Breast cancer surgery: Does menstrual timing affect prognosis?

There is no clear evidence that the optimal timing of breast cancer surgery is related to the menstrual cycle in premenopausal women.

Several studies have evaluated whether breast cancer surgery done during a particular phase of the menstrual cycle had an impact on long-term survival. One study published in 1998 suggested that the timing of surgery relative to the menstrual cycle did affect the risk of breast cancer recurrence. However, many subsequent studies have failed to confirm such a relationship between the timing of surgery and menstrual cycle. Several studies are currently ongoing to further clarify this issue.