WBR0506

Author	[[PageAuthor::Gonzalo A. Romero, M.D., Serge Korjian M.D. (Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Reproductive
Prompt	[[Prompt::A 60-year-old man presents to the outpatient clinic with complaints of increased urinary frequency and difficulty initiating urination. He was diagnosed with hypertension 10 years ago, and is maintained on amlodipine. His heart rate is 67/min, blood pressure is 135/85 mmHg, and temperature is 37.0 °C (98.6 °F). His physical exam is unremarkable except for a hard nodule palpated on digital rectal examination. The physician orders a prostate-specific antigen (PSA) assay that reveals an elevated concentration at 22 ng/mL. Which of the following is true about the patient's most likely diagnosis?]]
Answer A	AnswerA::It is diagnosed by elevated PSA levels
Answer A Explanation	AnswerAExp::The diagnosis of prostate cancer is not made by elevated PSA levels. Definitive diagnosis is by transrectal ultrasound guided biopsies of the prostate.
Answer B	AnswerB::It is always preceded by hyperplasia
Answer B Explanation	AnswerBExp::Prostate cancer does not arise from benign prostatic hyperplasia, and presence of hyperplasia does not increase the risk of cancer.
Answer C	AnswerC::It increases total and free PSA equally
Answer C Explanation	AnswerCExp::The ratio of free/total PSA in patients with prostate cancer is lower than those with BPH. Prostate cancer increases total PSA more than free PSA.
Answer D	AnswerD::It is frequently localized in the peripheral zone
Answer D Explanation	AnswerDExp::The peripheral zone is the most common zone for prostate cancer to develop, making the digital rectal exam a suitable choice to detect larger prostate tumors.
Answer E	AnswerE::It is commonly associated with renal failure
Answer E Explanation	AnswerEExp::Although severe invasive disease may cause obstruction and eventually lead to renal failure, given it's common localization in the peripheral zone, progression to renal failure is not a very common.
Right Answer	RightAnswer::D
Explanation	[[Explanation::Prostate cancer is the most common cancer in men, and the second most common cause of cancer deaths in the in men following lung cancer. Prostatic adenocarcinoma is a slow growing neoplasm whose incidence increases dramatically with increasing age. In fact, the prevalence among patients above 80 years of age may be as high as 80%. The most common location for prostate cancer to develop is the peripheral zone, making the digital rectal exam (DRE) a good method of screening for prostate cancer. In 2011, PSA was removed from the universal screening guidelines given the lack of evidence supporting its benefit. PSA is not used for the diagnosis of prostate cancer, but rather for follow-up after cancer resection. Several derivatives of PSA have been used to increase the sensitivity and specificity of the test. Free/Total PSA is one example. In men with prostate cancer, there is a lower proportion of free PSA causing a lower ratio of free/total PSA. Definitive diagnosis is made by transrectal ultrasound guided biopsies of the prostate gland. Current treatments include transurethral resection or radical prostatectomy both of which may be associated with erectile dysfunction and urinary incontinence. Metastatic disease may be seen in elderly patients presenting for back pain secondary to neoplastic seeding to the lumbar spine (classically osteoblastic). Advanced disease often requires radiation therapy and androgen ablation. It is important to note that prostate cancer does not arise from benign prostatic hyperplasia, and presence of the latter does not increase the risk of cancer. Educational Objective: Prostate adenocarcinoma is the most common cancer in men. It arises most commonly in the peripheral zone of the prostate. Diagnosis is by transrectal ultrasound guided biopsies of the prostate. Universal screening for prostate cancer with PSA is no longer recommended, the use of PSA should be tailored to individual cases and discussed with patients. References: Hayes JH, Barry MJ. Screening for prostate cancer with the prostate-specific antigen test: a review of current evidence. JAMA. 2014;311(11):1143-9. Jain S, Bhojwani AG, Mellon JK. Improving the utility of prostate specific antigen (PSA) in the diagnosis of prostate cancer: the use of PSA derivatives and novel markers. Postgrad Med J. 2002;78(925):646-50. Nelson WG, De marzo AM, Isaacs WB. Prostate cancer. N Engl J Med. 2003;349(4):366-81.]]
Approved	Approved::Yes
Keyword	WBRKeyword::Prostate cancer, WBRKeyword::Prostate specific antigen, WBRKeyword::PSA, WBRKeyword::Prostate, WBRKeyword::BPH, WBRKeyword::Benign prostatic hyperplasia, WBRKeyword::Cancer
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