Abstract
Introduction: Superparamagnetic iron oxide nanoparticles (SPIO) is an effective tracer for sentinel lymph node (SLN) identification. A common definition of an additional SLN is a node with ≥10% of the signal produced by the highest signaling SLN. This study aimed to investigate the risk of additional SLNs being metastatic based on percentage of the maximum magnetic signal.
Method: Individual SLN data from five Swedish and three Dutch studies (n=908) using SPIO in breast cancer patients were extracted from patients with SLN metastases. Additional SLNs were grouped based on the percentage of their magnetic signal compared to the highest signaling SLN (SLN1=100%). The risk of additional SLNs being metastatic by signal percentage was calculated. Chi-square-test was used to compare proportions.
Result: Of 156 patients with SLN metastases, 78 had only one SLN. Among 78 patients with ≥2 SLNs, a total of 204 SLNs were retrieved, 115 with metastases and 89 without. The risk of metastasis in SLN1 was 75.6% (59/78 nodes), in SLNs with 99-80% of SLN1 signal risk was 65.4% (17/26), 79-60%; 36.8% (7/19), 59-40%; 41.7% (10/24), 39-20%; 43.2% (16/37), and 19-10%; 37.5% (6/16)(p=0.25).
Removal of only the highest signaling SLN, would correctly stage 59/78 (75.6%) patients; the two highest signaling SLNs correctly staged 74/78 (94.9%); the three highest, 78/78(100%), respectively. The difference between 1 vs. 2 SLNs removed was 19% (p<0.001) and 2 vs. 3 SLNs: 5%(n.s.).
Discussion: In this exploratory analysis, removal of >3 SLNs following the 10% cutoff or adjustment of the cutoff did not result in a meaningful clinical benefit.
Method: Individual SLN data from five Swedish and three Dutch studies (n=908) using SPIO in breast cancer patients were extracted from patients with SLN metastases. Additional SLNs were grouped based on the percentage of their magnetic signal compared to the highest signaling SLN (SLN1=100%). The risk of additional SLNs being metastatic by signal percentage was calculated. Chi-square-test was used to compare proportions.
Result: Of 156 patients with SLN metastases, 78 had only one SLN. Among 78 patients with ≥2 SLNs, a total of 204 SLNs were retrieved, 115 with metastases and 89 without. The risk of metastasis in SLN1 was 75.6% (59/78 nodes), in SLNs with 99-80% of SLN1 signal risk was 65.4% (17/26), 79-60%; 36.8% (7/19), 59-40%; 41.7% (10/24), 39-20%; 43.2% (16/37), and 19-10%; 37.5% (6/16)(p=0.25).
Removal of only the highest signaling SLN, would correctly stage 59/78 (75.6%) patients; the two highest signaling SLNs correctly staged 74/78 (94.9%); the three highest, 78/78(100%), respectively. The difference between 1 vs. 2 SLNs removed was 19% (p<0.001) and 2 vs. 3 SLNs: 5%(n.s.).
Discussion: In this exploratory analysis, removal of >3 SLNs following the 10% cutoff or adjustment of the cutoff did not result in a meaningful clinical benefit.
| Original language | English |
|---|---|
| Article number | znae175.021 |
| Number of pages | 1 |
| Journal | British journal of surgery |
| Volume | 111 |
| Issue number | Suppl. 7 |
| DOIs | |
| Publication status | Published - 2 Aug 2024 |
