Evolution in Endometrial Cancer: Evidence From an Immunohistochemical Study

Endometrial carcinoma: association between mutational status, sites of metastasis, recurrence, and correlation with overall survival

PURPOSE

To investigate the association between sites of endometrial carcinoma (EC) recurrence and metastases, mutational status, race, and overall survival (OS).

METHODS

This single-center retrospective study evaluated patients with biopsy-proven EC that underwent genomic molecular testing between January 2015 and July 2021. Association between genomic profile and sites of metastases or recurrence was performed using Pearson's chi-squared or Fisher exact test. Survival curves for ethnicity and race, mutations, sites of metastases or recurrence were estimated using the Kaplan-Meier method. Univariable and multivariable Cox proportional hazard regression models were used.

RESULTS

The study included 133 women [median age 64 years (IQR 57-69)]. The most common mutation was TP53 (65/105 patients, 62%). The most common site of metastasis was the peritoneum (35/43, 81%). The most common recurrence was in lymph nodes (34/75, 45%). Mutations of TP53 and PTEN were significantly associated with Black women (p = 0.048, p = 0.004, respectively). In the univariable Cox regression analyses, TP53 mutation and presence of recurrence or metastases to the peritoneum were associated with lower OS (HR 2.1; 95% CI 1.1, 4.3; p = 0.03/ HR 2.9; 95% CI 1.6, 5.4; p = 0.0004; respectively). On multivariable Cox proportional hazards model ER expression (HR 0.4; 95% CI 0.22, 0.91; p = 0.03), peritoneal recurrence or metastases (HR 3.55; 95% CI 1.67, 7.57; p = 0.001), and Black race (HR 2.2; 95% CI 1.1, 4.6; p = 0.03) were significant independent predictors of OS.

CONCLUSIONS

The integration of EC mutational status and clinicopathological risk assessment demonstrated potential implications on the patterns of metastasis, recurrence, and OS.

Cancer of the corpus uteri: 2021 update

Endometrial cancer is the most common gynecological malignancy in high‐ and middle‐income countries. Although the overall prognosis is relatively good, high‐grade endometrial cancers have a tendency to recur. Recurrence needs to be prevented since the prognosis for recurrent endometrial cancer is dismal. Treatment tailored to tumor biology is the optimal strategy to balance treatment efficacy against toxicity. Since The Cancer Genome Atlas defined four molecular subgroups of endometrial cancers, the molecular factors are increasingly used to define prognosis and treatment. Standard treatment consists of hysterectomy and bilateral salpingo‐oophorectomy. Lymphadenectomy (and increasingly sentinel node biopsy) enables identification of lymph node‐positive patients who need adjuvant treatment, including radiotherapy and chemotherapy. Adjuvant therapy is used for Stage I–II patients with high‐risk factors and Stage III patients; chemotherapy is especially used in non‐endometrioid cancers and those in the copy‐number high molecular group characterized by TP53 mutation. In advanced disease, a combination of surgery to no residual disease and chemotherapy with or without radiotherapy results in the best outcome. Surgery for recurrent disease is only advocated in patients with a good performance status with a relatively long disease‐free interval.

The latest state‐of‐the‐art treatment for endometrial cancer is described, incorporating the most recent new data that influence its clinical management.

Systematic Next Generation Sequencing is feasible in clinical practice and identifies opportunities for targeted therapy in women with uterine cancer: Results from a prospective cohort study

BACKGROUND

Both incidence and mortality of uterine cancer are on the rise and mortality is higher for African American women. The aim of our study was to evaluate how Next Generation Sequencing (NGS) may facilitate identification of and intervention for treatment disparities when integrated into clinical workflows.

RESULTS

Our cohort included 159 uterine cancer patients with recurrent/progressive and newly diagnosed advanced stage and/or high-risk histology. The most common tumor histological subtypes included EEC (n = 67), SEC (n = 34), UCS (n = 20), and mixed (n = 14). Black patients were most likely to present with aggressive histology: (SEC, 34.0%) and carcinosarcoma (UCS, 14.0%). The four most common mutations across all subtypes were TP53, PIK3CA, PTEN, and ARID1A. There was racial disparity between Black versus non-Black patients who were initiated on targeted therapy (28.2% vs. 38.2%, respectively) and clinical trial (15% vs. 22.6%, respectively). Compared to non-Black patients, Black patients had a significantly higher percentage TP53 mutations (p < 0.05) and a significantly lower percentage ARID1A mutations (p < 0.05).

CONCLUSIONS

NGS for uterine malignancies provides actionable information for targetable mutations and/or clinical trial enrollment in most patients; further investigation is necessary to identify potentially modifiable factors contributing to current disparities that may improve targeted therapy uptake and clinical trial participation.

Phase II Trial of Cabozantinib in Recurrent/Metastatic Endometrial Cancer: A Study of the Princess Margaret, Chicago, and California Consortia (NCI9322/PHL86)

PURPOSE

The relevance of the MET/hepatocyte growth factor pathway in endometrial cancer tumor biology supports the clinical evaluation of cabozantinib in this disease.

PATIENTS AND METHODS

PHL86/NCI#9322 (NCT01935934) is a single arm study that evaluated cabozantinib (60 mg once daily) in women with endometrial cancer with progression after chemotherapy. Coprimary endpoints were response rate and 12-week progression-free-survival (PFS). Patients with uncommon histology endometrial cancer (eg, carcinosarcoma and clear cell) were enrolled in a parallel exploratory cohort.

RESULTS

A total of 102 patients were accrued. Among 36 endometrioid histology patients, response rate was 14%, 12-week PFS rate was 67%, and median PFS was 4.8 months. In serous cohort of 34 patients, response rate was 12%, 12-week PFS was 56%, and median PFS was 4.0 months. In a separate cohort of 32 patients with uncommon histology endometrial cancer (including carcinosarcoma), response rate was 6% and 12-week PFS was 47%. Six patients were on treatment for >12 months, including two for >30 months. Common cabozantinib-related toxicities (>30% patients) included hypertension, fatigue, diarrhea, nausea, and hand-foot syndrome. Gastrointestinal fistula/perforation occurred in four of 70 (6%) patients with serous/endometrioid cancer and five of 32 (16%) patients in exploratory cohort. We observed increased frequency of responses with somatic CTNNB1 mutation [four partial responses (PRs) in 10 patients, median PFS 7.6 months] and concurrent KRAS and PTEN/PIK3CA mutations (three PRs in 12 patients, median PFS 5.9 months).

CONCLUSIONS

Cabozantinib has activity in serous and endometrioid histology endometrial cancer. These results support further evaluation in genomically characterized patient cohorts.

Anti-estrogen Treatment in Endometrial Cancer: A Systematic Review

Introduction: Hormonal therapy in endometrial cancer (EC) is used for patients who wish to preserve fertility and for patients with advanced or recurrent disease in a palliative setting. First line hormonal therapy consists of treatment with progestins, which has a response rate of 25% in an unselected population. Treatment with anti-estrogens is an alternative hormonal therapy option, but there is limited data on the effect and side-effects of anti-estrogens in EC. Therefore, we performed a systematic review to investigate the response rate and toxicity of anti-estrogenic therapy in patients with endometrial cancer.

Methods: A systematic search in electronic databases was performed to identify studies on selective estrogen receptor modulators (SERM) and down-regulators (SERD) and aromatase inhibitors that reported on response rates (RR) among EC patients. Outcome in estrogen receptor (ER) positive and negative disease was assessed independently.

Results: Sixteen studies on advanced stage and recurrent EC were included. Ten studies investigated anti-estrogen monotherapy and seven investigated a combination of anti-estrogenic drugs with either progestin or targeted treatment. Due to heterogeneity in patient population, no meta-analysis was performed. The median age of the patients in the included studies ranged from 61 to 71 years and the proportion of low grade tumors ranged from 38 to 80%. The RR for tamoxifen ranged from 10 to 53%, for other SERMs and SERDs 9–31%, for aromatase inhibitors from 8 to 9%, for combined tamoxifen/progestin treatment 19–58%, for combined chemo- and hormonal therapy 43% and for combination of anti-estrogenic treatment with mammalian target of rapamycin (mTOR) inhibitors 14–31%. Toxicity consisted mainly of nausea and thrombotic events and was higher in combination therapy of chemotherapy and hormonal therapy and hormonal therapy and mTOR inhibitors compared to other therapies.

Conclusion: Tamoxifen or a combination of tamoxifen and progestin should be the preferred choice when selecting second line hormonal treatment because the RRs are similar to first line progestin treatment and the toxicity is low. The response can be optimized by selecting patients with endometrioid tumors and positive estrogen receptor status, which should be based on a pretreatment biopsy.

Immunohistochemical Profiles of Endometrioid Endometrial Carcinomas With and Without Metastatic Disease

A minority of endometrial carcinomas present at an advanced stage with a poor prognosis, and should be identified to individualize treatment. Immunohistochemical markers have been studied, but most have not been directly linked to metastasis. This study analyzes the immunohistochemical profile of endometrioid endometrial carcinomas (EECs) with and without metastases, and corresponding metastases. Tissue microarray slides from stage I EECs, stage III-IV EECs, and corresponding metastases were stained and scored for expression of β-catenin, E-cadherin, ER, PR, PTEN, p16, MLH1, PMS2, L1CAM, p53, p21, and MIB1. Scores were compared between primary stage I and III-IV EECs, stage III-IV EECs, and the corresponding metastases, and between intra-abdominal and distant metastases. Primary tumors with distant metastases had a significantly lower ER expression than those without metastases or with intra-abdominal metastases. Distant metastases had a significantly lower PR expression than the corresponding primary tumor and intra-abdominal metastases. In contrast, p16 and PTEN expression was significantly higher in intra-abdominal metastases compared with corresponding primary tumors. Immunohistochemistry predicts both presence and location of EEC metastases. Loss of ER and PR was related to distant spread, and increased expression of PTEN and p16 was related to intra-abdominal spread. Additional research should assess the use of these markers in the diagnostic workup as well as the possibility to target metastases through these markers.

Cancer of the corpus uteri

Endometrial cancer is the most common gynecological malignancy in high-income countries. Although the overall prognosis is relatively good, high-grade endometrial cancers have a tendency to recur. Recurrence needs to be prevented since the prognosis for recurrent endometrial cancer is dismal. Treatment tailored to tumor biology is the optimal strategy to balance treatment efficacy against toxicity. Standard treatment consists of hysterectomy and bilateral salpingo-oophorectomy. Lymphadenectomy (with ongoing studies of sentinel node biopsy) enables identification of lymph node positive patients who need adjuvant treatment, including radiotherapy and chemotherapy. Adjuvant radiotherapy is used for Stage I-II patients with high-risk factors and Stage III lymph node negative patients. In advanced disease, a combination of surgery to no residual disease and chemotherapy results in the best outcome. Surgery for recurrent disease is only advocated in patients with a good performance status with a relatively long disease-free interval.

Phenotypic Intratumoral Heterogeneity of Endometrial Carcinomas

Intratumoral heterogeneity has been shown to play an important role in diagnostic accuracy, development of treatment resistance, and prognosis of cancer patients. Recent studies have proposed quantitative measurement of phenotypic intratumoral heterogeneity, but no study is yet available in endometrial carcinomas. In our study we evaluated the phenotypic intratumoral heterogeneity of a consecutive series of 10 endometrial carcinomas using measures of dispersion and diversity. Morphometric architectural (%tumor cells, %solid tumor, %differentiated tumor, and %lumens) and nuclear [volume-weighted mean nuclear volume ((Equation is included in full-text article.))] parameters, as well as estrogen receptor, progesterone receptor, p53, vimentin, and beta-catenin immunoexpression (H-score) were digitally analyzed in 20 microscopic fields per carcinoma. Quantitative measures of intratumoral heterogeneity included coefficient of variation (CV) and relative quadratic entropy (rQE). In each endometrial carcinoma there was slight variation of architecture from field to field, resulting in globally low levels of heterogeneity measures (mean CV %tumor cells: 0.10, %solid tumor: 0.73, %differentiated tumor: 0.19, %lumens: 0.61 and mean rQE %tumor cells: 18.5, %solid tumor: 20.3, %differentiated tumor: 25.6, %lumens: 21.8). Nuclear intratumoral heterogeneity was also globally low (mean (Equation is included in full-text article.)CV: 0.23 and rQE: 27.3), but significantly higher than the heterogeneity of architectural parameters within most carcinomas. In general, there was low to moderate variability of immunoexpression markers within each carcinoma, but estrogen receptor (mean CV: 0.56 and rQE: 46.2) and progesterone receptor (mean CV: 0.60 and rQE: 39.3) displayed the highest values of heterogeneity measures. Intratumoral heterogeneity of immunoexpression was significantly higher than that observed for morphometric parameters. In conclusion, our study indicates that endometrial carcinomas present a variable but predominantly low degree of phenotypic intratumoral heterogeneity.

Endometrial cancer evolution: new molecular-biologic types and hormonal-metabolic shifts

The question hidden in the title of this manuscript (whether the topic develops or remains constant) is important for all areas of science. It is also a serious problem for endometrial cancer (EC) study. In recent times the incidence of EC gradually increases in parallel with obesity epidemics. The main point of this review was evaluation of changes in EC area in last few decades, which are not only seen in tumor incidence, but also in its biology, hormonal-metabolic characteristics of patients and in the ratio of risk and anti-risk factors. One can hope that data accumulated recently and summarized here under the notion of EC evolution will find its use for advancement of EC prevention and treatment.

High stathmin expression is a marker for poor clinical outcome in endometrial cancer: An NRG oncology group/gynecologic oncology group study

OBJECTIVE

Gynecologic Oncology Group (GOG) 177 demonstrated that addition of paclitaxel to a backbone of adriamycin/cisplatin improves overall survival (OS) and progression-free survival (PFS) for patients with advanced or recurrent endometrial cancer. Using patient specimens from GOG-177, our objective was to identify potential mechanisms underlying the improved clinical response to taxanes. Stathmin (STMN1) is a recognized poor prognostic marker in endometrial cancer that functions as a microtubule depolymerizing protein, allowing cells to transit rapidly through mitosis. Therefore, we hypothesized that one possible mechanism underlying the beneficial effects of paclitaxel could be to counter the impact of stathmin.

METHODS

We analyzed the expression of stathmin by immunohistochemistry (IHC) in 69 specimens from patients enrolled on GOG-177. We also determined the correlation between stathmin mRNA expression and clinical outcomes in The Cancer Genome Atlas (TCGA) dataset for endometrial cancer.

RESULTS

We first established that stathmin expression was significantly associated with shorter PFS and OS for all analyzed cases in both GOG-177 and TCGA. However, subgroup analysis from GOG-177 revealed that high stathmin correlated with poor PFS and OS particularly in patients who received adriamycin/cisplatin only. In contrast, there was no statistically significant association between stathmin expression and OS or PFS in patients treated with paclitaxel/adriamycin/cisplatin.

CONCLUSIONS

Our findings demonstrate that high stathmin expression is a poor prognostic marker in endometrial cancer. Paclitaxel may help to negate the impact of stathmin overexpression when treating high risk endometrial cancer cases.

Tumor grade and chemotherapy response in endometrioid endometrial cancer

The objective of this study is to evaluate the association between tumor grade and response to chemotherapy in patients with endometrioid endometrial adenocarcinoma.

Patients with advanced or recurrent endometrioid endometrial adenocarcinoma of known tumor grade who received at least 3 cycles of chemotherapy were retrospectively identified at three institutions. RECIST 1.1 criteria were used to assess response to neoadjuvant, postoperative or salvage chemotherapy. Chi-square testing was used to evaluate the association between tumor grade and chemotherapy response.

Ninety-one patients met inclusion criteria: 13 with grade 1, 29 with grade 2 and 49 with grade 3 tumors. Eighty-four percent of patients received chemotherapy for recurrence, 12% for postoperative residual disease, and 4% in the neoadjuvant setting. The majority (85%) received carboplatin and paclitaxel. Forty-six percent (6/13) of grade 1, 72% (21/29) of grade 2 and 43% (21/49) of grade 3 tumors achieved an objective response. Grade 2 tumors were more likely to respond to chemotherapy compared to grade 3 tumors (72% vs. 43%, p = 0.02; Table 2), and specifically more likely to respond to carboplatin/paclitaxel (72% vs. 41%, p = 0.016). Median progression-free survival for patients receiving chemotherapy for recurrence or progression was 9 months for grade 1, 8 months for grade 2, and 5 months for grade 3 tumors. Similar results between grade and treatment response were apparent in the subset of 37 patients with a recently re-assigned tumor grade (G2 88% vs. G3 44%, p = 0.032).

In this series of endometrioid endometrial cancers, grade 2 tumors had the best measurable response to chemotherapy.

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Multi-institution study of chemotherapy response in endometrioid endometrial cancer by tumor grade

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Grade 2 tumors were significantly more likely to respond to chemotherapy than grade 3 tumors.

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Compared with tumor grade at diagnosis, several tumors upgraded on biopsy performed at time of recurrence.

Treatment failure in endometrial carcinoma

OBJECTIVE

Our aim was to investigate the outcomes and prognostic factors after treatment failure of endometrial cancer.

METHODS

A total of 923 endometrial cancer patients were treated between 2000 and 2010, of which 109 experienced treatment failure. Treatment failure was defined as relapse after complete removal of all cancerous lesions or persistent/progressive disease despite treatment. Variables including clinicopathological features at initial treatment, type of primary treatment, failure pattern, salvage treatment, and outcomes were analyzed. Kaplan-Meier survival curves were compared with log-rank test. Cox proportional hazards regression model was used to identify significant prognostic factors.

RESULTS

Eighteen cases with persistent/progressive disease died shortly from primary diagnosis (1-23 months). The remaining 91 patients had recurrences in vagina only (8.8%), pelvis (3.3%), distant (63.7%), and combined pelvic-distant sites (24.2%). Median time to recurrence was 13.3 months (3.2-97.2 months). The median follow-up after recurrence of survivors was 60.5 months (10.6-121.7 months). The median survival after recurrence (SAR) was 20.3 months (1.9-121.7 months) with 5-year SAR rate of 32.4%. By multivariate analysis, initial stage II to IV (hazards ratio [HR], 3.41; 1.53-7.60; P = 0.003), type II histology (HR, 2.50; 1.28-4.90; P = 0.008), positive peritoneal cytology (HR, 2.23; 1.07-4.68; P = 0.033), and recurrence at multiple sites (HR, 2.51; 1.30-4.84; P = 0.006) were significantly associated with poor SAR. The 5-year SAR rates in patients with solitary vaginal, nodal/liver, or pulmonary/bony recurrence were 83.3%, 50.5%, and 24.2%, respectively. Ten cases with resectable or irradiatable recurrence at multiple sites or multiple relapses attained SAR greater than 5 years after multimodality salvage therapy.

CONCLUSIONS

Initial stage II to IV, type 2 histology, positive cytology, and recurrence at multiple sites were significant poor prognostic factors. Curative intent salvage therapy remains a viable option for cases with resectable or irradiatable multiple recurrences and solitary distant metastasis.

Gynecologic Cancer InterGroup (GCIG) Endometrial Cancer Clinical Trials Planning Meeting: taking endometrial cancer trials into the translational era

OBJECTIVE

The second Gynecologic Cancer InterGroup (GCIG) Endometrial Cancer Clinical Trials Planning Meeting was held on December 1, 2012, and included international multidisciplinary representatives of the 24 member groups. The aims were to review recent advances in molecular pathology of endometrial cancer, focusing on molecular-based therapy, and to identify key hypotheses and issues to be addressed through international collaborative clinical trials.

METHODS

Reviews and summaries of current knowledge were presented followed by parallel working group sessions for surgery, adjuvant and systemic therapy, and translational research. Plenary discussions were held to integrate translational and clinical issues, and a final discussion session to agree on key trial concepts.

RESULTS AND CONCLUSIONS

Proposals to take forward on the following trials were agreed: (1) lymphadenectomy to direct adjuvant treatment in women with high-risk endometrial cancer, including a sentinel node substudy; (2) conservative therapy for low-risk endometrial cancers in morbidly obese women with high surgical risks and for fertility-sparing treatment in premenopausal patients; (3) adjuvant therapy for women with early-stage carcinosarcoma. A proposal was made that a GCIG Early Phase Consortium be developed to serve as an international platform for rapid assessment of biomarkers.

Stathmin protein level, a potential predictive marker for taxane treatment response in endometrial cancer

Stathmin is a prognostic marker in many cancers, including endometrial cancer. Preclinical studies, predominantly in breast cancer, have suggested that stathmin may additionally be a predictive marker for response to paclitaxel. We first evaluated the response to paclitaxel in endometrial cancer cell lines before and after stathmin knock-down. Subsequently we investigated the clinical response to paclitaxel containing chemotherapy in metastatic endometrial cancer in relation to stathmin protein level in tumors. Stathmin level was also determined in metastatic lesions, analyzing changes in biomarker status on disease progression. Knock-down of stathmin improved sensitivity to paclitaxel in endometrial carcinoma cell lines with both naturally higher and lower sensitivity to paclitaxel. In clinical samples, high stathmin level was demonstrated to be associated with poor response to paclitaxel containing chemotherapy and to reduced disease specific survival only in patients treated with such combination. Stathmin level increased significantly from primary to metastatic lesions. This study suggests, supported by both preclinical and clinical data, that stathmin could be a predictive biomarker for response to paclitaxel treatment in endometrial cancer. Re-assessment of stathmin level in metastatic lesions prior to treatment start may be relevant. Also, validation in a randomized clinical trial will be important.

Molecular determinants of outcome with mammalian target of rapamycin inhibition in endometrial cancer

BACKGROUND

Targeting the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway is of increasing interest as a therapeutic strategy in many tumors. The aim of this study was to identify molecular markers associated with mTOR inhibitor activity in women with metastatic endometrial cancer.

METHODS

Archival tumor samples were collected from 94 women with recurrent or metastatic endometrial cancer who participated in 3 National Cancer Insitute of Canada Clinical Trials Group phase 2 trials investigating single-agent mTOR inhibitors: IND160A and IND160B (temsirolimus) and IND192 (ridaforolimus). Analyses included mutational profiling using the OncoCarta Panel version 1.0 and immunohistochemical expression of the tumor suppressor gene PTEN (phosphatase and tensin homologue) and stathmin, a marker of PI3K activation. Associations between biomarker results and clinical outcomes were assessed.

RESULTS

Mutations were found in 32 of 73 analyzed tumors, PIK3CA (21 patients) was the most common mutated gene. Co-mutations were seen in 8 tumors, most frequently KRAS and PIK3CA (4 cases). PTEN loss was observed in 46 of 85 samples analyzed and increased stathmin expression was observed in 15 of 65 analyzed samples. No correlation was observed between biomarkers and response or progression. In patients taking concurrent metformin, there was a trend toward lower progression, of 11.8% versus 32.5% (P = .14).

CONCLUSIONS

No predictive biomarker or combination of biomarkers for mTOR inhibitor activity were identified in this study. Restriction and enrichment of study entry, especially based on archival tumor tissue, should be undertaken with caution in trials using these agents.

Expression of estrogen receptors (α, β), cyclooxygenase-2 and aromatase in normal endometrium and endometrioid cancer of uterus

PURPOSE

Endometrial cancer (EC) is one of the most common malignancies of the female genital tract, but the etiology, especially its metabolism is still investigated. The aim of this study was to evaluate the presence and relative expression of Estrogen Receptors (α, β), Cyclooxygenase-2 and Aromatase in both endometrial cancer and normal mucosa.

MATERIAL/METHODS

Two groups of women were selected for the study: 1) patients with endometrioid endometrial cancer (FIGO I; G1 - G3) (n=35) and 2) subjects with normal endometrial tissue (control group, n=29). The expression of Estrogen Receptors (ERα, β), Cyclooxygenase-2 (COX-2), Aromatase were estimated by Western blot analysis. Furthermore, the associations between FIGO classification (stage: Ia, Ib), tumor grade (G) and expression of ERα, β, COX-2, aromatase proteins were evaluated. Overall and disease-free survival curves were generated according to the Kaplan-Meier method. Median follow-up time of the patients examined in this study was 39 months.

RESULTS

The relative expression of each examined protein was markedly higher in the endometrial cancer tissue as compared to the healthy endometrium. The trends towards greater expression along with a tumor progression was noticed (FIGO stage: Ia vs. Ib). Analysis of endometrial cancer risk factors and their influence on survival curves showed only an inverse significant correlations between obesity (BMI: 36.2; n=21) and disease-free survival in EC group (p=0.00872), but there was no significant association between obesity and overall survival (p=0.358).

CONCLUSIONS

Endometrioid endometrial cancer shows relatively higher expression of either ER, COX-2 and aromatase comparing to healthy mucosa, suggesting their involvement in tumor development and progression.

Conventional endometrioid adenocarcinomas of the endometrium recurring as clear cell tumors: comparative immunohistochemical analyses

Endometrial carcinomas are known to have the potential for recurrences that are distinctly discordant at the morphologic and immunophenotypic levels from their antecedent primary tumors. This report describes 3 patients with stage I, low or intermediate grade, conventional endometrioid carcinomas that recurred at the vaginal apex as notably clear cell-rich, higher grade, histotypically ambiguous neoplasms. Comparative immunohistochemical analyses were performed on all cases on both the original and the recurrent tumors using a panel of 8 biomarkers, including estrogen receptor, progesterone receptor, vimentin, p53, p16, hepatocyte nuclear factor 1β, BAF250a (ARID1A), and stathmin or oncoprotein-18 (STMN1). Notable immunophenotypic differences (relative to the original tumor) in case 1 included the relative loss of vimentin and estrogen receptor and the acquisition of p53, p16, and STMN1 expression in the recurrence. In case 2, significant p16 and STMN1 expression were identified only in the recurrence. In case 3, there were no significant immunophenotypic differences between the original tumor and the recurrence. In all 3 cases, the recurrent and original tumors showed no significant differences in BAF250a, hepatocyte nuclear factor 1β, and progesterone receptor expression. In summary, our cases confirm that endometrioid carcinomas can recur as clear cell-rich tumors. The relative acquisition of STMN1 expression in 2 of the 3 recurrences and p53 overexpression in 1 of 3 recurrences suggests that this phenomenon represents a form of tumor evolution, and this may be a potential contributor to tumor progression in these patients.