Answer

Breast cancer is the most common malignancy in women and is increasingly affecting younger individuals. Radiation therapy, a component of multimodal treatment, uses high energy to destroy tumors or remaining malignant cells.

During breast cancer radiation therapy, the radiation beam focuses on the breast tissue, chest wall, and nearby lymph nodes, such as the axillary and supraclavicular nodes. The reproductive organs are located in the pelvis, far from the irradiated area. Radiation directed at the chest does not affect the ovaries, deplete ovarian reserve, or damage the uterus.

Doctors and nurses observe a patient in the radiation therapy room via a computer system. Photo: Tam Anh General Hospital

While a small amount of radiation scatters during treatment, the dose escaping the chest area is very low, under 0,1 Gy (Gray - the unit for absorbed radiation dose). In contrast, a radiation dose exceeding 2 Gy, when directly aimed at the pelvic region, is typically required to cause ovarian failure.

The primary causes of fertility issues in women undergoing breast cancer treatment are mainly due to chemotherapy and hormone therapy. Chemotherapy drugs eliminate rapidly dividing cells, including cancer cells and immature follicles in the ovaries, leading to ovarian failure and temporary or permanent amenorrhea. The risk to fertility depends on the patient's age and the type of medication used.

Patients with hormone receptor-positive breast cancer require hormone-blocking medication for 5 to 10 years. Pregnancy during this treatment period carries a high risk of birth defects. Patients need to wait 5-10 years, until completing the hormone therapy regimen, before attempting pregnancy. By this time, women may have passed their biological "golden" period, experiencing natural ovarian decline, making conception more difficult.

Therefore, radiation therapy for breast cancer does not reduce or affect fertility. You should discuss your concerns thoroughly with your doctor to receive advice on reproductive matters and to plan an appropriate treatment regimen.

Master, Doctor Phan Thi Hong Dang

Department of Radiation Therapy, Oncology Center

Tam Anh General Hospital TP HCM