Ayako Kawabata

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.

Prognostic impact of interleukin-6 expression in stage I ovarian clear cell carcinoma

OBJECTIVE Ovarian clear cell carcinoma (OCCC) frequently presents at an early stage. In stage I OCCC, the prognosis differs according to substage. In particular, predictive biomarkers and new treatment strategies are needed for stage IC2/IC3 disease. We investigated tumor biology and prognostic factors for stage I OCCC from a clinicopathological perspective, including the expression of ARID1A and IL-6, which are considered critical for OCCC carcinogenesis. METHODS A retrospective cohort study of 192 patients with stage I OCCC treated at a single institution was performed. We calculated overall survival (OS) with respect to 12 clinicopathological parameters that included the unique and diverse histological features of OCCC. RESULTS The estimated 5-year OS rate in patients with all stage I OCCC was 88.9% during a median of 91months of follow-up. The multivariate analysis indicated that substage classification and IL-6 expression status were associated with poor OS (p=0.010 and p=0.027, respectively). Loss of ARID1A expression had no impact on survival; however, it was associated with substage (p=0.001), capsule rupture status (p=0.011), and ascites cytology (p=0.016). No clear association was found between ARID1A and IL-6 expressions. Histological findings, including the presence of endometriosis, adenofibroma, architectural pattern, and tumor cell type, showed no prognostic effects. CONCLUSIONS Both substage classification and IL-6 expression status may be independent prognostic factors in stage I OCCC. Therefore, IL-6 molecular stratification may be crucial in optimizing therapeutic strategies for early stage OCCC to improve survival.

Update on rare epithelial ovarian cancers: based on the Rare Ovarian Tumors Young Investigator Conference

There has been significant progress in the understanding of the pathology and molecular biology of rare ovarian cancers, which has helped both diagnosis and treatment. This paper provides an update on recent advances in the knowledge and treatment of rare ovarian cancers and identifies gaps that need to be addressed by further clinical research. The topics covered include: low-grade serous, mucinous, and clear cell carcinomas of the ovary. Given the molecular heterogeneity and the histopathological rarity of these ovarian cancers, the importance of designing adequately powered trials or finding statistically innovative ways to approach the treatment of these rare tumors has been emphasized. This paper is based on the Rare Ovarian Tumors Conference for Young Investigators which was presented in Tokyo 2015 prior to the 5th Ovarian Cancer Consensus Conference of the Gynecologic Cancer InterGroup (GCIG).

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.

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.