How often does breast cancer metastasize without going via the lymph nodes?

The short answer "very rarely". Breast cancer can spread locally - meaning up to the skin and into the the local ducts, but most commonly metastasizes to the rest of the body via the lymph system. Unfortunately, there are times when it has spread but the lymph nodes sampled did not have any cancer cells, so the staging is not correct. If this is personal, check with your oncologist for more info.

Distant metastasis in breast cancer can be thru the blood stream to many organs such as bone, liver, lungs, brain, etc. The rate of distant metastasis with newly diagnosed breast cancer is fairly low and in the range of 3-4 percent.