Patient-reported lymphedema after sentinel lymph node mapping in women with low-grade endometrial cancer.

Background: Sentinel lymph node mapping is a minimally invasive surgical staging procedure that allows identification of macro- and micrometastases. The implementation of sentinel lymph node mapping to women with low-grade endometrial cancer allows detection of lymph node metastases and avoids the morbidity of radical pelvic lymphadenectomy. The extent of myometrial invasion is highly predictive of lymph node metastases but is hard to determine precisely preoperatively. The exact rate of lymph node metastases in the large group of women with <50% myometrial invasion is low but unknown. The benefit of detecting metastases in this group should balance the risk of lymphedema. There is limited knowledge of early and late lymphedema and its impact on the quality of life in women with low-grade endometrial cancer following sentinel lymph node mapping.

Objective: The primary objective was to investigate the risk of patient-reported lymphedema after SLN mapping in women with low-grade endometrial cancer. In addition, we aimed to evaluate risk factors for lymphedema and the condition-specific quality of life (QoL) among women who reported lymphedema 12 months after surgery.

Study design: Women with presumed stage I low-grade endometrial cancer were included in a national prospective cohort study on SLN mapping from March 2017-February 2022. Women completed a package of validated patient-reported outcome measures (PROMs) before surgery, three and 12 months after surgery. The primary outcome was the leg lymphedema domain score from the European Organisation for Research and Treatment of Cancer endometrial cancer-specific module (EORTC QLQ-EN24). The lymphedema assessment was further supplemented by seven validated single items from the EORTC item library addressing lymphedema of legs, genitals, and groin. The disease-specific QoL was assessed using the validated Lymphedema quality of life tool (LYMQOL). Scores were linearly transformed to 0-100. A change from baseline of 8 points in leg lymphedema sum-score was considered clinically important. Mean difference scores over time with 95% CI were estimated. Multiple linear regression models evaluated baseline predictors associated with the 12 month postoperative lymphedema score, and if early lymphedema predicted lymphedema at 12 months after surgery. Lymphedema condition-specific QoL was evaluated for women with lymphedema.

Results: Seventy-nine % (486/617) completed PROMs at baseline and 12 months. The mean difference score of leg lymphedema from baseline to 12 months was 5.0, CI [3.3, 6.8], i.e., below the threshold for clinical importance. Baseline leg lymphedema score and BMI were positively associated with the leg lymphedema score at 12 months. The leg lymphedema score at three months was associated with a higher 12-month score. High scores of lymphedema at 12 months were negatively associated with the women's daily activities, appearance, emotional functioning, and global QoL and increased their subjective symptom burden.

Conclusions: Women with low-grade endometrial cancer have a low risk of lymphedema after SLN mapping. Leg swelling at baseline and BMI predicted more lymphedema at 12 months after surgery. Early lymphedema at three months predicted persistent lymphedema. A high leg lymphedema score at 12 months is associated with impairment in several aspects of QoL.