Risks of treating prostate cancer include impotence and incontinence, among other things. Prostate cancer is often slow-growing enough that men can avoid those risks by monitoring the status of their prostate. As you note, an enlarged without lumps is not considered to be a cancer risk. A lumpy prostate, enlarged or not, is a concern, but whether that makes it enough of a concern for further intervention is something only you can decide, in consultation with your doctor. If your prostate shows changes, new lumps, increased size, etc., that elevates the concern level. If you have voiding difficulty, urinary retention, etc., that impinges on your quality of life through incontinence, bladder infections, etc. then some sort of intervention seems prudent to consider.