Laparoscopic Surgery for Atypical Endometrial Hyperplasia with Awareness Regarding the Possibility of Endometrial Cancer.

Objectives: Although atypical endometrial hyperplasia (AEH) is considered a precancerous disease, the frequency with which AEH and endometrial cancer (EC) coexist is not low. Broadly, total laparoscopic hysterectomy (TLH) is performed for treating AEH; however, it is unclear what perioperative precautions need to be taken. This study aimed to clarify the points to be considered when performing TLH for AEH. Materials and Methods: We retrospectively identified 57 patients who underwent TLH for AEH in our hospitals. We extracted data on clinical characteristics, preoperative examinations (endometrial sampling and diagnostic imaging), surgical procedures, and final pathological diagnoses. Then, we statistically analyzed the difference in clinicopathological features and preoperative examinations between patients postoperatively diagnosed with EC and those diagnosed with AEH. Results: Twenty patients (35%) who underwent TLH for AEH were diagnosed with EC postoperatively (16 [28%] with stage IA EC and four [7.0%] with stage IB EC). We found no significant differences in clinical characteristics and preoperative evaluations between patients postoperatively diagnosed with EC and those diagnosed with AEH. The group with stage IB EC had a significantly higher median age and a significantly higher proportion of postmenopausal patients and patients with adenomyosis. Conclusion: It is important to recognize the risk of coexisting EC when performing TLH for AEH. High-precision endometrial sampling and contrast-enhanced magnetic resonance imaging are recommended for diagnosing AEH. In addition, surgical procedures for AEH are required to prevent cancer spillage in consideration of its coexistence, such as tubal sealing before manipulator insertion or avoiding using manipulator.

Scoring Systems of Peritoneal Dissemination for the Prediction of Operative Completeness in Advanced Ovarian Cancer.

BACKGROUND/AIM: We investigated the predictive value of scoring systems of peritoneal disseminations for complete surgery (CS) at primary debulking surgery (PDS) in advanced ovarian cancer. PATIENTS AND METHODS: We retrospectively enrolled eligible patients with clinical stages III or IVA selected for PDS from January 2015 to December 2019. Concern variables were predictive index value (PIV) and peritoneal cancer index (PCI) from operative and pathological reports. Primary endpoints were cutoffs to predict operative completeness using the receiver operating characteristic curve. RESULTS: Among 111 patients, PIV ≥8 and PCI ≥13 were the best predictors of incomplete PDS, including optimal and suboptimal surgeries (AUC=0.821 and 0.855, respectively). CS rates in PIV ≤6 and PCI ≤12 were significantly higher than in PIV ≥8 (89.3% vs. 47.2%; p<0.05) and PCI ≥13 (90.9% vs. 41.2%: p<0.05). CONCLUSION: PIV and PCI are potential predictors for CS at PDS.

Clinical Availability of Tumour Biopsy Using Diagnostic Laparoscopy for Advanced Ovarian Cancer.

BACKGROUND/AIM: Tumour biopsy using laparoscopy before neoadjuvant chemotherapy for advanced ovarian cancer has been widely accepted. However, there are few reports about its operative outcome compared to biopsy with laparotomy. We investigated the advantage of laparoscopic biopsy for advanced ovarian cancer. PATIENTS AND METHODS: We included 23 patients who underwent laparoscopy and 27 who underwent exploratory laparotomy before neoadjuvant chemotherapy between January 2012 and August 2020. We reviewed their medical records and evaluated their operative outcomes. RESULTS: Blood loss was significantly lower in the laparoscopy group (5 ml vs. 320 ml, p<0.05). The period until the initiation of neoadjuvant chemotherapy was significantly shorter in the laparoscopy group (12 days vs. 16 days, p<0.05). Overall survival did not differ significantly between the two groups (25.4 months vs. 24.7 months, p=0.53). CONCLUSION: Laparoscopic tumour biopsy is useful and safe for histological diagnosis, thereby allowing for early introduction to neoadjuvant chemotherapy.

Analysis of Surgical Procedure of Four Cases of Ovarian Pregnancies Treated with Laparoscopic Surgery.

Ovarian pregnancy is a rare disease, accounting for 0.5%-3% of ectopic pregnancies. Ovarian pregnancy risk factors and preoperative diagnosis have been extensively reported. However, its histopathology and surgical findings have been poorly studied. To examine appropriate surgical procedures, we investigated the clinical features, surgical findings, and histopathological examinations of four ovarian pregnancy cases treated in our hospital. In histopathological examination, most specimens did not contain ovarian tissues; in some cases, villous tissues were buried in a clot. Therefore, evaluating the appropriateness of surgical resection range from histopathological images was difficult. However, the postoperative course was favorable; no cases manifested complications. Considering all these facts, we regarded the surgical procedures of the four cases in this study as appropriate. For the treatment of ovarian pregnancies, especially for the outward development type, a sufficient therapeutic effect may be achieved even without extensive excision of the ovarian tissues by laparoscopic surgery.

Analysis of risk factors for patients with early-stage cervical cancer: A study of 374 patients.

AIM: This study aimed to identify the postoperative histological features affecting the prognosis of patients with early-stage cervical cancer who underwent open radical hysterectomy. METHODS: This retrospective study enrolled 374 patients with pT1a, 1b1 and 2a1 early-stage cervical cancer who underwent open radical hysterectomy between 2001 and 2018. Survival outcomes were analyzed by Kaplan-Meier method and compared with log-rank test. Using the Cox proportional hazards regression test, we conducted a multivariate analysis for disease-free survival and overall survival. RESULTS: Others histology, including other epithelial tumors and neuroendocrine tumors, had a significantly worse prognosis in both disease-free survival and overall survival than those of squamous cell carcinoma and adenocarcinoma (hazard ratio, 4.37 and 11.76; P = 0.006 and P = 0.002, respectively), along with lymph node metastasis (hazard ratio, 2.99 and 7.03; P = 0.009 and P = 0.001, respectively). CONCLUSION: Others histology including adenosquamous carcinoma had a poor prognosis in early-stage cervical cancer as with high-risk factors.

Neoadjuvant Chemotherapy for Patients With Diaphragmatic Lesions: A Prognostic Postoperative Analysis.

BACKGROUND/AIM: We aimed to analyse the prognosis of patients who underwent primary debulking surgery (PDS) and those who underwent interval debulking surgery (IDS) following four courses of paclitaxel+ carboplatin as preoperative chemotherapy to examine the usefulness of preoperative chemotherapy. PATIENTS AND METHODS: We included 45 patients with epithelial ovarian and peritoneal cancers accompanied with diaphragmatic lesions who underwent standard surgery combined with diaphragmatic surgery at two related institutions in January 2010-December 2013. Using medical records, we surveyed the recurrence period, recurrence site, and date of last confirmed survival, and analysed prognosis. RESULTS: The PDS and IDS groups comprised 32 and 13 patients (overall survival, 61.2 and 43.2 months), respectively. Progression-free survival in the PDS and IDS groups was 31.2 and 16.8 months, respectively. CONCLUSION: NAC-IDS can be a standard treatment option for patients with a tumour in the triangular ligament, in whom complete surgery is difficult.

A simple method of quantifying chemotherapy-induced peripheral neuropathy using PainVision PS-2100®.

AIM: This study aimed to validate a simplified method of quantifying chemotherapy-induced peripheral neuropathy using the PainVision PS-2100® (PV) electrical perception system. METHODS: We assessed patients diagnosed with epithelial ovarian cancer, fallopian tube cancer, or peritoneal cancer and were about to undergo first-time paclitaxel and carboplatin chemotherapy. Peripheral neuropathy was assessed before and after chemotherapy administration in all patients according to the National Cancer Institute-Common Terminology Criteria for Adverse Events Version 4.0 (NCI-CTCAE4.0), using a conventional assessment in combination with the PV system. The PV device comprises electrodes attached to the ulnar side of the forearm and the first joint of index fingers on both the left and right sides to measure the electrical perceptual threshold. The average of three threshold measurements was recorded for each patient. RESULTS: Thirty female patients (age 51.6 ± 12.2 [mean ± SD]) were included, and median number of chemotherapy drug treatments was 5 (first quartile: 4, second quartile: 5, and third quartile: 5). Twenty-seven patients (90%) reported posttreatment numbness; NCI-CTCAE4.0 perceptual anomaly grades were as follows: G1, 57 (40%); G2, 19 (13%); and G3, 7 (5%). A positive correlation was identified between right medial side PV threshold score and perceptual anomaly grade on measurements of the inner right-hand side only. CONCLUSION: Our preliminary results suggest that peripheral neuropathy may be quantified using PV. As CIPN often lowers QOL, it needs to be appropriately evaluated. Future studies with a larger patient cohort and methodological refinements to improve accuracy are warranted.

PIK3CA and KRAS mutations in cell free circulating DNA are useful markers for monitoring ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) exhibits distinct phenotypes, such as resistance to chemotherapy, poor prognosis and an association with endometriosis. Biomarkers and imaging techniques currently in use are not sufficient for reliable diagnosis of this tumor or prediction of therapeutic response. It has recently been reported that analysis of somatic mutations in cell-free circulating DNA (cfDNA) released from tumor tissues can be useful for tumor diagnosis. In the present study, we attempted to detect mutations in PIK3CA and KRAS in cfDNA from OCCC patients using droplet digital PCR (ddPCR). Here we show that we were able to specifically detect PIK3CA-H1047R and KRAS-G12D in cfDNA from OCCC patients and monitor their response to therapy. Furthermore, we found that by cleaving wild-type PIK3CA using the CRISPR/Cas9 system, we were able to improve the sensitivity of the ddPCR method and detect cfDNA harboring PIK3CA-H1047R. Our results suggest that detection of mutations in cfDNA by ddPCR would be useful for the diagnosis of OCCC, and for predicting its recurrence.

Dedifferentiated endometrial carcinoma: A report of three cases and review of the literature.

Dedifferentiated endometrial carcinoma, which is defined microscopically as the co-existence of undifferentiated carcinoma and grade 1 or 2 endometrioid adenocarcinoma, is an aggressive type of cancer regardless of the percentage of undifferentiated components. It is reported that undifferentiated carcinoma comprises 9% of endometrial carcinoma. The percentage of dedifferentiated endometrial carcinoma has been hypothesized to be 40% of undifferentiated carcinoma. A precise pathological diagnosis is essential for defining the appropriate therapeutic approach and prognosis. Furthermore, since there is an association between dedifferentiated endometrial carcinoma and Lynch syndrome, it is important to identify the patient's genetic background. The current case report presents three cases of dedifferentiated endometrial carcinoma treated in our hospital. In immunohistochemical staining for DNA mismatch-repair (MMR) proteins in dedifferentiated endometrial carcinoma, the components of undifferentiated carcinoma demonstrated a loss of MMR protein expression, and it is suspected that there may be a germline mutation in these cases. Therefore, Lynch syndrome should be suspected and the appropriate genetic approaches in cases of dedifferentiated endometrial carcinoma should be considered.

Feasibility of reduced port surgery applying Higuchi's transverse incision.

OBJECTIVE: Higuchi's transverse incision is made at a lower position than the Pfannenstiel transverse incision and is superior in terms of cosmetic outcomes. The purpose of this study was to examine the safety and efficacy of novel forms of reduced port surgery for ovarian cysts and uterine fibroids applying Higuchi's transverse incision. METHODS: In 33 patients with ovarian cysts who underwent low-position single-incision laparoscopic surgery (L-SILS)-modified single-port laparoscopy placed in the 2-3-cm Higuchi's incision above the pubis, patient's characteristics and perioperative outcomes were compared with those of patients who underwent multiport laparoscopy (n = 53). In addition, 18 patients with uterine fibroids who underwent dual-port laparoscopically assisted myomectomy without using power morcellators and conventional four-port laparoscopically assisted myomectomy were investigated. RESULTS: There were no significant differences between L-SILS and multiport laparoscopy in tumor diameter, bleeding, hospital stay, or postoperative pain. However, the L-SILS group demonstrated significantly shorter operative and pneumoperitoneum times (p < 0.01 and p < 0.01). In comparison with cases of uterine fibroids, no significant differences were found in maximum fibroid diameter, operative time, pneumoperitoneum time, or bleeding. However, the dual-port laparoscopically assisted myomectomy group demonstrated a significantly shorter length of hospital stay than the conventional laparoscopically assisted myomectomy group (p < 0.05). CONCLUSION: We reported novel forms of reduced port surgery applying Higuchi's transverse incision. It was suggested that these procedures are relatively simple, but ensure the same safety and efficacy as conventional methods. We intend to increase the number of cases and examine safety, efficacy, and patient satisfaction for these procedures.

Higuchi's transverse incision and a modification of this method for minimally invasive surgery.

STUDY OBJECTIVE: To describe Higuchi's transverse incision and a modification of this method for reduced port surgery (RPS). DESIGN: Descriptive study. SETTING: University hospital. PATIENTS: Those with ovarian cyst and uterine myoma. INTERVENTION: A platform is placed in the 2-3 cm Higuchi incision just above the pubis or on the pubis. Blunt dissection of the subcutaneous adipose tissue is performed. A T incision of the rectus abdominis fascia and a longitudinal incision of the peritoneum are performed. A LAP PROTECTOR and EZ access (Hakko Medical, Nagano, Japan) are used with the platform for single-incision laparoscopic surgery. The peritoneum and fascia are closed by continuous suture, and the skin is closed using the dermostitch technique. MAIN RESULTS: Higuchi's transverse incision is 2-3 cm in length and is made at a much lower position than the conventional Pfannenstiel transverse incision. The wound is covered by pubic hair, yielding an excellent esthetic outcome. The T incision of the rectus abdominis fascia secures a more extensive surgical field than the Pfannenstiel transverse incision. CONCLUSION: Higuchi's modified transverse incision ensures a sufficient visual field, yields an excellent esthetic outcome, and is safe, suggesting the potential use of this method for RPS.

Polypoid endometriosis of the ovary and müllerianosis of pelvic lymph nodes mimicking an ovarian carcinoma with lymph node metastasis.

Polypoid endometriosis is a distinctive variant of endometriosis with histological features simulating those of endometrial polyps. Müllerianosis is characterized by the presence of lesions at any site containing admixtures of endosalpingiosis, endometriosis, and endocervicosis. Here, we report a rare case of polypoid endometriosis of the ovary with müllerianosis of the pelvic lymph nodes in a 44-year-old woman without a past history of pelvic surgery. Magnetic resonance imaging revealed an ovarian tumor containing papillary nodules up to 3.0 cm in diameter and left pelvic lymph node enlargement. Nodules in ovarian tumor showed heterogeneous high intensity on T2-weighted image and high intensity on diffusion-weighted image and were mildly enhanced by gadolinium contrast material. Enlarged lymph node was markedly enhanced by gadolinium. We considered polypoid endometriosis in the differential diagnosis according to the results of the magnetic resonance imaging, and polypoid endometriosis was included in intraoperative consultation, however, ovarian carcinoma with lymph node metastasis could not be denied. According to histological examination, the final diagnosis was determined as polypoid endometriosis with glandular hyperplasia of the left ovary and müllerianosis in the obturator lymph nodes. To the best of our knowledge, this is the first report of polypoid endometriosis and müllerianosis of the pelvic lymph node.

Success rate and safety of tumor debulking with diaphragmatic surgery for advanced epithelial ovarian cancer and peritoneal cancer.

PURPOSE: In advanced epithelial ovarian and peritoneal cancer, residual tumor diameter correlates with prognosis; therefore, maximum debulking and optimal surgery (OS) for residual tumors <1 cm is warranted. Here, we clarified the efficacy of tumor debulking with diaphragmatic surgery (DS). METHODS: In 45 patients with epithelial ovarian or peritoneal cancer who underwent DS (ten, full-thickness resection; 35, stripping) between January 2010 and December 2013 at two related institutions, we retrospectively evaluated OS safety and success by surgical duration, blood loss, complications, hospitalization stay, and residual tumor diameter and site. RESULTS: Blood loss was 4,090.8 and 2,847.9 mL; surgical duration was 485.2 and 479.5 min; hospitalization stay was 21.7 and 24.8 days; and complications included intraoperative thoracotomy in 17 and 7 patients, unexpected thoracotomy in 11 and 3, chest drain insertion in one and three, and pleural effusion in 14 and 7, in the primary debulking surgery (PDS) and interval debulking surgery (IDS) groups, respectively. OS was successful in all patients with complete surgery (CS: no residual tumor) achieved in 16 (50.0%) and 9 (69.2%), residual tumor diameter < 5 mm in 11 (34.4%) and 2 (15.4%), and residual tumor diameter < 1 cm in 5 (15.6%) and 2 (15.4%) in the PDS and IDS groups, respectively. CONCLUSIONS: Tumor debulking surgery with DS resulted in controllable blood loss, and OS was successful in all patients without severe complications or postoperative treatment delay. Currently, OS is considered to have very few benefits over CS; thus, the success rate of CS rate should be improved while maintaining safety.

Pathology-oriented treatment strategy of malignant ovarian tumor in pregnant women: analysis of 41 cases in Japan.

BACKGROUND: The aim of this study was to investigate the impact of the histological findings on the treatment of malignant ovarian tumors in pregnant women. METHODS: This is a retrospective study of 41 patients diagnosed and treated for ovarian malignancy during pregnancy between 1985 and 2010. RESULTS: The median age of the study group was 30 years old, ranging from 20 to 41. Thirty-eight (92 %) patients were diagnosed with stage I, and one (2 %) with each of stages II, III, and IV. Twenty-five (61 %) patients had borderline malignancy, 8 (20 %) were diagnosed with epithelial ovarian cancer, 7 (17 %) with germ cell tumor, and one with sex cord stromal tumor. All patients received primary surgery; 7 (17 %) patients had cystectomy, 32 (78 %) had unilateral salpingo-oophorectomy, and 3 (7 %) underwent hysterectomy with bilateral salpingo-oophorectomy. Thirty-one (76 %) patients delivered live newborns; 21 had borderline tumor (84 %), 2 had ovarian cancers (25 %), and 8 had non-epithelial tumor (100 %). Six cases were terminated in order to perform the standard treatment for ovarian malignancy and 2 cases aborted spontaneously. CONCLUSION: In pregnant women, ovarian cancer is exceptionally less frequent compared with non-pregnant women, i.e. age-matched, statistically-corrected controls based on the Japanese annual report [8/33 (24 %) vs. control (60 %); ovarian cancer/(ovarian cancer + borderline tumor), P = 0.001]. The pregnant women with ovarian cancer chose to prioritize treatment of ovarian cancer at the sacrifice of their babies while those with borderline tumor or non-epithelial tumor were able to successfully deliver live newborns.

Ovarian cancer complicated by pregnancy: Analysis of 10 cases.

The objective of this study was to ascertain the evidence on ovarian cancer during pregnancy and compile recommendations derived from this information. This was a retrospective study, based on clinical histories from patients diagnosed and treated at 4 independent hospitals for ovarian cancer during pregnancy, between 1992 and 2009. The median age at diagnosis was 30 years (range, 24-41). Out of 10 cases of ovarian cancer, 2 patients showed either bleeding or abdominal pain, while 8 patients were asymptomatic. All 10 cases were diagnosed via ultrasound, and the masses were detected in the first trimester in 7 patients and in the second trimester in 2 patients. Of the diagnosed tumors, 8 cases were epithelial tumors including 6 adenocarcinomas and 2 borderline tumors, and 2 germ cell tumors. The primary ovarian malignancies were at stage I of the disease. Unilateral salpingo-oophorectomy was performed in 9 patients and cystectomy was performed in one patient. Chemotherapy was administered to 4 patients, in 1 case during pregnancy. Neonatal outcome analysis showed a full- or pre-term delivery in 6 cases, abortion in 1 case and therapeutic termination in 3 cases. The majority of cases of ovarian cancer in pregnancy were incidentally detected by ultrasound at an early stage, resulting in good prognosis for the mother and the neonate.

Pilot study of CD147 protein expression in epithelial ovarian cancer using monoclonal antibody 12C3.

AIM: CD147 is a membrane glycoprotein that is expressed in various cancer cells and is involved in tumor invasion and metastasis by inducing stromal fibroblastic cells to produce matrix metalloproteinases. This study was carried out to evaluate the correlation between CD147 expression and various clinicopathologic parameters, including histological grade and prognosis in a small sample set of human ovarian cancer patients. MATERIAL AND METHODS: Paraffin-embedded surgical tissue samples from 25 patients with ovarian serous and endometrioid adenocarcinoma were stained with anti-CD147 antibody (monoclonal antibody 12C3: MoAb 12C3) for immunohistochemical analysis. RESULTS: CD147 protein was expressed in 84.0% (21 of 25 cases) of cancerous lesions, but not in normal lesions. CD147 expression by ovarian cancer cells was inversely correlated with overall survival. There was no correlation between CD147 expression and histological grade. CONCLUSIONS: These results suggest that measurement of CD147 expression may enhance the understanding of the pathophysiology of epithelial ovarian cancer.

Hypoxia promotes glycogen synthesis and accumulation in human ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) has several significant characteristics based on molecular features that are distinct from those of ovarian high-grade serous carcinoma. Cellular glycogen accumulation is the most conspicuous feature of OCCC and in the present study its metabolic mechanism was investigated. The amount of glycogen in cells cultured under hypoxia increased significantly and approximately doubled after 48 h (P<0.01) compared to that under normoxic conditions. Periodic acid-Schiff positive staining also demonstrated intracellular glycogen storage. Western blot analysis revealed that HIF1α, which was overexpressed and stabilized under hypoxic conditions, led to an increase in the levels of cellular glycogen synthase 1, muscle type (GYS1), and conversely to a decrease in inactive phosphorylated GYS1 at serine (Ser) 641. Additional increases were observed in both protein phosphatase 1, which dephosphorylates and thereby induces GYS1 enzyme activity, and glycogen synthase kinase 3 beta (GSK3ß) phosphorylated at Ser9, which is inactive on phosphorylation of GYS1 and subsequently induces its enzyme activity. By contrast, the level of PYGM-b decreased. These results indicated that the glycogen accumulation under a hypoxic environment resulted in the promotion of glycogen synthesis, but did not lead to inhibition of glycogen degradation and/or consumption. Under hypoxic conditions, HAC2 cells showed activation of the PI3K/AKT pathway caused by a mutation in exon 20 of PIK3CA, encoding the catalytic subunit p110α of PI3K. The resulting activation of AKT (phosphoSer473) also plays a role as a central enhancer in glycogen synthesis through suppression of GSK3ß via phosphorylation at Ser9. Hypoxia decreased the cytocidal activity of cisplatin and doxorubicin to various degrees. In conclusion, the hypoxic conditions together with HIF1 expression and stabilization increased the intracellular glycogen contents and resistance to the anticancer drugs.

Three-dimensional culture using a radial flow bioreactor induces matrix metalloprotease 7-mediated EMT-like process in tumor cells via TGFbeta1/Smad pathway.

To confirm the usefulness of the radial flow type bioreactor (RFB) for a three-dimensional (3D) culture system, which provides a tissue architecture and molecular function mimicking the in vivo environment, molecular expression in the A431 human squamous carcinoma cell line during culture were analyzed under the physically different environments of 3D culture in the RFB, 2D culture in a monolayer as well as in nude mice. Time-dependent accumulation of autocrine transforming growth factor (TGF) beta1 was found in spent culture media obtained only from 3D cultured A431 cancer cells, which grew well with a stratified-sheet morphology. Cells in the RFB overexpressed matrix metalloproteinase 7 (MMP7) and showed an increased release of soluble 80-kDa fragments of E-cadherin into the media time-dependently, resulting in the reduction of E-cadherin protein at the cell surface without down-regulation of the mRNA. beta-Catenin and its nuclear partner, LEF1, were up-regulated and Wnt protein secretion was also accelerated. Additional up-regulation of the transcriptional factors, HMGA2 and down-stream Slug, was noted. TGFbeta1-dependent, MMP7-mediated up-regulation of beta-catenin/LEF1 signaling and TGFbeta1-activated HMGA2 pathways consequently converged with Slug overexpression, due to disassembly and further repression of E-cadherin expression, which was reproducible in the epithelial mesenchymal transition process without any manipulation. Other transcriptional factors, Notch/HEY1 and NF-kappaB, were also up-regulated in 3D-cultured cells. These signals recruited molecules related to extracellular matrix-cell remodeling and angiogenesis. Expression of several representative molecules in the 3D cultured cells was parallel with that in xenotransplanted A431 tumor tissues in nude mice. 3D culture of tumor cells in the RFB is a useful tool for cancer experimental biology and evaluation of cancer therapeutic-like systems in nude mice.

Irinotecan hydrochloride (CPT-11) and cisplatin as first-line chemotherapy after initial surgery for ovarian clear cell adenocarcinoma.

Patients with ovarian clear cell adenocarcinoma (OCCA) show a poor response to conventional platinum-based chemotherapy. Recently, it was reported that combination chemotherapy with cisplatin plus irinotecan hydrochloride (P-CPT) achieves high response rates for primary advanced and recurrent or resistant OCCA. We retrospectively reviewed the outcome of 20 OCCA patients treated with P-CPT by the Gynecology Service at The Jikei University Hospital after initial surgery. These patients received a total of 101 cycles of P-CPT, with a median of 5 cycles each. Two complete responses (CRs) were obtained in the three patients with measurable disease, and response duration was 7 and 15 months, respectively. One patient had stable disease (SD), and the time to progression was 5 months. The estimated 3- and 5-year survival rates were 69% and 69%, respectively. Our current data and previous reports suggest that P-CPT is a candidate first-line chemotherapy regimen for OCCA.