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Aberration in chromosomal structure characterizes almost all cancers and has profound biological significance in tumor development. It can be facilitated by various mechanisms including overexpression of cyclin E1 and centrosome amplification. As ovarian high-grade serous carcinoma has pronounced chromosomal instability, in this study we sought to determine whether increased copy number of CCNE1 which encodes cyclin E1 and centrosome amplification (>2 copies) occurs in its putative precursor, serous tubal intraepithelial carcinoma. We found CCNE1 copy number gain/amplification in 8 (22%) of 37 serous tubal intraepithelial carcinomas and 12 (28%) of 43 high-grade serous carcinomas. There was a correlation in CCNE1 copy number between serous tubal intraepithelial carcinoma and high-grade serous carcinoma in the same patients (P

The proposal that serous tubal intraepithelial carcinoma (STIC) is the precursor of ovarian high-grade serous carcinoma (HGSC) is based on several lines of investigation [1,2]. First, STICs are found in approximately 10–15% of Fallopian tubes removed prophylactically from women at high risk of developing ovarian carcinoma because of a germline BRCA mutation. Second, STICs are detected in 50–60% of cases of sporadic (without germline mutations of BRCA) ovarian, tubal,and so-called primary peritoneal HGSCs [3,4]. Third, STICs frequently up-regulate oncogene products, such as cyclin E1, Rsf-1, and fatty acid synthase, that are also overexpressed in HGSC [5]. Fourth, STICs have relatively shorter telomeres compared with concurrent ovarian HGSC, as occurs with precursor lesions in other sites. Finally, in a small series of five cases, STICs and concurrent ovarian HGSCs, the same TP53mutations were detected in STICs and HGSCs [12], indicating a potential clonal relationship. Besides exploiting the presence of TP53 mutations in STIC and HGSC as a method of showing a clonal relationship, detection of TP53 mutations in tissue specimens has utility in confirming the histological diagnosis of STIC since it has been reported that TP53 mutations occur in over 95% of ovarian HGSCs [6,7]. For histological diagnosis, however, detection of mutated TP53 is not practical and therefore immunohistochemical detection of p53 protein has been used as a surrogate marker. There have been only a few studies correlating p53 expression with TP53 mutation in ovarian HGSC [8–11] and none that we are aware of in STICs. Accordingly, we undertook the present study of STICs with concurrent pelvic HGSCs in order to (1) confirm a clonal relationship of STIC with HGSC in a relatively large series of cases, and (2) clarify the relationship of immunohistochemical expression of p53 protein with the mutational status of the TP53 gene.

Serous tubal intraepithelial carcinoma (STIC) has been proposed as a precursor for many pelvic high-grade serous carcinomas. Our previous analysis of the ovarian cancer genome identified several genes with oncogenic potential that are amplified and/or overexpressed in the majority of high-grade serous carcinomas. Determining whether these genes are upregulated in STICs is important in further elucidating the relationship of STICs to high-grade serous carcinomas and is fundamental in understanding the molecular pathogenesis of high-grade serous carcinomas. In this study, 37 morphologically defined STICs were obtained from 23 patients with stage IIIC/IV high-grade serous carcinomas. Both STICs and the high-grade serous carcinomas were analyzed for expression of Rsf-1 (HBXAP), cyclin E, fatty acid synthase (FASN) and mucin-4. In addition, they were examined for expression of established markers including p53, Ki-67 and p16. We found that diffuse nuclear p53 and p16 immunoreactivity was observed in 27 (75%) of 36 and 18 (55%) of 33 STICs, respectively, whereas an elevated Ki-67 labeling index (or=10%) was detected in 29 (78%) of 37 STICs. Cyclin E nuclear staining was seen in 24 (77%) of 35 STICs, whereas normal tubal epithelial cells were all negative. Increased Rsf-1 and FASN immunoreactivity occurred in 63%, and 62% of STICs, respectively, compared with adjacent normal-appearing tubal epithelium. Interestingly, only one STIC showed increased mucin-4 immunoreactivity. Carcinomas, when compared with STICs, overexpressed p16, Rsf-1, cyclin E and FASN in a higher proportion of cases. In conclusion, STICs express several markers including Rsf-1, cyclin E and FASN in high-grade serous carcinomas. In contrast, mucin-4 immunoreactivity either did not change or was reduced in most STICs. These results suggest that overexpression of Rsf-1, cyclin E and FASN occurs early in tumor progression.

There is compelling evidence to suggest that seroustubal intraepithelial carcinoma (STIC) is the likely primary sitefor the development of many pelvic high-grade serous carcino-mas (HGSCs). Identifying molecules that are upregulated inSTIC is important not only to provide biomarkers to assist inthe diagnosis of STIC but also to elucidate our understanding ofthe pathogenesis of HGSC. In this study, we performed RNAsequencing to compare transcriptomes between HGSC and nor-mal fallopian tube epithelium (FTE), and we identified LAMC1encoding laminin g1 as one of the preferentially upregulated genesassociated with HGSC. Reverse transcription polymerase chainreaction further validated LAMC1 upregulation in HGSC ascompared with normal FTE. Immunohistochemical analysis wasperformed on 32 cases of concurrent HGSC and STIC. The latterwas diagnosed on the basis of morphology, TP53 mutations, andp53 and Ki-67 immunohistochemical patterns. Laminin g1im-munostaining intensity was found to be significantly higher inSTIC and HGSC compared with adjacent FTE in all cases(P

There is mounting evidence that serous tubal intraepithelial carcinoma (STIC) is the immediate precursor of ovarian high-grade serous carcinoma (HGSC) (1–4) but the criteria for its diagnosis are not well established. A recent study, in fact, showed that interobserver reproducibility, even among expert gynecologic pathologists, was moderate at best (5). As more women with a family history of ovarian carcinoma undergo risk-reducing salpingo oophorectomy and as the SEE-FIM protocol, which allows more thorough evaluation of the fallopian tubes (6), becomes more widely used, this problem will become increasingly important. Pathologists will encounter not only STICs but other tubal abnormalities that may either be precursors of STICs or benign mimickers. In view of the difficulties in establishing a diagnosis on the basis of morphology alone, we have undertaken a number of studies to determine the most sensitive and specific methods of diagnosing STICs. We first investigated alterations in p53, because somatic mutation of TP53 is the most common molecular genetic change of HGSC. TP53 mutational status was correlated with p53 immunoreactivity and clinicopathologic characteristics (7). We found that STICs harbor TP53 mutations in the majority of the cases (91.3%) and these were the identical mutations found in the associated HGSC. Positive immunostaining for p53, however, depended on whether the mutations were missense mutations that resulted in strong staining or nonsense mutations that resulted in a truncated protein not recognized by the p53 antibody and therefore there was complete absence of staining. For these latter cases, in particular, we reasoned that the Ki-67 labeling index might be a useful adjunct to morphology and p53 immunostaining, because Mib1 staining would provide a sensitive and potentially quantifiable method of assessing proliferation in these lesions. Some previous studies have reported an increase in proliferation in STIC (range from 10% to 95%) compared with epithelium of the normal fallopian tube, but the range of the index in normal fallopian tube epithelium (FTE) has not been systematically evaluated so far (8,9). We therefore carried out the present study to determine the baseline Ki-67 proliferation index using Ki-67 staining in normal FTE compared with STICs.

A transrectal (TR) approach for natural orifice translumenal endoscopic surgery (NOTES) makes sense for colorectal surgery because the colotomy can be incorporated into subsequent anastomosis. Because cancer is a primary indication for left-sided colon resection, oncologic standards will have to be met by a NOTES procedure. This study aimed to assess whether pure TR rectosigmoidectomy can be performed with strict adherence to oncologic principles compared with a conventional laparoscopically assisted approach (LAP).Human male cadavers were allocated to either TR (n = 4) or LAP (n = 2). A simulated sigmoid lesion was created at 25 cm. Transrectal retrograde mobilization of the rectosigmoid was performed using conventional transanal endoscopic microsurgery (TEM) instrumentation. After ligation of the superior hemorrhoidal artery and further mobilization, the specimen was delivered transanally and divided extracorporeally. Using a circular stapler, NOTES colorectal anastomosis was performed. Lymph node yield, adequate resection margins, and operative time were compared with LAP.Transrectal retrograde rectosigmoid dissection was achieved in all attempts (4/4) and showed numbers of lymph nodes (median, 5; range, 3-6) similar to the LAP group (median, 4.5; range, 2-7). One pure TR approach failed to resect the lesion. Three TR procedures required additional mobilization via an abdominal approach to provide adequate margins. The mean length of TR specimens was 16 ± 4 cm compared with 31 ± 9 cm achieved by LAP (p0.01). The TR operative time was significantly longer (247 ± 15 vs 110 ± 14 min).Lymph node yield during TR rectosigmoidectomy was similar to that achieved by the LAP approach. However, conventional TEM instrumentation alone did not permit adequate colon mobilization. This indicates a need for flexible instrumentation or other technical solutions to perform true NOTES colectomies.

Short telomeres are one of the main genetic manifestations in human cancer, as they have been shown to play an important role in inducing chromosomal instability and in contributing to tumor progression. The purpose of this study was to determine if changes in telomere length occur in serous tubal intraepithelial carcinoma (STIC), the putative precursor of "ovarian" high-grade serous carcinoma (HGSC). Twenty-two STICs from 15 patients with concurrent but discrete HGSCs were analyzed for telomere length on formalin-fixed, paraffin-embedded sections by conducting p53 immunofluorescence to assist in identifying STICs and telomere-specific FISH. Telomere length (short, long, or no change) in STICs was compared with HGSCs using normal fallopian tube epithelium and stromal cells as controls. We found that STICs had the shortest telomeres, as 18 (82%) of 22 STICs had short telomeres, whereas only 2 (9%) showed no change and 2 (9%) had long telomeres compared with the normal-looking tubal epithelium. In contrast, among 12 paired HGSCs and STICs, 6 HGSCs showed an increase in telomere length, one showed a decrease in length and 5 did not show any change when compared with their matched STICs, although, such as STICs, the majority of HGSCs had shorter telomeres than the associated normal tubal epithelial cells. These differences in telomere length between normal tubal epithelial cells and STICs, and between STICs and HGSCs were statisticaly significant (P

Telomere shortening is one of the main genetic manifestations in human cancer which can contribute to initial chromosomal instability and ultimately tumor progression. The purpose of this study was to determine if changes in telomere length occur in serous tubal intraepithelial carcinoma (STIC), a putative precursor of “ovarian” high-grade serous carcinoma (HGSC). 22 STICs from 15 patients with concurrent HGSCs were analyzed by performing telomere-specific FISH and p53 immunofluorescence, to assist in identifying STICs. Telomere length in STICs was compared to HGSCs using normal fallopian tube epithelium (NFT), and stromal cells as controls. Telomeres length of these HGSCs was compared to 134 HGSCs, serving as a validation set. Immunostaining for Ki67, a proliferation index, and H2AX, a marker of DNA damage, was also performed. We found that STICs had the shortest telomeres, as 18 (82%) STICs had short telomeres, while 2 (9%) showed no change, and 2 (9%) had long telomeres compared to the NFT (Table 1). The majority of HGSCs also displayed shorter telomeres than the associated NFT. However, among 12 paired HGSCs and STICs, 7 HGSCs showed a significant increase in telomere length, 1 showed a decrease in length and 4 did not show any change when compared to their matched STICs. These differences between NFT and STICs, and between STICs and HGSCs were significant (p< 0.05). Finally, we found a weak correlation between telomere length in STICs and the percentage of H2AX positive cells (R2= 0.1021). In conclusion, the finding of shortened telomeres, which have been shown to be one of the earliest molecular changes in carcinogenesis, in the vast majority of STICs provides further support to the proposal that STICs are precursors of HGSC and opens new areas of research in elucidating the early events of ovarian high-grade serous carcinogenesis.Table 1:The relative telomere length in NFT, STIC, and HGSC in the same patients (SD, Standard Deviation; NA, Not Available).PatientSTICNFTSTICHGSCP-value STICP-value STICP-value HGSC nonoMeanSDMeanSDMeanSDcompared to NFTcompared to HGSCcompared to NFTKi67 (%)yH2AX (%)1Tl9.93.76.519.71.51.70.35670.174< 0.00019002T28.65.94.32.64.03.60.00060.7130.000660502T38.65.94.93.74.03.60.00510.3440.000640603T417.55.13.32.5NANA< 0.0001NANA503T517.55.16.83.3NANA< 0.0001NANA200 T622.07.87.04.514.26.6< 0.00010.0001< 0.000160100 T722.07.83.02.114.26.6< 0.00010.0001< 0.0001601005TS9.24.43.94.66.53.4< 0.00010.01570.010110906T93.92.236.16.144.011.9< 0.00010.002< 0.000120807T108.23.43.73.73.44.1< 0.00010.767< 0.0001301008Til14.712.70.80.95.83.9< 0.00010.0001< 0.0001801009T1217.210.19.05.48.04.60.00020.443< 0.000180NA9T1317.210.19.05.28.04.60.00020.443< 0.000180NA10T143.22.80.81.6NANA0.0001NANA1010010T153.22.81.51.6NANA0.0055NANA5010010T163.22.80.00.1NANA< 0.0001NANA504011T172.82.02.63.328.523.00.77750.0001 Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-343.