Frequent microsatellite instability in synchronous ovarian and endometrial adenocarcinoma and its usefulness for differential diagnosis

Colorectal metastasis to the gallbladder mimicking a primary gallbladder malignancy: histopathological and molecular characteristics

AIMS

Outcomes of colorectal cancer (CRC) treatment and survival have steadily improved during the past decades, accompanied by an increased risk of developing second primary tumours and metastatic tumours at unusual sites. Metastatic CRC can show mucosal colonisation, thereby mimicking a second primary tumour. This potential confusion could lead to incorrect diagnosis and consequently inadequate treatment of the patient. The aim of this study was to differentiate between metastatic CRC and a second primary (gallbladder cancer, GBC) using a combination of standard histopathology and molecular techniques.

METHODS AND RESULTS

Ten consecutive patients with both CRC and GBC were identified in our region using the Dutch National Pathology Archive (PALGA). Two patients served as negative controls. Histology of GBC was reviewed by nine pathologists. A combination of immunohistochemistry, microsatellite analysis, genomewide DNA copy number analysis and targeted somatic mutation analysis was used to aid in differential diagnosis. In two patients, CRC and GBC were clonally related, as confirmed by somatic mutation analysis. For one case, this was confirmed by genomewide DNA copy number analysis. However, in both cases, pathologists initially considered the GBC as a second primary tumour.

CONCLUSIONS

Metastatic CRC displaying mucosal colonisation is often misinterpreted as a second primary tumour. A combination of traditional histopathology and molecular techniques improves this interpretation, and lowers the risk of inadequate treatment.

Guidelines to Aid in the Distinction of Endometrial and Endocervical Carcinomas, and the Distinction of Independent Primary Carcinomas of the Endometrium and Adnexa From Metastatic Spread Between These and Other Sites

In most cases of suspected endometrial neoplasia tumor origin can be correctly assigned according to a combination of clinical, radiologic, and pathologic features, even when the latter are based upon the examination of relatively small biopsy samples. However there are well-recognized exceptions to this rule which continue to create diagnostic difficulty, and sometimes difficulties persist even after the detailed examination of resection specimens. Among the most common problems encountered in practice are the distinction of primary endometrial and primary endocervical adenocarcinomas, and the determination of tumor origin when there is synchronous, multifocal involvement of gynecologic tract sites, for example the endometrium and the ovary. However, accurate diagnosis in these cases is important because this has significant staging, management and prognostic implications. In this review we discuss the value and limitations of key morphologic, immunophenotypic and molecular findings in these diagnostic scenarios.

Potential for Mitochondrial DNA Sequencing in the Differential Diagnosis of Gynaecological Malignancies

In the event of multiple synchronous gynecological lesions, a fundamental piece of information to determine patient management, prognosis, and therapeutic regimen choice is whether the simultaneous malignancies arise independently or as a result of metastatic dissemination. An example of synchronous primary tumors of the female genital tract most frequently described are ovarian and endometrial cancers. Surgical findings and histopathological examination aimed at resolving this conundrum may be aided by molecular analyses, although they are too often inconclusive. High mitochondrial DNA (mtDNA) variability and its propensity to accumulate mutations has been proposed by our group as a tool to define clonality. We showed mtDNA sequencing to be informative in synchronous primary ovarian and endometrial cancer, detecting tumor-specific mutations in both lesions, ruling out independence of the two neoplasms, and indicating clonality. Furthermore, we tested this method in another frequent simultaneously detected gynecological lesion type, borderline ovarian cancer and their peritoneal implants, which may be monoclonal extra-ovarian metastases or polyclonal independent masses. The purpose of this review is to provide an update on the potential use of mtDNA sequencing in distinguishing independent and metastatic lesions in gynecological cancers, and to compare the efficiency of molecular analyses currently in use with this novel method.

MicroRNA signatures discriminate between uterine and ovarian serous carcinomas

Synchronous endometrial and ovarian malignancies occur in 5% of women presenting with endometrial cancer and 10% of patients presenting with ovarian malignancy. When a high-grade serous carcinoma concurrently involves both ovary and endometrium, pathological determination of whether they are synchronous primaries or metastatic tumors from one primary site can be challenging. MicroRNAs (miRNA) are 22-nucleotide noncoding RNAs that are aberrantly expressed in cancer cells and may inherit their cellular lineage characteristics. We explored possible differential miRNA signatures that may separate high-grade ovarian serous carcinoma from primary endometrial serous carcinoma. Forty-seven samples of histologically pure high-grade serous carcinoma of both uterine (16 case) and ovarian primaries (31 cases) were included. Expression of 384 mature miRNAs was analyzed using ABI TaqMan Low-Density Arrays technology. A random forest model was used to identify miRNAs that together could differentiate between uterine and ovarian serous carcinomas. Among 150 miRNAs detectable at various levels in the study cases, a panel of 11-miRNA signatures was identified to significantly discriminate between ovarian and uterine serous carcinoma (P < .05). A nested cross-validated convergent forest plot using 6 of the 11 miRNA signature was eventually established to classify the tumors with 91.5% accuracy. In conclusion, we have characterized a miRNA signature panel in this exploratory study that shows significant discriminatory power in separating primary ovarian high-grade serous carcinoma from its endometrial counterpart.

Deficiency of hMLH1 and hMSH2 expression is a poor prognostic factor in Early Gastric Cancer (EGC)

Purpose: The aim of the study was to investigate the effect of deficiency of hMLH1 and hMSH2 expression on the prognosis of early gastric cancer (EGC) in Chinese populations.

Methods: A total of 160 EGC patients who underwent curative gastrectomy with lymphadenectomy from January 2011 to July 2014 at Xinhua Hospital were evaluated. The expression rates of hMLH1 and hMSH2 were examined using tissues preserved in paraffin blocks by immunohistochemical staining. The clinicopathological characteristics and prognosis of EGC with deficient hMLH1 and hMSH2 were analyzed.

Results: On immunohistochemical staining, the loss expression of hMLH1 and hMSH2 were observed in 89 (55.6%) and 45 (28.1%), respectively. The hMLH1 deficiency was associated with the middle third of tumor location (P = 0.041). According to Kaplan-Meier survival analysis and Log-Rank test, the loss expression of hMLH1 and hMSH2 were associated with worse survival than positive hMLH1 (HR = 0.247, 95% CI = 0.078-0.781, P = 0.017) and hMSH2 (HR = 0.174, 95% CI = 0.051-0.601, P = 0.006) in EGC.

Conclusion: The main conclusions were as follows: The hMLH1 deficiency was preferred to the middle third of EGC. Lymph node metastasis (LNM) was a prognostic factor of EGC. And the prognosis of EGC patients with deficient mismatch repair (dMMR, mainly including deficient hMLH1 and hMSH2) was obviously worse than proficient mismatch repair (pMMR).

Practical issues related to uterine pathology: staging, frozen section, artifacts, and Lynch syndrome

This review covers three areas in endometrial tumor pathology: International Federation of Gynecology and Obstetrics (FIGO) staging, the use of frozen section, and Lynch syndrome. The section on FIGO staging will emphasize problems that practicing pathologists often confront, such as measuring the depth of myometrial invasion, assessing for the presence of cervical stromal invasion, detecting low-volume lymph node metastases, and recognizing synchronous endometrial and ovarian tumors and artifacts. The frozen section portion of this review will focus on the performance characteristics of intraoperative examination of the uterus to determine tumor grade and depth of myometrial invasion, including suggestions for alternative methods. The last portion of this review will provide an overview of Lynch syndrome and a discussion of the rationale and methods of screening for Lynch syndrome.

Differential vimentin expression in ovarian and uterine corpus endometrioid adenocarcinomas: diagnostic utility in distinguishing double primaries from metastatic tumors

This study aimed to assess the diagnostic value of vimentin expression in differentiating endometrioid adenocarcinoma of primary uterine corpus and ovarian origin. Immunohistochemical analyses for the expression of vimentin in tumoral epithelial cells were performed on 149 endometrioid adenocarcinomas wherein the primary sites were not in question, including whole tissue sections of 27 carcinomas of uterine corpus origin (and no synchronous ovarian tumor), 7 carcinomas of ovarian origin (and no synchronous uterine corpus tumor) and a tissue microarray (TMA) containing 91 primary uterine corpus and 24 primary ovarian carcinomas. We also assessed 15 cases that synchronously involved the uterine corpus and ovary, 15 cases of metastasis to organs/tissues other than uterine corpus or ovary as well as 7 lymph node metastases. Vimentin was negative in 97% (30/31) of primary ovarian carcinomas. In contrast, 82% (97/118) of primary uterine corpus carcinomas were vimentin-positive. Vimentin expression was discordant in 53% of synchronous tumors. The sensitivity and specificity of negative vimentin staining in predicting an ovarian primary were 97% and 82%, respectively, whereas parallel values for positive vimentin staining in predicting a primary uterine tumor were 82% and 97%, respectively. The pattern of vimentin expression in all cases was maintained in their respective regional lymph nodes and distant metastases. In conclusion, ovarian and uterine corpus endometrioid adenocarcinomas have different patterns of vimentin expression. If validated in larger and/or different data sets, these findings may have diagnostic value in distinguishing metastatic lesions from double primary tumors involving both sites.

Preoperative identification of synchronous ovarian and endometrial cancers: the importance of appropriate workup

OBJECTIVE

For treatment of patients with both endometrial and ovarian cancer, it is important to discriminate between 2 primary tumors and metastatic disease. Currently, criteria are based on postoperative findings. The aim of this study was to determine whether clinical parameters can discriminate between these groups preoperatively and whether a practical guideline could improve appropriate workup and treatment.

METHODS

A total of 45 patients with a diagnosis of both endometrium and ovarian cancer between 1998 and 2009 and were included for analysis. Clinical and pathological data were obtained, and initial CA-125 was registered; patients had a diagnosis of 2 primary tumors or tumors with metastasis. All patients were reclassified according to workup and treatment.

RESULTS

Patients with synchronous primary tumors were significantly younger, presented more often with abnormal uterine bleeding, and had a lower initial CA-125 than both metastatic groups (P < 0.05). With age and CA-125 included in a polytomic logistic regression model, 83.3% of diagnoses could be classified correctly. In 15 of 17 patients presented with adnexal mass, workup was incomplete owing to lack on information of the endometrial status. In patients presenting with abnormal uterine bleeding, 13 of 21 patients had an incomplete workup leading to staging laparotomy secondary to initial surgical treatment in 2 patients.

CONCLUSIONS

Patients with synchronous endometrial and ovarian cancers are young, often present with abnormal uterine bleeding and have a low initial CA-125. Adequate workup with attention to both ovarian and endometrial status, especially in young patients with a wish to preserve fertility, is important to make the right decision for treatment.

Clinicopathological characteristics of patients with synchronous primary endometrial and ovarian cancers: A review of 43 cases

Synchronous primary endometrial and ovarian cancers are uncommon. The purpose of this study was to evaluate the clinicopathological characteristics, treatment and prognosis of synchronous primary endometrial and ovarian cancers. The clinicopathological characteristics of 43 patients with synchronous primary endometrial and ovarian cancers in the Obstetrics and Gynecology Hospital of Fudan University between 1999 and 2009 were retrospectively reviewed. Our results revealed that the median age at the time of diagnosis was 51 years (range, 29-71). The common presenting symptoms were abnormal uterine bleeding (AUB, 65.12%), abdominal mass (25.58%), abdominal pain and abdominal fullness (39.53%). An elevated CA125 level was observed in the majority of patients (n=20, 76.9%). Endometrioid type accounted for 60.47% of uterine carcinomas and different pathological types, including serous adenocarcinoma, clear cell carcinoma, adenosquamous and acanthoadenocarcinoma, were also identified in synchronous primary endometrial and ovarian cancers. All patients underwent surgical intervention (hysterectomy and bilateral salpingo-oophorectomy with pelvic lymphadenectomy or debulking surgery). The 5-year survival rate was 86.05% and nine patients had recurrence (20.93%). The early stage group (FIGO stages I and II) had more favorable prognosis than the advanced stage group (FIGO stages III and IV; P<0.05). In conclusion, synchronous primary endometrial and ovarian cancers are different from either primary endometrial carcinoma or ovarian cancer and are usually identified at early stages with a good prognosis.

Ovarian endometrioid adenocarcinoma: incidence and clinical significance of the morphologic and immunohistochemical markers of mismatch repair protein defects and tumor microsatellite instability

A subset of women with uterine cancer exhibiting defective mismatch repair (MMR) proteins and microsatellite instability (MSI) may have Lynch syndrome, which also confers a risk for colorectal cancer and other cancers in the patient and in her family. Screening algorithms based on clinical and pathologic criteria are effective in determining which patients with uterine cancer are most likely to benefit from definitive genetic testing for Lynch syndrome. Ovarian cancer, particularly endometrioid adenocarcinoma, is also associated with Lynch syndrome, although the risk is much smaller than for uterine cancer. This study evaluated whether the morphologic criteria [tumor-infiltrating lymphocytes (TILs), peritumoral lymphocytes (PTLs), dedifferentiated morphology)] currently used to screen uterine cancer for further Lynch syndrome testing can be applied to ovarian cancer. Among 71 patients with pure ovarian endometrioid adenocarcinoma treated at a single institution, 13% had a tumor with TILs, 3% had PTLs, and none had dedifferentiated morphology. Overall, 10% of tumors had abnormal MMR protein status, defined as complete immunohistochemical loss of expression of MLH1, MSH2, MSH6, and/or PMS2. Each of these tumors with abnormal MMR status demonstrated MSI using a polymerase chain reaction-based assay evaluating 5 mononucleotide repeat markers. No relationship was found between patient age, TILs, PTLs, or a spectrum of other morphologic variables and MMR protein status/MSI. Only 1/7 tumors with abnormal MMR/MSI had TILs/PTLs. Among 14 patients who died, 12 (86%) had normal MMR status. Among 7 patients with tumors with abnormal MMR/MSI, 5 (71%) were alive without disease. Concurrent uterine tumor was present in 5/7 patients whose ovarian tumor had abnormal MMR/MSI. This study suggests that the morphologic criteria used to screen patients with uterine cancer for further Lynch syndrome testing are not applicable in patients with ovarian cancer. Although abnormal MMR/MSI did not carry prognostic value in this study, it did predict the involvement of the uterus by the tumor. Thus, in patients with ovarian endometrioid adenocarcinoma who undergo uterus-sparing surgery, abnormal MMR/MSI should prompt further diagnostic evaluation of the endometrium for tumor.

Survival outcome of women with synchronous cancers of endometrium and ovary: a 10 year retrospective cohort study

Objective

Synchronous occurrence of endometrial and ovarian tumors is uncommon, and they affect less than 10% of women with endometrial or ovarian cancers. The aim of this study is to describe the epidemiological and clinical factors; and survival outcomes of women with these cancers.

Methods

This is a retrospective cohort study in a large tertiary institution in Singapore. The sample consists of women with endometrial and epithelial ovarian cancers followed up over a period of 10 years from 2000 to 2009. The epidemiological and clinical factors include age at diagnosis, histology types, grade and stage of disease.

Results

A total of 75 patients with synchronous ovarian and endometrial cancers were identified. However, only 46 patients met the inclusion criteria. The median follow-up was 74 months. The incidence rate for synchronous cancer is 8.7% of all epithelial ovarian cancers and 4.9% of all endometrial cancers diagnosed over this time frame. Mean age at diagnosis was 47.3 years old. The most common presenting symptom was abnormal uterine bleeding (36.9%) and 73.9% had endometrioid histology for both endometrial and ovarian cancers. The majority of the women (78%) presented were at early stages of 1 and 2. There were 6 (13.6%) cases of recurrence and the 5 year cumulative survival rate was at 84%.

Conclusion

In our cohort, we found that majority of women afflicted with synchronous cancer of the endometrium and ovary were younger at age of diagnosis, had early stage of cancer and good survival.

Endometrial carcinomas: a review emphasizing overlapping and distinctive morphological and immunohistochemical features

This review focuses on the most common diagnostic pitfalls and helpful morphologic and immunohistochemical markers in the differential diagnosis between the different subtypes of endometrial carcinomas, including: (1) endometrioid versus serous glandular carcinoma, (2) papillary endometrioid (not otherwise specified, villoglandular and nonvillous variants) versus serous carcinoma, (3) endometrioid carcinoma with spindle cells, hyalinization, and heterologous components versus malignant mixed müllerian tumor, (4) high-grade endometrioid versus serous carcinoma, (5) high-grade endometrioid carcinoma versus dedifferentiated or undifferentiated carcinoma, (6) endometrioid carcinoma with clear cells versus clear cell carcinoma, (7) clear cell versus serous carcinoma, (8) undifferentiated versus neuroendocrine carcinoma, (9) carcinoma of mixed cell types versus carcinoma with ambiguous features or variant morphology, (10) Lynch syndrome-related endometrial carcinomas, (11) high-grade or undifferentiated carcinoma versus nonepithelial uterine tumors. As carcinomas in the endometrium are not always primary, this review also discusses the differential diagnosis between endometrial carcinomas and other gynecological malignancies such as endocervical (glandular) and ovarian/peritoneal serous carcinoma, as well as with extra-gynecologic metastases (mainly breast and colon).

DNA mismatch repair deficiency in endometrial carcinoma

Microsatellite instability (MSI) is the hallmark of a molecular pathway to carcinogenesis due to sporadic or inherited abnormalities of DNA mismatch repair genes. Inherited mutations are seen in hereditary nonpolyposis colorectal cancer syndrome. Endometrial carcinoma shows as high an incidence of MSI as does colorectal carcinoma. This review provides a framework for the gynecologic pathologist to understand the complexities of MSI in endometrial carcinoma, by discussing the basic mechanisms of mismatch repair and carcinogenesis, testing, the morphologic features of MSI endometrial cancer and the contradictory data regarding prognosis.

Hereditary non-polyposis colorectal cancer or Lynch syndrome: the gynaecological perspective

PURPOSE OF REVIEW

Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch syndrome is characterized by a number of other cancers including colorectal, endometrial and ovarian cancer. This review covers the gynaecological aspects of managing women with HNPCC: diagnostic criteria, molecular tests for diagnosis, cancer risks and different strategies for surveillance and prevention.

RECENT FINDINGS

Studies correcting for ascertainment bias found slightly lower penetrance estimates than those obtained from high-risk families. HNPCC linked ovarian cancer presents at an earlier age and stage and has similar survival rates as sporadic cancer. In endometrial tumours, microsatellite instability or immunohistochemistry has limited effectiveness in selecting individuals for genetic testing, due to molecular differences. Population-based data indicate that a significant proportion of mismatch repair gene carriers would be missed by current clinical criteria. Effective risk prediction models complement clinical risk assessment. Effectiveness of screening is unproven and prophylactic surgery is the best preventive option for women who have completed their families. Multimodal screening protocols from the age of 30-35 years are being evaluated.

SUMMARY

Risk of endometrial cancer in women with Lynch syndrome is as high as the risk of colorectal cancer. Further research is needed to identify the appropriate strategy for clinical risk assessment and optimize screening. A multidisciplinary approach is necessary to manage these women.

Predicting Clinical Outcome in Patients Diagnosed with Synchronous Ovarian and Endometrial Cancer

Purpose: Patients with synchronous ovarian and endometrial cancers may represent cases of a single primary tumor with metastasis (SPM) or dual primary tumors (DP). The diagnosis given will influence the patient's treatment and prognosis. Currently, a diagnosis of SPM or DP is made using histologic criteria, which are frequently unable to make a definitive diagnosis.

Experimental Design: In this study, we used genetic profiling to make a genetic diagnosis of SPM or DP in 90 patients with synchronous ovarian/endometrial cancers. We compared genetic diagnoses in these patients with the original histologic diagnoses and evaluated the clinical outcome in this series of patients based on their diagnoses.

Results: Combining genetic and histologic approaches, we were able make a diagnosis in 88 of 90 cases, whereas histology alone was able to make a diagnosis in only 64 cases. Patients diagnosed with SPM had a significantly worse survival than patients with DP (P = 0.002). Patients in which both tumors were of endometrioid histology survived longer than patients of other histologic subtypes (P = 0.025), and patients diagnosed with SPM had a worse survival if the mode of spread was from ovary to endometrium rather than from endometrium to ovary (P = 0.019).

Conclusions: Genetic analysis may represent a powerful tool for use in clinical practice for distinguishing between SPM and DP in patients with synchronous ovarian/endometrial cancer and predicting disease outcome. The data also suggest a hitherto uncharacterized level of heterogeneity in these cases, which, if accurately defined, could lead to improved treatment and survival.

Coexisting endometrial and ovarian carcinomas: a retrospective clinicopathological study

The purpose of this study was to characterize patients diagnosed with synchronous primary carcinomas of the endometrium and ovary. Between 1985 and 2002, 46 patients with synchronous primary carcinomas of the endometrium and ovary were identified. Clinical and pathological information was obtained from the database and pathological reports. Kaplan-Meier survival analysis, log rank tests of survival differences, and multivariate Cox regression analysis were performed. Median age at diagnosis was 55 years. Twenty-one patients (46%) had an endometrioid histology both of their endometrial and ovarian cancers. Patients with younger age, high uterine differentiation grade, and early-stage ovarian cancer had a more favorable prognosis than those with older age, low grade of differentiation, and advanced stage disease. The Cox proportional hazards model analysis indicates that young age and high grade of differentiation are independent prognostic factors. In this series of patients, women with synchronous primary cancer of the endometrium and ovary were young; the survival rate was greater in patients aged less than 50 years and in patients with an early stage. No significantly different survival between patients with endometrioid carcinoma and patients with non-endometrioid carcinomas was detected.

Synchronous early-stage endometrial and ovarian cancer

OBJECTIVE

To explore the clinicopathologic findings and oncological outcome of early-stage synchronous endometrial and ovarian malignancies.

METHODS

A retrospective study of 93 women with synchronous stage I ovarian and stage I-II endometrial cancer treated between December 1981 and August 2005 in the gynecologic oncology department of San Gerardo Hospital, Italy.

RESULTS

Fifty-one percent of the ovarian tumors were stage Ia and 71% of the endometrial cancers had minimal myometrial invasion. Endometrioid histology and grade 2 disease were prevalent in both sites. Hyperplasia and endometriosis coexisted in 71% and 22% of endometrial and ovarian cancers, respectively. The actuarial 5-year disease-free and overall survival rates were 83% and 96%, respectively.

CONCLUSION

The incidence of synchronous endometrial and ovarian cancer is not negligible, especially among young women. Synchronous cancers show very favorable pathologic features and have an excellent oncologic outcome. Adjuvant therapy should be tailored according to surgical staging and histology.

Synchronous primary cancers of the endometrium and ovary

Simultaneous detection of malignancy in the endometrium and ovary represents an uncommon event. The objective of the study was to clarify the possible factors that influenced on the survival. From 1977 to 2005, totally 27 patients fulfilled the criteria and were included in the study. The medical records and the pathologic reports were reviewed. The histologic determination was followed by the World Health Organization Committee classification, and cancer stage was based on the staging system of the FIGO. The Kaplan-Meier survival analyses were generated and compared by the log-rank test. The incidence of synchronous primary endometrial and ovarian cancers was 3.3% in patients with endometrial cancer and 2.7% in patients with ovarian cancer. The mean survival in the group of similar histology (n= 15) was 63 months, and 48 months in the group of dissimilar histology (n= 12) (P= 0.63). The mean survival in the group of early stage (n= 21) was 68 months and 15 months in the group of advanced stage (n= 6) with statistic significance (P= 0.0003). However, the impact of adjuvant therapy on survival did not reach statistic significance (P= 0.15 for chemotherapy; P= 0.69 for radiotherapy). We conclude that the majority of the patients belonged to concordant endometrioid histology in endometrium and ovary, and it tends to be early stage and low grade with favorable prognosis. The stage had more significant influence on the survival than the histology. Adjuvant therapy should be given especially in patients with advanced stage although the optimal management remained to be determined.

The high frequency of de novo promoter methylation in synchronous primary endometrial and ovarian carcinomas

PURPOSE

The methylation status of hMLH1, CDKN2A, and MGMT was investigated in a panel of synchronous cancers of the ovary and endometrium, fulfilling the clinicopathologic criteria for independent primary tumors to define the possible role of epigenetic mechanisms in the development of these cancers.

EXPERIMENTAL DESIGN

Bisulfite-converted DNA from 31 tumors (13 endometrial and 18 ovarian carcinomas) and from matched normal tissue of 13 patients was analyzed by a methylation-specific PCR assay at the CpG-rich 5' regions of all three genes. In all tumors, we also investigated the presence of microsatellite instability and hMLH1 immunohistochemical expression in relation to hMLH1 hypermethylation status.

RESULTS

Methylation of hMLH1, CDKN2A, and MGMT was detected in 39%, 41%, and 48% of endometrial and ovarian tumors, respectively. hMLH1 hypermethylation was observed in all tumors of five patients, and it was invariably associated with loss of hMLH1 protein and presence of microsatellite instability. CDKN2A and MGMT methylation was randomly detected among both endometrial (45% and 24% of cases, respectively) and ovarian carcinomas (39% and 39% of cases, respectively). Concordant methylation at two or three genes was observed in 35% of cases.

CONCLUSIONS

Epigenetic inactivation of hMLH1, CDKN2A, and MGMT may be a common and early event in the development of synchronous primary endometrial and ovarian carcinomas and may qualify as a marker of a field cancerization encompassing the ovary and endometrium. Detection of MGMT hypermethylation may be useful to define a set of gynecologic malignancies with a specific sensitivity to alkylating chemotherapy.

Lack of association between microsatellite instability and benign adrenal tumors

BACKGROUND

The adrenal gland may give rise to pheochromocytomas, which are catecholamine-producing tumors originating from the adrenal medulla, or to adrenocortical tumors, which derive from the adrenocortical cortex and may be secreting or not. The genetic mechanisms underlying the formation of these tumors include somatic mutations in susceptibility genes, especially in the familial forms, and allelic loss, especially in chromosome 1.

AIM

The aim of this study was to investigate a third genetic mechanism by evaluating microsatellite instability using the reference markers (Bat25, Bat26, D2S123, D5S346, D17S250) validated by the National Cancer Institute. Microsatellite loci were analyzed in 32 benign tumors, including 11 pheochromocytomas and 21 adrenocortical tumors, in patients with and without familial syndrome.

RESULTS

The different alleles of microsatellite loci were reliably detected by DNA fragments analysis, whereas data obtained after melting-point analysis on the Lightcycler were inconsistent. No microsatellite instability was detected in any tumor. One patient with a unilateral pheochromocytoma showed a loss of heterozygosity for D17S250. A second patient with a MEN-2A syndrome and a two-sided pheochromocytoma exhibited a loss of heterozygosity for D2S123 in the right tumor only and a retention of heterozygosity for all markers in the left tumor.

CONCLUSIONS

These results suggest that microsatellite instability, evaluated by the five reference markers of the National Cancer Institute, is not a feature of benign adrenal tumors.