How soon after I finish radiation treatments for breast cancer can I donate blood?

The FDA allows the medical director for each blood collection facility to determine eligibility for volunteer blood donation of potential donors with a history of soft tissue malignancies. In general, the deferral length varies from one to five years following completion of therapy. Please contact the medical director of your local blood center and review your case.

Far too soon, however well you are.

In the USA, the general criterion is "Donors who have had cancer of a solid organ or tissue (such as the lung, liver, breast) are permitted to donate if they have been symptom-free and cancer-free for a defined period of time, usually two to five years" - http://www.uptodate.com/contents/blood-donation-an...

Edit: as Tarkarri says, in some other places, cancer is a permanent disqualification. Same in the UK: I've been a regular donor, and I confirmed recently with the Blood Service that I can't donate again.

Check with your Dr and the local blood bank.

Here in Australia you face a life long ban from donating after a cancer diagnosis.

The Canadian Blood service wouldn't use me as a donor after cancer..

You should talk to your oncologist. While in theory the treatment shouldn't be an issue, your body may still be recovering and adding this stress may be a bad idea.

Besides, what is the rush?

It would be years, if ever. Just because you had any kind of treatment doesn't mean you have no cancer cells floating around.