Clinical characteristics and radiation therapy modality of younger patients with early-stage endometrial cancer, a multicenter study in China's real world.

BACKGROUND: Endometrial cancer is a prevalent gynecologic malignancy found in postmenopausal women. However, in the last two decades, the incidence of early-stage has doubled in women under 40 years old. This study aimed to investigate the clinical and pathological characteristics and adjuvant therapeutic modalities of both young and not -young patients with early-stage endometrial cancer in China's real world. METHODS: This retrospective study analyzed patients with early-stage endometrial cancer at 13 medical institutions in China from 1999 to 2015. The patients were divided into two groups: young (≤ 45 years old) and non-young (> 45 years old). Statistical comparisons were conducted between the two groups for clinical characteristics, pathological features, and survival. The study also identified factors that affect local recurrence-free survival (LRFS) using Cox proportional risk regression analysis. Propensity score matching (1:1) was used to compare the effects of local control between vaginal brachytherapy (VBT) alone and pelvic external beam radiotherapy (EBRT) ± VBT. RESULTS: The study involved 1,280 patients, 150 of whom were 45 years old or younger. The young group exhibited a significantly higher proportion of stage II, low-risk, lower uterine segment infiltration (LUSI), and cervical invasion compared to the non-young group. Additionally, the young patients had significantly larger maximum tumor diameters. The young group also had a significantly higher five-year overall survival (OS) and a five-year LRFS. Age is an independent risk factor for LRFS. There was no significant difference in LRFS between young patients with intermediate- to high-risk early-stage endometrial cancer who received EBRT ± VBT and those who received VBT alone. CONCLUSIONS: In the present study, young patients had better characteristics than the non-young group, while they exhibited higher levels of aggressiveness in certain aspects. The LRFS and OS outcomes were better in young patients. Age is an independent risk factor for LRFS. Additionally, VBT alone may be a suitable option for patients under 45 years of age with intermediate- to high-risk early-stage endometrial cancer, as it reduces the risk of toxic reactions and future second cancers while maintaining similar local control as EBRT.

Practice patterns of adjuvant radiotherapy in women with stage I to II endometrial carcinoma: a real-world multi-institutional analysis in China.

BACKGROUND: This study aimed to report clinical practice patterns of postoperative radiotherapy for stage I to II endometrial carcinoma (EC) patients treated in 13 Chinese medical centers. METHODS: We included early stage EC patients treated by hysterectomy and adjuvant RT between 2003 and 2017 from 13 institutions. Patients were classified into 4 risk groups based on ESMO-ESGO-ESTRO recommendations (2014). RESULTS: A total of 1,227 cases were analyzed. Along the 15 years of the study, an increasing tendency was found towards administration for vaginal brachytherapy (VBT) alone, while the proportion of external beam pelvic radiotherapy (EBRT) alone remained stable in the corresponding period. When radiation modalities were stratified by risk groups, proportion of VBT alone significantly increased in all risk groups. The higher the risk, the later VBT became the main adjuvant treatment modality. However, EBRT alone or with VBT remained the main adjuvant method for high-risk patients. There were 13 dose-fractionation schemes for VBT alone with the scheme of 30 Gy in 6 fractions prescribed at 0.5cm under the vaginal mucosa accounting for most. There were 17 schemes for VBT boost and the most common schedule was 10 Gy in 2 fractions. The upper 3-5cm part of vagina was the most frequent target. 89.6% of the practitioners performed two-dimensional VBT technique. The median dose for EBRT was 50 Gy. From 2003 to 2017, conventional radiotherapy was gradually replaced by three-dimensional conformal radiotherapy modality and intensity modulated radiotherapy. CONCLUSION: We report a significant shift from EBRT to VBT alone for high-intermediate-risk, intermediate-risk and low-risk EC patients from 2003 to 2017 while EBRT remained the main radiation modality for high-risk early stage patients. There has been remarkable heterogeneity among VBT dose fractionation schedules across China. TRIAL REGISTRATION: The clinical trial ID was ChiCTR-PRC-17010712. It was authorized by the Institutional Review Board of Peking Union Medical College Hospital (N0. S-K139).

Overview of adjuvant radiotherapy on survival, failure pattern and toxicity in stage I to II endometrial carcinoma: a long-term multi-institutional analysis in China.

BACKGROUND: This research aimed to provide an overview of the impact of adjuvant vaginal brachytherapy (VBT) and external beam pelvic radiotherapy (EBRT) with or without VBT on survival in stage I to II EC patients in China from a long-term multi-institutional analysis. METHODS: We retrospectively analyzed stage I to II EC patients from 13 institutions treated between 2003 and 2015. All patients underwent surgical staging and received adjuvant RT. Patients were divided into groups of low-risk (LR), intermediate-risk (IR), high-intermediate-risk (HIR) and high-risk (HR). Survival statistics, failure pattern, and toxicity of different radiation modalities in different risk groups were analyzed. RESULTS: A total of 1048 patients were included. HR disease represented 27.6%, HIR 17.7%, IR 27.7% and LR 27.1%, respectively. Endometrioid adenocarcinoma (EAC) and non-endometrioid carcinoma (NEC) accounted for 92.8 and 7.2%. A total of 474 patients received VBT alone and 574 patients received EBRT with or without VBT. As for EAC patients, the 5-year overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) rate was: 94.6, 90.4, 93.0 and 91.6%, respectively. For LR patients, EBRT (with or without VBT) seemed to be a risk factor. With the higher risk category, the survival benefit of EBRT gradually became remarkable. EBRT (with or without VBT) significantly increased DFS, LRFS and DMFS compared to VBT alone in the HR group (p < 0.05). Distant metastasis was the main failure pattern for all risk groups. As for NEC patients, the 5-year OS, DFS, LRFS and DMFS rate was: 93.4, 87.2, 91.7 and 89.3%, respectively. As for toxicity, EBRT (with or without VBT) significantly increased the incidence of grade 1-2 gastrointestinal, urinary, and hematological toxicity. CONCLUSIONS: For stage I to II EC patients, EAC accounted for the majority and had better prognosis than NEC. For EAC patients, VBT alone resulted in comparable survival to EBRT in the LR, IR and HIR groups, while EBRT significantly increased survival in the HR group. EBRT had higher rate of toxicity than VBT.