A risk scoring system to determine recurrence in early-stage type 1 endometrial cancer: a French multicentre study.

BACKGROUND: To develop a risk scoring system (RSS) to determine recurrence in women with early-stage type 1 endometrial cancer (EC).

METHODS: Data of 396 women with early-stage type 1 EC who received primary surgical treatment between January 2001 and December 2012 were abstracted from multicentre database (training set). A risk model for predicting recurrence was developed and internally validated with the bootstrap technique. The RSS was externally validated using data from an independent population.

RESULTS: Overall, the recurrence rate was 12.1 %. The median follow-up and initial time to recurrence were 34 (range 1-152) and 26 (range 1-151) months, respectively. Recurrence was associated with five variables: age ≥60 years, histological grade III, primary tumor diameter >2 cm, depth of myometrial invasion ≥50 %, and the positive lymphovascular space involvement status. These variables were included in the RSS and assigned scores. A total score of 6.5 points corresponded to the optimal threshold of the RSS. For women with a score <6.5 or ≥6.5, the recurrence rates were 8.4 % (30/357) and 48.7 % (19/39) in the training set, respectively. At this threshold, the diagnostic accuracy of the RSS was 87 %. Areas under the curve of the receiver-operating characteristics for predicting recurrence at internal and external validation were 0.74 [95 % confidence interval (CI) 0.71-0.77] and 0.82 (95 % CI 79-85), respectively.

CONCLUSIONS: This RSS identified two subsets of women with low and high risk of recurrence among women with early-stage type 1 EC. It could be helpful to better define indications for nodal staging and adjuvant therapy.