breast cancer passed from sister(donor) to sister (recipient) via stem celltransplant
 

donor sister has not yet come down with bc, but recipient sister's biopsy showed genetic "fingerprint" of having originated in stem cells donated by sister

This shows breast cancer can be dormant in bone marrow for many many years and we do not yet understand all the factors (host, and otherwise) which cause it to "awaken and come to life"

Breast Cancer Res Treat. 2008 Feb 9 [Epub ahead of print]
Donor-derived breast cancer in a bone marrow transplantation recipient.

Golfinopouloss V, Pentheroudakis G, Kamakari S, Metaxa-Mariatou V, Pavlidis N.
Department of Medical Oncology, Ioannina University Hospital, Niarchou Avenue, 45500, Ioannina, Greece, me01593@cc.uoi.gr.
We present the case of a young lady who had been treated for acute myelocytic leukemia at the age of 14 by means of allogeneic bone marrow transplantation, the donor being her sister. At the age of 28 she underwent modified radical mastectomy for invasive breast adenocarcinoma. Genetic analysis revealed chimeric cellular populations on both the tumour and normal tissues of the patient with preponderance of donor-derived cells. We conclude that the patient's epithelia had been repopulated by donor-derived hemopoietic stem cells which gave rise to a malignant mammary neoplasm several years later. The donor remains healthy to date. This case adds weight to the theory of pluripotent normal and neoplastic stem cell histogenesis and emphasizes the pivotal role of supporting host stroma in carcinogenesis.
PMID: 18264757 [PubMed - as supplied by publisher]