCs of the usual type. We conclude that ILCs and well-differentiated IDCs show similar proliferation and cell cycle control antigen profiles. Despite their unusual histologic features, most ILC variants appear to maintain a characteristic ILC immunophenotype.