No one knows for sure if the bleeding can spread cancer cells, but there is a theory accepted by some in the medical world - Primary is the boss - so you have a primary tumor. This tumor may seed other locations - say - into your nodes etc... however they may sit dormant until after the primary is gone (or partially removed by a biopsy) at which time they become active.

This is why chemo is effective as it is systemic. Cisplatin may not KILL cancer tumors, but individual cells it is more effective against.

Also you may note. Most surgeons work from clean to dirty. For example - you have a tumor in your tongue, and the neck is supposed to be clear but they want to remove nodes anyway, generally the surgeon would do the dissection first then do the tongue, so as to prevent the spread, through blood and instruments to a "clean" area. People thought I was stupid when I asked my dr. which he was doing first, he said the neck dissection, and then asked if I had a medical background.

;o)

Just two theories... and realistically medicine is really theory, and application.