Tamoxifen is a medication commonly used in breast cancer treatment. It works by blocking the effects of estrogen in breast tissue, which can help prevent breast cancer cells from growing. In this trial, it is being used as part of a fertility preservation strategy.

Recombinant FSH (Follicle Stimulating Hormone) is a hormone medication that stimulates the ovaries to produce multiple eggs. It is commonly used in fertility treatments to help women produce more eggs during a single cycle. In this trial, it is being combined with Tamoxifen to help preserve fertility before chemotherapy treatment.

Oocyte vitrification is a rapid freezing technique used to preserve a woman’s eggs. This is not a medication but rather a laboratory procedure that allows unfertilized eggs to be stored for future use.

Embryo freezing is another preservation technique where fertilized eggs (embryos) are frozen for future use. Like vitrification, this is a procedure rather than a medication.

Breast cancer – A disease that begins when cells in the breast start to grow out of control. These cells usually form a tumor that can often be seen on an x-ray or felt as a lump. The cancer starts in the cells of the breast, typically either in the ducts that carry milk or the glands that make milk. It occurs when breast cells begin to grow abnormally, dividing more rapidly than healthy cells. These cells can spread through the breast to the lymph nodes and to other parts of the body. The disease can affect both women and men, though it’s much more common in women.