As far as one can read, it cannot. MPNs (ET, PV, MF, unspecified) do not behave like solid tumour cancers that can metastasise to other organs.
MPNs might be secondary to other cancers, mostly as the aftermath of chemotherapy years after, or they might share mutations with other cancers, which could increase the likelihood that someone with MPNs might have a secondary cancer, but it does not spread as a solid tumour cancer does.
It is another story when MPNs transform into leukaemia, but MPNs themselves do not spread to other organs.

I haven't heard that .if you have myleofibrosis ,the bone marrow can start moving to your long bones and the liver and spleen .bone marrow doesn't become tumors.

Hi Robin,
In everything I have heard about cancers, movement through the body via the blood supply can happen, so anything is possible.