Like Cheerpul, I wonder if your wife was told she had a BI-RADS Category 5 imaging result, rather than a Stage 5 cancer? (If she was told "Stage 5" this is not part of the official TNM staging classification.)
The official stages for breast cancer are Stages 0 through Stage IV, and each stage and subcategory of the stages has clearly defined features.
Another breast cancer Web site had an article that mentioned Stage V in its title, but not in the article itself. After I pointed out the error to them, they indicated they would make a correction. (They also mentioned that some people "unofficially" talk about Stage V when there is nothing more that can be done except palliative treatment.) I also came across a Web site for alternative/herbal medicine which referred to that erroneous/unofficial stage designation.
I don't think it is a good idea for people to "make things up as they go along" like that, because it tends to confuse people and to impede effective communication by deviating from the published and widely accepted stages used throughout the medical and survivor communities.
Best wishes...
Did your wife just have a mammogram and were the results of the mammogram scored with a BIRADS score of 5? I have not heard of stage 5 cancer, there are only 4. However, a BIRADS score of 5 is what I had about a year ago and it did turn out that I had a small tumor of cancer and much DCIS, which are precancerous cells.
A BIRADS score of 5 does not always mean there is definitely cancer present, but there is something highly suspicious on the mammogram that needs to be checked out. The next step may be an ultrasound, MRI and/or biopsy.
In the time of initial diagnosis, it is easy to get the unfamiliar terms confused. Please check the report again and we will do whatever we can to help. I am thinking of you.