Fertility issues following breast cancer treatment

About 15% of breast cancers occur in women younger than 45 years, equivalent to about 5,000 women annually in the United Kingdom. These women are of childbearing age, and demographic changes with the birth in the United Kingdom, so that the average age of first pregnancy is 29 years, many of these women have not completed their family, and in some cases may not even started.

While the demographics of delivery have changed the survival of women with breast cancer has improved, with rates of 5-year survival of about 80% [1]. It is largely a consequence of the adoption of effective adjuvant treatment, chemotherapy and hormonal treatments, but these may themselves be temporary or permanent effects on fertility of a woman.

This raises important issues for women of childbearing age who are on the brink of systemic treatment for breast cancer in terms of the potential impact of this treatment on their fertility. The question of what might be offered in terms of fertility protection becomes important and, indeed, if it is 'safe' to get pregnant after breast cancer diagnosis - and, if so, when it could be considered and there is a risk of miscarriage or damage to the baby.

The impact of systemic treatment on fertility

Chemotherapy can cause temporary or permanent amenorrhea by class of drug, intensity and duration of treatment and the woman's age at time of treatment. Typically alkylating agents are such as cyclophosphamide, is associated with secondary infertility. In the past, this group included diagrams of CMF (cyclophosphamide, methotrexate, 5-fluorouracil), leading to high levels of infertility, regardless of age. These regimens have been largely replaced by chemotherapy with anthracyclines more modern, with or without taxanes, such as FEC (5-fluorouracil, epirubicin, cyclophosphamide), AC (doxorubicin, cyclophosphamide) and either paclitaxel or docetaxel. These treatments are less cytotoxic gonadotoxic [4,5].Typically, such treatments have little effect on fertility in women treated for less than 30 years of age, but it is high (almost 80%) of infertility in women over 40 years, and intermediate levels between 30 and 40 (Table 1) . targeted agents such as trastuzumab (Herceptin) and bevacizumab (Avastin), appear to have little effect on fertility, but has been associated with fetal abnormalities when administered to women who become pregnant accidentally. These materials are intended for a long time, and women should be strongly advised not to get pregnant when to use them, or up to 3 months from the end, because of their long half-life.