Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Prostate Cancer ?
    ### Response:
    Key Points
                    - Prostate cancer is a disease in which malignant (cancer) cells form in the tissues of the prostate.    - Prostate cancer is the second most common cancer among men in the United States.
                
                
                    Prostate cancer is a disease in which malignant (cancer) cells form in the tissues of the prostate.
    