Assessing the effect of guideline introduction on clinical practice and outcome in patients with endometrial cancer in Japan: a project of the Japan Society of Gynecologic Oncology (JSGO) guideline evaluation committee

OBJECTIVE: The Japan Society of Gynecologic Oncology (JSGO) published the first practice guideline for endometrial cancer in 2006. The JSGO guideline evaluation committee assessed the effect of this guideline introduction on clinical practice and patient outcome using data provided by the Japan Society of Obstetrics and Gynecology (JSOG) cancer registration system. METHODS: Data of patients with endometrial cancer registered between 2000 and 2012 were analyzed, and epidemiological and clinical trends were assessed. The influence of guideline introduction on survival was determined by analyzing data of patients registered between 2004 and 2009 using competing risk model. RESULTS: In total, 65,241 cases of endometrial cancer were registered. Total number of patients registered each year increased about 3 times in the analyzed period, and the proportion of older patients with type II endometrial cancer rapidly increased. The frequency of lymphadenectomy had decreased not only among the low-recurrence risk group but also among the intermediate- or high-recurrence risk group. Adjuvant therapy was integrated into chemotherapy (p<0.001). Overall survival did not significantly differ before and after the guideline introduction (hazard ratio [HR]=0.891; p=0.160). Additional analyses revealed patients receiving adjuvant chemotherapy showed better prognosis than those receiving adjuvant radiation therapy when limited to stage I or II (HR= 0.598; p=0.003). CONCLUSION: It was suggested that guideline introduction influenced the management of endometrial cancer at several aspects. Better organized information and continuous evaluation are necessary to understand the causal relationship between the guideline and patient outcome.