Smoking when studied by researchers has never yielded definitive proof that it is a direct cause of lung cancer. The thing we should look at is the effect smoking has on the cells ability to maintain themselves. The effects of the chemicals contained in the smoke from today's cigarettes, cigars, or any other tobacco products may not cause the direct manipulation of the genes that control the growth of the cell. But, they may rather inhibit the cell from growing and replacing it's self during the cells life cycle, thus causing the cell to try to work overtime and effect a change in the DNA that forces the cell to grow and divide( replace it's self ) at a rapid pace to keep up with the inhibiting effects of the chemicals.

A uterine biopsy, medically referred to as an endometrial biopsy, is a procedure performed by a doctor to collect tissue cell samples from the lining of the endometrium, or uterus. By collecting these tissue samples and then examining them under a microscope, a doctor can determine the source or cause of many uterine problems. 

In most cases, a uterine biopsy can be performed in a doctor’s office, or your doctor may schedule the procedure at a hospital or other medical facility. There are several ways a uterine biopsy can be attained, most of which will involve minimal discomfort and no anesthesia. One method, called a D&C, which stands for dilation and curettage, is done with general or local anesthesia. In all methods of tissue cell collection, an instrument is passed through the cervix and into the uterus for collection. 

Colon cancer is when some cells in the colon malfunction and a distortion or mutation occurs in the replication of cells. That mutation then duplicates and on it goes except these cells are abnormal and start developing a source of nutrition by forming blood sources nearby and taking over the organism. This group of cells will then form a blob or tumor, the tumor will probably ulcerate and that bleeding will cause anemia. The cancer can develop anywhere in the colon and can form from a small growth called a polyp. 

I gained weight also. ER+pr+. With Breast cancer most do gain weight and it's not from eating too much. 

Stress, chemicals and steroids all play a part and mess with your metabolism. Try your best to eat clean protein to maintain muscle mass and lots of vegetables / 1-2 fruits for nutrition. I lacked the knowledge going into it and lost a great deal of muscle. 

Thanks sydneyluv, I will definitely do that...they also put me on a water pill as I was retaining fluids.