I have not heard that Grade 1 is more likely to return, and it certainly seems counter-intuitive, since that means the cells are well-differentiated and much
more closely resemble normal cells
than, say, Grade 3, which is highly aggressive and typically where one worries more about potential spread or recurrence.
But if what you say is true, and if it would be likely to be the same low-grade cells in a new primary tumor, then you have already substantially reduced that risk d/t your BLM.