Influence of the sentinel node outcome analysed by one-step nucleic acid amplification on the risk for postmastectomy radiation therapy and the scheduling of immediate breast reconstruction

Background In patients with cT1-T3N0 breast cancer, postmastectomy radiation therapy (PMRT) is considered a contraindication for immediate breast reconstruction (IBR) due to a high risk of complications. The sentinel node biopsy (SNB) is an important determinant for PMRT. In this study, we evaluated the impact of SNB outcome on the planning of IBR after mastectomy. Methods Data of patients undergoing mastectomy and SNB in Zuyderland Medical Centre between 2016 and 2019 were retrospectively analysed. Perioperative factors influencing the planning of IBR and SNB results assessed by the intraoperative one-step nucleic acid amplification (OSNA) were registered. Results Of 397 patients, 169 opted for IBR. One hundred and seven IBRs were performed: 101 tissue expanders, 5 deep inferior epigastric perforator flaps and 1 latissimus dorsi flap. Eighteen patients (18/107) had macrometastases in the SNB, in six of them IBR was cancelled due to the indication for PMRT (33%). In the other 12 patients IBR was executed as planned. A delayed reconstruction was performed in 59 patients. Conclusion In breast cancer patients undergoing mastectomy with macrometastases in the SNB, IBR was postponed in 33% due to risk on PMRT. To predict this risk, we advise to acknowledge the SNB outcome by using OSNA before proceeding to IBR.

Automated summary

This study evaluated the impact of sentinel node biopsy (SNB) outcome on immediate breast reconstruction (IBR) planning in breast cancer patients undergoing mastectomy. It found that in patients with macrometastases in the SNB, 33% of IBRs were postponed due to the risk of postmastectomy radiation therapy (PMRT).