Penis, cancer of the: A malignant tumor in which cancer cells develop in the tissues of the penis. It is rare in the US. A physician should be consulted for growths or sores on the penis, any unusual discharge from the penis, or bleeding. If warranted, a biopsy is performed. If cancer is found, more tests are done to find out whether the cancer has spread to other parts of the body (staging). Treatment options include surgery, radiation therapy, chemotherapy, and biological therapy. The chance of recovery and choice of treatment depend on the stage of the cancer and the patient's general state of health. Men who are not circumcised at birth may have a higher risk of getting cancer of the penis.