My bunny did have uterine cancer...but had no symptoms! It was only by chance they caught it (she has a swollen nipple that didnt react to antibiotics so they removed it and asked if i wanted her spayed at the same time, had biospys done and she had two different cancers, unrelated!)
She ate fine, was the same personality wise, ran around fine, didnt seem in pain when picked up...
If your bunny is young then youv got nothing to worry about, mine was 7 when she go it (i didnt know about the cancer and syaying then), and the vet said they normally see it in buns 5+, the older they are the more likely theyll get it.
Sorry that i cant help with symptoms, i dont know if all buns show no symptoms or whether just mine, we may have caught it early for her so it may have no progressed to symptoms.