Kang Ren

Timing of adjuvant radiotherapy for early-stage endometrial carcinoma: a single-center retrospective cohort study

To investigate the appropriate timing of radiotherapy (RT) after hysterectomy in women with early-stage endometrial cancer (EC). We analyzed the data of 1,062 patients with early-stage EC who underwent postoperative RT at our hospital between April 1999 and November 2020. Restricted cubic spline were used to explore the relationship between the surgery-radiotherapy interval (SRI) and local recurrence-free survival (LRFS). The maximally selected rank statistics method was used to identify the optimal threshold for SRI. The overall survival (OS), disease-free survival (DFS), LRFS, and distant metastasis-free survival (DMFS) rates were estimated using the Kaplan-Meier method. Multivariate analysis was performed using the Cox proportional hazards regression. In entire cohort, patients with SRI ≥42 days had worse survival. In multivariate analysis, SRI was an independent prognostic factor for OS (p=0.011), DFS (p=0.019), LRFS (p=0.013) and DMFS (p=0.050). However, in piecewise Cox regression, the significance of SRI for DMFS disappeared. In the subgroup analysis, the optimal cut-off value for SRI in the high-intermediate risk (HIR) and high-risk (HR) groups was 33 days. Multivariate analysis showed that SRI was an independent prognostic factor only for LRFS (p=0.033) and marginally associated with OS (p=0.055). The timing of postoperative RT is crucial in patients with early-stage EC. Adjuvant RT should be initiated as soon as the vaginal cuff is healed, while for HIR and HR patients, it should be initiated within 33 days.

Recurrent patterns after postoperative radiotherapy for early stage endometrial cancer: A competing risk analysis model

AbstractObjectiveThe study aimed to evaluate site‐specific recurrent patterns via competing risks analysis and hazard function to provide evidence for adjuvant treatment and follow‐up for early staged endometrial cancer (EC).MethodsA total of 858 patients with International Federation of Gynecology and Obstetrics stage I–II EC who received adjuvant radiotherapy at our institution (2000–2017) were included. The radiotherapy modality comprised external beam radiotherapy (EBRT) with or without vaginal brachytherapy (VBT) or VBT alone. Competing risks analysis and hazard rate function were employed to evaluate the recurrence rate according to the ESMO–ESGO–ESTRO risk classification.ResultsThe 5‐year overall survival rates of the low‐risk (LR), intermediate‐risk (IR), high–intermediate risk (HIR), and high‐risk (HR) groups were 96.1%, 95%, 93%, and 89.7%, respectively (p = 0.018). Sixty‐eight patients developed recurrence. The 5‐year incidence of distant recurrence was the highest in the HR group (14.87%), followed by the HIR (7.71%), IR (5.27%), and LR (1.26%) groups (Gray's test, p < 0.001). The LR and IR groups showed late metastasis behaviors for distant metastasis. The HR group presented a large magnitude of distant metastasis with an early peak that increased beyond 3 years. Subgroup analysis revealed that EBRT±VBT tended to reduce the locoregional relapse rate compared with VBT in the HIR–HR group (2.36% vs. 7.73%, Gray's test, p = 0.08).ConclusionThe established competing risk modeling demonstrated different recurrence patterns across the risk groups and radiotherapy modes. A better understanding of the change in site‐specific recurrence behavior allows more targeted adjuvant treatment and surveillance regimens.

A modified delineation method of para‐aortic nodal clinical target volume in patients with locally advanced cervical cancer

AbstractPurposeTo validate the nodal center coverage (NCC) of the three mainstream delineation methods of para‐aortic nodal clinical target volume (CTV) and propose a modified delineation method of para‐aortic nodal CTV in prophylactic extended‐field irradiation (EFI) of cervical cancer.MethodsA total of 106 patients with para‐aortic lymph nodes (PALNs) identified on PET/CT were included at Peking Union Medical College Hospital between 2011 and 2020. PALNs were classified as left lateral para‐aortic (LLPA), aorto‐caval (AC), and right para‐caval (RPC). Distances from the nodal center to the aorta and inferior vena cava (IVC) were measured. The NCC of the three mainstream delineation methods of para‐aortic nodal CTV (CTV‐K, CTV‐S, and CTV‐D) and a modified CTV (CTV‐M) was calculated. Radiotherapy plans were created based on 4 CTVs for 10 selected patients who received prophylactic EFI. The chi‐squared test and the Student's t‐test were performed.ResultsWe identified 344 PALNs (216 LLPA, 101 AC, and 27 RPC) in 106 patients. Mean distance from the nodal center to the aorta was 9.6 mm in the LLPA and 7 mm in the AC and from the nodal center to the IVC was 5.6 mm in the AC and 5.6 mm in the RPC. CTV‐D improved the NCC of 98% compared with 92% for CTV‐K (p = 0.002) and 95% for CTV‐S (p = 0.046). CTV‐M provided the same satisfactory NCC as CTV‐D (97% vs. 98%, p = 0.485). The V50Gy to the duodenum, the Dmean to the bilateral kidneys, and the V45Gy to the small bowel were significantly lower on the CTV‐M‐based plan than on the CTV‐D‐based plan (p = 0.001, 0.011, and 0.001, respectively).ConclusionCTV‐D provided more satisfactory NCC than CTV‐K and CTV‐S. CTV‐M provided the same satisfactory NCC as CTV‐D and reduced the dose to the critical structures.

Study of Early Stage Endometrial Cancer Based on Molecular Classification and Traditional Risk Stratification to Guide Adjuvant Radiotherapy Decisions

The purpose of this study is to compare the efficacy and toxicity of early stage endometrial cancer based on molecular classification and conventional risk stratification adjuvant therapy decision-making, and to provide high-quality evidence-based medical evidence for individualized adjuvant therapy selection under the guidance of fine stratification system of endometrial cancer.