The combination of sentinel lymph node mapping and use of uterine intraoperative restrictive frozen section (RFS) in patients with low-grade endometrial cancer can decrease the rate of complete lymphadenectomy without reducing the detection of lymphatic metastasis, according to a study presented at the 2016 Society of Gynecologic Oncology (SGO) Annual Meeting, held March 19–22 in San Diego, California.
This study (abstract 40) suggests the potential to minimize overtreatment and avoid complications such as lymphedema that can accompany a full lymph node dissection.
To best minimize the rate of lymphadenectomy, Abdulrahman K. Sinno, MD, of the Kelly Gynecologic Oncology Service at Johns Hopkins School of Medicine in Baltimore, and colleagues compared three lymphatic assessment strategies for detecting lymphatic metastasis in patients with grade I/II endometrial cancer or complex atypical hyperplasia.
“Using sentinel lymph node mapping combined with a RFS strategy, we were able to decrease the rate of lymphadenectomy from 36% of all patients with low-grade endometrial carcinoma, to 9%,” Sinno told Cancer Network. “More importantly, our ability to detect lymphatic metastasis was not decreased, which speaks to the oncologic safety of this algorithm.”
Lymphadenectomy in endometrial cancer patients is associated with increased costs, longer operating room time and longer hospital stay as well as overall complications that can lead to an overall decrease in quality of life. “The risk of lymphedema is variable based on the type of lymphadenectomy performed and the tool used to measure lymphedema,” said Sinno. A recent study of patients after a pelvic lymphadenectomy found the risk of lymphedema to be about 23%, and as many as 30% of patients with symptomatic lymphedema remain undiagnosed.
The standard approach at the Kelly Gynecologic Oncology Service at Johns Hopkins Hospital, adopted by the center in 2012, is standard sentinel lymph node mapping and use of uterine frozen section to then triage patients that may require complete pelvic or para-aortic lymphadenectomy. In the single center study, Mills and study coauthors compared this standard protocol to two theoretical strategies for their ability to detect lymphatic metastasis and decrease the rate of lymphadenectomy using a prospective database of 114 early-stage endometrial cancer patients. The two other options were use of universal frozen section and no sentinel lymph node mapping or sentinel lymph node mapping plus RFS. The three options were analyzed using a retrospective modeling analysis.
Of the 114 patients who received the standard protocol, 42 patients (36.8%) had a complete lymphadenectomy. Applying the two additional hypothetical strategies, the universal frozen section approach had a poorer detection of lymph node metastasis compared to the standard protocol or use of RFS. Use of sentinel lymph node plus RFS led to a complete lymphadenectomy rate lower than the standard protocol or the universal frozen section approach (9.2%, 36.8%, and 36.8%, respectively; P = .004). Use of RFS did not decrease the detection of lymph node metastasis.
In 2014, the National Comprehensive Cancer Network listed sentinel lymph node mapping as an alternative to complete lymphadenectomy in those women undergoing hysterectomy surgery for early-stage endometrial cancer when performed by experienced gynecologic oncology surgeons.
“We have completely shifted our algorithm at Johns Hopkins University based on the results of this study,” Sinno noted. “We will be utilizing the sentinel lymph node/RFS strategy on all patients with low grade endometrial cancer.”
Next, Sinno said he and colleagues are exploring the role of sentinel lymph node mapping in high-grade endometrial carcinoma.