Efficacy and safety of same-day preparation with sodium picosulfate plus magnesium citrate on the day of colonoscopy for bowel preparation: Multicenter, single-arm, open-label study.

BACKGROUND AND AIM: Sodium picosulfate plus magnesium citrate (SP + MC) is a well-tolerated bowel preparation agent. However, Japan currently approves only two methods of taking SP + MC: the day-before and split-dose preparation, without approval of same-day preparations. This study aimed to evaluate the efficacy and safety of same-day SP + MC preparations. METHODS: This was a multicenter, single-arm, nonrandomized, open-label study. We enrolled 145 Japanese patients between June and December 2023. The patients received two sachets of SP + MC dissolved in 300 ml of water and 1200 mL or more of clear liquid on the day of colonoscopy. Bowel cleansing efficacy, adverse events (AEs), and patient satisfaction were evaluated. RESULTS: Of the enrolled patients, 137 underwent colonoscopy according to our protocol. Bowel preparation was adequate in 133 patients (97.1%). The mean total Boston Bowel Preparation Score was 8.3 ± 1.2. Five patients experienced AEs (3.6%): two (1.5%), abdominal pain; one (0.73%), ischemic enteritis; one (0.73%), vomiting or nausea; and one (0.73%), headache. All AEs were treated conservatively. None of the patients exhibited abnormal blood test results or clinical symptoms after receiving SP + MC. Regarding patient satisfaction, all patients were able to take SP + MC as directed; 136 (99.2%) expressed a preference for this bowel preparation for future colonoscopies. CONCLUSION: The same-day SP + MC preparation showed high bowel-cleansing efficacy and satisfaction in Japanese patients without serious AEs.

Prognostic significance of adjuvant chemotherapy in stage I-II endometrial carcinoma patients who underwent lymphadenectomy.

BACKGROUND: Endometrial carcinoma, the most common gynecologic carcinoma, has an excellent prognosis post-surgery when diagnosed early. The role of postoperative adjuvant chemotherapy in stages I-II endometrial carcinoma remains controversial. This study assesses the efficacy of adjuvant chemotherapy in improving prognosis for these patients. METHODS: A retrospective analysis was conducted on 1223 stage I-II endometrial carcinoma patients who underwent surgical treatment including total hysterectomy, bilateral salpingo-oophorectomy, and lymph-node biopsy or dissection across four Jikei University School of Medicine-affiliated facilities between 2001 and 2018. Patients were divided into low intermediate risk (LIR) and high intermediate risk (HIR) groups based on recurrence risk. Propensity score matching adjusted for various covariates was used to compare progression-free survival (PFS) and overall survival (OS) between patients who received adjuvant chemotherapy and those who did not. RESULTS: The study included 443 eligible patients, with 288 in the LIR group and 155 in the HIR group. Post propensity score matching, no significant difference in PFS or OS was observed between the observation and adjuvant chemotherapy groups within both risk categories. Notably, the 5-year OS for LIR was 97.6% in the observation group and 96.7% in the chemotherapy group; for HIR, the 5-year OS was similarly high with no significant difference. CONCLUSIONS: The findings suggest that postoperative adjuvant chemotherapy does not significantly contribute to the improvement of recurrence or prognosis in patients with stage I-II endometrial carcinoma who are categorized outside the low-risk group and have no lymph-node metastasis.

Therapeutic effect of dose-dense paclitaxel plus carboplatin with or without bevacizumab for Japanese patients with epithelial ovarian cancer.

BACKGROUND: Evidence regarding chemosensitivity to different therapeutic regimens in epithelial ovarian cancer (EOC) remains limited. This study aimed to investigate EOC implementation in daily clinical practice and reveal favorable regimens for EOC among Japanese patients. METHODS: We retrospectively collected clinical data of patients newly diagnosed with EOC from 2012 to 2021 at our affiliated institutions. We evaluated overall survival (OS) and progression-free survival (PFS) of conventional paclitaxel plus carboplatin (TC) vs. dose-dense TC (ddTC) according to the eligibility of GOG262 and JGOG3016 and those with bevacizumab (BEV) vs. without BEV based on GOG218. Further, we evaluated OS and PFS of ddTC and ddTC + BEV to TC + BEV among patients with stage III/IV. RESULTS: The ddTC group (n = 402) demonstrated longer PFS and OS than the TC group (n = 165) (adjusted hazard ratios [aHRs] [95% confidential intervals (CIs)]: 0.69 [0.55-0.88] and 0.67 [0.50-0.90], respectively). The group with BEV (n = 158) demonstrated a longer PFS than those without BEV (n = 296) (0.74 [0.57-0.95]), but not for OS (0.84 [0.60-1.17]). The ddTC and ddTC + BEV groups (n = 259 and 117) demonstrated no statistically significant differences in PFS and OS than the TC + BEV group (n = 75) (1.09 [0.79-1.50] and 0.74 [0.52-1.08] for PFS and 0.89 [0.59-1.34] and 0.73 [0.50-1.05] for OS, respectively). CONCLUSION: Our study may indicate ddTC, BEV, and their combination regimen as the promising first-line chemotherapy option among Japanese patients with advanced EOC.

Numerous lesions of gastric adenocarcinoma of fundic-gland and fundic gland-mucosa type in a patient.

A man in his 60 s underwent upper gastrointestinal endoscopy at our hospital, which revealed a 30-mm elevated lesion in the upper stomach (main lesion). There were several discolored, flat mucosal lesions and slightly elevated, reddish, subepithelial mass-like lesions (multiple secondary lesions) in the gastric fornix and body. Histopathological examination of several biopsied secondary lesions revealed gastric adenocarcinoma of fundic-gland type (GA-FG) or gastric adenocarcinoma of fundic gland-mucosa type (GA-FGM). The main lesion was suspected to be GA-FGM on magnifying endoscopy with narrow-band imaging. It was removed using endoscopic submucosal dissection for therapeutic and diagnostic purposes. The histopathological diagnosis of the resected lesion was GA-FGM, which was surrounded by two GA-FGM and > 30 GA-FG lesions. Total gastrectomy was considered; however, the patient declined further surgical treatment. Therefore, he was followed up with biannual endoscopy and computed tomography. At five years postoperatively, no tumor growth or metastasis has been observed.

Magnifying endoscopy with narrow-band imaging for diagnosis of subtype of gastric intestinal metaplasia.

BACKGROUND AND AIM: Patients with incomplete gastric intestinal metaplasia (GIM) have a higher risk of gastric cancer (GC) than those with complete GIM. We aimed to clarify whether micromucosal patterns of GIM in magnifying endoscopy with narrow-band imaging (M-NBI) were useful for diagnosis of incomplete GIM. METHODS: We enrolled patients with a history of endoscopic resection of GC or detailed inspection for suspicious or definite GC. The antrum greater curvature and corpus lesser curvature were regions of interest. Areas with endoscopic findings of light blue crest and/or white opaque substance (WOS) were defined as endoscopic GIM, and subsequent M-NBI was applied. Micromucosal patterns were classified into Foveola and Groove types, and targeted biopsies were performed on GIM with each pattern. GIM was classified into complete and incomplete types using mucin (MUC)2, MUC5AC, MUC6, and CD10 immunohistochemical staining. The primary endpoint was the association between micromucosal pattern and histological subtype. The secondary endpoint was endoscopic findings associated with incomplete GIM. RESULTS: We analyzed 98 patients with 156 GIMs. Univariate analysis (odds ratio [OR] 3.4, P = 0.004), but not multivariate analysis (OR 0.87, P = 0.822), demonstrated a significant association between micromucosal pattern and subtype. The antrum (OR 3.7, P = 0.006) and WOS (OR 43, P = 0.002) were independent predictors for incomplete GIM. The WOS had 69% sensitivity and 93% specificity. CONCLUSIONS: The M-NBI micromucosal pattern is not useful for diagnosis of GIM subtype. WOS is a promising endoscopic indicator for diagnosis of incomplete GIM. (UMIN-CTR000041119).

Evaluation of non-hematologic toxicity in patients with cervical cancer after Type 3 radical hysterectomy followed by concurrent chemoradiotherapy: a retrospective study.

OBJECTIVE: To investigate the safety of concurrent chemoradiotherapy after Type 3 radical hysterectomy, focusing on non-hematologic toxicity. METHODS: Between January 2010 and December 2017, 236 patients diagnosed with cervical cancer Stages IB1-II (FIGO2008) and who had undergone Type 3 radical hysterectomy at the Jikei Medical University School-related four hospitals were included. Of these 236 patients, 134 had undergone adjuvant concurrent chemoradiotherapy after Type 3 radical hysterectomy (radical hysterectomy + concurrent chemoradiotherapy group), and 102 received no adjuvant therapy after Type 3 radical hysterectomy (radical hysterectomy group). The frequency of non-hematologic toxicities, especially lymphedema, pelvic infection, renal dysfunction, ileus and diarrhea, was investigated in the radical hysterectomy + concurrent chemoradiotherapy and radical hysterectomy groups using univariate and multivariate analyses. In these analyses, age, extent of lymph node dissection and preoperative clinical stage were included as risk factors for five complications. The risk factors for grade ≤ 2 adverse events were statistically evaluated. RESULTS: The frequency of lower extremity lymphedema (22 vs. 10%), renal dysfunction (13 vs. 3%), and diarrhea (13 vs. 0%) was significantly higher in the radical hysterectomy + CRRT group than that in the radical hysterectomy group. Logistic regression analysis revealed that adjuvant concurrent chemoradiotherapy significantly affected the occurrence of grade ≥ 2 lymphedema (P < 0.01) and renal dysfunction (P < 0.01). CONCLUSIONS: Concurrent chemoradiotherapy after Type 3 radical hysterectomy is associated with a higher incidence of renal dysfunction, lower extremity lymphedema and diarrhea. A more appropriate adjuvant therapy needs to be established.

Genetic characteristics of platinum-sensitive ovarian clear cell carcinoma.

OBJECTIVE: Most ovarian clear cell carcinomas are resistant to platinum-based chemotherapy, while a small subset shows a positive response. The aim of this study was to clarify the clinical, pathological and genetic characteristics of platinum-sensitive ovarian clear cell carcinomas. METHODS: The study included 53 patients with stage III-IV ovarian clear cell carcinoma who had residual tumours after primary surgery and received platinum-based therapy between 2009 and 2018. A retrospective examination of platinum sensitivity was performed using the criterion of ≥6 months from the last day of first-line platinum therapy until recurrence/progression. Cases determined to be platinum-sensitive were subjected to immunohistochemical staining, genomic analyses using target sequencing (i.e. NCC Oncopanel) and homologous recombination deficiency (myChoice® HRD Plus) assays. RESULTS: Of the 53 stage III-IV ovarian clear cell carcinoma cases, 11 (21%) were platinum-sensitive. These cases showed better progression-free and overall survival than platinum-resistant cases (hazard ratio = 0.16, P < 0.001). Among the seven sensitive cases whose tumour tissues were available for molecular profiling, five were pure ovarian clear cell carcinoma based on pathological and genetic features, whereas the remaining two cases were re-diagnosed as high-grade serous ovarian carcinoma. The pure ovarian clear cell carcinomas lacked BRCA1 and BRCA2 mutations, consistent with the absence of the homologous recombination deficiency phenotype, whereas two cases (40%) had ATM mutations. By contrast, the two high-grade serous ovarian carcinoma cases had BRCA1 or BRCA2 mutations associated with the homologous recombination deficiency phenotype. CONCLUSION: The subset of platinum-sensitive ovarian clear cell carcinomas includes a majority with pure ovarian clear cell carcinoma features that lack the homologous recombination deficiency phenotype.

Short- and long-term morbidity of total parietal peritonectomy for advanced ovarian cancer.

OBJECTIVE: Total parietal peritonectomy is gradually being recognized as a surgical option for advanced ovarian cancer; however, evidence regarding its efficacy and safety remains insufficient. Herein, we aimed to assess the short- and long-term post-operative safety profiles of total parietal peritonectomy. METHODS: We reviewed the medical records of post-operative morbidity and mortality of patients who underwent cytoreductive surgery with total parietal peritonectomy for stage III and IV ovarian cancer between April 2018 and January 2023. RESULTS: Fifty patients were enrolled in the study: 31 who underwent primary cytoreductive surgery and 19 who underwent interval cytoreductive surgery. The median age of all patients was 57 (range, 23-74) years. The median follow-up period was 22 (range, 3-59) months. Of 44 patients (88%) with stage IIIC/IV, 38 patients (76%) had high-grade serous carcinoma. The complete resection rates were 94%, 91%, and 100% in all patients, the primary cytoreductive surgery group, and the interval cytoreductive surgery group, respectively. There were 63 post-operative complication events overall, including 17 (27%) major complication events in 15 patients within 1 year post-operatively. Ten major complications occurred within 30 days of surgery, mainly in the primary cytoreductive surgery group (9 cases). Regarding complication type, the most frequent major event was pleural effusion (3 cases, 7%). After 30 days, there were a total of 17 all-grade complication events, of which ileus and hydronephrosis were major complications in 3 cases each (18%). There were no mortalities related to cytoreductive surgery. The scheduled adjuvant chemotherapy could be completed in 96% of patients. CONCLUSIONS: Total parietal peritonectomy is a feasible procedure for managing advanced ovarian cancer. Short- and long-term complications may include pleural effusion and ileus/hydronephrosis, respectively.

Adjuvant Chemotherapy for Endometrial Cancer (ACE) trial: A randomized phase II study for advanced endometrial carcinoma.

This study evaluated the feasibility and efficacy of three postoperative adjuvant chemotherapy regimens for endometrial cancer. Endometrioid cancer patients with intermediate-risk stage I and II or high-risk stage III and IV disease were randomly assigned to receive six cycles of either paclitaxel-epirubicin-carboplatin (TEC), paclitaxel-anthracycline (doxorubicin)-carboplatin (TAC), or dose-dense paclitaxel-carboplatin (ddTC). The primary end-point was the completion rate (CRate) of six cycles of treatment. The secondary end-points were progression-free survival (PFS) and overall survival (OS). One hundred and one patients were treated as follows: 33 received TEC, 33 TAC, and 35 ddTC. The CRates for TEC, TAC, and ddTC were 94%, 64%, and 69%, respectively (P = .005). The TEC CRate was significantly higher than for the other two groups. However, the PFS and OS outcomes were not statistically different between the three groups. The 2-year survival rates were 94%, 97%, and 97% for TEC, TAC, and ddTC, respectively. When compared to the current standard treatments for endometrial cancer, TEC is a promising candidate for a phase III trial based on its significantly superior CRate and equivalent PFS and OS. This study is registered with UMIN Clinical Trials Registry (UMIN000008911).

A comparative study of demarcation line diagnostic performance between non-magnifying observation with white light and non-magnifying observation with narrow-band light for early gastric cancer.

BACKGROUND AND AIMS: With the improvement in endoscopic equipment functions, narrow-band imaging (NBI) for endoscopic observation of the stomach, which is an organ with a large lumen, is now feasible. Studies evaluating the NBI utility without magnifying endoscopy to diagnose the invasion extent for the demarcation line identification in early gastric cancer have not been reported. This study aimed to investigate the demarcation line diagnostic performance of NBI in early gastric cancer compared to that of white-light imaging (WLI) using prospectively collected consecutive specimens from early gastric cancer patients. METHODS: Thirty consecutive lesions were collected from patients who underwent endoscopic submucosal dissection for early gastric cancer. Next, 30 NBI and 30 WLI images, each with the same degree of gastric wall extension, angle, and layout for one lesion, were selected, and a total of 60 images were prepared for testing. The early gastric cancer invasion ranges in the endoscopic images was plotted using the web-developed software, and 264 independent endoscopists, unaware of the diagnosis, performed the web tests, with the concordance rates between the ranges of responses. After estimating the actual early gastric cancer invasion ranges, the NBI and WLI results were compared. RESULTS: The concordance rates for NBI and WLI images were 43.1% (95% confidence interval [CI] 42.5-43.7%) and 37.2% (95% CI 36.6-37.7%), respectively, showing that the concordance rate for NBI was significantly higher than that for WLI. CONCLUSION: This study suggested that NBI was more useful for identifying demarcation lines than WLI.

miR-23b-3p Plays an Oncogenic Role in Hepatocellular Carcinoma.

BACKGROUND: Reports show miR-23b to be a cancer-related biomarker in various cancer types. Interestingly, it has a dual role of oncogenic and tumor-suppressive functions, depending on the cancer type. This study focused on the unknown association of miR-23b-3p with hepatocellular carcinoma (HCC). METHODS: Expression of miR-23b-3p was measured in nine HCC cell lines and 125 resected human HCC samples by TaqMan microRNA assays. To detect its downstream target, miR-23b-3p mimic and inhibitor constructs were transfected and analyzed. RESULTS: HepG2, a high miR-23b-3p-expressing cell line, was transfected with a miR-23b-3p inhibitor construct, whereas SK-Hep1, a low miR-23b-3p-expressing cell line, was transfected with a mimic construct. Proliferation of HCC cells was activated by miR-23b-3p overexpression and diminished by its knockdown. Then, 125 clinical HCC samples were examined to measure miR-23b-3p expression. Tumor expression of miR-23b-3p was upregulated in 48 cases (38%) and downregulated in 77 cases (62%). The upregulated cases were correlated with elderly patients (P = 0.015). These patients also showed significantly poor overall survival [hazard ratio (HR), 3.10; 95% conflidence interval (CI), 1.57-6.29; P = 0.001] in a multivariate analysis. Furthermore, mitochondrial metabolism-related genes (MICU3 and AUH) were detected as specific binding targets. CONCLUSION: The study showed that miR-23b-3p functions as an oncogenic microRNA in HCC cell lines. Its overexpression in resected HCC tissues was a significant prognostic factor of overall survival. Both MICU3 and AUH may be candidate gene targets of miR-23b-3p.

High Serum Uric Acid Levels Could Be a Risk Factor of Hepatocellular Carcinoma Recurrences.

BACKGROUND: The Apolipoprotein-related MORtality RISk (AMORIS) study in Sweden revealed that serum uric acid (SUA) was significantly associated with hepatobiliary cancer occurrence. However, the association with postoperative hepatocellular carcinoma (HCC) recurrence has not been reported. METHODS: A total of 256 surgically resected HCC patients were included (from January 2003 to December 2017) in this study. Comparisons in terms of clinicopathologic factors and long-term outcomes were made between patients with high SUA (>6.1 mg/dl) at the time of hepatectomy and low SUA. Besides, SUA data at one postoperative year (1POY) of the same cohort were collected and analyzed in the same manner. RESULTS: About 88.8% of tumor relapse sites were the remnant liver. High SUA levels were associated with male and well-differentiated HCCs. Recurrence-free survival (RFS) of high SUA patients was significantly inferior to low SUA patients [median survival time (MST): 22.7 vs. 28.5 mo, P = 0.033], whereas no difference was observed in overall survival (MST: both not reached, P = 0.771). RFS of high SUA patients at 1POY also showed significantly poorer outcomes than low SUA patients (MST: 29.3 vs. 57.0 mo, P = 0.049). CONCLUSIONS: High SUA implies a significant risk factor of activating hepatocarcinogenesis. Keeping the SUA level low may be recommended after HCC resections.

Characteristic endoscopic findings of gastric adenocarcinoma of fundic-gland mucosa type.

BACKGROUND AND STUDY AIMS: Gastric adenocarcinoma of fundic-gland type (GA-FG) was first proposed as a new entity of gastric adenocarcinoma in 2010. Subsequently, gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM) was reported as a subtype of gastric adenocarcinoma. This study aimed to investigate the endoscopic findings of GA-FGM and to evaluate the differences between GA-FGM and GA-FG. PATIENTS AND METHODS: This was a single-center retrospective study. Participants were selected from patients with gastric cancer treated at Fukuoka University Chikushi Hospital, between September 2007 and May 2020. Patients histologically diagnosed with GA-FGM or GA-FG were enrolled, and endoscopic findings were analyzed in detail. RESULTS: A total of 12 GA-FGM lesions (12 patients) and 14 GA-FG lesions (13 patients) were analyzed. The two lesion types showed similar features: most lesions were of elevated type, located in the upper stomach, and developed in the stomach without Helicobacter pylori infection. On conventional endoscopy using the dye-spraying method, well-demarcated fine granular areas were observed in 7 GA-FGM lesions (58%) but not in any GA-FG lesions, with a significant difference between the two groups (P = 0.001). Magnifying endoscopy with narrow-band imaging (NBI) showed that 11 GA-FGM lesions (92%) met the diagnostic criteria for cancer according to the vessel plus surface classification system, whereas none of the GA-FG lesions met the same criteria (0%, 0/14) (P = 0.001). CONCLUSION: Our results suggest that magnifying endoscopy with NBI is a potentially useful method for the diagnosis of GA-FGM.

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.

An open-label, randomized, phase II trial evaluating the efficacy and safety of standard of care with or without bevacizumab in platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer patients previously treated with bevacizumab for front-line or platinum-sensitive ovarian cancer: rationale, design, and methods of the Japanese Gynecologic Oncology Group study JGOG3023.

BACKGROUND: We present the study rationale and design of the JGOG3023 study, an open-label, parallel-arm, randomized, phase II trial that aimed to assess the efficacy and safety of chemotherapy with or without bevacizumab in patients with platinum-resistant recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who were previously treated with bevacizumab for front-line or platinum-sensitive ovarian cancer. We hypothesize that patients treated with a combination of single-agent chemotherapy and bevacizumab will show improved progression-free survival (PFS) compared with those treated with single-agent chemotherapy alone, in the setting beyond disease progression following prior bevacizumab treatment. METHODS/DESIGN: A total of 106 patients who have recurrence or progression of ovarian cancer, while receiving chemotherapy or within 6 months after the final dose of platinum, after completing at least three cycles of bevacizumab plus platinum chemotherapy will be randomized in a 1:1 ratio to treatment with single-agent chemotherapy or single-agent chemotherapy combined with bevacizumab. For chemotherapy, one of the following four drugs will be chosen by an investigator: pegylated liposomal doxorubicin, topotecan, paclitaxel, or gemcitabine. The primary endpoint is investigator-assessed PFS. The secondary endpoints are overall survival, objective response rate, number of paracentesis, and response rate by CA125. Safety will be evaluated by the incidence of adverse events. DISCUSSION: This study will assess the efficacy and safety of bevacizumab in combination with single-agent chemotherapy, which could be used continuously after disease progression following standard platinum-based chemotherapy with bevacizumab. TRIAL REGISTRATION: UMIN000017247 (registered April 22, 2015).

Establishment of a Novel Histopathological Classification of High-Grade Serous Ovarian Carcinoma Correlated with Prognostically Distinct Gene Expression Subtypes.

Recently, The Cancer Genome Atlas data revealed four molecular subtypes of high-grade serous ovarian carcinoma (HGSOC) exhibiting distinct prognoses. We developed four novel HGSOC histopathological subtypes by focusing on tumor microenvironment: mesenchymal transition, defined by a remarkable desmoplastic reaction; immune reactive by lymphocytes infiltrating the tumor; solid and proliferative by a solid growth pattern; and papilloglandular by a papillary architecture. Unsupervised hierarchical clustering revealed four clusters correlated with histopathological subtypes in both Kyoto and Niigata HGSOC transcriptome data sets (P < 0.001). Gene set enrichment analysis revealed pathways enriched in our histopathological classification significantly overlapped with the four molecular subtypes: mesenchymal, immunoreactive, proliferative, and differentiated (P < 0.0001, respectively). In 132 HGSOC cases, progression-free survival and overall survival were best in the immune reactive, whereas overall survival was worst in the mesenchymal transition (P < 0.001, respectively), findings reproduced in 89 validation cases (P < 0.05, respectively). The CLOVAR_MES_UP single-sample gene set enrichment analysis scores representing the mesenchymal molecular subtype were higher in paclitaxel responders than nonresponders (P = 0.002) in the GSE15622 data set. Taxane-containing regimens improved survival of cases with high MES_UP scores compared with nontaxane regimens (P < 0.001) in the GSE9891 data set. Our novel histopathological classification of HGSOC correlates with distinct prognostic transcriptome subtypes. The mesenchymal transition subtype might be particularly sensitive to taxane.