Hormone injections helped a lot with my "agressive" and stroppy sow, she had one very small ovarian cyst but a lot of "PMT" to go with it! I had to split her from the other girls as she was so sexually aggressive and always trying to be the dominant pig.
Personally, from my own experience and those of a few others who have gone down both routes, I believe spay should be last resort, as it is big surgery. Hormone injections (HCG / Chorulon) are the 'safest' port of call, hence the most recommended first one, and will deal with the hormonal side of things as well as cysts (if cysts are present).
If a course of injections doesn't work, and there are no cysts/cysts not large enough to be drained, then a spay could turn out to be the logical option.
Try to discuss the options with your vet if possible, and ask if there are actually ovarian cysts etc.