If I said 5 layers, I misspoke. I had one known positive sentinel node (through biopsy). At the time of unilateral mastectomy another sentinel node looked positive… and it was (micro infiltrated). So, my surgeons removed the “ next in line” layer of nodes , 5 , which were negative. Those 5 nodes would have been the “next in line” to become infiltrated with the cancer. The fact that they were negative was a very good diagnostic indication that distant metastasis had not occurred. This is my understanding.

Hope this helps.