Prostate Cancer

PROSTATE CANCER 41A

A 73-year-old African American man presents to a primary care clinician to establish care. He has not seen a doctor for some time, but low back pain and difficulty initiating and maintaining a stream of urine have prompted his visit today. His family history is notable for his father having prostate cancer. On physical examination, he has tenderness to palpation over the lumbar spine, and his digital rectal examination (DRE) reveals a large focal hard prostate nodule. His laboratory testing reveals a serum prostate-specific antigen (PSA) concentration of 21.3 ng/mL.

What are the salient features of this patient’s problem? How do you think through his problem?

Salient features: Older African American man; obstructive urinary symptoms; focal prostatic nodule; highly elevated PSA; low back pain and tenderness over the lumbar spine suggesting bony metastasis

How to think through: Prostate cancer detection is challenging. For every clinically important case of prostate cancer identified, routine PSA testing detects many cancers that will not progress to clinically significant disease. Prostate cancer, however, is a leading cause of cancer-related death among men. What risk factors for prostate cancer are present in this patient? (Family history and African American heritage.) What is the most potentially alarming finding on physical examination in this case? (Lumbar tenderness suggesting metastatic disease.) What are the next diagnostic steps? (Transrectal ultrasonography and biopsy of the prostate, computed tomography [CT] of the abdomen and pelvis, and radionuclide bone scan.) Without the significant elevation in PSA, would a biopsy be warranted in this case? (Yes. Asymmetry or nodules on DRE should be evaluated histologically.) Does the high PSA value in this case increase the likelihood of extracapsular extension? (Yes. Although PSA levels are challenging to interpret because of fluctuation and overlap with benign prostatic hypertrophy, a level >10 ng/mL is a strong indication of extracapsular disease.) To what sites does prostate cancer metastasize? (Usually bone.) Are bony metastases in prostate cancer osteolytic or osteoblastic, and do they cause elevated serum alkaline phosphatase? (Osteoblastic. Yes, serum alkaline phosphatase and calcium may be elevated.) How is prostate cancer classified to guide treatment and prognosis? (The TNM [tumor, node, metastasis] staging system, incorporating the Gleason score for pathologic tumor grade, and the PSA value.)