Unresolved Issues in the Chemotherapeutic Management of Gynecologic Malignancies

Expression profiling of 22 genes involved in the PI3K-AKT pathway identifies two subgroups of high-grade endometrial carcinomas with different molecular alterations

Previously, we showed that PIK3CA and p53 alterations in uterine endometrial carcinomas correlate with poor prognosis. However, the contribution of phosphatidylinositol 3-kinase (PI3K) -AKT deregulation to endometrial carcinogenesis is not completely understood. The purpose of this study was to analyze alterations of this pathway in endometrial carcinomas and correlate them with the most common genetic abnormalities. Expression profiling of 22 genes involved in PI3K-AKT signaling pathway was analyzed in 38 endometrial carcinomas using TaqMan low-density array (TLDA) analysis. The gene expression pattern was analyzed by hierarchical clustering analysis. Unsupervised clustering divided the high-grade endometrial carcinomas into two clusters. One cluster identified tumors with alterations in the PI3K-AKT signaling pathway (exon 20 PIK3CA mutations and/or PTEN mutations 9/15; 60%), and p16 protein overexpression (8/13; 62%). Almost all non-endometrioid adenocarcinomas (serous and clear cell adenocarcinomas) were segregated into this cluster. In contrast, the other cluster identified tumors with p53 alterations (6/6; 100%), p16 protein overexpression (5/5; 100%), and exon 9 PIK3CA mutations (2/6; 33%). Exon 20 PIK3CA and PTEN mutations were not found in this subgroup. Low-grade endometrial carcinomas clustered in a third subgroup characterized by high frequency of PTEN mutations (10/17; 59%) and microsatellite instability (6/17; 35%). Our results show that gene expression profile differences in the PI3K-AKT signaling pathway identify two subgroups of high-grade endometrial carcinomas with different molecular alterations (PI3K-AKT pathway vs p53 alterations) that may have distinct roles in endometrial carcinogenesis. Identification of these subgroups can provide insight into the biology of these tumors and may facilitate the development of future treatments.

Phase I clinical trials in 85 patients with gynecologic cancer: the M. D. Anderson Cancer Center experience

OBJECTIVE

Disseminated gynecologic cancers are usually fatal due to chemoresistance. Recently, rationally developed, targeted agents are entering the early clinical trials setting. We assessed patients with metastatic gynecologic cancers in a dedicated phase I clinical trials clinic in order to determine their outcome.

METHODS

We reviewed records for 89 consecutive patients with gynecologic cancers referred to the Phase I Clinical Trials Program, 85 (96%) of whom were treated on > or = 1 trial.

RESULTS

Cancer diagnoses were ovarian (N=43), uterine (N=19), cervix (N=17), and other. Median age was 58 years; median number of prior cytotoxic regimens, five. Two patients (2.4%) achieved a CR; four (4.7%), a PR; and eight (9.4%), SD > or = 6 months (total CR/PR/SD > or = 6 months=16.5%) for the first phase I trial. Twenty-five patients enrolled on a second trial and three, on a third (N=113 trials total). Combining response data for all trials, of the 85 patients, two achieved CR (2.4%), nine achieved PR (10.6%), and 12 (14%) had SD for > or = 6 months. One-year survival was 30% (95% CI, 21% to 44%). There was no difference in time-to-treatment failure (TTF) on phase I versus the patient's last standard treatment.

CONCLUSION

Twenty-three of 85 patients (27%) with advanced, heavily pretreated, gynecologic cancers achieved CR/PR/SD > or = 6 months on a phase I trial, and overall TTF on phase I was comparable to that of last conventional therapy, suggesting that participation in a phase I trial is a reasonable option for these patients.

Is the current concept of recurrent ovarian carcinoma as a chronic disease also applicable in platinum resistant patients?

PURPOSE

The treatment of recurrent ovarian carcinoma (ROC) has become increasingly oriented according to the therapy principles of a chronic disease. We evaluated whether it is justifiable to also apply this concept to the treatment of platinum resistant patients with their known poor prognosis and short overall survival (OS).

METHODS

We analyzed the overall courses of 85 unselected ROC patients and defined the following groups: A, platinum resistant patients (n=39); subgroup A.1, those who received no or at maximum one line of palliative chemotherapy (n=15, 38.5%); subgroup A.2, those who received>or=two therapy lines (n=24, 61.5%); B, platinum sensitive patients, n=46.

RESULTS

Group A had significantly lower OS than group B (median: 16 vs. 25 months; p=0.019). Group A.1 had significantly worse outcome compared to group A.2 (median: 5 vs. 21.5 months; p<0.001). The comparison between study group A.2 and group B showed comparable survival rates (p=0.738). Considering only the patients who had completed treatment courses, the median number of therapy lines administered was higher in group A.2 than in group B (4 vs. 3; p=0.008).

CONCLUSIONS

There is not only the known dichotomy between platinum sensitive and resistant ROC patients, but rather also within the platinum resistant subgroup itself. There is a considerably large subgroup of platinum resistant patients who will subsequently enter a phase where multiple treatment programs will be considered and administered. These patients have similar survival rates compared to those from the platinum sensitive patient group and the therapy principles of a chronic disease are applicable.

Diabodies targeting epithelial membrane protein 2 reduce tumorigenicity of human endometrial cancer cell lines

PURPOSE

Endometrial cancer is the most common gynecologic malignancy. One promising biomarker is epithelial membrane protein 2 (EMP2), and its expression is an independent prognostic indicator for tumors with poor clinical outcome expression. The present study assesses the suitability of EMP2 as a therapeutic target.

EXPERIMENTAL DESIGN

Human monovalent anti-EMP2 antibody fragments were isolated from a human phage display library and engineered as bivalent antibody fragments (diabodies) with specificity and avidity to both EMP2 peptides and native cell-surface EMP2 protein. Diabodies were assessed using cell death and apoptosis assays. In addition, the efficacy of EMP2 diabodies on endometrial cancer tumors was determined using mouse xenograft models.

RESULTS

Treatment of human endometrial adenocarcinoma cell lines with anti-EMP2 diabodies induced significant cell death and caspase-3 cleavage in vitro. These responses correlated with cellular EMP2 expression and were augmented by progesterone, which physiologically induces EMP2 expression. In vivo, treatment of subcutaneous human xenografts of HEC-1A cell lines with anti-EMP2 diabodies suppressed tumor growth and induced cell death in the xenograft.

CONCLUSIONS

These findings suggest that EMP2 may be a potential pharmacologic target for human endometrial cancer.

Quality of Life Considerations in Gynecologic Cancer

Quality of life (QOL) is a fundamental consideration for patients with life threatening diseases. Major evolving paradigms are discussed: improved QOL with laparoscopic surgery, the impact on QOL of intraperitoneal chemotherapy for optimally cytoreduced ovarian cancer, combination therapy, sexuality, and survivorship. The goals of treatment for many patients with gynecologic tumors remain largely palliative, and patient reported QOL is the primary outcome determining the utility of treatment. Particularly in this area, QOL endpoints are increasingly important in clinical trials. The QOL issues facing gynecologic cancer patients, the use of validated QOL instruments, recent advances in the evaluation of interventions, and changes in concepts related to QOL are reviewed.