Cancer patients who have been successfully treated for their disease face the prospect of its return if stored ovarian (or testicular) tissue is transplanted back into their bodies without adequate checks, according to researchers at two university hospitals in Israel. Writing in Europe’s leading reproductive medicine journal, Human Reproduction, the researchers say that hundreds of cancer patients worldwide have ovarian tissue and, in some cases, testicular tissue frozen in the hope of being able to have children after their cancer treatment has finished; but they warn that few fertility centres have the skills and use the technology needed to check the tissue for residual cancer cells, making it possible for the original cancer to re-infect the body when the tissue is re-implanted to restore the patients’ fertility.
“The interest in ovarian tissue storage as a real option for preserving fertility in cancer patients has increased. However, genuine concerns regarding the possible recrudescence [re-appearance] of the primary disease following re-implantation of stored ovarian tissue with malignant cells exist,” write the authors. The first author of the report, Dr Dror Meirow, said: “We think it’s vitally important to raise awareness amongst cancer patients, fertility specialists, oncologists and haematologists. There are few fertility centres in the world with the expertise and the technology to run the types of tests on tissue that are needed to detect residual cancer. “However, not every reproductive service that has surgical skills and freezing facilities can be safely responsible for ovarian tissue cryopreservation. We suggest that these centres should store tissue for future investigation, and samples can be shipped to specialist centres for analysis.”
Dr Meirow, who leads the fertility preservation programme in the IVF Unit at Chaim Sheba Medical Center, Tel Hashomer (headed by Professor Jehoshua Dor), carried out the research with Professor Dina Ben Yehuda, director of the Hematology Division at Hadassah University Hospital, Jerusalem. Dr Meirow said that fertility centres with close connections to cancer and haematological centres should be able to work together in order to adopt the correct methods for checking stored tissue.
Before collecting tissue from the 58 young women in this study, Dr Meirow and his colleagues used various imaging methods (sonography, CT and PET scans) to look for cancer in the pelvis and ovaries of the patients; the women were about to receive chemotherapy for haematological cancers such as Hodgkin’s lymphoma, non-Hodgkin’s lymphoma and leukaemia, between 1997 and 2007. They found cancer in the pelvic area of two patients, and therefore ovarian tissue was not harvested. They collected tissue from the other 56 patients and, in addition to freezing strips for future transplantation; they also froze a smaller piece of ovarian tissue separately for each patient. They planned to use these extra strips for future checks for the presence of cancer cells, using the most modern methods that would be available at the time the tissue was thawed and prepared for transplantation.