Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Takaharu Yamawaki.
Obstetrics & Gynecology | 1996
Nobuhiro Takeshima; Yasuo Hirai; Naotake Tanaka; Takaharu Yamawaki; Kazuhiro Yamauchi; Katsuhiko Hasumi
Objective To analyze the incidence of pelvic lymph node metastasis in endometrial carcinoma with no myometrial invasion. Methods Between 1971 and 1995, 684 women with stage I endometrial carcinoma underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy. The incidence of pelvic lymph node metastases in 100 cases without myometrial invasion was examined. Results Histologic examination of the surgical specimens revealed a single pelvic lymph node metastasis in each of four cases. The incidence of pelvic lymph node metastasis was four of 83 in grade 1, zero of 13 in grade 2, and zero of four in grade 3 tumors. Conclusion Pelvic lymph node metastasis in endometrial cancer with no myometrial invasion is not rare, even with grade 1 tumors. Lymphadenectomies may be necessary in all patients with endometrial cancer, except when clinical or operative factors increase the procedures risk of morbidity.
Acta Cytologica | 2012
Kenji Yanoh; Yasuo Hirai; Atsuhiko Sakamoto; Daisuke Aoki; Takuya Moriya; Masamichi Hiura; Takaharu Yamawaki; Keiko Shimizu; Hiroki Nakayama; Hiroshi Sasaki; Tsutomu Tabata; Masatsugu Ueda; Yasuhiro Udagawa; Yoshiaki Norimatsu
Objective: To evaluate the sensitivity and specificity of endometrial cytology obtained by intrauterine sample using a descriptive reporting format for endometrial cytological diagnosis. Study Design: 10,152 consecutive endometrial scrapings obtained in 13 different Japanese hospitals were analyzed. Cytological results were classified as ‘negative for malignancy’, ‘atypical endometrial cells’ (ATEC), ‘endometrial hyperplasia’, ‘atypical endometrial hyperplasia’ or ‘malignant tumor’. ATEC was subclassified as ‘ATEC, of undetermined significance’ (ATEC-US) and ‘ATEC, cannot exclude atypical endometrial hyperplasia or more’ (ATEC-A). Cytological results were compared with the histological diagnosis as a gold standard. When the cytological result was ‘negative for malignancy’ and there was no subsequent histological examination, the case was considered a true negative when the endometrium was assessed as normal on transvaginal ultrasonography and there was no abnormal uterine bleeding. Results: 1,083 cases in which histology was not performed, 557 cases of ‘unsatisfactory specimen’ and 76 cases of ATEC-US were excluded. In the remaining 8,436 cases, the sensitivity and specificity, positive predictive value and negative predictive value for detecting atypical endometrial hyperplasia or malignant tumors were 79.0 and 99.7, 92.9 and 98.9%, respectively. Conclusion: The current diagnostic standards for endometrial cytology in Japan were established. Specificity is satisfactory for excluding cancer or precancerous diseases.
Journal of Obstetrics and Gynaecology Research | 1996
Takaharu Yamawaki; Nobuhiro Takeshima; Yoshio Shimizu; Hideo Teshima; Katsuhiko Hasumi
Objective: To assess whether squamous cell carcinoma (SCC) antigen and carcinoembryonic antigen (CEA) are useful as tumor markers of vulvar cancer.
International Medical Case Reports Journal | 2015
Yukari Nagao; Kazuhiro Osato; Michiko Kubo; Takuya Kawamura; Tomoaki Ikeda; Takaharu Yamawaki
Uterine rupture rarely occurs during pregnancy, but it is a critical situation if so. It is already known that a history of uterine surgeries, such as cesarean section or myomectomy, is a risk factor for uterine rupture. Currently, the laparoscopic adenomyomectomy is a widely performed procedure, but associated risks have not been defined. We observed a case of spontaneous uterine rupture in a patient during the 35th week of gestation, after a laparoscopic adenomyomectomy. A 42-year-old, gravida 2, para 0 woman became pregnant after a laparoscopic adenomyomectomy and her pregnancy was conventional. At a scheduled date in the 35th week of gestation, after combined spinal epidural anesthesia and frequent uterine contractions, a weak pain suddenly ensued. After 13 minutes of uterine contractions, vaginal bleeding was evident. A cesarean section was performed, and the uterine rupture was found in the scar. After a laparoscopic adenomyomectomy, a pregnant uterus can easily rupture by rather weak and short uterine contractions, and is characterized by vaginal bleeding. When uterine bleeding is observed in pregnant women that have a history of adenomyomectomy, one should consider uterine rupture.
International Journal of Gynecological Cancer | 2014
Takaya Shiozaki; Tsutomu Tabata; Tomomi Yamada; Yuka Yamamoto; Takaharu Yamawaki; Tomoaki Ikeda
Objective The objective of this study was to elucidate factors that affect prognosis in patients with stage I endometrial cancer. Methods The study group comprised 265 patients with stage I endometrial cancer treated surgically at either of our facilities between January 1998 and December 2010 (238 patients with negative peritoneal cytology and 27 patients with positive peritoneal cytology). Progression-free survivals were evaluated between the 2 groups, and multivariate analysis was conducted with correlation factors including positive peritoneal cytology, vessel permeation, lymph node dissection, histologic diagnosis, age at diagnosis, adjuvant chemotherapy, and the depth of myometrial invasion. Results Disease-free survival was significantly poorer for patients with positive peritoneal cytology than those with negative peritoneal cytology on stage I disease (P = 0.000). The stratified log-rank test with vessel permeation shows the similar results. By univariate Cox model, positive peritoneal cytology, vessel permeation, and systemic lymph node dissection at surgery are significant factors on stage I endometrial cancer. Conclusions Although this is a small-scale preliminary study with adjustment of other factors, positive peritoneal cytology can contribute to the risk of progression-free survival in patients with stage I endometrial cancer.
International Journal of Gynecological Cancer | 2013
Takaya Shiozaki; Tsutomu Tabata; Nei Ma; Takaharu Yamawaki; Takashi Motohashi; Eiji Kondo; Kouji Tanida; Toshiharu Okugawa; Tomoaki Ikeda
Objective Although CXC chemokine receptor type 4 (CXCR4) is known to be expressed in various solid tumors and plays an integral role in cancer invasion and metastasis, expression of CXCR4 in human vulvar cancer has not yet been investigated. We examined distribution and expression of this chemokine receptor in specimens of invasive and noninvasive human vulvar neoplasms to elucidate its clinical significance. Methods Study patients were 38 consecutive patients (31 with primary vulvar cancers and 7 with intraepithelial neoplasms) treated at one of our hospitals. Sections of all specimens were evaluated for CXCR4 expression by means of immunohistochemistry. Relations between CXCR4 expression and clinicopathologic features including prognosis were investigated. Results None of the 7 vulvar intraepithelial lesions expressed CXCR4. Of the 31 invasive vulvar tumor samples examined, 19 (61%) stained positively for CXCR4; 15 (68%) of 22 squamous cell carcinomas and 2 (29%) of 7 Paget tumors were CXCR4 positive. The difference in expression between invasive cancers and intraepithelial neoplasms was significant (P = 0.003). FIGO (International Federation of Gynecology and Obstetrics) stage III–IV cancers, in comparison to FIGO stage I–II cancers, were more likely to be positive for CXCR4 (82% vs 50%, P = 0.08). In terms of disease-free survival, prognosis of cancers that expressed CXCR4 was poorer than that of CXCR4-negative cancers (P = 0.013), but in terms of disease-specific survival, prognosis did not differ significantly between CXCR4-positive and -negative cancers (P = 0.111). Conclusions More than half of invasive squamous cell vulvar cancers can be expected to express CXCR4, and CXCR4 expression correlates with poor disease prognosis.
Journal of Obstetrics and Gynaecology Research | 2018
Miki Akasaka; Kazuhiro Osato; Mito Sakamoto; Tomohisa Kihira; Tomoaki Ikeda; Takaharu Yamawaki
Amniotic fluid embolism (AFE) causes consumption coagulopathy, which requires a massive transfusion to save the mothers life. The preparation of such a massive transfusion is too time‐consuming in extremely emergent clinical settings and occasionally leads to devastating side effects such as transfusion‐associated acute lung injury. C1 esterase inhibitor (C1INH) is a protein with the ability to inhibit complement, coagulation and kinin pathways. The C1INH concentration in AFE patients is low, and it has been speculated that the administration of C1INH concentrate could have a striking and beneficial effect on AFE patients in critical condition by ameliorating their perturbed coagulation system. We report the case of a 32‐year‐old Japanese AFE patient in whom deteriorated vital signs and coagulopathy recovered within minutes after an injection of C1INH concentrate. C1INH concentrate can quickly revive the deteriorated vital signs and the atonic uterus that stem from AFE and may reduce the total amount of transfusion.
Journal of Obstetrics and Gynaecology Research | 2017
Kazuhiro Suzuki; Madoka Furuhashi; Takuya Kawamura; Michiko Kubo; Kazuhiro Osato; Takaharu Yamawaki
Cervical cancer onset initially occurs during youth. Papanicolaou tests performed in early pregnancy can detect cervical cancer; however, Papanicolaou tests during pregnancy have been noted to be inaccurate, reflecting changes associated with pregnancy. Therefore, we assessed the effect of pregnancy on Papanicolaou test results.
Gynecologic Oncology | 1996
Takaharu Yamawaki; Yasuo Hirai; Nobuhiro Takeshima; Katsuhiko Hasumi
Gynecologic Oncology | 1997
Takaharu Yamawaki; Yoshio Shimizu; Katsuhiko Hasumi