Age ≥60 y May Not be an Appropriate Adverse Risk Factor in Adjuvant Treatment of Patients With Early-Stage Endometrial Carcinoma: A Multi-Institutional Analysis in China.

PURPOSE/OBJECTIVE(S) To explore the effect of age at diagnosis as a continuous variable on survival and treatment choice of patients with early-stage endometrial carcinoma (EC). MATERIALS/METHODS We retrospectively analyzed data from patients with early-stage EC from January 1999 to December 2015 in multiple institutions in China. All patients received primary hysterectomy/bilateral salpingo-oophorectomy and adjuvant radiotherapy for EC confirmed pathology of stage I and II disease (FIGO 2009 staging). All patients were divided into low-risk, intermediate-risk, high-intermediate-risk and high-risk groups according to ESMO-ESGO-ESTRO risk classification. This retrospective study was approved by the Ethics Review Committee of Peking Union Medical College Hospital, Chinese Academy of Medical Sciences [Protocol number S-K139]. The clinical trial ID of the study is ChiCTR-PRC-17010712. Evaluation of all data met the requirements of the Helsinki Declaration. RESULTS The median follow-up time was 57months, and the 5-year cancer-specific survival (CSS) was 95.7%. Age as a continuous variable was an independent prognostic factor for CSS. With an increase in age, the hazard ratio (HR) for CSS increases gradually. Other independent prognostic factors included myometrial invasion (MI), grade, and chemotherapy. In the stratified analysis of age, the HRs of age on CSS in patients >70y were 5.516, 5.015, 4.469, 4.618, 5.334, and 5.821 after adjusting for cancer characteristics, local treatment, chemotherapy and treatment-related late toxicity. In patients 66-70-year-old, the HRs were 2.509, 2.074, 2.101, 2.091, 2.157 and 1.621 after adjusting for the above covariates. In patients ≤65y, there was no significant difference in the HR of age on CSS after adjustment. CONCLUSION Age as a continuous variable is an independent prognostic factor and 65 year-old may be the best cut-off point for CSS in patients with early-stage EC in the Asian population. Adjuvant radiotherapy can reduce the HR of age on CSS for patients >65 years. AUTHOR DISCLOSURE S. Sun: None. L. Zou: None. T. Wang: None. Z. Liu: None. J. He: None. X. Sun: None. W. Zhong: None. F. Zhao: None. X. Li: None. S. Li: None. H. Zhu: None. Z. Ma: None. W. Wang: None. J. Meng: None. F. Zhang: None. X. Hou: None. L. Wei: None. K. Hu: None.