A 56-year-old African American man with a history of hypercholesterolemia and obesity presents with a 6-week history of reduced urinary stream. Upon further questioning, he also admits to generalized weakness, loss of appetite, and a dull lower backache during this time, which he attributes to being ""out of shape."" He denies fever, chills, chest pain, shortness of breath, abdominal pain, hematuria, frequency, hesitancy, flank pain, dysuria, abnormal penile discharge, a history of trauma, alcohol use, or smoking. He states that he had an extramarital affair about 2 months ago and did not use any barrier methods during sexual intercourse. The physical exam is notable for a man who is in no acute distress, and he has normal vital signs. He is found to have a distended bladder on abdominal exam; there is vertebral tenderness of the lumbosacral spine as well as a firm non-tender nodularity of prostate upon digital rectal exam.
What is the most likely diagnosis?
1) Benign prostatic hyperplasia
2) Prostate cancer
3) Urinary tract infection
4) Renal calculi