Yes, I was. I was bullied daily by my employer after I let her know that I had been diagnosed with cancer. I continued to work and fulfill my work responsibilities, but she made comments each day to the effect of "When you quit, make sure and give us two weeks notice" or often making fun of my loss of hair. I needed the job, and so I didn't say anything at the time. I later found out that that workplace had a history of harassing people with cancer. So yes, it does happen.