Tentative Uterine Cancer, Cramping, Dark Discharge, Nausea, Blood In Stools. If Tumor Is Dying Won't That Indicate It Is Not Cancer?

Question: I am a 62 year old woman recently tentatively diagnosed with cancer of the uterus. In July I started to experience constipation. It would last about 2 weeks and just when I was starting to feel better it would re-occur.I also developed nausea and dry heaves which caused me to lose my appetite resulting in weight loss. Mid-Sept I was trying to do a bowe movement and pushed so hard that there was blood in the toilet bowl. I was startled by this development but thought all of the straining I had been doing caused a hemoroid. Everything was normal for the next 3 weeks, Early Oct. I had the same thing happen in the middle of the night and following morning with more blood than the first time. I was very alarmed and went to the nearest ER. An ultrsound was done and I was told that I had a small fibroid and not to worry because they were rarely cancerous. At that point i was having cramping and paid right abov e the pubic area intermittantly during the day. I was advised to see a gyno ritght away which I did. She took a biopsy last week and said to her assitant that the tumor was breaking up. I commented that sounded like a good thing but she had not answer to me. On the follow up after the MRI she said the tumor was 10CM when the day of the biopsy it was 7CM/ I am experiencing some mild cramping and a dark rust colored discharge with a lot of black grainy stuff. If the tumor is dying wouldn't that indicate that is not cancer. As for the major cramping I had at the time of the ER visit it left 3 days later. I bled upon making a bowel movement for 10 days after ER visit.I became regular again for the most part and can exert pressure to defecate with no blood at all.I have expressed this to my gyne oncologist but I really I wondering about the diagnosis. I have taken Tylonel for cramping pain and other symptoms have abated. I have a problem with nausea still and my appetite is consistent. I weigh 211 from 249 last weigh in in 2007 but am not eating at all like I used to. Please give me some insight. Thank you!

Thank youn for getting back to me. I neglected to mention that five days after the ER visit I passed a chunk of liver colored material about 1 1/2" by 1 1/2". it was 5/16 inch thick. The pathologist did not have a definitive answer to the type of cancer as of Fri. The onologist was of the opinion that the course of treatment would be radiation,chemo, then possibly surgery if the tumor was smaller.
The mri showed that there was some lymph nodes swollen. I can only hope that the treatment can turn things around. I realize that it is serious.