Genetic imbalance on chromosome 17 in papillary serous carcinoma of the peritoneum

Multicenter Clinicopathological Study of High-Grade Serous Carcinoma Presenting as Primary Peritoneal Carcinoma

OBJECTIVE

We conducted a multicenter clinicopathological study to characterize patients with high-grade serous carcinoma presenting as primary peritoneal carcinoma (clinical PPC).

METHODS

At 9 sites in Japan, patients with clinical PPC diagnosed according to Gynecologic Oncology Group criteria were enrolled retrospectively. The Gynecologic Oncology Group criteria allow for minor ovarian involvement by high-grade serous carcinoma. There was no systematic detailed histopathological review of the fallopian tubes to determine whether they were involved by serous carcinoma.

RESULTS

There were 139 patients and 64% were aged 60 years or older. Median pretreatment serum CA-125 was 1653.5 IU/mL. Pretreatment performance status was poor in more than 50%, endometrial cytology was positive in 40.3%, and the preoperative clinical diagnosis was correct in 72.7%. Primary debulking surgery was performed in 36% of patients, whereas 64% underwent neoadjuvant chemotherapy (NAC) with interval debulking surgery (IDS). The main tumor sites were the upper abdomen (greater omentum), extrapelvic peritoneum, mesentery, and diaphragm. Lymph node metastasis was found in 46.8% of patients undergoing systematic retroperitoneal node dissection. The optimal surgery rate was 32.0% with primary debulking surgery versus 53.9% with NAC and IDS (P = 0.0139). The response rate was 82.0% with NAC and 80.6% with postoperative chemotherapy. Median progression-free survival was 19.0 months and median overall survival was 41.0 months. Multivariate analysis showed that prognostic factors for progression-free survival were NAC and residual tumor diameter after debulking surgery, whereas the only prognostic factor for overall survival was the residual tumor diameter.

CONCLUSIONS

This study identified various characteristics of clinical PPC. Neoadjuvant chemotherapy with IDS is a reasonable treatment strategy, and complete debulking surgery is optimum.

Extrauterine high-grade serous carcinomas with bilateral adnexal involvement as the only two disease sites are clonal based on tp53 sequencing results: implications for biology, classification, and staging

A previous multicenter study of 67 cases of Stage I/II tubo-ovarian high-grade serous carcinoma with complete tubal sampling identified 7 cases in which there were only two disease sites, comprising tumor involving opposite adnexa with no extra-adnexal involvement. This study aimed to determine whether such low-stage extrauterine high-grade serous carcinomas with only two sites of involvement, located on opposite adnexa, have identical or different TP53 mutations in order to investigate their clonal relationship. DNA extracted from both sites of involvement was subjected to TP53 sequencing (n=6) or sequencing of one site and mutation confirmation by droplet digital PCR for the other site (n=1). Of the 7 cases analyzed, 1 case had unilateral serous tubal intraepithelial carcinoma with contralateral ovarian high-grade serous carcinoma, 3 had tubal high-grade serous carcinomas (±serous tubal intraepithelial carcinoma) with contralateral ovarian high-grade serous carcinoma, 2 had bilateral ovarian high-grade serous carcinomas with normal tubes, and 1 had bilateral fallopian tube high-grade serous carcinoma with normal ovaries. All 7 cases showed identical TP53 mutations in tumor from both disease sites. Therefore, these rare cases of high-grade serous carcinoma confined to opposite adnexa all show clonal identity between the two sites of involvement, suggesting unifocal origin and metastasis rather than multifocal origin. Our results suggest that serous tubal intraepithelial carcinoma or adnexal high-grade serous carcinoma can metastasize to the contralateral adnexa without peritoneal involvement. Given the clonal relationship between the two sites, such cases should be considered stage II, with stage I reserved for cases with unilateral and unifocal adnexal involvement. Furthermore, serous tubal intraepithelial carcinoma without invasion should be taken to constitute a disease site for staging purposes.

Tissue glycomics distinguish tumour sites in women with advanced serous adenocarcinoma

In the era of precision medicine, the tailoring of cancer treatment is increasingly important as we transition from organ‐based diagnosis towards a more comprehensive and patient‐centric molecular diagnosis. This is particularly the case for high‐grade serous adenocarcinomas of the ovary and peritoneum, which are commonly diagnosed at an advanced stage, and collectively treated and managed similarly. We characterized the N‐ and O‐glycome of serous ovarian (OC) and peritoneal cancer (PC) tissues using PGC‐LC‐ESI‐IT‐MS/MS profiling and validated the discriminatory glycans and their corresponding glyco‐gene expression levels using cell lines and transcriptomic data from 232 patients. Overall, the N‐ and O‐glycan repertoires of both cancer types were found to comprise mostly of α2,6‐sialylated glycan structures, with the majority of N‐glycans displaying the biantennary mono‐ and disialylation as well as bisecting‐type biantennary glycans. The MS profiling by PGC‐LC also revealed several glycan structural isomers that corresponded to LacdiNAc‐type (GalNAcβ1‐4GlcNAc) motifs that were unique to the serous ovarian cancers and that correlated with elevated gene expression of B4GALNT3 and B4GALNT4 in patients with serous cancer. Statistical evaluation of the discriminatory glycans also revealed 13 N‐ and 3 O‐glycans (P < 0.05) that significantly discriminated tumour‐sampling sites, with LacdiNAc‐type N‐glycans (m/z 1205.0²⁻ and m/z 1059.4²⁻) being associated with ovarian‐derived cancer tissue and bisecting GlcNAc‐type (m/z 994.9²⁻) and branched N‐glycans (m/z 1294.0²⁻ and m/z 1148.4²⁻) upregulated at the metastatic sites. Hence, we demonstrate for the first time that OC and PC display distinct molecular signatures at both their glycomic and transcriptomic levels. These signatures may have potential utility for the development of accurate diagnosis and personalized treatments.

Upregulation of miR-497 induces hepatic insulin resistance in E3 rats with HFD-MetS by targeting insulin receptor

OBJECTIVE

The study aims to find regulatory microRNA(s) responsible for down-regulated insulin receptor (InsR) in the liver of HFD-MetS E3 rats with insulin resistance.

METHODS

Firstly, hepatic insulin resistance in HFD-MetS E3 rats was evaluated by RT-qPCR, western blotting, immunohistochemistry and PAS staining. Secondly, the candidate miRNAs targeting rat InsR were predicted through online softwares and detected in the liver of HFD-MetS E3 rats with insulin resistance. Then, the expression of InsR, phosphorylated IRS-1 (pIRS-1) at Tyr632, phosphorylated AKTs (pAKTs) at Ser473 and Thr308, phosphorylated GSK-3β (p GSK-3β) at Ser9, phosphorylated GS (pGS) at Ser641 and the glycogen content were detected in CBRH-7919 cells treated with 100 nM insulin for different time periods by western blotting or PAS staining respectively, after transient transfection with miR-497 mimics or inhibitors for 24 h. Lastly, the relation between miR-497 and InsR was further determined using dual luciferase reporter assay.

RESULTS

Elevated miR-497 was negatively related with down-regulated InsR in the liver of HFD-MetS E3 rats with insulin resistance. Comparing with the mNC group, glycogen content and the expression of InsR, pIRS-1 (Tyr632), pAKTs (Ser473 and Thr308) and pGSK-3β (Ser9) decreased significantly in CBRH-7919 cells, while pGS (Ser641) increased significantly, after transient transfection with miR-497 mimics for 24 h and treatment with 100 nM insulin for corresponding time periods, counter to those results in CBRH-7919 cells after similar procedures with miR-497 inhibitors and insulin. In addition, dual luciferase reporter assay further confirmed that miR-497 can bind to the 3'UTR of rat InsR.

CONCLUSION

Insulin receptor is the target gene of miR-497, and elevated miR-497 might induce hepatic insulin resistance in HFD-MetS E3 Rats through inhibiting the expression of insulin receptor and confining the activation of IRS-1/PI3K/Akt/GSK-3β/GS pathway to insulin.

Downregulated miR-195 detected in preeclamptic placenta affects trophoblast cell invasion via modulating ActRIIA expression

Background

Preeclampsia (PE) is a pregnancy-specific syndrome manifested by on-set of hypertension and proteinuria after 20 weeks of gestation. Abnormal placenta development has been generally accepted as initial cause of the disorder. Recently, miR-195 was found to be down-regulated in preeclamptic placentas compared with normal pregnant ones, indicating possible association of this small molecule with placental pathology of preeclampsia. By far the function of miR-195 in the development of placenta remains unknown.

Methodology/Principal Findings

Bioinformatic assay predicted ActRIIA as one of the targets for miR-195. By using Real-time PCR, Western blotting and Dual Luciferase Assay, we validated that ActRIIA was the direct target of miR-195 in human trophoblast cells. Transwell insert invasion assay showed that miR-195 could promote cell invasion in trophoblast cell line, HTR8/SVneo cells, and the effect could be abrogated by overexpressed ActRIIA. In preeclamptic placenta tissues, pri-miR-195 and mature miR-195 expressions were down-regulated, whereas ActRIIA level appeared to be increased when compared with that in gestational-week-matched normal placentas.

Conclusions/Significance

This is the first report on the function of miR-195 in human placental trophoblast cells which reveals an invasion-promoting effect of the small RNA via repressing ActRIIA. Aberrant expression of miR-195 may contribute to the occurrence of preeclampsia through interfering with Activin/Nodal signaling mediated by ActRIIA in human placenta.

Potentially important microRNA cluster on chromosome 17p13.1 in primary peritoneal carcinoma

MicroRNAs are a group of small non-coding RNAs approximately 22 nucleotides in length. Recent work has shown differential expression of mature microRNAs in human cancers. We characterized the alteration in expression of a select group of microRNAs in primary peritoneal carcinoma relative to matched cases of ovarian serous carcinoma. MicroRNA expression was analysed using semi-quantitative stem-loop RT-PCR on a set of 34 formalin-fixed paraffin-embedded samples. Protein expression of p53 and bcl-2 was quantified in the corresponding tissue microarray. We provide definitive evidence that there is downregulation of a select group of microRNAs in tumours meeting Gynaecological Oncology Group criteria for primary peritoneal carcinoma relative to ovarian serous carcinoma. Specifically, we show decreased p53 expression and downregulation of miR-195 and miR-497 from the microRNA cluster site at chromosome 17p13.1 in primary peritoneal carcinoma relative to ovarian serous carcinoma. miR-195 and miR-497 may have potential roles as tumour-suppressor genes in primary peritoneal tumourigenesis.

Platinum resistance and impaired survival in patients with advanced primary peritoneal carcinoma: matched-case comparison with patients with epithelial ovarian carcinoma

OBJECTIVE

The objective of the study was to compare chemotherapy response and survival of patients with advanced primary peritoneal carcinoma (PPC) vs those with epithelial ovarian carcinoma (EOC).

STUDY DESIGN

From 1998 to 2004, 43 PPC patients were identified and matched to 129 patients with International Federation of Gynecology and Obstetrics stage IIIC-IV EOC by criteria abstracted from medical records. Primary endpoints were chemotherapy response, platinum resistance, progression-free survival (PFS), and overall survival (OS).

RESULTS

All patients received primary platinum-taxane chemotherapy. There was no significant difference in achieving a clinical complete response. PPC patients were more likely to be platinum resistant at 6 months and had significantly impaired PFS and OS. After multivariate analysis, PPC was independently associated with a worse prognosis for both survival endpoints.

CONCLUSION

PPC was associated with a similar initial response but a higher rate of platinum resistance and shorter PFS and OS. Consideration of these results may be useful for patient counseling, trial stratification, and molecular comparisons.

Primary peritoneal anaplastic giant cell carcinoma: case report of an unusual and highly malignant müllerian neoplasm

Virtually all primary peritoneal carcinomas (PPCs) are of serous papillary type. We report an unusual histologic type of PPC composed of anaplastic giant cells, which exhibited an aggressive clinical course. A 72-year-old woman presented with lower abdominal pain. Computed tomography showed a diffuse omental thickening. The patient underwent an exploratory laparotomy with omentectomy, total hysterectomy, bilateral salpingo-oophorectomy, and appendectomy. Pathologic examination revealed extensive omental replacement by tumor but only superficial surface cortical involvement of both ovaries, a disease distribution consistent with a typical müllerian-derived PPC. However, this neoplasm was composed of diffuse anaplastic tumor giant cells, rather than serous carcinoma, which is the usual histologic type encountered in PPC. The patient died within 1 month after surgery. We report this unusual histologic variant of PPC to raise awareness that anaplastic giant cell carcinoma may arise in the pelvic peritoneum as a primary tumor.

Peritoneal carcinoma in women with genetic susceptibility: implications for Jewish populations

Women from families with multiple cases of breast and ovarian cancer, specifically those who carry cancer-associated mutations of BRCA1 or BRCA2 are at increased life-time risk for peritoneal carcinoma, even after previous surgery to remove the ovaries, fallopian tubes and uterus. Hereditary breast-ovarian cancer (HBOC) syndrome and the associated BRCA1 and BRCA2 mutations are particularly prevalent in women of Jewish lineage, and specific BRCA1 and BRCA2 germline mutations have been linked with peritoneal carcinoma and HBOC syndrome in Jewish populations, especially those of Ashkenazi descent. This review presents the currently available data and looks forward toward further and better understanding of peritoneal carcinoma in women with inherited susceptibility. Over 90% of peritoneal cancer in patients from HBOC syndrome kindreds and associated with BRCA1 and BRCA2 mutations are serous carcinomas, which is equivalent with the proportion of ovarian cancers that are serous carcinomas in similar patients. The best indications are that while many peritoneal carcinomas in genetically susceptible women may arise directly from malignant transformation of the peritoneum, others might represent metastases from primary ovarian or fallopian tube carcinomas. Although the incidence of borderline ovarian tumors may not be increased in HBOC syndrome kindreds and those who carry cancer-associated BRCA1 and BRCA2 mutations, these individuals could be susceptible to malignant transformation of borderline lesions of the ovaries and peritoneum. Moreover, recent reports raise the question of possibly increased risk in Jewish carriers of germline BRCA1 mutations for uterine papillary serous carcinoma, which could be the source of metastasis to the peritoneum in some cases. The penetrance of cancer-associated BRCA1 mutations for ovarian cancer is estimated to be 11%-54%, and for BRCA2 mutations the penetrance for ovarian cancer is 11%-23%. So far, available screening methods appear to be insufficient for early detection of many ovarian cancers. Prophylactic oophorectomy has been found to reduce the risk for ovarian cancer in women from HBOC kindreds and those who carry cancer-associated BRCA1 and BRCA2 mutations, leaving a residual risk for peritoneal carcinomatosis of well less than 5%. Therefore, surgical removal of the ovaries, fallopian tubes and uterus, after child-bearing has been completed and by early in the fifth decade of life, are appropriate prophylactic procedures in women whose genetic susceptibility puts them at increased risk for cancers of mullerian tract origin, including ovarian and fallopian tube carcinomas and possibly serous carcinoma of the uterus. Hysterectomy, as well as salpingo-oophorectomy, removes the gynecologic organs targeted for malignant transformation in genetically susceptible women and simplifies decisions regarding hormone replacement therapy and chemical prophylaxis and treatment of breast cancer. Unless a transabdominal operative approach is otherwise indicated, laparoscopic-assisted transvaginal techniques are well suited for intra-abdominal exploration, cytology, biopsies and prophylactic salpingo-oophorectomy and hysterectomy in women with hereditary susceptibility to gynecologic cancer.

Prophylactic oophorectomy

Because of the lack of effective alternatives and the simplicity of the procedure, prophylactic oophorectomy is viewed as the best available tool for reducing the individual risk of ovarian cancer. The genetics of hereditary ovarian cancer are described in this chapter and a careful risk-versus-benefit assessment is provided with respect to two populations of patients that appear suitable candidates for this procedure. These include patients with increased risk of developing ovarian cancer due to hereditary genetic predisposition, in which the lifetime risk of ovarian cancer may be as high as 16-65%, depending on the penetrance of the germ-line mutation. Additionally, routine salpingo-oophorectomy in patients over 40 years undergoing scheduled gynaecological surgery or colorectal surgery might reduce the overall incidence of ovarian cancer by as much as 5% in the general population.

Allelotype of papillary serous peritoneal carcinomas

OBJECTIVE

Papillary serous peritoneal carcinoma (PSPC) is histologically indistinguishable from papillary serous ovarian carcinoma (PSOC) with a similar clinical presentation, yet may differ in its carcinogenesis. The purpose of this study was to determine the incidence of allelic loss and the frequency of p53 mutation by p53 overexpression in PSPC compared to PSOC.

METHODS

An allelotype analysis of 26 patients with PSPC was performed using 39 microsatellite markers from 25 chromosomal arms. Thirty-seven previously studied patients with PSOC served as the comparison. P53 mutations were detected by immunohistochemical protein overexpression.

RESULTS

There was significantly less LOH in PSPC than PSOC. Both the number of chromosomes with LOH and the proportion of tumors with allelic loss were less frequent. Significant LOH, defined as >/=30% of informative tumors having loss at a chromosome locus, was seen on 4 chromosome arms in PSPC: 12p, 17p, 17q, and 18q, compared to 18 arms in PSOC: 4q, 5q, 6p, 6q, 9p, 9q, 12p, 12q, 13q, 15q, 16q, 17p, 17q, 18q, 19p, 19q, 22q, and Xq (P < 0.001). The median LOH frequency was higher in PSOC than PSPC, 43% versus 33%, respectively (P = 0.013), and more PSOC tumors had LOH than PSPC tumors, 91% versus 65% (P = 0.042). P53 overexpression was detected in 80% of PSPC tumors.

CONCLUSIONS

LOH occurs less frequently in PSPC compared to PSOC. Chromosomal regions with high frequencies of LOH common to PSPC and PSOC, such as 12p, 17p, 17q, and 18q, may harbor tumor suppressor genes important in the carcinogenesis of both malignancies and likely include p53.