Uterine Cavity Assessment and Endometrial Gene Expression in Tamoxifen Treated Breast Cancer Patients

Breast cancer is the most prevalent malignancy amongst women and approximately 13% of newly diagnosed breast cancer patients are diagnosed between the ages 20-34 [1]. At this age group women are at the peak of their reproductive years, and many have not yet completed family planning. Moreover the age at first birth has steadily increasing in developed nations [2] and more than a quarter of the deliveries are in women above the age of 35. Despite repeated reports in the literature of a worse prognosis in young breast cancer patients, newer treatments have none-the-less improved the outcome amongst young women and for some early stage disease subtypes the outcome is similar to that of older women [3,4]. These increasing numbers of breast cancer survivors are concerned with post-cancer quality of life issues, such as the ability to have children after completing treatment [5-6], hence it is critical to discuss fertility preservation and the ability to conceive when breast cancer is diagnosed [7-9].

Treatment for early breast cancer involves local therapy that includes surgery and adjuvant radiation therapy as well as systemic therapies including chemotherapy, biological therapy and hormonal therapy. Chemotherapy protocols for breast cancer include different combinations of alkylating agents, platinum derivates and taxanes that are toxic to the ovaries, destroy primordial follicle stockpiles, which directly represent ovarian reserve and can result in infertility and premature menopause [10-12].

Tamoxifen Citrate, a Selective Estrogen Receptor Modulator (SERM), competes with estrogen for binding sites in the Estrogen Receptor (ER) in target tissues such as breast. The drug has been in use for over 30 years with a proven high therapeutic index and significant efficacy. The drug is effective in reducing breast cancer recurrence and improving patient's survival across all age groups. The drug is effective in young pre-menopausal breast cancer patients [13-15] . Recently, it has been reported (16) that breast cancer survivors who take tamoxifen for ten years have half the risk of dying from estrogen receptor positive breast cancer. Therefore the new ASCO (American Society of Clinical Oncology ) recommendations are to increase the period of tamoxifen treatment.

However, at this period these patients cannot conceive, in order to enable pregnancy patients should hold Tamoxifen treatment, either with complete termination, or (a more suitable option with the new recommendations) a tamoxifen free window to allow pregnancy should be offered. If ovarian function is preserved women can try to get a spontaneous pregnancy. In patients that suffer from ovarian failure post chemotherapy treatments or embryos (or eggs) that were stored at diagnosis during fertility preservation procedure can be used.

Pregnancies post (and even during) tamoxifen treatment are reported but former breast cancer patients achieve lower pregnancy rate when performing embryo transfer with embryos that were frozen prior to treatment. The chances to conceive post tamoxifen treatments and even more with prolong Tamoxifen treatments are not determined. This becomes of major importance when a limited window of time is allowed for conception.