Diagnosed with narrow urethra. Symptom were frequent urination, vaginitis, many urinary tract infections. Doctor went in with scope and dye. He said he had to stretch urethra just to get scope in and that it is not pliable. I have had triple neg. breast cancer in 2011. Currently on antibiotics but he also wants me to use estrogen cream by rubbing on labia twice a week for 4 months. Will this be beneficial and safe since I have had cancer?