(Dallas –March 11, 2022 1:21 p.m.)–Both clinical and pathologic factors can be used to predict lymph node recurrence after sentinel lymph nodes yet the first post-operative ultrasound may be an important step in determining residual disease in the dissected basin, according to a study presented at The Society of Surgical Oncology 2022 International Conference on Surgical Care.
The Multicenter Selective Lymphadenectomy Trial II (MSLT-II) resulted in a shift in the management of tumor positive sentinel lymph nodes from completion node dissection to nodal observation. While there is no apparent survival advantage with completion node dissection this change in practice leaves some patients with nodal disease in the sentinel lymph node basin.
Researchers lead by Jennifer Keller, MD, from Saint John’s Providence, Santa Monica, Calif. sought to evaluate prognostic factors for predicting sentinel node basin recurrence.
Dr. Keller and participating centers randomized 1,939 patients within MSLT-II — 968 were assigned to nodal observation. In this study, patients were included if they underwent an ultrasound of the sentinel node basin(s) within four months of surgery. The trial excluded those with positive by sentinel lymph node RT-PCR or if sentinel lymph node pathologic data was incomplete. Primary tumor, patient, and sentinel lymph node characteristics were evaluated. The first post-operative ultrasound was considered abnormal if more than one of the following were true: length:depth >2, hypoechoic center or focal subcapsular lesion. Univariate and multivariate analysis were performed to determine independent factors for predicting sentinel node basin recurrence.
Of the 737 patients included in this study 193 (26.2%) had sentinel node basin recurrence. There were 73 (9.9%) abnormal ultrasounds and 46 of 147 (23.8%) basins with subsequent recurrence vs 27 of 517 (5%) basins without recurrence had an abnormal ultrasound. On multivariate analysis, age (adjusted odds ratio [aOR] 1.02, 95% CI 1.0-1.03), increasing Breslow thickness (aOR 1.14, 95% CI 1.01-1.28), primary tumor ulceration (aOR 2.07, 95% CI 1.42-3.02), and abnormal PSNB-US (aOR 5.00, 95% CI 2.97 -8.64) were significantly (p < 0.05) associated with SNBR.
“We found that primary tumor location and sentinel lymph node burden were not found to be significantly associated with sentinel node basin recurrence. By combining all the predictive factors, a multimodal model was created to predict sentinel node basin recurrence with an AUC of 0.76,” Dr. Keller reported.
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