1. Survivin expression in endometrial carcinoma: a tissue microarray study with correlation with PTEN and STAT-3
Judit Pallares, Jose Luis Martínez-Guitarte, Xavier Dolcet, David Llobet, Montserrat Rue, José Palacios, Jaime Prat, Xavier Matias-Guiu Int J Gynecol Pathol. 2005 Jul;24(3):247-53. doi: 10.1097/01.pgp.0000163849.37129.d4.
Evasion of apoptotic cell death plays a key role in cancer development. Survivin is a member of the inhibitor of apoptosis proteins, which also has a role in the control of cell division. Survivin may be overexpressed in some tumors and has been suggested to be related to PTEN, beta-catenin, p53 [all of them frequently abnormal in endometrial carcinomas (ECs)], and STAT-3. A tissue microarray was constructed from paraffin-embedded blocks of 95 ECs, previously studied for microsatellite instability and for alterations in PTEN, k-RAS, and CTNNB-1. Immunohistochemical evaluation included 1) survivin, 2) markers of cell proliferation and apoptosis (Ki67-MIB1 and M 30-neoepitope cytokeratin 18), and 3) proteins involved in cell signaling pathways (PTEN, phospho-AKT, beta-catenin, p53, and STAT-3). Survivin expression was frequent in ECs (75.95%) but did not show any statistical significant correlation with histological type and grade, stage, overall survival, or mitotic and apoptotic indexes. Survivin expression had a statistical significant correlation with decreased PTEN expression (r = -0.383, p = 0.001), increased phospho-AKT (r = 0.70, p < 0.001), and positive STAT-3 immunostaining (r = 0.6, p < 0.001). Survivin expression did not show statistical correlation with either beta-catenin or p53 alterations. The results suggest that increased survivin expression is frequent in ECs and may be dependent on STAT-3 and PI3 K/AKT activation. Because PTEN abnormalities are very frequent in ECs, the results from this study indicate that PTEN may interfere with the process of apoptosis and cell proliferation by promoting survivin expression.
2. PTEN-positive and phosphorylated-Akt-negative expression is a predictor of survival for patients with advanced endometrial carcinoma
Kazunori Uegaki, et al. Oncol Rep. 2005 Aug;14(2):389-92.
PTEN and the PI3K/Akt pathway are involved in the development and/or progression of endometrial carcinoma. To clarify the impact of the pathway-related molecules on prognosis, we analyzed PTEN, phosphorylated-Akt (p-Akt), and Ki-67 expression by immunohistochemistry in 99 patients with advanced endometrial carcinoma. PTEN-negative or PTEN-mixed staining was found in 66% of tumors. Positive staining of p-Akt was found in 40% of tumors. Loss of PTEN expression (negative or mixed) was significantly associated with positive p-Akt expression. The patients with PTEN-positive and p-Akt-negative expression clearly showed a higher survival rate than patients in the other groups. Subsequent multivariate analysis revealed that the combination of PTEN/Akt expression was an independent prognostic factor. Examining the relationship between p-Akt expression and Ki-67 labeling index (LI), we found that negative p-Akt was related to a decrease in Ki-67 LI. Additionally, the patients with low Ki-67 LI, as determined by p-Akt-expression status, had a better prognosis. In the present study, we demonstrated that PTEN-positive and p-Akt-negative expression was a predictor of survival for patients with advanced endometrial carcinoma. This study suggests the clinical significance of PTEN and p-Akt expression analysis in treatment decisions for patients with advanced endometrial carcinoma.
3. Phase II study of everolimus and letrozole in patients with recurrent endometrial carcinoma
Brian M Slomovitz, et al. J Clin Oncol. 2015 Mar 10;33(8):930-6. doi: 10.1200/JCO.2014.58.3401. Epub 2015 Jan 26.
Purpose: The phosphoinositol-3 kinase (PI3K) pathway is frequently dysregulated in endometrial cancer (EC). Hormonal manipulation leads to response in some patients with EC, but resistance derived from PI3K pathway activation has been documented. Targeting mammalian target of rapamycin (mTOR) may overcome endocrine resistance. We conducted a two-institution phase II trial of everolimus and letrozole in women with recurrent EC. Patients and methods: Patients were considered incurable, had measurable disease, and were treated with up to two prior cytotoxic regimens. Everolimus was administered orally at 10 mg daily and letrozole was administered orally at 2.5 mg daily. Each cycle consisted of 4 weeks of therapy. Patients were treated until progression, toxicity, or complete response (CR). The primary end point was the clinical benefit rate (CBR), which was defined as CR, partial response, or stable disease (≥ 16 weeks) by RECIST 1.0 criteria. Translational studies were performed to correlate biomarkers with response. Results: Thirty-eight patients were enrolled (median age, 62 years; range, 24 to 82 years). Thirty-five patients were evaluable for response. The CBR was 40% (14 of 35 patients); the median number of cycles among responders was 15 (range, seven to 29 cycles). The confirmed objective response rate (RR) was 32% (11 of 35 patients; nine CRs and two partial responses; median, 15 cycles; range, eight to 29 cycles). Twenty percent of patients (seven of 35 patients) were taken off treatment after a prolonged CR and at the discretion of the treating clinician. None of the patients discontinued treatment as a result of toxicity. Serous histology was the best predictor of lack of response. Patients with endometrioid histology and CTNNB1 mutations responded well to everolimus and letrozole. Conclusion: Everolimus plus letrozole results in a high CBR and RR in patients with recurrent EC. Further development of this combination in recurrent endometrioid EC is under way.
