Expression and mutation of p53 in tumor effusion cells of patients with ovarian carcinoma: response to cisplatin-based chemotherapy

Cell adhesion molecule profiles, proliferation activity and p53 expression in advanced epithelial ovarian cancer induced malignant ascites-Correlation of tissue microarray and cytology microarray

INTRODUCTION

Peritoneal dissemination accompanied by ascites formation is common in epithelial ovarian cancer (EOC). Adhesion molecules are crucial in metastatic spread and the latter involves epithelial-mesenchymal transition (EMT). This study aimed at: (1) clarifying whether E-cadherin and β-catenin expression and proliferative activity in metastatic ovarian cancer are inter-related; (2) Identifying possible correlations between cell adhesion molecular expression profiles, the proliferative activity and p53 expression of tumor cells and tumor grade and stage; (3) testing the cytology microarray (CMA) technique in analyzing metastasis formation.

MATERIAL AND METHODS

Both tumorous and ascitic samples from 27 EOC patients were examined by using tissue microarray (TMA) and cytology microarray (CMA), respectively. CMA blocks were constructed using cores from each cell block of the ascitic specimens. Expression of E-cadherin, β-catenin, Ki-67 and p53 was immunohistochemically detected both in TMA and CMA blocks.

RESULTS

E-cadherin expression was higher in ascitic cells than in primary tumor cells (p = .294). β-catenin expression was significantly lower in ascitic cells than in primary tumor cells (p = .006). Expression of Ki-67 was lower and expression of p53 was higher in primary tumors than in ascitic cells, for p53 the difference was significant (p = .001). Both Ki-67 and p53 expression elevated significantly in high-grade primary tumor cells and in ascites cells (p = .039, and p = .004, respectively).

CONCLUSION

Epithelial-mesenchymal transition- mesenchymal-epithelial transition is suggested as the best descriptive term for our IHC observations which accompany increased proliferative activity of ascitic cells. The CMA method is an adequate and reliable method for the analysis of ascitic tumor cells disseminating from ovarian malignancies.

Prediction of Optimal Cytoreductive Surgery of Serous Ovarian Cancer With Gene Expression Data

OBJECTIVES

Cytoreductive surgery is the cornerstone of ovarian cancer (OVCA) treatment. Detractors of initial maximal surgical effort argue that aggressive tumor biology will dictate survival, not the surgical effort. We investigated the role of biology in achieving optimal cytoreduction in serous OVCA using microarray gene expression analysis.

METHODS

For the initial model, we used a gene expression signature from a microarray expression analysis of 124 women with serous OVCA, defining optimal cytoreduction as removal of all disease greater than 1 cm (with 64 women having optimal and 60 suboptimal cytoreduction). We then applied this model to 2 independent data sets: the Australian Ovarian Cancer Study (AOCS; 190 samples) and The Cancer Genome Atlas (TCGA; 468 samples). We performed a second analysis, defining optimal cytoreduction as removal of all disease to microscopic residual, using data from AOCS to create the gene signature and validating results in TCGA data set.

RESULTS

Of the 12,718 genes included in the initial analysis, 58 predicted accuracy of cytoreductive surgery 69% of the time (P = 0.005). The performance of this classifier, measured by the area under the receiver operating characteristic curve, was 73%. When applied to TCGA and AOCS, accuracy was 56% (P = 0.16) and 62% (P = 0.01), respectively, with performance at 57% and 65%, respectively. In the second analysis, 220 genes predicted accuracy of cytoreductive surgery in the AOCS set 74% of the time, with performance of 73%. When these results were validated in TCGA set, accuracy was 57% (P = 0.31) and performance was at 62%.

CONCLUSION

Gene expression data, used as a proxy of tumor biology, do not predict accurately nor consistently the ability to perform optimal cytoreductive surgery. Other factors, including surgical effort, may also explain part of the model. Additional studies integrating more biological and clinical data may improve the prediction model.

Is it possible to diagnose malignancy from fluid in cystic ovarian tumors?

OBJECTIVE

p53 gene mutations are frequently identified in ovarian cancer tissue. The aim of this study was to investigate whether wild type or mutated genomic DNA can be identified in ovarian cystic fluid specimens.

STUDY DESIGN

Forty-eight Japanese patients with cystic ovarian tumors (30 benign cysts, 8 borderline malignant tumors, and 10 cancers) were investigated. Cystic fluid and tumor tissue were obtained during surgery. After DNA extraction from the cystic fluid, polymerase chain reaction (PCR) and sequence analysis for exons 4-9 of the p53 gene was performed. In two cases of mucinous cystic tumor of borderline malignancy and endometrioid adenocarcinoma, the p53 gene sequences were determined. Immunohistochemical staining for abnormal p53 gene product was also performed.

RESULTS

DNA was successfully extracted from all cystic fluid specimens. Furthermore, exons 4-9 of the p53 gene could be identified by electrophoresis from all samples. In a mucinous cystic tumor of borderline malignancy, one point mutation was identified at codon 223 in exon 6 (CCT → CTT) of the p53 gene. Aberrant p53 gene product was also observed in the tumor cells by immunohistochemical staining. Moreover, in another case of endometrial adenocarcinoma, a point mutation at codon 245 in exon 7 (GGC → AGC) was detected by the direct sequencing of the amplified Exon. Notably, the mutation was not present in the peripheral blood (PB) sample and tissue specimens from the patient.

CONCLUSION

In cystic ovarian tumors, cystic fluid may provide informative material for molecular studies since it reflects the p53 status of tumor tissue in the cyst wall. This system might help to identify ovarian malignancy without resection of the tumor tissues.

Does tumour biology determine surgical success in the treatment of epithelial ovarian cancer? A systematic literature review

Background:

Ovarian cancer is the most lethal gynaecological cancer. Progression-free and overall survival is significantly related to surgical success and residual disease volume. It is unclear whether this survival advantage is due to an intrinsic biological element of the tumour cells which enables successful surgery and improved prognosis, or alternatively the number of tumour sustaining cells remaining irrespective of differences in biology.

Methods:

A systematic review of the literature was performed identifying studies that have investigated the association between biomarkers and surgical outcomes. We attempted validation of these results using The Cancer Genome Atlas ovarian cancer data sets.

Results:

Thirty studies were identified of which sixteen determined protein expression, eight gene expression and one DNA methylation in association with surgical debulking. Individualised linear models adjusting for batch, stage and age identified only expression of the genes MTDH and insulin-like growth factor-1 receptor (IGF1R) to be significantly associated with debulking surgery (P<0.05, false discovery rate (FDR)<5%), although in the case of IGF1R this was in the opposite direction to previous findings.

Conclusion:

The majority of studies are limited by design, include heterogeneous samples and lack adjustment for major confounding factors. High quality detailed clinical annotations should be routinely collected in future to more accurately evaluate biomarkers of surgical outcome.

Family History of Cancer Rather Than p53 Status Predicts Efficacy of Pegylated Liposomal Doxorubicin and Oxaliplatin in Relapsed Ovarian Cancer

Background:

The aim of the study was to assess the efficacy of pegylated liposomal doxorubicin (PLD) and oxaliplatin in patients affected by relapsed epithelial ovarian cancer with a family history of BRCA and p53 mutations.

Methods:

Seventy-two women received a median of 7.5 courses of PLD at 30 to 35 mg/m2 plus oxaliplatin at 70 mg/m2, and associations between BRCA1/2 and TP53 status and overall survival (OS) were determined. Thirty-eight had a short platinum-free interval (PFI; <12 months), and 34 had a long PFI (≥12 months).

Results:

Nine patients had BRCA1 mutations, and 1 had a BRCA2 mutation. Platinum sensitivity was associated with OS (P = 0.0001). At a median follow-up of 9.3 months, objective response rate, median time to progression, and OS were 47.3%, 5.8 months, and 12.9 months, respectively, in short PFI compared with the 76.5%, 11.5 months, and 47.7 months in long PFI. p53 status did not correlate to these parameters. The median time to progression was 11.5 months for high-risk patients versus 6.5 months for patients with sporadic cancer (P = 0.0188), and the median OS from the start of treatment was 48.7 and 16.2 months (P = 0.0032), respectively. Toxicity was mostly grade 1 or 2.

Conclusions:

High response rates in the long-PFI patients indicate that this treatment is beneficial and well tolerated. Platinum sensitivity and positive family history and/or a BRCA1/BRCA2 mutation are a useful predictor of response.

Associations between p53 overexpression and multiple measures of clinical outcome in high-risk, early stage or suboptimally-resected, advanced stage epithelial ovarian cancers A Gynecologic Oncology Group study

OBJECTIVE

The Gynecologic Oncology Group (GOG) performed a detailed analysis of p53 overexpression in previously-untreated women with invasive early or advanced stage epithelial ovarian cancer (EOC).

METHODS

Women were eligible for the study if they provided a tumor block for translational research and participated in either GOG-157, a randomized phase III trial of three versus (vs.) six cycles of paclitaxel+carboplatin in high-risk, early stage EOC, or GOG-111, a randomized phase III trial of cyclophosphamide+cisplatin vs. paclitaxel+cisplatin in suboptimally-resected, advanced stage EOC. The N-terminal DO-7 p53 antibody was used to examine the expression of the major normal and mutant p53-isoforms. p53 overexpression was defined as >or=10% tumor cells exhibiting nuclear staining.

RESULTS

p53 was overexpressed in 51% (73/143) and 66% (90/136) of cases in the GOG-157 and GOG-111 cohorts, respectively. In the GOG-157 cohort, p53 overexpression was not associated with any clinical characteristics or overall survival (OS) but was associated with worse progression-free survival (PFS) (logrank test: p=0.013; unadjusted Cox modeling: p=0.015). In the GOG-111 cohort, p53 overexpression was associated with GOG performance status (p=0.018) and grade (p=0.003), but not with age, stage, cell type or with tumor response and disease status after primary chemotherapy, PFS or OS. Adjusted Cox regression modeling demonstrated that p53 overexpression was not an independent prognostic factor for PFS or OS in either cohort.

CONCLUSIONS

p53 overexpression assessed by DO-7 immunostaining is common in early and advanced stage EOC, but has limited prognostic value in women treated with surgical staging and platinum-based combination chemotherapy.

Effusion cytology in ovarian cancer: new molecular methods as aids to diagnosis and prognosis

Carcinoma of the ovary is the leading cause of death from gynecologic cancer in western countries. Ovarian carcinoma is commonly associated with the accumulation of fluid that contains malignant cells in the peritoneal and pleural cavities. This article details the current knowledge regarding the diagnostic and biologic characteristics of ovarian carcinoma cells in effusions, and the genotypic and phenotypic differences between solid primary tumors and metastatic lesions. Finally, we present a new approach, by which the analysis of fresh frozen viable cells allows us to study in vivo the links between expression and activity of extracellular mediators, membrane receptors, intracellular signaling, and transcription factors, and their potential therapeutic and prognostic significance.