論文

＜文献概要＞子宮頸がん検診は,健康増進法に基づいて市町村が実施する,いわゆる対策型検診のひとつとなっている.子宮頸部細胞診による子宮頸がん検診は,有効性として死亡率減少効果が認められるがん検診として広く実施されている.一方,子宮頸がんの原因であるヒトパピローマウイルス(HPV)の核酸を検出するHPV検査も,細胞診と比較する形で,浸潤がん罹患率減少を指標とした有効性が確認され,2024年4月から30～60歳に対して,5年に1回のHPV検査単独法による子宮頸がん検診が実施できるようになった.しかし,検診の結果に応じて次に行う検診や精密検査の時期と方法が異なること,いままでの検診にはない追跡精検が設定されるなど,そのアルゴリズムは複雑であり,いままで以上に精緻な精度管理が求められることから,「がん予防重点健康教育及びがん検診実施のための指針」のなかに,実施にあたって満たすべき要件が示されている.これまでわが国にはHPV検査単独法の経験がないことから,導入したとしても,十分な精度管理(検診実施機関の運営,アルゴリズムの遵守など)のもとで実施できるかなどについて評価するためのパイロット事業と位置づけるべきである.

遺伝性腫瘍はすでに原因遺伝子が明らかとなっているものだけでも多岐にわたるが,なかでも遺伝性乳癌卵巣癌(BRCA1/2遺伝子),Lynch症候群(DNAミスマッチ修復遺伝子),Peutz-Jeghers症候群(STK11/LKB1遺伝子),Cowden症候群(PTEN遺伝子)は関連腫瘍として子宮頸癌,子宮体癌,卵巣癌を引き起こすリスクが知られており,婦人科がんと関連のある遺伝性腫瘍として,この4疾患をその臨床的特徴とともに熟知しておくことが重要である。また,婦人科遺伝性がん診療を取り巻く社会環境が大きく変化してきていることに留意し,最新の臨床情報を得ながら日々の診療に当たる必要がある。(著者抄録)

Background: Risk-reducing salpingo-oophorectomy is performed for the primary prevention of ovarian cancer in patients with hereditary breast-ovarian cancer syndrome. We performed risk-reducing salpingo-oophorectomy for the first time in Japan in 2008, and we experienced 20 cases of risk-reducing salpingo-oophorectomy through 2019. In the past, the use of risk-reducing salpingo-oophorectomy in Japan was restricted because it was not covered by a Japanese National Health Insurance. Since April 2020, risk-reducing salpingo-oophorectomy has been covered by insurance for patients with breast-ovarian cancer syndrome and pre-existing breast cancer, and this surgery is expected to become more widely implemented in Japan. Methods: To contribute to the widespread use of risk-reducing salpingo-oophorectomy in the future, we retrospectively reviewed 20 cases of risk-reducing salpingo-oophorectomy at our hospital cohort study to clarify the issues in its implementation. Results: The variant genes for which risk-reducing salpingo-oophorectomy was indicated were BRCA1 and BRCA2 in 13 (65%) and 7 patients (35%), respectively. The median age at which risk-reducing salpingo-oophorectomy was performed was 49 years (range, 38-58), 13 patients (65%) had gone through menopause, and 16 patients (80%) had a history of breast cancer. Of the five patients (25%) with vasomotor symptoms, four received Chinese medicine, and only one received hormone replacement therapy. Occult cancer was detected in the removed ovaries in two patients (10%), although no postoperative peritoneal carcinogenesis has been observed to date. Conclusions: Women who paid for risk-reducing salpingo-oophorectomy out of pocket were older than the recommended age at which the procedure should be performed, and this may explain the higher rate of occult cancers than previously reported. We need to perform risk-reducing salpingo-oophorectomy at the recommended age to ensure that the procedure is effective for primary prevention.

Microsatellite instability-high (MSI-H) is an important biomarker for predicting the effect of immune checkpoint inhibitors (ICIs) on advanced solid tumors. Microsatellite instability-high is detected in various cancers, but its frequency varies by cancer type and stage. Therefore, precise frequency is required to plan ICI therapy. In this study, the results of MSI tests actually carried out in clinical practice were investigated. In total, 26 469 samples of various cancers were examined between December 2018 and November 2019 to determine whether programmed cell death-1 blockade was indicated. The results of MSI tests were obtained for 26 237 (99.1%) of these samples. The male : female ratio was 51:49 and mean age was 64.3 years. In all samples, the overall frequency of MSI-H was 3.72%. By gender, the frequency of MSI-H was higher in female patients (4.75%) than in male patients (2.62%; P <.001). A comparison by age revealed that the frequency of MSI-H was significantly higher in patients younger than 40 years of age (6.12%) and 80 years or older (5.77%) than in patients aged between 60 and 79 years (3.09%; P <.001). Microsatellite instability-high was detected in 30 cancer types. Common cancer types were: endometrial cancer, 16.85%; small intestinal cancer, 8.63%; gastric cancer, 6.74%; duodenal cancer, 5.60%; and colorectal cancer, 3.78%. Microsatellite instability-high was detected in cancer derived from a wide variety of organs. The frequency of MSI-H varied by cancer type and onset age. These data should prove especially useful when considering ICI treatment.

Objectives: This review aims to introduce preoperative scoring systems to predict lymph node metastasis (LNM) and ongoing clinical trials to investigate the therapeutic role of lymphadenectomy for endometrial cancer. Methods: We summarized previous reports on the preoperative prediction models for LNM and evaluated their validity to omit lymphadenectomy in our recent cohorts. Next, we compared characteristics of two ongoing lymphadenectomy trials (JCOG1412, ECLAT) to examine the survival benefit of lymphadenectomy in endometrial cancer, and described the details of JCOG1412. Results: Lymphadenectomy has been omitted for 64 endometrial cancer patients who met low-risk criteria to omit lymphadenectomy using our scoring system (LNM score) and no lymphatic failure has been observed. Other two models also produced comparable results. Two randomized phase III trials to evaluate survival benefit of lymphadenectomy are ongoing for endometrial cancer. JCOG1412 compares pelvic lymphadenectomy alone with pelvic and para-aortic lymphadenectomy to evaluate the therapeutic role of para-aortic lymphadenectomy for patients at risk of LNM. For quality assurance of lymphadenectomy, we defined several regulations, including lower limit of the number of resected nodes, and submission of photos of dissected area to evaluate thoroughness of lymphadenectomy in the protocol. The latest monitoring report showed that the quality of lymphadenectomy has been well-controlled in JCOG1412. Conclusion: Our strategy seems reasonable to omit lymphadenectomy and could be generalized in clinical practice. JCOG1412 is a high-quality lymphadenectomy trial in terms of the quality of surgical procedures, which would draw the bona-fide conclusions regarding the therapeutic role of lymphadenectomy for endometrial cancer.

Objective: To evaluate the efficacy and safety of niraparib in Japanese women with heavily pretreated ovarian cancer. Methods: This Phase 2 open-label, single-arm study enrolled Japanese women with homologous recombination deficiency-positive relapsed, high-grade serous ovarian, fallopian tube, or primary peritoneal cancer who had completed 3–4 lines of therapy. The starting dose of niraparib was 300 mg administered once daily in continuous 28-day cycles until objective progressive disease, unacceptable toxicity, consent withdrawal or discontinuation. The primary endpoint, objective response rate (ORR), was assessed by the investigator using RECIST version 1.1. Safety evaluations included the incidence of treatment-emergent adverse events (TEAEs), including serious TEAEs. Results: Twenty women were enrolled and the confirmed ORR in the full analysis set (FAS) was 35.0% (7/20), consisting of 1 complete response and 6 partial responses. Disease control rate in the FAS was 90.0%. The most frequently reported TEAEs (>50%) were anemia, nausea, and platelet count decreased. One patient (5.0%) had TEAEs leading to discontinuation of niraparib whereas reductions or interruptions were reported in 14 (70.0%) and 15 (75.0%) patients, respectively. The median dose intensity (202.9 mg daily) corresponded to a relative dose intensity of 67.6%. Conclusion: Efficacy and safety of niraparib in heavily pretreated Japanese women was comparable to that seen in an equivalent population of non-Japanese women. No new safety signals were identified.

Background: Sentinel lymph node (SN) biopsy is essential for evaluating survival and minimal treatment-related morbidity associated with cervical, endometrial, and vulvar cancer in Japan. As such, our aim in this study was to evaluate the current practice pattern of using SN biopsy for cervical, endometrial, and vulvar cancer in Japan. Methods: We deployed a 47-question survey on the use of SN biopsy for gynecological cancers to 216 gynecological oncology training facilities. The survey included information on the use of SN biopsy for uterine (cervical and endometrial) and vulvar cancers; details on the type, timing, and concentration of tracers used; surgical approach used for SN biopsy; method of biopsy and pathological examination; and facilities’ experience with clinical research on SN biopsy. Results: The response rate was 84% (181/216), with 40 facilities (22%) having experience in SN biopsy for gynecological cancers, 34 (85%) for uterine cancers, and 15 (37%) for vulvar cancers. Radioisotope, indocyanine green (ICG), and blue dyes were available for the detection of uterine cancers in 21 (52%), 25 (62%), and 19 (48%) facilities and for vulvar cancers in 9 (22%), 3 (7%), and 11 (27%) facilities, respectively. Thirty-four facilities (85%) used intraoperative frozen section procedure for diagnosis when possible, with 24 (71%) of these facilities using 2-mm specimen cuts. Diagnosis included pathological examination (85%), immunostaining (57%), and one-step nucleic acid amplification (5%). Conclusion: Increasing research evidence, providing insurance coverage for radioisotope tracers, and increasing the availability of training are expected to increase the use of SN biopsy in Japan.

Several human papillomaviruses (HPV) are associated with the development of cervical carcinoma. HPV DNA synthesis is increased during the differentiation of infected host keratinocytes as they migrate from the basal layer of the epithelium to the spinous layer, but the molecular mechanism is unclear. Nucleosome positioning affects various cellular processes such as DNA replication and repair by permitting the access of transcription factors to promoters to initiate transcription. In this study, nucleosome positioning on virus chromatin was investigated in normal immortalized keratinocytes (NIKS) stably transfected with HPV16 or HPV18 genomes to determine if there is an association with the viral life cycle. Micrococcal nuclease-treated DNA analyzed by Southern blotting using probes against HPV16 and HPV18 and quantified by nucleosome scanning analysis using real-time PCR revealed mononucleosomal-sized fragments of 140–200 base pairs that varied in their location within the viral genome according to whether the cells were undergoing proliferation or differentiation. Notably, changes in the regions around nucleotide 110 in proliferating and differentiating host cells were common to HPV16 and HPV18. Our findings suggest that changes in nucleosome positions on viral DNA during host cell differentiation is an important regulatory event in the viral life cycle.

Objective: The purpose of our study was to conduct a detailed survey of radical hysterectomy in Japanese patients with early-stage cervical cancer, and to compare oncologic outcomes between open and minimally invasive radical hysterectomy. Methods: In Japan during 2015, the medical records of 929 patients with FIGO stage IB1 and IIA disease treated with radical hysterectomy were retrospectively reviewed. We assessed patients’ characteristics, disease-free survival (DFS), overall survival (OS) and prognostic factors for survival. Results: The median patient age was 44 (20–80) years. Most patients (94.4%) had stage IB1 disease. Of the patients who underwent radical hysterectomy, 91.2% underwent open surgery and 8.8% underwent minimally invasive surgery (MIS). The median follow-up period was 40.8 months (range, 0.49–51.1 months). The rate of DFS and OS at 4 years in all patients was 88.3% and 96.4%, respectively. Multivariate analysis identified age (≥ 47), adenocarcinoma histology, tumor size (≥ 2 cm), parametrial invasion, positive lymph node metastasis and institutional accreditation as independent predictors of recurrence, and adenocarcinoma, other cell types, and positive lymph node metastasis as independent predictors of death. Oncologic outcomes in all patients were similar between open and MIS, including DFS and OS. Conclusion: The survival rate of the Japanese patients underwent radical hysterectomy for early-stage cervical cancer was favorable. No significant differences were observed for DFS and OS between open and MIS performed by a limited number of surgeons at a limited number of facilities in Japan. Further investigations are required to identify the appropriate patients might benefit from MIS.

Objective: Background: Case Reports: Conclusions: Rare disease Endometriosis is defined as the growth of ectopic endometrial tissue beyond the uterine cavity, and endometriosis on the uterine cervix is a rare variant. Although asymptomatic patients with cervical endometriosis or those with minor symptoms are treated conservatively, there are reports of life-threatening hemorrhage due to cervical endometriosis. Here, we report 2 cases of massive genital bleeding caused by cervical endometriotic cysts and we performed a literature review. Case 1: A 32-year-old woman presented to our hospital due to massive genital bleeding on her 11th day of menstruation. An arterial hemorrhage in a cervical endometriotic cyst was suspected. As pressure hemostasis proved difficult, urgent uterine artery embolization (UAE) by interventional radiology was performed. Angiography during the UAE showed extravascular leakage from the branch of the left uterine artery. After embolization, hemostasis was achieved. No further genital bleeding was observed, and transvaginal ultrasound showed the cyst has continued to shrink for 9 months after the UAE with sequential dienogest, a progesterone receptor agonist, treatment. Case 2: A 43-year-old woman presented to our hospital with increasing massive genital bleeding after completing a 12-day course of 0.5 mg of norgestrel and 0.05 mg of ethinyl estradiol as a treatment for irregular intermenstrual bleeding. We suspected cervical endometriotic cyst rupture on imaging and performed an urgent laparoscopic total hysterectomy. In the excised uterine specimen, a cystic lesion that contained old, blood-like fluid was macroscopically observed in the cervix and was diagnosed pathologically as endometriosis. Cervical endometriotic cyst rupture is rare; however, it should be kept in mind as a differential diagnosis when treating massive genital bleeding because urgent intervention is sometimes required to control the bleeding.

PURPOSE This phase III, multicenter, randomized, open-label study investigated the efficacy and safety of nivolumab versus chemotherapy (gemcitabine [GEM] or pegylated liposomal doxorubicin [PLD]) in patients with platinum-resistant ovarian cancer. MATERIALS AND METHODS Eligible patients had platinum-resistant epithelial ovarian cancer, received # 1 regimen after diagnosis of resistance, and had an Eastern Cooperative Oncology Group performance score of # 1. Patients were randomly assigned 1:1 to nivolumab (240 mg once every 2 weeks [as one cycle]) or chemotherapy (GEM 1000 mg/m2 for 30 minutes [once on days 1, 8, and 15] followed by a week’s rest [as one cycle], or PLD 50 mg/m2 once every 4 weeks [as one cycle]). The primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS), overall response rate, duration of response, and safety. RESULTS Patients (n 5 316) were randomly assigned to nivolumab (n 5 157) or GEM or PLD (n 5 159) between October 2015 and December 2017. Median OS was 10.1 (95% CI, 8.3 to 14.1) and 12.1 (95% CI, 9.3 to 15.3) months with nivolumab and GEM or PLD, respectively (hazard ratio, 1.0; 95% CI, 0.8 to 1.3; P 5 .808). Median PFS was 2.0 (95% CI, 1.9 to 2.2) and 3.8 (95% CI, 3.6 to 4.2) months with nivolumab and GEM or PLD, respectively (hazard ratio, 1.5; 95% CI, 1.2 to 1.9; P 5 .002). There was no statistical difference in overall response rate between groups (7.6% v 13.2%; odds ratio, 0.6; 95% CI, 0.2 to 1.3; P 5 .191). Median duration of response was numerically longer with nivolumab than GEM or PLD (18.7 v 7.4 months). Fewer treatment-related adverse events were observed with nivolumab versus GEM or PLD (61.5% v 98.1%), with no additional or new safety risks. CONCLUSION Although well-tolerated, nivolumab did not improve OS and showed worse PFS compared with GEM or PLD in patients with platinum-resistant ovarian cancer.

Background: Emerging evidence has shown that charged metabolites, such as amino acids, may play an important role in the pathogenesis of various metabolic disorders, many of which women in the postmenopausal period are at high risk of developing. This study examined the metabolic profile of middle-aged Japanese women to investigate alterations in charged metabolites induced by menopausal transition. Methods: The participants were 1193 female residents aged 40–60 at the baseline survey of the Tsuruoka Metabolomics Cohort Study. We investigated the cross-sectional association of menopausal status with 94 metabolomic biomarkers assayed in fasting plasma samples via capillary electrophoresis time-of-flight mass spectrometry using linear regression analysis. Results: Among the participants, 529 were premenopausal, 132 were in menopausal transition (MT), and 532 were postmenopausal. Significant differences were found in age, blood pressure, glucose and lipid levels, and smoking and drinking habits among the three groups. The concentrations of 5 metabolites in the MT group and 15 metabolites in the postmenopausal group were significantly higher than those in the premenopausal group after adjusting for confounding factors. When classified into pathways, these metabolites were related to the tricarboxylic cycle, urea cycle, and homocysteine metabolism, some of which are linked to arteriosclerosis. Conclusion: Multiple charged metabolites were associated with women's menopausal status, showing a gradual increase as women shifted from pre-, to peri-, to postmenopause. These findings might reflect the early changes behind the increased risk of dyslipidemia, diabetes, cardiovascular disease, and osteoporosis in later life.

Cervical cancer ranks high among the cancers that affect people in their 20s and 30s. Cervical cancer is characterized by the presence of precancerous lesions, which can be detected by cancer screenings; some precancerous lesions are amenable to treatment, which can halt the progression to invasive cancer. As a result, cervical cancer screening has been shown to reduce the incidence of invasive cancer and its mortality. On the other hand, many precancerous lesions do not progress to invasive cancer, but stagnate or disappear spontaneously. In Japan, there is a nationwide cytological screening program for residents, and the screening is performed every two years after the age of 20. There are also screening programs provided by the workplaces in Japan. According to the National Health Survey 2019, the checkup rates of any type of cervical cancer screenings are low: 15.1% for those aged 20–24, 36.6% for those aged 25–29, and 49.4% for those aged 30–34. Statistics are reported every year for the nationwide screening, and according to them, the positive screening rate is 2.1% for all ages, but 4.5% and 3.2% for those in their 20s and 30s, respectively. On the other hand, the percentage of people with positive test results who undergo follow-up examinations or confirmatory tests should be at least 90%, but it is 72.1% for all ages, 72.0% for those in their 30s, and even lower for those in their 20s, at 67.1%. Improving the rate of people getting screenings and subsequent examinations is a challenge even among the young.

Background: This study aimed to investigate the clinical benefit of dose-dense paclitaxel plus carboplatin (TC) with bevacizumab therapy for advanced ovarian, fallopian tube, and primary peritoneal cancer patients in the neoadjuvant setting. Methods: Ovarian, fallopian tube or primary peritoneal cancer patients with stage III–IV disease received neoadjuvant chemotherapy (NAC) every 3 weeks consisting of paclitaxel (80 mg/m2) on days 1, 8, and 15; carboplatin (AUC 6.0 mg/mL × min.) on day 1; and bevacizumab (15 mg/kg) on day 1. Interval debulking surgery (IDS) was performed after 3 cycles of dose-dense TC-bevacizumab therapy. The primary endpoint was the rate of complete resection by IDS. Secondary endpoints were treatment completion rate, treatment exposure, response rate to NAC, adverse events, and perioperative complications. Results: Twenty-four patients were included in this study. The median age was 55.5 years (37–80 years), and most patients had high-grade serous carcinoma accounted (n = 18). IDS was performed in all patients with complete resection achieved in 75% (95% confidence interval: 57.7–92.3%). The lower limit exceeded the preset threshold rate of 55%. The response rate to NAC was 79%, and serum CA125 levels were in the normal range after NAC in 57% of patients. Grade 4 hematological toxicities and grade 3/4 non-hematological toxicities occurred in 29% and 17% of patients during NAC, respectively. Grade 3/4 perioperative complications were seen in 29% of patients, but no gastrointestinal perforations or treatment-related deaths occurred. Conclusions: Neoadjuvant dose-dense TC-bevacizumab therapy was well tolerated, and a satisfactory rate of complete resection by IDS was achieved.

In the field of drug repurposing, the use of statins for treating dyslipidemia is considered promising in ovarian cancer treatment based on epidemiological studies and basic research findings. Biomarkers should be established to identify patients who will respond to statin treatment to achieve clinical application. In the present study, we demonstrated that statins have a multifaceted mode of action in ovarian cancer and involve pathways other than protein prenylation. To identify biomarkers that predict the response to statins, we subjected ovarian cancer cells to microarray analysis and calculated Pearson’s correlation coefficients between gene expression and cell survival after statin treatment. The results showed that VDAC1 and LDLRAP1 were positively and negatively correlated with the response to statins, respectively. Histoculture drug response assays revealed that statins were effective in clinical samples. We also confirmed the synergistic effects of statins with paclitaxel and panobinostat and determined that statins are hematologically safe to administer to statin-treated mice. Future clinical trials based on the expression of the biomarkers identified in this study for repurposing statins for ovarian cancer treatment are warranted.

Uterus transplantation (UTx) is now a potential option to allow women with uterine factor infertility to give birth. However, UTx is still at an experimental stage, and basic animal studies, including in nonhuman primates, are needed for the accumulation of data prior to clinical application. Considering that UTx may provide new hope to Japanese women, we launched UTx research in 2009 and have since accumulated a large archive of results in the UTx research field. Furthermore, we have carried out various activities aimed at the implementation of clinical applications of UTx in Japan while clarifying the ethical and social issues involved. Currently, the clinical application of UTx in Japan is just around the corner, and it is expected that UTx research will develop further in the future. Herein, we summarize our basic experiences using non-human primates and our activities with the goal of future clinical applications.

Background: We evaluated the feasibility of neoadjuvant chemotherapy, followed by debulking surgery, for clinically diagnosed FIGO stage IVb endometrial cancer (protocol number: JGOG2046). Methods: The experimental treatment consisted of 3 cycles of paclitaxel (180 mg/m2) plus carboplatin (AUC5) followed by debulking surgery, including total abdominal hysterectomy, bilateral salpingo-oophorectomy, and 3 cycles of adjuvant chemotherapy. Patients were considered as eligible if they were pathologically diagnosed as primary endometrial cancer, and had both endometrial tumor and distant metastasis confirmed by imaging examinations. The primary endpoint was the incidence of patients who completed debulking surgery after the neoadjuvant chemotherapy. Results: While 51 patients were enrolled from 23 hospitals, the final study cohort consisted of 49 patients with a mean age of 59.0 years. Although the response ratio of the neoadjuvant chemotherapy was 65.3% (95% CI 50.4–78.3%), 67.3% (95% confidence interval (CI) 52.5–80.1%) underwent debulking surgery after the neoadjuvant chemotherapy and 59.2% (95% CI 45.2–71.8%) completed the protocol treatment including 3 courses of adjuvant chemotherapy. The median disease-free survival time was 9.1 months (95% CI 6.5–11.9), while the median overall survival time was 23.2 months (95% CI 11.9–27.8). A patient with sigmoid colon cancer and another with cervical cancer were included in this study. Conclusions: Neoadjuvant chemotherapy followed by debulking surgery was a feasible and acceptable treatment for metastatic endometrial cancer. (225 words).