Ovarian tissue cryopreservation for cancer patients: who is appropriate?

Abstract

In recent decades there has been parallel progress in the fields of cancer chemotherapy and reproductive medicine technology, which has led to increasing numbers of women surviving their malignancies, often with significant reproductive impairment, and a range of choices for the potential preservation of fertility, including storage of embryos, mature oocytes, immature oocytes or ovarian tissue. Although each of these procedures has specific relative advantages and disadvantages, there are no clear guidelines for selection of patients for such interventions. There are six distinct issues that should be considered before making any recommendations regarding the appropriateness of any of the range of measures aimed at enhancing the future reproductive capacity of the patient: (1) the risk of sterility with the proposed treatment program; (2) the overall prognosis for the patient; (3) the potential risks of delaying chemotherapy; (4) the impact of any future pregnancy upon the risk of tumour recurrence; (5) the impact of any required hormonal manipulation on the tumour itself; and (6) the possibility of tumour contamination of the harvested tissue. For illustrative purposes, it is reasonable to assume that the preservation of future fertility is likely to be a priority for women under the age of 40 years. Within this group in 1996 in the Australian State of Victoria (total population, ˜4.6 million), there were 837 cases of cancer diagnosed (annual incidence rate, ˜60 per 100 000 population). Of those afflicted, it is estimated that 10% were pre-pubertal, 38% were treated by potentially curative surgery alone, 15% had cancers of the reproductive tract, and 5% were treated with palliative intent. Thus the remaining 32% of patients with invasive cancer in this age group (267 per year) are potentially curable, and require initial treatment, including chemotherapy. These tumours comprise predominantly breast cancer (161 cases or 19%), sarcomas of bone and soft-tissue (32 cases or 4%), and the haematologic malignancies (Hodgkin’s disease, non-Hodgkin’s lymphomas, and the leukaemias, each approximately 25 cases or 3%). Consideration of procedures that may preserve future fertility would be appropriate in this group of patients. Current data relating to the six issues noted earlier using contemporary treatment programmes will be presented and discussed as they apply to each of these categories of patient. An understanding of the relative importance of each of these factors to patients with a range of malignancies will facilitate the safe and appropriate application of the available methods to maintain the possibility of future child-bearing.