X chromosomal and autosomal loss of heterozygosity and microsatellite instability in human cervical carcinoma

The study analyzes tumor material and normal tissue from 27 patients with pure squamous cell carcinoma of the uterine cervix for loss of heterozygosity (LOH) and microsatellite instability (MSI) on 14 autosomal and 11 X chromosomal loci. Overall, 4-40% of the informative cases showed LOH at autosomal regions with the highest frequency at 3p (21-40%) and a marked frequency at 2q35-q37.1 (12.5%) and 17p13.3 (10%), representing regions with putative tumor suppressor gene (TSG) function. The frequency of X chromosomal LOH ranged from 4% to 20%, with a maximum at Xq28 (20%) and Xq11.2-q12 (17%), again indicating alterations in TSG. A 12% LOH was seen at Xq21.33-q22.3, a region encoding a protein with a regulatory function in the cell cycle via cyclin-dependent kinases. MSI was detected in autosomal regions in up to 7% in regions linked to the X chromosome in up to 11%, probably indicating alterations of mismatch repair mechanisms. Our results and those obtained from the literature suggest that autosomal LOH and MSI in carcinomas of the cervix uteri are predominantly found at regions with putative TSG function. Beside TSG alterations, X chromosomal LOH is probably more strongly connected to disturbances in cell cycle regulation.     

Possible involvement of loss of heterozygosity in malignant transformation of ovarian endometriosis

Objective

Although histological and epidemiological studies have suggested that endometriosis has malignant potential, the molecular mechanism underlying the malignant transformation of endometriosis is poorly understood. Ovarian cancer arising from endometriosis (OCEM) may provide an ideal model for genetic studies. To investigate the genetic alterations during transformation of ovarian endometriosis into cancer, we analysed loss of heterozygosity (LOH) and mutations of tumour-related genes in OCEM cases (n = 12) that fulfilled the histological criteria and in solitary ovarian endometriosis (n = 12).

Methods

Each paraffin-embedded section was microdissected to isolate the endometriotic epithelium, transitional epithelium, and cancer cells. Extracted DNA was amplified by nested PCR. LOH was identified with fluorescence-labelled microsatellite markers. Mutations of tumour-related genes PTEN, TP53, and K-ras were examined by bidirectional DNA sequencing.

Results

With 13 microsatellite markers on six chromosomes, we detected 31 and eight LOH events in OCEMs and in solitary ovarian endometriosis, respectively. In the OCEM group, 18 LOH events were found in cancer cells alone, while 13 LOH events were found in all cancer, transitional, and endometriotic tissues. High frequencies of LOH were detected on chromosomes 9p, 10q, and 13q. However, only two point mutations were detected in cancer cells in one case.

Conclusion

Our study suggested that accumulated LOH events on some chromosome loci may be involved in malignant transformation of endometriosis, while mutations in certain tumour-related genes are not.     

Loss of heterozygosity on chromosome 17q in epithelial ovarian tumors: association with carcinomas with serous differentiation.

Loss of heterozygosity (LOH) on chromosome 17q is frequent in epithelial ovarian tumors, but its clinicopathologic significance remains to be elucidated. DNA of 50 patients with epithelial ovarian tumors was extracted from blood and from fresh-frozen and paraffin-embedded tissue (14 benign, 7 borderline, and 29 malignant). Six microsatellite loci were amplified by PCR (D17S250, TRHA1, D17S800, D17S855, D17S579, D17S513). LOH was scored by the absence or reduction of the signal to less than 50% of one of the alleles in tumor DNA compared with normal DNA. LOH was identified on chromosome 17q in at least one locus in 12 tumors (24%), all of them carcinomas (12 of 29 tumors, 41.3%). It occurred more frequently among high-grade serous carcinomas (8 of 14 tumors, 57%) and mixed endometrioid-serous carcinomas (2 of 5, 40%). LOH was detected in all informative markers of 10 tumors, suggesting the complete loss of an entire chromosome 17 homologue. Patients with LOH-positive carcinomas were older than those with LOH-negative malignant tumors (mean ages 67 and 49). The results support the hypothesis that LOH on chromosome 17q may be associated with the development of ovarian cancers in elderly patients, particularly with high-grade serous or mixed endometrioid-serous carcinomas.     

Investigation of loss of heterozygosity at specific loci on chromosomes 3p, 6q, 11p, 17p and 17q in ovarian cancer

In an attempt to further define the genetic events in the pathogenesis and progression of human ovarian cancer, an analysis of constitutional and ovarian carcinoma DNA samples revealed loss of heterozygosity (LOH) at specific loci on chromosomes 3p (38%), 6q (23%), 11p (33%), 17p (82%) and 17q (62%). In contrast, LOH was not observed in benign or borderline tumors. No significant association could be demonstrated between LOH at the loci studied and tumor stage, histologic subtype, grade or patient outcome. Further analyses of large tumor panels are now required to determine the relationship between LOH at these loci and the clinicopathological behavior of ovarian tumors.     

Benign, borderline, and malignant endometrioid neoplasia arising in endometriosis in association with tamoxifen therapy.

Tamoxifen therapy may result in a variety of endometrial proliferative lesions, including adenocarcinoma, and as recently suggested, proliferative changes within endometriosis. This report describes an endometrioid adenocarcinoma arising in ovarian endometriosis in a patient taking tamoxifen. There were also foci of benign and borderline endometrioid adenofibroma in the same ovary and a synchronous endometrioid endometrial adenocarcinoma in the uterus. The spectrum of benign, borderline, and malignant endometrioid neoplasia arising within endometriosis suggests that tamoxifen, as a result of its estrogenic effects, may cause proliferative and, in rare instances, malignant changes in endometriosis.     

A histologic study of ovarian endometriosis with emphasis on hyperplastic and atypical changes.

One hundred ninety-four cases of ovarian endometriosis, encountered during a 3-year period, were studied. In addition to endometrial-type epithelium and stroma that were present in each of these cases, oviduct-type epithelium was demonstrated in 26, papillary epithelial-lined projections in 7, and hobnail cells in 36 patients. Forty-three cases showed reactive epithelial changes, probably due to inflammation and regeneration. There were 4 cases of adenomatous hyperplasia. Severe epithelial atypism was seen in 7 patients (3.6%), 1 in conjunction with adenomatous hyperplasia. Although the areas of severe epithelial atypism in ovarian endometriosis may be of reactive origin, one must also consider the possibility that in some instances these atypical changes may constitute a neoplastic potential.     

Malignant transformation of endometriosis and genetic alterations of K-ras and microsatellite instability.

OBJECTIVES: To clarify the role of specific genetic alterations in the multi-step process of malignant transformation of endometriosis. METHODS: In cases of ovarian endometrioid carcinoma, we separated regions of normal endometriosis, atypical endometriosis and ovarian endometrioid carcinoma by laser microdissection, and examined K-ras mutation and microsatellite instability in each separated tissue sample. RESULTS: We detected K-ras mutation and microsatellite instability in endometrioid carcinoma tissue, but not in normal or atypical endometriosis bordering the cancerous region. CONCLUSIONS: The present findings suggest that K-ras mutation and microsatellite instability are associated with malignant transformation from atypical endometriosis to ovarian endometrioid carcinoma.     

Increased prevalence of p53 overexpression from typical endometriosis to atypical endometriosis and ovarian cancer associated with endometriosis

OBJECTIVE: To evaluate the expression of p53, c-erb-B-2, MIB1 and Bcl-2 in normal endometrium, endometriosis, atypical endometriosis and ovarian cancer associated with endometriosis, looking for immunohistochemical markers that may help determine endometriosis with premalignant potential. STUDY DESIGN: Between 1948 and 1999, 410 epithelial ovarian cancers and 521 cases of endometriosis were surgically treated at Fundación Jiménez Díaz. Pathology reports and slides were reviewed. Four groups were defined: (1) endometriosis/cancer (n=17); (2) atypical endometriosis (n=6); (3) endometriosis (n=17); (4) endometrium (n=7). Tumors and controls were immunostained and evaluated for expression of p53, c-erb-B-2, MIB1 and Bcl-2. Statistical analysis was performed using Chi-square for linear trends, Fisher exact and Kruskal-Wallis tests. RESULTS: Of the 410 cancers, 17 (4.1%) had associated endometriosis and of the 521 endometriosis, 6 (1.2 %) had atypical changes. Fourteen of 17 (82.4%) cancers associated with endometriosis and all atypical endometriosis had p53 overexpression. Only 2 of 17 (11.8%) endometriosis and none of the endometriums had mutant p53 (P<0.01). We found a trend towards increased expression of MIB1 (0.073) in the cancer and atypical endometriosis groups, and no differences in expression of Bcl-2 or c-erb-B-2. The sensitivity and specificity of p53 as a marker for the diagnosis of atypical endometriosis and cancer associated with endometriosis were 87%; CI 95% (73.2-100%) and 92% (80.6-100%), respectively. When comparing all groups, the mean positive p53 and MIB1 cell count was statistically significant (P=0.01). CONCLUSIONS: Overexpression of p53 in atypical endometriosis and cancer associated with endometriosis is a common finding and may be used to identify endometriosis with premalignant potential.     

Immunohistochemical localization of aromatase and apoptosis-associated proteins in ovarian serous cystadenocarcinoma arising from ovarian endometriosis

OBJECTIVE: To determine the risk of neonatal death (NND) in relation to birth weight for gestational age and the presence or absence of maternal hypertensive disease in preterm neonates. DESIGN: Record linkage of maternity data and neonatal mortality data. SETTING: Scotland, UK. POPULATION: A group of 6946 live singleton preterm neonates without lethal congenital abnormalities born at 24-32 weeks between 1986 and 1992 inclusive. This group included 1448 cases of maternal hypertensive disease and 850 neonatal deaths. MAIN OUTCOME MEASURE: Neonatal death. RESULTS: The median birth weight for each gestational week was estimated from a fitted curve and each birth weight was recalculated as a multiple of the relevant median. The frequency of NND was much higher at lower gestations (73% at 24 weeks down to 2% at 32 weeks). Though the overall frequency of NND was lower in cases with hypertensive disease (8.6% versus 13.2%) this can be attributed to the fact that there were relatively fewer hypertensive cases in the high risk group at 24-27 weeks. In the 5498 cases not associated with maternal hypertensive disease, there were 726 NNDs. The mean MoM of birthweight for these NNDs was 0.982 (95% CI 0.967-0.996); this was only marginally different from the population mean (0.998; 95% CI 0.993-1.004). In the 1448 cases with maternal hypertensive disease, there were 124 NNDs. The overall birthweight for gestational age in the hypertensive group was substantially less than that of the whole population (mean MoM 0.84; 95% CI 0.83-0.85) and that of the 124 NNDs was still lower (mean MoM 0.75; 95% CI 0.724-0.782). For both hypertensive and non-hypertensive cases, inspection of the data categorised into deciles showed that there was a continuous increase in the frequency of NND throughout the weight range, being lowest for the heaviest babies and highest for those in the lower centiles. CONCLUSION: (1) There is a relationship between birthweight for gestational age and risk of NND in infants born at 24-32 weeks; (2) this relationship is a continuum throughout the whole range of birthweight, not focused exclusively on a group defined as SGA; (3) provided appropriate birthweight standards are used, there is no extra effect on mortality from maternal hypertensive disease.     

Small cell carcinoma with neurosecretory granules arising in an ovarian dermoid cyst.

A rare small cell carcinoma with neurosecretory granules arising in an ovarian dermoid cyst with 7 years survival after conservative surgery and adjuvant chemotherapy with cisplatin, adriamycin, and cyclophosphamide is described. Light microscopy showed the typical uniformly small cells with hyperchromic nuclei and scanty basophilic cytoplasm within the mature cystic teratoma. Although none of the immunohistochemical stains were reactive, electron microscopy demonstrated the membrane-bound neurosecretory granules in some tumor cells. The related literature is reviewed and the issues concerning treatment options in this unusual malignancy are discussed.     

Analysis of p53 and c-erbB-2 expression in ovarian endometrioid carcinomas arising in endometriosis.

We assessed the immunohistochemical expression of p53 and c-erbB-2 oncoproteins in 13 ovarian endometrioid adenocarcinomas arising from endometriosis (group 1) and compared the findings with 15 otherwise similar cases without associated endometriosis (group 2). Tumors in group 1 showed a higher expression of both p53 and c-erbB-2 (p = 0.015 and p = 0.048, respectively). The expression of the two proteins was also significantly associated in group 1 (p = 0.013) but not in group 2 (p = 0.63) tumors. The different pattern of expression of p53 and c-erbB-2 in the two groups suggests that different molecular pathways may be involved in their pathogenesis.     

Endometrioid carcinoma of the Fallopian tube arising in tubo-ovarian endometriosis. A case report

The primitive endometrioid carcinoma of the fallopian tube is exceptional. Only three cases have been reported in the literature. Its rise on tubal endometriosis like for the ovary needs to meet the strict histological criteria established by Sampson and Scott in 1953. We report one case observed on a patient aged 45 years, who needed a total hysterectomy with bilateral annexectomy for menometrorrhagias associated to uterine leiomyomas which resisted to medical treatment. The finding of a primitive intra-epithelial endometrioid carcinoma of the left fallopian tube developed on bilateral tubo-ovarian endometriosis was fortuitously found during histological examination. Our observation seems to be unique since it shows an evident filiation between the lesions of tubal endometriosis and the adjoining endometrioid carcinoma contrary to the similar unique case reported in the literature where the link between the two lesions has not been demonstrated.     

遗传性卵巢癌组织中BRCA1基因杂合性丢失的研究

目的：探讨乳腺癌基因（ＢＲＣＡ１）在遗传性卵巢癌发生、发展中的作用,并分析ＢＲＣＡ１ 基因杂合性丢失（ＬＯＨ）。方法：应用多聚合酶链反应技术（ＰＣＲＴ）,对１０份遗传性卵巢癌组织中ＢＲＣＡ１ 基因内部的Ｄ１７Ｓ８５５ 微卫星位点进行ＬＯＨ检测。结果：２份发生杂合性丢失,ＬＯＨ发现率为２０％ 。结论：ＢＲＣＡ１在遗传性卵巢癌中具有肿瘤抑制基因的作用,同时不能排除其他肿瘤抑制基因的作用。     

Endometrioid carcinoma of the ovary and endometriosis: the association in postmenopausal women.

Histologic material from 42 patients with endometrioid carcinomas of the ovary was reviewed. Ovarian endometriosis was present in 11 cases (26%) and 8 of these patients were postmenopausal. The exact site of transition from benign to malignant epithelium was observed in 4 cases. The clinical characteristics of patients with associated endometriosis were not significantly different from those without this finding except that endometriosis was present only in patients with Grade 1 or Grade 2 carcinomas. These data suggest that ovarian endometriosis in the postmenopausal patient has the potential to undergo malignant transformation and, when detected, should be removed surgically.     

Xp22.2-3 loss of heterozygosity is associated with germline BRCA1 mutation in ovarian cancer

OBJECTIVE: X-Chromosome loss of heterozygosity (LOH) occurs in approximately 40% of ovarian cancers. We have previously demonstrated an association between nonrandom X-chromosome inactivation and germline BRCA1 mutation. The current study examines the association between X-chromosome LOH and BRCA1 mutation. METHODS: Ninety tumor DNA (81 ovary, 5 fallopian tube, 4 primary peritoneal) and matched peripheral blood mononuclear cell DNA samples were examined for LOH with 11 X-chromosome microsatellite DNA markers. RESULTS: Tumor DNA demonstrated frequent LOH at the Xp22.2-3 region (37.7% at DXS6807). Loss of heterozygosity on Xp was twice as common in tumor DNA from germline BRCA1 mutation carriers (9/14 vs 19/67, P = 0.02). In four evaluable samples, Xp22.2-3 LOH preferentially occurred from the active X allele. CONCLUSIONS: Our data support the hypothesis that an Xp22.2-3 gene product interacts with or modifies the expression of BRCA1 in some hereditary ovarian cancers.     

Microsatellite instability,MLH1 promoter methylation,and loss of mismatch repair in endometrial cancer and concomitant atypical hyperplasia

OBJECTIVE: MLH1 methylation is associated with the microsatellite instability (MSI) phenotype in endometrial cancer and atypical endometrial hyperplasia, a premalignant precursor to carcinoma. The observation that methylation is also seen in atypical endometrial hyperplasia without MSI suggests that methylation is an early event in endometrial tumorigenesis. Our objective was to determine if methylation is always present in MSI-positive atypical hyperplasia concomitant with MSI-positive, methylation-positive carcinoma. METHODS: We used laser capture microdissection to study MLH1 methylation and MSI in a large series of endometrial cancer cases that had previously been shown to have methylation and the MSI-high (MSI-H) phenotype. We resampled areas of carcinoma from 27 patients along with 51 foci of concomitant atypical endometrial hyperplasia. RESULTS: Consistent with previous reports, we saw MLH1 methylation in areas of atypical endometrial hyperplasia that did not show MSI. In addition, we noted that 18% of the MSI-H atypical endometrial hyperplasia DNAs lacked methylation of critical cytosines in the MLH1 promoter. Immunohistochemistry studies showed that these MSI-H unmethylated foci of atypical endometrial hyperplasia failed to express MLH1, as did regions of simple hyperplasia. CONCLUSION: Methylation of the MLH1 promoter is an early event in endometrial tumorigenesis. Given that not all MSI-positive tissues had methylation at cytosines -229 and -231, it appears that methylation may not be required for MLH1 silencing and loss of mismatch repair.