Where is this margin ?

Thank you Beesie,

During my mastectomy for DCIS the lateral margin, lateral aspect of superior anterior and lateral aspect of posterior margin were positive. The surgeon resected the lateral and superior lateral and the re-excision was negative for atypia and malignancy. However about the re-exision the pathologist wrote: status of these margins may differ from those detected in the main lumpectomy specimen; correlation with clinical findings is required. The RO recommended radiation because he said it was unclear if the margins were positive or not specially the posterior. He also recommended the radiation because I had 0.3 mm of micromets in 1/6 nodes and LVI. I remember I asked the RO and he said there was nothing in the chest wall. So I was confused. I cannot stop thinking about these margins. I also asked the surgeon about the margins and she said the margins are fine. She said that it is imposible to take every cancer cell and that she did not recomend to take more tissue during the expanders exchange. So I did the radiation and I am on Tamoxifen. Can Tamoxifen stop the DCIS cells?

Thank you for your kind answer Waves2Star