Manual vacuum aspiration (women's MVA) for endometrial biopsy for patients with suspected endometrial malignancies.

AIM: Endometrial biopsy is generally performed with a metal uterine curette sonde; however, recently, many types of vacuum aspirators are available, including the manual vacuum aspiration (MVA) system. We used the women's MVA system for endometrial sampling and evaluated its effectiveness in determining the presence of endometrial malignancy. METHODS: Forty-seven samples were examined using the following procedures after measuring endometrial thickness by transvaginal ultrasonography: fractional curettage biopsy (Bx; 20 samples), total curettage under general anesthesia (T/C; 13 samples), and MVA (14 samples). The quality of the endometrial samples was classified into four types: 1-4, where 1 denoted poor and 4, good quality. RESULTS: The mean score of the MVA group was significantly higher than that of the partial curettage biopsy group (p = 0.0065). No differences were observed between the MVA and total curettage groups (p = 1.00). When patients were divided into two groups according to endometrial thickness (<10 mm or ≥10 mm) and analyzed, both the MVA and T/C groups did not show a significant difference in their scores compared to the Bx group when the endometrial thickness was <10 mm. However, when the endometrial thickness was ≥10 mm, the MVA and T/C groups had significantly better scores than the Bx group (p = 0.0225 and p = 0.0244, respectively). Vagal reflex, as an adverse event, was observed only in two patients in the Bx group (2/20, 10%). CONCLUSION: Considering its quality and safety, Karman-type MVA for endometrial sampling could be an alternative to fractional curettage using a metallic uterine curette sonde.

Surgical margin status and recurrence pattern in invasive vulvar Paget's disease: A Japanese Gynecologic Oncology Group study.

OBJECTIVE: To examine the association between surgical margin status and recurrence pattern in invasive vulvar Paget's disease. METHODS: This is a preplanned secondary analysis of a previously organized nationwide retrospective study in Japan (JGOG-1075S). Women with stage I-IV invasive vulvar Paget's disease who received surgical treatment from 2001-2010 were examined (n=139). Multivariable analysis was performed to assess local-recurrence, distant-recurrence, and all-cause mortality based on surgical margin status. RESULTS: The median age was 70 years. The majority had stage I disease (61.2%), and the median tumor size was 5.0cm. Nodal metastasis was observed in 15.1%. Simple vulvectomy (46.0%) was the most common surgery type followed by radical vulvectomy (28.1%). More than half received vulvar reconstructive surgery (59.0%). Positive surgical margin was observed in 35.3%, and close margin <1cm was observed in 29.5%. Vulvectomy type was not associated with surgical margin status (P=0.424). The median follow-up was 5.8 years. Positive surgical margin was associated with increased local-recurrence (5-year cumulative rates for positive versus negative margin: 35.8% versus 15.0%, P=0.010) but not distant-recurrence (18.3% versus 16.0%, P=0.567). Positive surgical margin was also associated with increased all-cause mortality (5-year overall survival rates for positive versus negative margin: 72.6% versus 88.2%, P=0.032). In multivariable analysis, positive surgical margin remained an independent factor associated with increased risk of local-recurrence (hazard ratio 2.80, 95% confidence interval 1.18-6.63) and all-cause mortality (hazard ratio 2.87, 95% confidence interval 1.20-6.83). CONCLUSION: Positive surgical margin appears to be common in invasive vulvar Paget's disease that is associated with increased local-recurrence and all-cause mortality risks. Role of alternative surgical technique or adjuvant therapy merits further investigation to improve local disease control.

The mesenchymal transition subtype more responsive to dose dense taxane chemotherapy combined with carboplatin than to conventional taxane and carboplatin chemotherapy in high grade serous ovarian carcinoma: A survey of Japanese Gynecologic Oncology Group study (JGOG3016A1).

OBJECTIVE: Recently, we established new histopathological subtypes of high-grade serous ovarian cancer (HGSOC) that include the mesenchymal transition (MT) type, the immune reactive (IR) type, the solid and proliferative (SP) type and the papillo-glandular (PG) type. Furthermore, we identified that the mesenchymal transcriptome subtype might be sensitive to taxane. We investigated whether these different histopathological subtypes of HGSOC require individualized chemotherapy for optimal treatment. METHODS: We conducted the Japanese Gynecologic Oncology Group (JGOG) 3016A1 study, wherein we collected hematoxylin and eosin slides (total n = 201) and performed a histopathological analysis of patients with HGSOC registered in the JGOG3016 study, which compared the efficacy of conventional paclitaxel and carboplatin (TC) and dose-dense TC (ddTC). We analyzed the differences in progression-free survival (PFS) and overall survival (OS) among the four histopathological subtypes. We then compared the PFS between the TC group and the ddTC group for each histopathological subtype. RESULTS: There were significant differences in both PFS and OS among the four histopathological subtypes (p = 0.001 and p < 0.001, respectively). Overall, the MT subtype had the shortest PFS (median 1.4 y) and OS (median 3.6 y). In addition, the MT subtype had a longer PFS in the ddTC group (median 1.8 y) than in the TC group (median 1.2 y) (p = 0.01). Conversely, the other types had no significant difference in PFS when the two regimens were compared. CONCLUSIONS: The MT type of HGSOC is sensitive to taxane; therefore, the ddTC regimen is recommended for this histopathological subtype.

The Clinical Features of Recurrent Endometrial Cancer in Japan: Chemotherapy Instead of Radiotherapy as Postoperative Adjuvant Treatment.

OBJECTIVE: Chemotherapy is a standard adjuvant treatment after primary surgery for endometrial cancer in Japan. We aimed to characterize the clinical features of recurrent endometrial cancer (REC) patients in Japan. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 112 REC patients who were primarily treated at 1 of 3 university hospitals in Japan from 2005 to 2012. We analyzed overall survival since the first recurrence (R-OS) in accordance with several factors. RESULTS: Median patient age was 64 years. The median follow-up period was 48 months. The distributions of cancer stage and histological subtype lacked distinctive features, and most patients had a high risk for recurrence at the time of the primary surgery. Although approximately 78% of patients received adjuvant chemotherapy, 85/112 patients (76%) experienced recurrence within 2 years after the initial treatment ended. For patients receiving adjuvant chemotherapy, regional lymph node (LN) and distant-site recurrence were more frequent (>40%) than vaginal or intra-abdominal recurrence. Median survival and 5-year R-OS were 27 months and 26.1%, respectively. The R-OS was significantly better for patients aged 65 years or older, those with negative peritoneal cytology at the time of primary surgery, those with recurrence within regional LN (eg, pelvic LN or para-aortic LN under the renal vein) and/or vagina, and those who underwent surgery and/or radiotherapy after recurrence. A multivariate analysis indicated that positive peritoneal cytology, a disease-free interval of less than 12 months, recurrent lesions in 2 or 3 areas, and treatment excluding surgery or radiotherapy were independent predictors of poor prognosis after recurrence. CONCLUSIONS: Adjuvant chemotherapy was insufficient to reduce the incidence of distant recurrence. The prognosis of patients recurred within regional LN and/or vagina was significantly better than that of patients with recurrence in other lesions because of treatment with surgery and/or radiotherapy. The disease-free interval was a significant prognostic factor for REC patients.

Clinical features of long-term survivors of recurrent epithelial ovarian cancer.

BACKGROUND: Although recurrent epithelial ovarian cancer (EOC) is generally regarded as an incurable disease, some patients survive more than 5 years after the first recurrence. The aim of this study was to evaluate the clinical features of patients with recurrent EOC who achieve long-term survival. METHODS: We retrospectively reviewed the medical records of 164 patients with recurrent EOC and analyzed the clinical stage, histologic subtype, primary treatment, disease-free interval (DFI), recurrence site, secondary treatment, and overall survival from the time of the first recurrence (R-OS), using the Kaplan-Meier method and the log-rank test. RESULTS: The median R-OS for all 164 patients was 25 months and the 5-year R-OS rate was 25.4 %. There were no significant differences in R-OS according to the disease stage. The median R-OS was significantly shorter in the 6-12-month DFI group (23 months) than in the ≥12-month DFI group (61 months) (p = 0.0002), while there was no significant difference between the 6-12 and 3-6-month DFI groups (20 months) (p = 0.161). Of the 164 patients, only 14 survived >5 years after the first recurrence. Most of them underwent surgery and/or radiotherapy in combination with chemotherapy and underwent >18 cycles of platinum-based chemotherapy throughout their treatments (median 22 cycles; range 4-44). CONCLUSIONS: If high sensitivity to platinum is maintained, patients with recurrent EOC may have prolonged survival following repeated platinum-based chemotherapy cycles. Moreover, their prognosis improves when chemotherapy is combined with secondary cytoreductive surgery and/or irradiation.

Development of a simple high-performance liquid chromatography-ultraviolet detection method for olaparib in patients with ovarian cancer.

Olaparib is a small-molecule inhibitor of poly(ADP)-ribose polymerase (PARP) used as maintenance therapy for recurrent ovarian cancer and newly diagnosed advanced ovarian cancer after initial chemotherapy. An exposure-toxicity correlation has been reported between the probability of anemia, a common adverse event associated with olaparib, and the steady-state minimum plasma concentration (Cmin) as well as the predicted maximum plasma concentration (Cmax). On the other hand, olaparib exhibits high interpatient variability with regard to the area under the concentration-time curve, Cmax, and Cmin. Therefore, we developed a simple and sensitive assay based on high-performance liquid chromatography with ultraviolet light (HPLC-UV) for the therapeutic drug monitoring of olaparib. The analysis was performed on an octadecylsilyl column with a mobile phase consisting of 0.5% KH2PO4 (pH 4.5) and acetonitrile (71:29, v/v), at a flow rate of 0.8 mL/min. Olaparib and an internal standard (imatinib) were well separated from the co-extracted material, with retention times of 13.6 and 11.5 min, respectively. The calibration curve for olaparib showed linearity over the concentration range of 0.10-10.0 µg/mL (r2 = 0.9998). The intra- and inter- day validation coefficients ranged from 1.79 to 4.13% and 1.37 to 3.55%, respectively. Measurement accuracy ranged from - 6.07 to 3.26%, with a recovery rate of more than 91.06%. The developed method was then applied to evaluate the plasma olaparib concentrations in patients with ovarian cancer. Our findings demonstrate that HPLC-UV is an economical, simple, and sensitive method for clinical application and holds promise for the effective drug monitoring of olaparib during ovarian cancer treatment.

Adjuvant chemotherapy for stage I clear cell carcinoma of the ovary: an analysis of fully staged patients.

OBJECTIVE: Although postoperative adjuvant chemotherapy is generally recommended for early-stage ovarian cancer, it remains unclear whether adjuvant chemotherapy is also effective for clear cell carcinoma (CCC). METHODS: Seventy-three patients with stage I CCC of the ovary who had undergone complete surgical staging formed the study population (stage IA, 20 patients; stage IC, 53 patients). Survival and multivariate analyses were retrospectively performed to determine the effectiveness of postoperative chemotherapy in these patients. RESULTS: Of the total (73 patients), 30 patients received adjuvant chemotherapy (stage I C-positive), whereas 43 patients did not (stage I C-negative). The 5-year progression-free survival (PFS) and 5-year overall survival (OS) rates for the stage I C-positive group were 80.1% and 87.4% compared with 73.9% and 81.7% for the stage I C-negative group. The differences in survival between these groups were not significant (PFS: P = 0.610; OS: P = 0.557). Four of the patients with stage IA CCC underwent chemotherapy, whereas the remaining 16 patients received no additional therapy. No recurrence was observed in either group. Of the patients with stage IC CCC, 26 patients underwent chemotherapy (stage IC C-positive) and 27 received no additional therapy (stage IC C-negative). There was no statistical difference in PFS and OS between the stage IC C-positive and stage IC C-negative groups. Of the patients with stage IC without artificial rupture, the 5-year PFS rates of the C-positive and C-negative patients were 69.6% and 34.6%, respectively, but the 5-year OS rates were 75.0% and 70.0%, respectively (not significant). Multivariate analyses confirmed that the presence or absence of adjuvant chemotherapy was not a prognostic indicator. CONCLUSIONS: The current study was performed only in fully staged patients, suggesting that postoperative adjuvant chemotherapy is not necessary for stage IA CCC patients. For patients with stage IC CCC patients, adjuvant chemotherapy suppressed recurrence, but the effectiveness was insufficient in our limited study. Further studies are required to clarify this.

[Present status and tasks for genetic testing and risk-reducing surgery in patients with hereditary breast and ovarian cancer].

In Japan, awareness of hereditary breast and ovarian cancer (HBOC) has gradually increased among health care workers and the general population. We focus on two current topics: genetic testing and risk-reducing surgery for HBOC. Genetic testing for BRCA1 and BRCA2, the genes responsible for HBOC, is performed to diagnose HBOC. PCR-direct sequencing is a standard method used for BRCA1/2 mutation analysis. Recently, genetic rearrangement of BRCA1 was reported in a Japanese patient with HBOC. Therefore, MLPA tests are also being included in routine genetic testing for the disease. The result of "uncertain significance, " which indicates unclear pathogenic significance, is obtained in about 3% of all patients who undergo BRCA1/2 genetic tests. Furthermore, novel candidate genes for HBOC, such as RAD51C, PALB2, and BRIP1, were recently identified. Prophylactic surgical intervention for HBOC includes procedures such as risk-reducing bilateral salpingo-oophorectomy (RRSO) and risk-reducing mastectomy(RRM). In Japan, RRSO is performed in very few patients at present. Increasing evidence from overseas indicates that RRSO contributes to a decreased incidence of ovarian/breast cancers and lowers overall mortality. Therefore, a system for performing RRSO was established in our institute. RRSO was approved to be performed as a clinical examination by our Institutional Review Board. The clinical significance of ipsilateral complete mastectomy and RRM remains unclear. Based on the NCCN guidelines, conservative mastectomy with radiation therapy is relatively contraindicated in patients with HBOC. However, several studies have reported that conservative mastectomy with radiation the rapydoes not increase the incidence of recurrent or metachronous breast cancers in the ipsilateral breast of mutation-positive patients when compared to mutation-negative or control patients. However, more aggressive malignancies seem to be included in the mutation-positive group(especially BRCA1 -mutation-positive cases). RRM clearly reduced the incidence of breast cancers. RRM may also be allowed as a treatment option for HBOC in Japan.

Oral Gonadotropin-Releasing Hormone Antagonist Relugolix Has the Same Effect as Gonadotropin-Releasing Hormone Agonist Injections in Terms of Preparation for Transcervical Resection Myomectomy.

For preparing the optimal condition in transcervical resection (TCR) surgery, gonadotropin-releasing hormone (GnRH) agonist has been utilized. Recently, an oral GnRH antagonist (relugolix) is available and acts directly on GnRH receptor, avoiding flare up and reducing blood E2 levels rapidly. We retrospectively compared the oral GnRH antagonist (n = 14) effect to that of subcutaneous GnRH agonist (n = 19) for the pretreatment of endometrium in TCR myomectomy. Endometrial thickening was determined by intraoperative videos. The color tone of the endometrium in the normal part was assessed by digital image processing. The median duration of the first GnRH agonist injection and the surgery was 67 days (21-136 days), which is significantly longer than that of the oral GnRH antagonist group, 18.5 days (7-157 days P < 0.01). Both the GnRH agonist and antagonist groups did not exhibit prominence in the endometrium. The GnRH antagonist group showed the same degree of whiteness in the normal endometrium as the GnRH agonist group. The oral GnRH antagonist administration could rapidly atrophy the endometrium and create an optimal surgical field for TCR in a short period.

Stage IA ovarian cancers: comparison of sonographic findings and histopathologic types between patients with normal and elevated serum cancer antigen 125 levels.

OBJECTIVES: The purpose of this study was to compare sonographic findings and histopathologic types of stage IA ovarian cancers between groups with normal and elevated cancer antigen 125 (CA-125) levels. METHODS: Between 2000 and 2009, 146 stage IA ovarian cancers were treated surgically (85 invasive and 61 borderline, 73 self-referred with tumor-related symptoms, 20 self-referred with nonspecific symptoms, 52 identified through screening, and 1 other). Of these, 87 cases (60%) had normal serum CA-125 levels (<35 U/mL). Their pre-operative sonographic findings and histopathologic types were compared to those of cases with elevated CA-125 levels. RESULTS: Statistically significant differences were found between the proportions of patients with elevated CA-125 levels in groups having tumors with maximal diameters of less than 20 cm and at least 20 cm (P = .03) and groups having tumors with less than 50% and 50% to 80% solid components (P = .02). In the group with normal CA-125 levels, we found predominantly mucinous adenocarcinoma in multilocular cysts with less than 50% solid components (25 cases), and clear cell adenocarcinoma in unilocular cysts with less than 50% solid components (12 cases), whereas in the group with elevated CA-125 levels, mucinous adenocarcinoma in multilocular cysts with less than 50% solid components (19 cases) and endometrioid adenocarcinoma in solid tumors (≥80% solid components) were predominant (5 cases). CONCLUSIONS: Stage IA ovarian cancers with normal CA-125 levels tend to be smaller, have less solid components, and have a slightly different distribution of histopathologic types than cancers with elevated CA-125 levels.

Relaxin-2 May Suppress Endometriosis by Reducing Fibrosis, Scar Formation, and Inflammation.

BACKGROUND: Relaxin (RLX)-2, produced by the corpus luteum and placenta, is known to be potentially effective in fibrotic diseases of the heart, lungs, kidneys, and bladder; however, its effectiveness in endometriosis has not yet been investigated. In the present study, we conducted a comprehensive study on the effect of RLX-2 on endometriosis. We checked the expressions of LGR-7, a primary receptor of RLX-2, in endometriomas using immunohistochemistry. Endometriotic stromal cells (ESCs) purified from surgical specimens were used in in vitro experiments. The effects of RLX-2 on ESCs were evaluated by quantitative-PCR, ELISA, and Western blotting. Gel contraction assay was used to assess the contraction suppressive effect of RLX-2. The effect of RLX-2 was also examined in the endometriosis mouse model. LGR-7 was expressed in endometriotic lesions. In ESCs, RLX-2 increased the production of cAMP and suppressed the secretion of interleukin-8, an inflammatory cytokine, by 15% and mRNA expression of fibrosis-related molecules, plasminogen activator inhibitor-1 (PAI-1), and collagen-I by approximately 50% (p < 0.05). In the gel contraction assay, RLX-2 significantly suppressed the contraction of ESCs, which was cancelled by removing RLX-2 from the medium or by adding H89, a Protein Kinase A (PKA) inhibitor. In ESCs stimulated with RLX-2, p38 MAPK phosphorylation was significantly suppressed. In the endometriosis mouse model, administration of RLX-2 significantly decreased the area of the endometriotic-like lesion with decreasing fibrotic component compared to non-treated control (p = 0.01). RLX-2 may contribute to the control of endometriotic lesion by suppressing fibrosis, scar formation, and inflammation.

The use of conization to identify and treat severe lesions among prediagnosed CIN1 and 2 patients in Japan.

OBJECTIVE: To evaluate the clinical efficiency of identifying patients with suspicious severe lesions by conization among prediagnosed cervical intraepithelial neoplasia (CIN) 1 and 2 patients in Japan. METHODS: The data in a Japanese nation-wide registry for cervical cancer (2009 and 2011) was collected to analyze the clinical efficacy of pre- and postdiagnosis for 13,215 Japanese women who underwent treatment by conization. Their preoperative and postoperative histologic findings and clinical outcomes were evaluated using standard statistical procedures including clinical and demographic characteristics. RESULTS: Almost half of 1,536 women who were treated by conization after the prediagnosis of CIN1 and 2 because the lesions showed no evidence of natural regression actually contained CIN1-2 (45.0%), CIN3 (47%), or invasive cancer (2.7%) in their cervical tissue. They underwent conization either for therapeutic (treatment) (78.5%) or diagnostic (21.5%) reasons. Invasive disease was diagnosed postoperatively more often in diagnostic cases (6.1%) than in therapeutic cases (2.8%). All the patients survived their diagnostic and therapeutic conization after approximately 30 months of follow up. CONCLUSION: Our study shows that the continuous observation of the prediagnosed CIN1 and 2 cases by the combination of cytology, colposcopy and histology in Japan has worked successfully to identify severe lesions by using conization as well in the process.

Clinical significance of systematic retroperitoneal lymphadenectomy during interval debulking surgery in advanced ovarian cancer patients.

OBJECTIVE: To investigate the clinical significance of systematic retroperitoneal lymphadenectomy during interval debulking surgery (IDS) in advanced epithelial ovarian cancer (EOC) patients. METHODS: We retrospectively reviewed the medical records of 124 advanced EOC patients and analyzed the details of neoadjuvant chemotherapy (NACT), IDS, postoperative treatment, and prognoses. RESULTS: Following IDS, 98 patients had no gross residual disease (NGRD), 15 had residual disease sized <1 cm (optimal), and 11 had residual disease sized ≥1 cm (suboptimal). Two-year overall survival (OS) and progression-free survival (PFS) rates were 88.8% and 39.8% in the NGRD group, 40.0% and 13.3% in the optimal group (p<0.001 vs. NGRD for both), and 36.3% and 0% in the suboptimal group, respectively. Five-year OS and 2-year PFS rates were 62% and 56.1% in the lymph node-negative (LN-) group and 26.2% and 24.5% in the lymph node-positive (LN+) group (p=0.0033 and p=0.0024 vs. LN-, respectively). Furthermore, survival in the LN+ group, despite surgical removal of positive nodes, was the same as that in the unknown LN status group, in which lymphadenectomy was not performed (p=0.616 and p=0.895, respectively). Multivariate analysis identified gross residual tumor during IDS (hazard ratio, 3.68; 95% confidence interval, 1.31 to 10.33 vs. NGRD) as the only independent predictor of poor OS. CONCLUSION: NGRD after IDS improved prognosis in advanced EOC patients treated with NACT-IDS. However, while systematic retroperitoneal lymphadenectomy during IDS may predict outcome, it does not confer therapeutic benefits.

Assessment of transposed ovarian movement: how much of a safety margin should be added during pelvic radiotherapy?

The purpose of this study was to analyze transposed ovarian movement. Data from 27 patients who underwent ovarian transposition after surgical treatment for uterine cancer were retrospectively analyzed. Computed tomography (CT) images including transposed ovaries were superimposed on other CT images acquired at different times, and were matched on bony structures. Differences in ovarian position between the CT images were measured. The planning organ at risk volume (PRV) margins were calculated from the formula of the 90% reference intervals (RIs) and the 95% RI, which were defined as mean ± 1.65 standard deviation (SD) and mean ± 1.96 SD, respectively. The 90% RI in the cranial, caudal, anterior, posterior, left and right directions were 1.5, 1.5, 1.4, 1.0, 1.7 and 0.9 cm, respectively. The 95% RI in the corresponding directions were 1.5, 2.0, 1.7, 1.2, 1.9 and 1.2 cm, respectively. These data suggest that bilateral ovaries need a PRV margin of ∼2 cm in all directions. The present study suggests that a transposed ovary needs the same PRV margin as a normal ovary (∼2 cm). Even after transposition, ovaries should be kept away from the radiation field to take into consideration the degree of ovarian movement.

Association of PTEN mutation with HPV-negative adenocarcinoma of the uterine cervix.

Serous, mucinous, endometrioid, and clear cell adenocarcinomas arise from reproductive organs of mullerian origin. Although the mutation of PTEN, a tumor suppressor, is known to be involved in tumorigenesis of endometrioid adenocarcinomas of the endometrium and ovary, the role of PTEN alteration in endometrioid adenocarcinoma of the cervix remains to be investigated. To elucidate the molecular pathogenesis of cervical adenocarcinoma and adenosquamous carcinoma, and in particular to examine the potential role of PTEN mutation in endometrioid-type cancer of the cervix, we analyzed 32 cervical adeno- or adenosquamous carcinomas (8 endometrioid adenocarcinomas, 14 mucinous adenocarcinomas and 10 adenosquamous carcinomas) for PTEN mutations and HPV infections. PTEN mutation was detected in 2 of 8 (25.0%) endometrioid cases, 2 of 14 (14.3%) mucinous cases, and none of 10 (0%) adenosquamous cases. HPV DNA was detected in 11 out of 18 (61.1%) PTEN wild-type adenocarcinomas and 8 out of 10 (80.0%) adenosquamous carcinomas. Among 11 HPV-negative adenocarcinomas, 40.0% (2/5) endometrioid cases and 33.3% (2/6) mucinous cases were shown to be PTEN mutated, while no cases (0/21) were PTEN-mutant in the remainder (i.e. adenosquamous carcinomas and HPV-positive adenocarcinomas). The current observations suggest that PTEN mutation is frequently detected in HPV-negative adenocarcinomas of the cervix and the most prevalent occurrence of PTEN mutation in endometrioid subtype is keeping with endometrial and ovarian carcinomas.

High-risk ovarian cancer based on 126-gene expression signature is uniquely characterized by downregulation of antigen presentation pathway.

PURPOSE: High-grade serous ovarian cancers are heterogeneous not only in terms of clinical outcome but also at the molecular level. Our aim was to establish a novel risk classification system based on a gene expression signature for predicting overall survival, leading to suggesting novel therapeutic strategies for high-risk patients. EXPERIMENTAL DESIGN: In this large-scale cross-platform study of six microarray data sets consisting of 1,054 ovarian cancer patients, we developed a gene expression signature for predicting overall survival by applying elastic net and 10-fold cross-validation to a Japanese data set A (n = 260) and evaluated the signature in five other data sets. Subsequently, we investigated differences in the biological characteristics between high- and low-risk ovarian cancer groups. RESULTS: An elastic net analysis identified a 126-gene expression signature for predicting overall survival in patients with ovarian cancer using the Japanese data set A (multivariate analysis, P = 4 × 10(-20)). We validated its predictive ability with five other data sets using multivariate analysis (Tothill's data set, P = 1 × 10(-5); Bonome's data set, P = 0.0033; Dressman's data set, P = 0.0016; TCGA data set, P = 0.0027; Japanese data set B, P = 0.021). Through gene ontology and pathway analyses, we identified a significant reduction in expression of immune-response-related genes, especially on the antigen presentation pathway, in high-risk ovarian cancer patients. CONCLUSIONS: This risk classification based on the 126-gene expression signature is an accurate predictor of clinical outcome in patients with advanced stage high-grade serous ovarian cancer and has the potential to develop new therapeutic strategies for high-grade serous ovarian cancer patients.