Removal of Ovary for Ca Breast

Today I performed a Laparoscopic removal of both ovaries in a 40 years old lady.And as I had to remove the ovaries I had to remove her uterus as well.Ovaries weren't diseased.Then what was the reason for this unindicated removal of ovaries ? Well about 8 months back she was diagnosed with Ca breast and had Mastectomy followed by chemotherapy.But it is a known fact that Breast cancers can be estrogen and progesterone dependent.So for a better effect of chemotheraputic agent,tamoxifen and to reduce the recurrence of Ca Breast ,it is advised to get the ovaries removed. So if a breast cancer sufferer has completed her family or has a high chance of recurrence this rather drastic surgery can actually improve the long term prognosis of the patient. I hope it works well for her and she has many more years of her life to enjoy.