p21 and p53 Immunostaining and survival following systemic chemotherapy for urothelial cancer

Clinicopathological significance and prognostic analysis of p21 and EGFR in colorectal cancer: a retrospective analysis on 12 319 cases in China

AIMS

Colorectal cancer (CRC) is the third most common malignancy worldwide. Accurate pathological diagnosis and predictive abilities for treatment response and prognosis are crucial for patients with CRC. This study aims to analyse the expressions of p21 and EGFR in CRC and their relationships with clinicopathological characteristics and prognosis to enhance diagnostic and prognostic evaluations.

METHODS

This study conducted a retrospective analysis of p21 and EGFR expressions in 12 319 Chinese patients with CRC using immunohistochemistry. The relationships between these expressions and clinicopathological characteristics and survival outcomes were explored through statistical and survival analyses.

RESULTS

Differential expressions of p21 and EGFR in CRC were closely related to clinicopathological characteristics and significantly impacted overall survival (OS). p21 expression was associated with the primary tumour site, mucinous subtype, lymphovascular invasion, perineural invasion, circumferential resection margin, T stage, N stage, tumour, node, metastases (TNM) stage, and mismatch repair status. EGFR expression was related to mucinous subtype, tumour differentiation, lymphovascular invasion, perineural invasion, tumour size, T stage, N stage, TNM stage and BRAF gene mutation. p21 and EGFR expressions were positively correlated (r=0.11). High p21 expression correlated with favourable OS, whereas high EGFR expression predicted poorer OS. A prognostic nomogram incorporating these biomarkers and clinical variables demonstrated robust predictive power for patient survival rates.

CONCLUSION

p21 and EGFR serve as potential indicators for pathological diagnosis, risk stratification, and predicting treatment efficacy and prognosis in patients with CRC. The study's findings provide valuable references for personalised treatment and prognosis evaluation in clinical practice.

ESR1 fusions and therapeutic resistance in metastatic breast cancer

Breast cancer is the most frequent female malignant tumor, and the leading cause of cancer death in women worldwide. The most common subtype of breast cancer is hormone receptor positive that expresses the estrogen receptor (ER). Targeting ER with endocrine therapy (ET) is the current standard of care for ER positive (ER+) breast cancer, reducing mortality by up to 40% in early- stage disease. However, resistance to ET represents a major clinical challenge for ER+ breast cancer patients leading to disease recurrence or progression of metastatic disease. Salient drivers of ET resistance are missense mutations in the ER gene (ESR1) leading to constitutive transcriptional activity and reduced ET sensitivity. These mutations are particularly prominent and deleterious in metastatic breast cancer (MBC). In addition to activating ESR1 point mutations, emerging evidence imposes that chromosomal translocation involving the ESR1 gene can also drive ET resistance through the formation of chimeric transcription factors with constitutive transcriptional activity. Although these ESR1 gene fusions are relatively rare, they are enriched in ET resistant metastatic disease. This review discusses the characteristics of ER fusion proteins and their association with clinical outcomes in more aggressive and metastatic breast cancer. The structure and classification of ER fusion proteins based on function and clinical significance are also addressed. Finally, this review summarizes the metastatic phenotypes exhibited by the ER fusion proteins and their role in intrinsic ET resistance.

Molecular Mechanisms of Endocrine Resistance in Estrogen-Positive Breast Cancer

The estrogen receptor is a vital receptor for therapeutic targets in estrogen receptor-positive breast cancer. The main strategy for the treatment of estrogen receptor-positive breast cancers is blocking the estrogen action on estrogen receptors by endocrine therapy but this can be restricted via endocrine resistance. Endocrine resistance occurs due to both de novo and acquired resistance. This review focuses on the mechanisms of the ligand-dependent and ligand-independent pathways and other coregulators, which are responsible for endocrine resistance. It concludes that combinatorial drugs that target different signaling pathways and coregulatory proteins together with endocrine therapy could be a novel therapeutic modality to stop endocrine resistance.

Assessment of the extent of unpublished studies in prognostic factor research: a systematic review of p53 immunohistochemistry in bladder cancer as an example

OBJECTIVES

When study groups fail to publish their results, a subsequent systematic review may come to incorrect conclusions when combining information only from published studies. p53 expression measured by immunohistochemistry is a potential prognostic factor in bladder cancer. Although numerous studies have been conducted, its role is still under debate. The assumption that unpublished studies too harbour evidence on this research topic leads to the question about the attributable effect when adding this information and comparing it with published data. Thus, the aim was to identify published and unpublished studies and to explore their differences potentially affecting the conclusion on its function as a prognostic biomarker.

DESIGN

Systematic review of published and unpublished studies assessing p53 in bladder cancer in Germany between 1993 and 2007.

RESULTS

The systematic search revealed 16 studies of which 11 (69%) have been published and 5 (31%) have not. Key reason for not publishing the results was a loss of interest of the investigators. There were no obviously larger differences between published and unpublished studies. However, a meaningful meta-analysis was not possible mainly due to the poor (ie, incomplete) reporting of study results.

CONCLUSIONS

Within this well-defined population of studies, we could provide empirical evidence for the failure of study groups to publish their results that was mainly caused by loss of interest. This fact may be coresponsible for the role of p53 as a prognostic factor still being unclear. We consider p53 and the restriction to studies in Germany as a specific example, but the critical issues are probably similar for other prognostic factors and other countries.

Biomarkers in bladder cancer: translational and clinical implications

Bladder cancer is associated with high recurrence and mortality rates. These tumors show vast heterogeneity reflected by diverse morphologic manifestations and various molecular alterations associated with these disease phenotypes. Biomarkers that prospectively evaluate disease aggressiveness, progression risk, probability of recurrence and overall prognosis would improve patient care. Integration of molecular markers with conventional pathologic staging of bladder cancers may refine clinical decision making for the selection of adjuvant and salvage therapy. In the past decade, numerous bladder cancer biomarkers have been identified, including various tumor suppressor genes, oncogenes, growth factors, growth factor receptors, hormone receptors, proliferation and apoptosis markers, cell adhesion molecules, stromal factors, and oncoproteins. Recognition of two distinct pathways for urothelial carcinogenesis represents a major advance in the understanding and management of this disease. Nomograms for combining results from multiple biomarkers have been proposed to increase the accuracy of clinical predictions. The scope of this review is to summarize the major biomarker findings that may have translational and clinical implications.

Promoter hypermethylation in tumour suppressor genes and response to interleukin-2 treatment in bladder cancer: a pilot study

PURPOSE

Non-muscle invasive bladder cancer (BC) is a highly recurrent disease, with the first recurrences arising shortly after transurethral resection of the bladder (TURB). Topical administration of interleukin-2 (IL-2) has been shown as an effective adjuvant therapy for BC; however, predictive biomarkers that may identify suitable subgroups of patients are lacking. In this pilot study we sought to determine the prognostic value of epigenetic and genetic inactivation of tumour suppressor genes (TSGs) among BC patients treated with IL-2.

METHODS

After complete TURB, patients with multifocal superficial BC were treated with five daily intravesical instillations of IL-2. Promoter hypermethylation in six TSGs and the TP53 gene mutations were prospectively assessed by methylation-specific PCR and automated capillary single-strand conformation polymorphism in 21 primary bladder cancer specimens and ten bladder wall biopsies collected during follow-up.

RESULTS

After IL-2 treatment, 9 out of 21 (43%) patients did not develop recurrent tumour within the 1 year of follow-up period. The mean duration of recurrence-free survival in the rest of the study group was 112 days. In the current pilot study, BC with p16 gene hypermethylation had a lower risk of recurrence after treatment with IL-2, as compared to IL-2 treated BC without p16 hypermethylation (p = 0.02). Significant associations were observed between tumour grade and the mean methylation index (p = 0.003), as well as the hypermethylation of the RARbeta gene (p = 0.048).

CONCLUSION

Our preliminary data suggest that DNA methylation biomarkers may assist in selection of BC patients for efficient IL-2 therapy.

P21 and p27: roles in carcinogenesis and drug resistance

Human cancers arise from an imbalance of cell growth and cell death. Key proteins that govern this balance are those that mediate the cell cycle. Several different molecular effectors have been identified that tightly regulate specific phases of the cell cycle, including cyclins, cyclin-dependent kinases (CDKs) and CDK inhibitors. Notably, loss of expression or function of two G1-checkpoint CDK inhibitors - p21 (CDKN1A) and p27 (CDKN1B) - has been implicated in the genesis or progression of many human malignancies. Additionally, there is a growing body of evidence suggesting that functional loss of p21 or p27 can mediate a drug-resistance phenotype. However, reports in the literature have also suggested p21 and p27 can promote tumours, indicating a paradoxical effect. Here, we review historic and recent studies of these two CDK inhibitors, including their identification, function, importance to carcinogenesis and finally their roles in drug resistance.

The Role of Perioperative Chemotherapy in the Treatment of Urothelial Cancer

Cancer of the urothelium is the fourth most common malignancy in men in the U.S. and the ninth most common in women. More than 63,000 Americans will be diagnosed with bladder cancer this year (47,010 men and 16,200 women), and more than 13,000 (8,970 men and 4,210 women) can expect to die of their disease. The approximate 5:1 ratio of incidence to mortality roughly parallels the frequency of superficial to invasive disease. Efforts to improve this ratio have generated a potential paradigm shift in the treatment of urothelial cancer, incorporating increasingly active chemotherapy into treatment regimens for high-risk tumors in both the pre-and postoperative settings. This review summarizes the evolution of chemotherapeutic treatment of urothelial cancer and the rationale for its perioperative administration and addresses the future directions of clinical research in this field.

Prognostic markers for bladder cancer: International Consensus Panel on bladder tumor markers

The International Consensus Panel on cytology and bladder tumor markers evaluated markers that have the ability to predict tumor recurrence, progression, development of metastases, or response to therapy or patient survival. This article summarizes those findings. The panel mainly reviewed articles listed in PubMed on various prognostic indicators for bladder cancer. Based on these studies, most of which were case-control retrospective studies, various prognostic indicators were classified into 6 groups: (1) microsatellite-associated markers, (2) proto-oncogenes/oncogenes, (3) tumor suppressor genes, (4) cell cycle regulators, (5) angiogenesis-related factors, and (6) extracellular matrix adhesion molecules. The panel concluded that although certain markers, such as Ki-67 and p53, appear to be promising in predicting recurrence and progression of bladder cancer, the data are still heterogeneous. The panel recommends that identifying definitive criteria for test positivity, a clearly defined patient population, standardization of techniques used to evaluate markers, and clearly specified endpoints and statistical methods will help to bring accurate independent prognostic indicators into the clinical management of patients with bladder cancer.

Identifying Superficial, Muscle-Invasive, and Metastasizing Transitional Cell Carcinoma of the Bladder

PURPOSE

Expression profiling by DNA microarray technology permits the identification of genes underlying clinical heterogeneity of bladder cancer and which might contribute to disease progression, thereby improving assessment of treatment and prediction of patient outcome.

EXPERIMENTAL DESIGN

Invasive (20) and superficial (22) human bladder tumors from 34 patients with known outcome regarding disease recurrence and progression were analyzed by filter-based cDNA arrays (Atlas Human Cancer 1.2; BD Biosciences Clontech) containing 1185 genes. For 9 genes, array data were confirmed using real-time reverse transcription-PCR. Additionally, Atlas array data were validated using Affymetrix GeneChip oligonucleotide arrays with 22,283 human gene fragments and expressed sequence tags sequences in a subset of three superficial and six invasive bladder tumors.

RESULTS

A two-way clustering algorithm using different subsets of gene expression data, including a subset of 41 genes validated by the oligonucleotide array (Affymetrix), classified tumor samples according to clinical outcome as superficial, invasive, or metastasizing. Furthermore, (a) a clonal origin of superficial tumors, (b) highly similar gene expression patterns in different areas of invasive tumors, and (c) an invasive-like pattern was observed in bladder mucosas derived from patients with locally advanced disease. Several gene clusters that characterized invasive or superficial tumors were identified. In superficial bladder tumors, increased mRNA levels of genes encoding transcription factors, molecules involved in protein synthesis and metabolism, and some proteins involved into cell cycle progression and differentiation were observed, whereas transcripts for immune, extracellular matrix, adhesion, peritumoral stroma and muscle tissue components, proliferation, and cell cycle controllers were up-regulated in invasive tumors.

CONCLUSIONS

Gene expression profiling of human bladder cancers provides insight into the biology of bladder cancer progression and identifies patients with distinct clinical phenotypes.