High-throughput interrogation of PIK3CA, PTEN, KRAS, FBXW7 and TP53 mutations in primary endometrial carcinoma.

OBJECTIVE: Endometrial cancer patients may benefit from systemic adjuvant chemotherapy, alone or in combination with targeted therapies. Prognostic and predictive markers are needed, however, to identify patients amenable for these therapies. METHODS: Primary endometrial tumors were genotyped for >100 hot spot mutations in genes potentially acting as prognostic or predictive markers. Mutations were correlated with tumor characteristics in a discovery cohort, replicated in independent cohorts and finally, confirmed in the overall population (n=1063). RESULTS: PIK3CA, PTEN and KRAS mutations were most frequently detected, respectively in 172 (16.2%), 164 (15.4%) and 161 (15.1%) tumors. Binary logistic regression revealed that PIK3CA mutations were more common in high-grade tumors (OR=2.03; P=0.001 for grade 2 and OR=1.89; P=0.012 for grade 3 compared to grade 1), whereas a positive TP53 status correlated with type II tumors (OR=11.92; P<0.001) and PTEN mutations with type I tumors (OR=19.58; P=0.003). Conversely, FBXW7 mutations correlated with positive lymph nodes (OR=3.38; P=0.045). When assessing the effects of individual hot spot mutations, the H1047R mutation in PIK3CA correlated with high tumor grade and reduced relapse-free survival (HR=2.18; P=0.028). CONCLUSIONS: Mutations in PIK3CA, TP53, PTEN and FBXW7 correlate with high tumor grade, endometrial cancer type and lymph node status, whereas PIK3CA H1047R mutations serve as prognostic markers for relapse-free survival in endometrial cancer patients.

Expression of ERCC1, p53, and class III ß-tubulin do not reveal chemoresistance in endometrial cancer: results from an immunohistochemical study.

BACKGROUND: In non-small cell lung cancer, expression of excision repair cross-complementation group 1 (ERCC1) and p53 correlates with platinum resistance and class III ß-tubulin with resistance to taxanes. The potential to personalize treatment in endometrial cancer remains uninvestigated. METHODS: Patients received platinum-based chemotherapy, with or without paclitaxel. Patients were divided into 2 groups: group A (n = 33) consisted of patients with early-stage endometrial cancer treated with adjuvant chemotherapy. Group B (n = 116) included cases with primary advanced or recurrent disease. Immunohistochemistry was performed to analyze the expression of ERCC1 and p53, for all cases, and class III ß-tubulin for cases treated with paclitaxel. The findings were correlated with response according to Response Criteria in Solid Tumors; recurrence-free, disease-specific survival; and established prognostic markers. RESULTS: The mean age of 149 patients was 64 years (range, 31-84 years). Distribution of histopathologic subtypes was as follows: 44 endometrioid (30%), 92 serous/clear cell (62%), and 13 carcinosarcomas (8%).In group A, 11 (33%) and 19 patients (58%) showed expression for ERCC1 and p53, respectively. Seven (78%) of nine patients receiving paclitaxel were positive for class III ß-tubulin. There was no correlation between expression of ERCC1, p53, or class III ß-tubulin and recurrence or survival. In group B, 25 (22%) and 61 patients (64%) were positive for ERCC1 and p53, respectively. Fifty-two (74%) of seventy patients receiving paclitaxel were positive for class III ß-tubulin. Only p53 expression correlated with survival (P = 0.01). CONCLUSIONS: In contrast to theoretical assumptions, the current study did not reveal evidence that the expression of ERCC1 and class III ß-tubulin predicts response to cytotoxic treatment and patient outcome in endometrial cancer.

Kit gene in endometrial carcinoma: an immunohistochemical and mutational analysis.

OBJECTIVE: : Because the outcome of recurrent disease of endometrial carcinoma is cumbersome, the development of target treatment strategies is critical. We evaluated KIT, a receptor tyrosine kinase, to determine a potential role for imatinib mesylate in the treatment of endometrial carcinoma. MATERIALS AND METHODS: : Immunohistochemical analysis for KIT expression was performed on paraffin sections from 45 patients: 30 primary and 15 recurrent tumors. Fifteen primary cases were available for mutation analysis. RESULTS: : Histopathological distribution of paraffin-embedded tissue was as follows: 30 type I and 15 type II endometrial carcinoma. Histopathological distribution of fresh-frozen tissue was as follows: 8 type I and 7 type II. Cases did not show KIT expression or mutations in mutational hotspot exons of KIT gene. CONCLUSIONS: : On the basis of the absence of KIT expression or mutations, endometrial carcinoma is unlikely to respond to imatinib mesylate.

Clinical usefulness of EGFR gene copy number as a predictive marker in colorectal cancer patients treated with cetuximab: a fluorescent in situ hybridization study.

PURPOSE: To evaluate the usefulness and the pitfalls inherent to the assessment of the epidermal growth factor receptor (EGFR) gene copy number (GCN) by fluorescence in situ hybridization (FISH) for outcome prediction to cetuximab in metastatic colorectal cancer. The value of testing KRAS mutation status, in addition to EGFR GCN, was also explored. EXPERIMENTAL DESIGN: FISH analysis of 87 metastatic colorectal cancer patients treated with cetuximab was done, recording individual GCN per cell and using different samples per tumor. Performances of published cutoff points and different summaries of EGFR GCN distribution were assessed for response prediction. RESULTS: In our data set, two published cutoff points performed less well than in their training set, yielding positive predictive values and negative predictive values between 40.0% and 48.3% and between 81.0% and 86.5%, respectively. Among summaries of GCN distribution explored, mean and right-tailed distribution of GCN yielded the highest performances. A mean EGFR GCN > or = 2.83 provided an area under the curve of 0.71. Important heterogeneity of repeated measures of mean EGFR GCN was observed within tumors (intraclass correlation, 0.61; within-class SD, 0.40), leading to potential misclassifications of FISH status in 7 of 18 (38.8%) patients if a cutoff point were used. In multivariable analysis, EGFR GCN testing provided significant information independent of the KRAS status to predict response (P = 0.016) and overall survival (P = 0.005). CONCLUSIONS: We confirm the association between increased EGFR GCN and outcome after cetuximab. However, because of reproducibility concerns, any decision making based on published cutoff points is not warranted.