Published papers

Objective Regional lymph node (LN) dissection is a standard surgical procedure for endometrial cancer, but there is currently no clear consensus on its therapeutic significance. We aimed to determine the impact of regional LN dissection on the outcome of endometrial cancer. Methods Study subjects comprised 36,813 patients who were registered in the gynecological tumor registry of the Japan Society of Obstetrics and Gynecology, had undergone initial surgery for endometrial cancer between 2004 and 2011, and whose clinicopathological factors and prognosis were appropriate for our investigation. The following clinicopathological factors were obtained from the registry: age, surgical stage classification, Union for International Cancer Control tumor, node, metastasis classification, histological type, histological differentiation, presence or absence of LN dissection, and postoperative treatment. We retrospectively analyzed the clinicopathological factors and therapeutic outcomes for patients with endometrial cancer. Results Analysis of all subjects showed that the group that underwent LN dissection had a significantly better overall survival than the group that did not undergo dissection. Analysis based on stage showed similar results across groups, except for stage Ia. Analysis based on stage and histological type showed similar results across groups, except for stage Ia endometrial carcinoma G1 or Ia G2. Multivariate analysis of prognostic factors indicated that LN dissection is an independent prognostic factor and that it has a greater impact on prognosis than adjuvant chemotherapy. Conclusion Despite the limitations of a retrospective study with some biases, the results suggest that LN dissection in endometrial cancer has a prognostic effect.

Objective: To optimize prediction for intestinal invasion of epithelial ovarian cancer. It is important to achieve debulking surgery to improve prognosis in ovarian cancer; intestinal resection is adopted if the cancer is invaded and resectable, but the preoperative evaluation method of intestinal invasion is still controversial. Methods: Patients (n = 174) who underwent primary debulking surgery for epithelial ovarian cancer were recruited for retrospective study; 28 and 146 patients were classified into the invasion and non-invasion groups, whether they needed intestinal resection or not. We collected clinical data including evaluation of computed tomography (CT), magnetic resonance imaging (MRI), and barium contrast radiography, and analyzed their accuracy. Results: The sensitivity and specificity for intestinal invasion were 33.3% and 98.6%, 42.9% and 98.6%, and 66.7% and 93.9% in CT, MRI, and barium contrast radiography, respectively. CT and MRI combined showed a sensitivity of 58.3% and specificity of 96.9%; all three methods combined was the most sensitive combination, showing a sensitivity of 79.2% and specificity of 90.8%. Conclusion: Combination of CT, MRI, and barium contrast radiography predicts intestinal invasion with the highest sensitivity. These three modalities, however, could not predict all intestinal invasion. Patients should be informed of the possibility of unexpected extensive resection.

[Objective] Lynch syndrome (LS) is an autosomal dominant inherited disorder caused by a germline pathogenic variant in DNA mismatch repair (MMR) genes. Endometrial cancer frequently precedes another LS-associated tumor. This study aimed to clarify the incidence and features of LS in young Japanese endometrial cancer patients. [Methods] Sixty-five patients aged 40 years or younger, who were diagnosed with endometrial cancer, were enrolled in this study. Targeted sequencing of a hereditary colorectal cancer-related gene panel including the MMR genes MLH1, MSH2, MSH6, and PMS2 was conducted on DNA samples extracted from blood cells. [Results] Overall, 6 missense variants (2 in MSH2, 2 in MSH6, and 2 in PMS2), 1 inframe deletion variant in MSH2, 1 splice variant in MSH2, and 1 two-base substitution in the 3’ untranslated region in MLH1 were detected in 9 (13.8%) patients. Among these, the splice variant c.1276G > T (p.Ile411_Gly426del16) in MSH2 was annotated as pathogenic, while other variants were of uncertain significance. The patient with the pathogenic variant had a family history of endometrial and colorectal cancer and was diagnosed with endometrial cancer at age 35. [Conclusion] The incidence of LS among Japanese endometrial cancer patients of reproductive age (≤ 40 years) in this study was at least 1.5%; however, 12.3% of patients had variants of uncertain significance in MMR genes.

Atypical polypoid adenomyoma (APA) is an intrauterine tumor for which hysteroscopic tumor resection allows for fertility preservation. Complete resection is important because of the high recurrence rate of APA, but is difficult due to the lack of characteristic hysteroscopic findings. We previously reported a case in which photodynamic diagnosis (PDD) was useful for detection of APA. Here, we report two additional cases of APA treated by hysteroscopic resection with PDD. The procedure was approved by the ethical committee. Case 1: A 35-year-old female who underwent hysteroscopic surgery for a submucosal tumor suspected to be APA with hypermenorrhea. Case 2: A 37-year-old female in whom hysteroscopic surgery was performed for a residual APA lesion after hormone therapy. In Case 1, PDD identified the tumor borders and this enabled as complete resection as possible. In Case 2, lesions could not be identified clearly under white light, but some areas were PDD-positive and were excised. Among 19 specimens from these two cases and the previously reported case, all PDD-positive specimens were pathologically diagnosed as APA. The sensitivity and specificity of PDD for APA were 76.9% and 100%, respectively. These results suggest that PDD can contribute to identification of APA.

子宮頸がん検診の手法の中で死亡率と罹患率の減少効果が直接的に示されたものは細胞診単独法のみで、現在わが国の地域保健・健康増進事業での検診手法としても採用されている。また子宮頸がんの原因とされるハイリスクHPV感染の有無を調べるHPV検査単独法は、研究での罹患率減少効果によって検診の有効性が示されたことから、近年では検診への導入がいろいろな国や地域で検討されている。一方、がん検診事業を実施して実際に対象集団における死亡や罹患の減少という効果を得られるかは、ある程度妥当な検診手法を用いたうえで、検診事業全体を適切に運用する必要がある。検診事業の運用が良好と言えるためには、精度管理体制の整備、検診受診者のモニタリング、診断・治療体制の整備など、運用状況に関する条件を満たす必要があり、それらを満たすものがorganized screening、すなわち組織型検診と言われる。そこで、わが国へのHPV検査単独法を導入するのみならず、それによって効果を上げることを念頭におき、わが国で実施されている住民検診、職域での検診、個人が任意で受ける検診それぞれの体制が、組織型検診の必要条件とされる各項目をどの程度充足しているかの現状を検討した。また、HPV検査単独法での効果を上げるために特に留意すべき条件を、そのアルゴリズムの特性から検討した。その結果、いずれの検診様式でも組織型検診の条件の充足が十分ではなかった。一方、HPV検査単独法での検診で期待される効果を得るにはそれらの条件すべてを準備すべきであり、特に精度管理体制の整備と検診受診者のモニタリング、診断・治療体制の整備に注力する必要があると考えられた。HPV検査単独法導入の検討は、同時に子宮頸がん検診事業の組織型検診の必要条件充足を伴うべきである。(著者抄録)

In 2017, the Japan Society of Clinical Oncology (JSCO) published the JSCO Clinical Practice Guidelines 2017 for Fertility Preservation in Childhood, Adolescent, and Young Adult Cancer Patients. These were the first Japanese guidelines to address issues of oncofertility. In this field of medicine, sustained close cooperation between oncologists and reproductive specialists is essential from the diagnosis of cancer until many years after completion of cancer treatment. These JSCO guidelines were intended to guide multidisciplinary medical staff in considering the availability of fertility preservation options and to help them decide whether to provide fertility preservation to childhood, adolescent, and young adult cancer patients before treatment starts, with the ultimate goal of improving patient survivorship. The guidelines are presented as Parts 1 and 2. This article (Part 1) summarizes the goals of the guidelines and the methods used to develop them and provides an overview of fertility preservation across all oncology areas. It includes general remarks on the basic concepts surrounding fertility preservation and explanations of the impacts of cancer treatment on gonadal function by sex and treatment modality and of the options for protecting/preserving gonadal function and makes recommendations based on 4 clinical questions. Part 2 of these guidelines provides specific recommendations on fertility preservation in 8 types of cancer (gynecologic, breast, urologic, pediatric, hematologic, bone and soft tissue, brain, and digestive).

The Japan Society of Clinical Oncology (JSCO) published the "JSCO Clinical Practice Guidelines 2017 for Fertility Preservation in Childhood, Adolescent, and Young Adult Cancer Patients" in 2017. This was the first guideline in cancer reproductive medicine in Japan. In the field of cancer reproductive medicine, close cooperation between an oncologist and a physician for reproductive medicine is important from before treatment initiation until long after treatment. The guideline takes into consideration disease specificity and provides opinions from the perspective of oncologists and specialists in reproductive medicine that are in line with the current state of the Japanese medical system. It is intended to serve as a reference for medical staff in both fields regarding the availability of fertility preservation therapy before the start of cancer treatment. Appropriate use of this guideline makes it easier to determine whether fertility preservation therapy is feasible and, ultimately, to improve survivorship in childhood, adolescent, and young adult cancer patients. In this article (Part 2), we describe details by organ/system and also for pediatric cancer.

Background: This study aimed to determine the incidence of pelvic fistulas in cervical cancer patients treated with bevacizumab in Japanese clinical practice. Methods: A post-marketing surveillance (PMS) study was conducted between June 2016 and February 2018 to survey physicians who treated advanced or recurrent cervical cancer patients with bevacizumab (according to the product label). The clinical/treatment status of patients with pelvic fistulas was assessed in an additional retrospective case series study. Results: 142 patients were included in the PMS study (median age 51 years; 66.9% squamous cell carcinoma; 66.2% recurrent cervical cancer; 64.1% previous radiotherapy). Patients received a median of seven bevacizumab doses. Six patients, all of whom had a history of pelvic irradiation, developed seven fistulas (4.2%; 95% confidence interval, 1.56–8.96), and five patients had also undergone pelvic surgery. The case series study of the patients who developed fistulas indicated that three patients had high cumulative bladder and rectal doses of radiation, and two of them had undergone salvage re-irradiation for pelvic recurrence. The other three patients underwent both radical hysterectomy and adjuvant radiotherapy, but did not receive an excessive radiation dose to the bladder or rectum. Conclusions: This study found that the upper limit of the 95% confidence interval for pelvic fistula incidence did not exceed the incidence reported in the GOG 240 study. To ensure an adequate benefit-risk assessment of bevacizumab in cervical cancer patients, a comprehensive evaluation of prior treatment is essential and the possibility of unexpected fistulas, even after careful evaluation, should be considered.

Objective: To identify candidate predictors for the prognosis of cervical intraepithelial neoplasia 2 (CIN2) lesions and evaluate the prognostic value of the local immune response. Methods: One hundred fifteen CIN2 patients were enrolled. The percentage of p16-, minichromosome maintenance complex component 2-or apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G)-positive cells was determined immunohistochemically. Tumor-infiltrating lymphocytes (TILs) in intertumoral lesions were scored using an automated system. CIN3 disease progression and regression rates were estimated by the Kaplan–Meier method. A case-control study was conducted to screen CIN2 prognostic factors in 10 regression and 10 progression patients. Selected factors were examined in a cohort study to determine their prognostic value for CIN2. Results: Among all participants, the cumulative progression and regression rates at 60 months were 0.477 and 0.510, respectively. In the case-control study, p16-and APOBEC3G-positive cells were higher in the progression group (p=0.043, p=0.023). Additionally, CD4+ cell infiltration was enhanced in the regression group (p=0.023). The cohort study revealed a significantly increased progression rate in patients with elevated p16-positive cells (p<0.001), and increased CD4+ TIL infiltration was associated with better regression (p=0.011). Kaplan– Meier analysis according to human papillomavirus (HPV) positivity revealed a greater CIN3 development risk in HPV16-positive patients than in HPV16-negative cases. Finally, multivariate analysis identified HPV16 infection and CD4+ TIL infiltration as independent prognostic factors in CIN2 regression. Conclusion: CD4+ TIL infiltration in intertumoral lesions was related with CIN2 regression. Our findings suggest CD4+ TIL infiltration may be useful for the triage of CIN2 patients.

Objective: To evaluate the accuracy of preoperative endometrial biopsy and magnetic resonance imaging (MRI) of endometrial cancer compared with that of intraoperative frozen section. Methods: This retrospective study included 264 patients who underwent surgery with intraoperative frozen section for endometrial cancer at our institution between 2014 and 2018. Diagnosis was determined by histologic type, grade, and myometrial invasion. Concordance rate, sensitivity, and specificity of preoperative diagnosis and intraoperative frozen diagnosis were calculated, in comparison to the final pathologic diagnosis. Results: Preoperative and intraoperative diagnoses showed no statistically significant difference in determining histologic type and grade (P = 0.152). Intraoperative diagnosis showed higher sensitivity for endometrioid carcinoma grade 3 and other types, and higher specificity for grade 1. For myometrial invasion, intraoperative diagnosis showed significantly higher concordance rate than preoperative MRI findings (P < 0.01). Intraoperative diagnosis showed higher sensitivity and specificity in patients with and without myometrial invasion, respectively. Conclusion: Higher agreement between intraoperative and final diagnoses, especially in myometrial invasion, suggests that intraoperative frozen section is a good indicator for appropriate surgical procedure decision making.

Background: The influence of the coronavirus disease 2019 (COVID-19) pandemic on the number of newly diagnosed gynecological cancers has not been extensively investigated in Japan. This study determined the impact of COVID-19 on the incidence of gynecological cancer. Methods: Using the Japanese Society of Obstetricians and Gynecologic Oncology registry database, the distribution of the number of patients based on clinical staging or tumor-node-metastasis classifications before and during the COVID-19 pandemic was analyzed to compare the trends. The clinical staging classification of cervical cancer in Japan was based on the International Federation of Gynecology and Obstetrics (FIGO) 2008 from 2018 to 2020 and on the FIGO 2018 from 2021. Since FIGO-2018 classified N1 cases as stage IIIC, we focused on T classification without referencing the clinical staging (FIGO staging) of patients with cervical cancer in 2021. Results: The number of patients with endometrial cancer and malignant ovarian tumors of all clinical stages increased uniformly yearly, while that of those with stage III cervical cancer rapidly increased in 2021 owing to the adoption of the revised classification. On comparing cases of cervical cancer in 2020 and 2021, we found that T1 cases decreased and T2 and T3 cases increased in 2021 compared to those in 2020 (p = 0.006). Cervical intraepithelial neoplasia/adenocarcinoma in situ incidence decreased in 2020 compared to that in 2019 but increased again in 2021. The number of patients with cervical cancer decreased in most prefectures in 2020. Conclusion: The incidence of locally advanced cervical cancer increased during the COVID-19 pandemic.

Aim: This study aimed to clarify the impact of coronavirus disease 2019 on gynecology practice in Japan, in particular, on surgeries for benign gynecological diseases. Methods: An online questionnaire was distributed to 966 facilities in Japan, including core facilities, facilities participating in perinatal and gynecologic oncology registries, and facilities certified for training by the Japanese Society of Obstetrics and Gynecology Endoscopy. The number of surgeries performed was compared between 2019 and 2020, when the novel coronavirus disease was prevalent. Results: Five hundred and eighty (58.2%) facilities responded. The total number of surgeries decreased from 129 648 in 2019 to 118 565 in 2020, by 8.5%, for all surgical procedures. However, there was a clear increase in the number of robotic surgeries performed in 2020 compared to that in 2019 for all populations. The number of total hysterectomies decreased markedly from 15 385 in 2019 to 12 531 in 2020, a fall of 10.1%. Conclusions: The number of surgeries for benign gynecological diseases decreased by 8.5% in 2020 compared to that in 2019. This value is among the lowest in the world.

背景:放線菌症は主に嫌気性グラム陽性桿菌Actinomyces israeliiによる慢性化膿性肉芽腫性感染症であり,子宮内避妊器具(intrauterine device:IUD)の長期留置と関連が示唆されている.今回画像上は子宮体癌が疑われたが細胞診で子宮放線菌症を診断し,菌叢解析で別の起因菌が示唆された1例を経験した.症例:50歳代,女性.下腹部痛で前医受診,MRI検査で子宮内に直腸浸潤を伴う軟部影を認め,子宮体癌の直腸浸潤疑いで当院へ紹介された.細胞診(Papanicolaou染色)で灰青色の菌塊の細胞像を認め,悪性所見は認めなかった.子宮放線菌症と診断し,6ヵ月間の抗菌薬加療を行った.後方視的検証として子宮内腔洗浄液の菌叢解析を行い,Actinomyces mediterraneaが確認された.結論:IUD長期留置例で細胞診は,子宮放線菌症の診断に臨床的有用ではあるが,菌叢解析により新たにActinomyces mediterraneaが起因菌となる可能性が示唆された.放線菌症のさらなる病態解明につながることが期待される.(著者抄録)

The association between germline BRCA1 and BRCA2 pathogenic variants (mutations: gBRCAm) and ovarian cancer risk is well established. Germline testing alone cannot detect somatic BRCA1/2 pathogenic variants (sBRCAm), which is calculated based on the proportion of tumor BRCAm (tBRCAm) from tumor samples and gBRCAm. Homologous recombination deficiency (HRD) results mainly from genetic/epigenetic alterations in homologous recombination repair-related genes and can be evaluated by genomic instability status. In Japan, the prevalence of tBRCAm, sBRCAm, and HRD remains unclear. This multicenter, cross-sectional, observational study, CHaRacterIzing the croSs-secTional approach to invEstigate the prevaLence of tissue BRCA1/2 mutations in newLy diagnosEd advanced ovarian cancer patients (CHRISTELLE), evaluated the prevalence of tBRCAm, sBRCAm, and HRD in tumor specimens from newly diagnosed patients with ovarian cancer who underwent gBRCA testing. Of the 205 patients analyzed, 26.8% had a tBRCAm, including tBRCA1m (17.6%) and tBRCA2m (9.3%). The overall prevalence of tBRCAm, gBRCAm, sBRCAm, and HRD-positive status was 26.8%, 21.5%, 6.3%, and 60.0%, respectively. The calculated sBRCAm/tBRCAm ratio was 23.6% (13/55), and the prevalence of gBRCA variant of uncertain significance was 3.9%. These results suggest gBRCA testing alone cannot clearly identify the best course of treatment, highlighting the importance of sBRCA testing in Japan. The present results also suggest that testing for tBRCA and HRD should be encouraged in advanced ovarian cancer patients to drive precision medicine.