Objective: This study aims to estimate the population-based incidence of gestational trophoblastic diseases (GTDs) and to identify the characteristics of gestational trophoblastic neoplasia (GTN) in Japan. Methods: The annual number of GTD and live births from 1974 to 2018 were used to estimate the incidence of GTD. The data of 1,574 GTN cases from 1999 to 2018 were analyzed to identify the characteristics of low-risk GTN, high-risk GTN, placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor (ETT). Results: The incidence of hydatidiform mole was 2.02 per 1,000 live births on average which decreased from 1974 to 2008 and increased from 2009 to 2018. The incidence of low-risk GTN, high-risk GTN, PSTT, and ETT was 15.3, 3.5, 0.3, and 0.07 per 100,000 live births, respectively. The estimated incidence of post-molar GTN was 9.8% of molar patients. High-risk GTN was diagnosed more pathologically, had more various kinds of antecedent pregnancies, and had longer intervals after the antecedent pregnancy compared to low-risk GTN. Furthermore, 8.2% of high-risk GTN occurred after the subsequent non-molar pregnancy of hydatidiform mole. The cumulative percentage of developing high-risk GTN after hydatidiform mole reached 89.3% at the 60th month. Conclusion The incidence of hydatidiform mole, low-risk GTN, high-risk GTN was 2.02 per 1,000 live births, 15.3 per 100,000 live births, and 3.5 per 100,000 live births, respectively. High-risk GTN was diagnosed more pathologically and later after the antecedent pregnancy than low-risk GTN. Following molar patients for five years is needed to improve the mortality of malignant GTN.

Cervical, endometrial, and ovarian cancers, have both high morbidity and mortality among the gynecologic malignant tumors in Japan. The present study was conducted using both the population-based cancer registry and the gynecologic cancer registry to elucidate the characteristics of gynecologic malignant tumors in Japan. Based on nationwide estimates from the population-based cancer registry in Japan, the morbidities and mortality of cervical, endometrial, and ovarian cancers were obtained and used for analysis. Clinicopathologic factors for cervical cancer, endometrial cancer, ovarian cancer, including age, clinical stage, postsurgical stage, histological type, therapeutic strategy, and prognosis were retrieved from the gynecologic cancer registry published by the Japan Society of Obstetrics and Gynecology and used for analysis. The morbidities of cervical, endometrial, and ovarian cancers were 10,908, 13,606, and 9,384 women in 2012, respectively. The prevalence of endometrial cancer has significantly and consistently been increasing and represents the most common gynecologic malignant tumor in Japan. The mortalities of cervical, endometrial, and ovarian cancers were 2.1, 1.3, and 3.2 per 100,000 in 2012, respectively. In 2014, 52.2% of cervical cancer patients were classified as stage I, 22.5% as stage II, 10.2% as stage III, and 11.2% as stage IV. In addition, 71.9% of endometrial cancer patients were classified as stage I, 6.0% as stage II, 13.3% as stage III, and 7.5% as stage IV. Finally, 43.2% of ovarian cancer patients were classified as stage I, 9.1% as stage II, 27.6% as stage III, and 7.2% as stage IV. Twelve point five percent of ovarian cancer patients received neoadjuvant chemotherapy.
Drug Therapy ; Endometrial Neoplasms ; Female ; Genital Neoplasms, Female ; Gynecology ; Humans ; Japan* ; Mortality ; Obstetrics ; Ovarian Neoplasms ; Prevalence ; Prognosis ; Registries ; Uterine Cervical Neoplasms

Objective: International Federation of Gynecology and Obstetrics (FIGO) staging for ovarian, fallopian tube, and peritoneal cancers was revised in 2014. The aim of this study is to clarify whether the revised FIGO2014 staging reflects the prognosis of patients with ovarian cancer by histological type in Japan. Methods: We extracted 9,747 patients who were diagnosed with ovarian cancer since 2004 until 2008 and who could be classified into appropriate stages from the Gynecologic Cancer Registry of Japan Society of Obstetrics and Gynecology. These cases were analyzed after revision to FIGO2014 based on the pTNM classification. Results: Among stage I, the 5-year overall survival rate (5y-OS) in FIGO2014 was 94.9% in stage IA, 92.3% in stage IC1, 86.1% in IC2, and 84.9% in IC3 with significant differences between stages IA and IC1 (p=0.012), IC1 and IC2 (p<0.001). There was a significant difference between stages IA and IC1 in clear cell and mucinous carcinoma but not in serous and endometrioid carcinoma. Among stage III, the 5y-OS was 75.6% in stage IIIA1, 68.9% in IIIA2, 58.6% in IIIB, and 44.4% in IIIC, with significant differences between stages IIIA2 and IIIB (p=0.009), IIIB and IIIC (p<0.001). Among stage IV, the 5y-OS was 43.1% in stage IVA *and 32.1% in IVB with a significant difference (p=0.002). Conclusion The results suggest that changes in classification for stage III and stage IV are appropriate, but the subclassification for stage IC might be too detailed. There was a discrepancy of prognosis by histological type between stage IA and IC1.