What are the long-term effects of breast cancer?

Variable: Many women with breast cancer have their disease limited to the breast, treatment of which will have no long-term effects. Some women will have disease outside the breast which requires chemotherapy, which carries some risks to other organs. A percentage of these women with systemic disease will succumb to the ca if it takes over a vital organ.

It depends: Depends to the stage of the disease, the type of treatment received and the body's response to the treatment. In most cases after completion of treatment there is no or little long term effects. If there is metastatic disease, there will be many different adverse effects based on the organ involved. If a mastectomy is done, there will be loss of the breast. As you can see there is no one answer.