I also have a very tall Umbrella Plant. I have cut it back once, and it has regrown from where I cut it. It has now reached the ceiling again, but seems to have stopped that growth and grown another branch a bit further down, which now measures about 8 inches. My plant is very healthy and has never lost any lower leaves, I have had it now for about 4-5 years. I did read that the bit you cut off can be re-rooted, but I had no luck with that. Also, I have read that these plants do not like to be moved about,and prefer a bright, out of the sun, position. I must say that my plant has thrived on this information. So,shivvy, cut yours down to a height you will be happy with and then watch it grow again.