From the Research
The current evidence does not strongly support that IVF hormones significantly increase the risk of ductal carcinoma in situ (DCIS). Most large-scale studies have found no substantial link between fertility treatments and breast cancer, including DCIS. IVF medications like gonadotropins (Follistim, Gonal-F), GnRH agonists (Lupron), and hCG trigger shots temporarily elevate estrogen levels, which theoretically could promote estrogen-sensitive tissue growth. However, this short-term exposure differs from the prolonged hormone exposure associated with breast cancer risk.
According to a study published in 2005 1, a combined analysis of cohort studies including a total of 60,050 women treated with ovulation induction/IVF showed no significant association between these treatments and increased risk of breast cancer. Another study published in 2014 2 found that co-administration of tamoxifen during conventional controlled ovarian hyperstimulation for in vitro fertilization in breast cancer patients increases the safety of fertility-preservation treatment strategies, with no increased long-term recurrence risk.
Women with pre-existing risk factors for breast cancer (family history, BRCA mutations) should discuss their specific situation with their reproductive endocrinologist and oncologist before starting IVF. The temporary hormonal changes from IVF don't appear to significantly alter long-term breast cancer risk, though research continues in this area. Regular breast cancer screening according to age-appropriate guidelines remains important for all women, including those undergoing fertility treatments.
Some studies have suggested that certain protocols, such as the use of letrozole, may be preferred due to lower peak estrogen levels 3, 4. However, the overall evidence suggests that IVF hormones do not significantly increase the risk of DCIS.
Key points to consider:
- No substantial link between fertility treatments and breast cancer, including DCIS
- Temporary hormonal changes from IVF do not significantly alter long-term breast cancer risk
- Women with pre-existing risk factors should discuss their situation with their reproductive endocrinologist and oncologist
- Regular breast cancer screening remains important for all women, including those undergoing fertility treatments.