Prostate cancer

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Prostate cancer is a common type of cancer among men. The prostate gland is part of the male reproductive system. Treatment for prostate cancer works best when the disease is found early.

Epidemiology

Among men who died and were organ donors, the prevalence at prostate cancer at autopsy was:[1]

  • age <50: 0.5% had prostate cancer
  • age 50–59: 23% had prostate cancer
  • age 60-69: 35% had prostate cancer
  • age 70 or more: 46% had prostate cancer

Diagnosis

A clinical prediction rule has been validated for predicted an abnormal prostate biopsy.[2] The calculator is online.

The prostate specific antigen (PSA) velocity does not help detect prostate cancer.[3]

Prognosis

5-Year Relative Survival Rates By Year Dx By Cancer Site All Ages, All Races, Male 1975-2000.

Gleason score

The Gleason score is the "sum of the numbers associated with the most common histologic pattern plus the secondary pattern."[4] The two numbers are based on the histologic grade:

Gleason grade[5]
Gleason histologic grade prognosis
1 - 2 well differentiated
3 moderately differentiated
4 poorly differentiated
5 undifferentiated
Gleason score and prognosis[5]
Gleason score
(sum of the primary and secondary histologic grades)		 prognosis
< 6 indolent
6 - 8 intermediate
> 8 aggressive

A clinical prediction rule is available at http://www.prostate-riskindicator.com/en/w6-intro.html.

Staging

Prostate cancer staging information from the National Cancer Institute's Physician Data Query


Treatment

Prostate cancer treatment information from the National Cancer Institute's Physician Data Query


The choice of treatment depends on the stage of the cancer (whether it affects part of the prostate, involves the whole prostate, or has spread to other parts of the body). It also depends on the patient age and general health. There are three treatment options for cancer that has not spread beyond the prostate; however, a systematic review for the Agency for Healthcare Research and Quality concluded that " Assessment of the comparative effectiveness and harms of localized prostate cancer treatments is difficult because of limitations in the evidence."[6]

Watchful waiting / active surveillance

Watchful waiting may be appropriate if the cancer is growing slowly and not causing problems. In this strategy, the doctor will check regularly for changes in the patient condition. This strategy may be appropriate when:[7][8]

  • SA level of 10 ng/mL or lower
  • Gleason score of 6 or lower
  • Clinical stage of T1c or T2a

Surgery

The most common type of surgery is a radical prostatectomy. The surgeon takes out the whole prostate and some nearby tissues. Side effects may include loss of sexual function (impotence) or problems holding urine (incontinence), which can go away within a year of surgery. But some men continue to have problems and have to wear a pad.

An operation called nerve-sparing surgery gives some men a better chance of keeping their sexual function.

Robotic-assisted, minimally invasive radical prostatectomy may result in "shorter length of (hospital) stay, fewer respiratory and miscellaneous surgical complications and strictures, and similar postoperative use of additional cancer therapies but experienced more genitourinary complications, incontinence, and erectile dysfunction."[9]

Radiation therapy

Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. There are two kinds of radiation therapy. External radiation therapy is beamed into the prostate from a machine outside the body. Internal radiation therapy uses radioactive “seeds” that are placed in the prostate, into or near the tumor itself. Like surgery, radiation therapy can cause problems with impotence, not as likely to cause urinary incontinence as surgery. But it can cause rectal problems such as pain and soreness, rectal urgency, and trouble controlling bowel movements.

Hormone therapy

After radiation therapy, some men are treated with hormone therapy. This is used when chances are high that the cancer will come back. Hormone therapy is also used for prostate cancer that has spread beyond the prostate. Side effects of hormone treatments include hot flashes, loss of sexual function, and loss of desire for sex.

Screening

Some doctors think that men should have regular prostate specific antigen (PSA) tests, and others do not. The reason is even knowing that this test can catch a cancer before it causes symptoms, it is not sure that PSA tests save lives. Also, PSA tests find small cancers that would never grow or spread. When that happens, a man may have surgery or other heavy treatments that are not needed. Researchers are studying ways to improve the PSA test so that it catches only cancers that need treatment.

Clinical practice guidelines

Clinical practice guidelines may help guide decisions to screen:

"the evidence is insufficient to recommend for or against routine screening for prostate cancer using prostate-specific antigen (PSA) testing or digital rectal examination (DRE). This is a grade I recommendation"
"The PSA test and the DRE should be offered annually beginning at age 50 to men who have a life expectancy of at least 10 years. Men at high risk should begin testing at age 45. Information should be provided to patients about benefits and limitations of testing."

Interpreting the results of screening tests

Two clinical prediction rules help predict the probability of cancer based on the level of the prostate-specific antigen and other clinical findings.[16][17]

Evidence from trials

Randomized controlled trials of screening for prostate cancer[18][19][20][21][22][23]
Study name Patients Intervention Comparison Outcome Rates Relative risk ratio Comment
Screening group Control group
Norrköping:[18]
2011		 9,000 Swedish males
• Age range: 50-69 years		 Triennial screening (four screenings from 1987 to 1996) Usual care. Prostate cancer mortality after 20 years 2.0% (30/1494) 1.7% (130/7532) 1.16 PSA was only available for the last two screens.
Göteborg:[19]
2010		 20,000 Swedish males
• Age range: 50-64 years		 Biennial screening Usual care. Prostate cancer mortality after 14 years 0.5% 0.9% 0.56† 76% followup. Benefit found, but overdiagnosis also occurred. Number needed to treat = 293.
PLCO:[20]
2009		 76,693 American males
• Median age range: 60-64 years
• 86% anglo		 Annual screening Usual care.
52% of subjects in usual care group received screening outside of the study		 Prostate cancer mortality after 7 years 2% 1.7% 1.22 No benefit found
ERSPC:[21]
2009		 162,243 European males
• Mean age: 61 years
• Races not stated		 Screening every four years Usual care.
Rate of screening in the control group not stated, but estimated to be 20% prior to the trial.		 Prostate cancer mortality after 9 years 0.3% 0.4% 0.80† Number needed to treat = 1410.
Quebec:[22][23]
1999		 46,486 Canadian males Frequency not stated Usual care Prostate cancer mortality at 11 years 0.1% 0.5% 0.26 Did not use intention to treat analysis.
† p < 0.05

A meta-analysis of the trials has concluded there is no mortality benefit.[24]

References

  1. ↑ Yin M, Bastacky S, Chandran U, Becich MJ, Dhir R (2008). "Prevalence of incidental prostate cancer in the general population: a study of healthy organ donors". J. Urol. 179 (3): 892–5; discussion 895. DOI:10.1016/j.juro.2007.10.057. PMID 18207193. Research Blogging.
  2. ↑ Eyre SJ, Ankerst DP, Wei JT, Nair PV, Regan MM, Bueti G et al. (2009). "Validation in a multiple urology practice cohort of the Prostate Cancer Prevention Trial calculator for predicting prostate cancer detection.". J Urol 182 (6): 2653-8. DOI:10.1016/j.juro.2009.08.056. PMID 19836788. Research Blogging.
  3. ↑ Vickers, Andrew J.; Cathee Till, Catherine M. Tangen, Hans Lilja, Ian M. Thompson. "An Empirical Evaluation of Guidelines on Prostate-specific Antigen Velocity in Prostate Cancer Detection". Journal of the National Cancer Institute. DOI:10.1093/jnci/djr028. Retrieved on 2011-02-28. Research Blogging.
  4. ↑ Walsh PC, DeWeese TL, Eisenberger MA (December 2007). "Clinical practice. Localized prostate cancer". N. Engl. J. Med. 357 (26): 2696–705. DOI:10.1056/NEJMcp0706784. PMID 18160689. Research Blogging.
  5. ↑ 5.0 5.1 Harnden P, Shelley MD, Coles B, Staffurth J, Mason MD (May 2007). "Should the Gleason grading system for prostate cancer be modified to account for high-grade tertiary components? A systematic review and meta-analysis". Lancet Oncol. 8 (5): 411–9. DOI:10.1016/S1470-2045(07)70136-5. PMID 17466898. Research Blogging.
  6. ↑ Timothy J. Wilt et al., “Systematic Review: The Comparative Effectiveness and Harms of Treatments for Clinically Localized Prostate Cancer,” Ann Intern Med (February 4, 2008): http://www.annals.org/cgi/content/full/0000605-200803180-00209v1.
  7. ↑ Hayes JH, Ollendorf DA, Pearson SD, Barry MJ, Kantoff PW, Stewart ST et al. (2010). "Active surveillance compared with initial treatment for men with low-risk prostate cancer: a decision analysis.". JAMA 304 (21): 2373-80. DOI:10.1001/jama.2010.1720. PMID 21119084. Research Blogging.
  8. ↑ Hoffman RM, Zeliadt SB (2010). "The cautionary tale of PSA testing.". Arch Intern Med 170 (14): 1262-3. DOI:10.1001/archinternmed.2010.222. PMID 20660847. Research Blogging.
  9. ↑ Hu JC, Gu X, Lipsitz SR, Barry MJ, D'Amico AV, Weinberg AC et al. (2009). "Comparative effectiveness of minimally invasive vs open radical prostatectomy.". JAMA 302 (14): 1557-64. DOI:10.1001/jama.2009.1451. PMID 19826025. Research Blogging.
  10. ↑ U.S. Preventive Services Task Force (2002). "Screening for prostate cancer: recommendation and rationale". Ann. Intern. Med. 137 (11): 915-6. PMID 12458992. [e]
  11. ↑ Harris R, Lohr KN (2002). "Screening for prostate cancer: an update of the evidence for the U.S. Preventive Services Task Force". Ann. Intern. Med. 137 (11): 917-29. PMID 12458993. [e]
  12. ↑ U.S. Preventive Services Task Force (December 2002)). Screening for Prostate Cancer. Retrieved on 2006-09-14.
  13. ↑ Smith RA, von Eschenbach AC, Wender R, et al (2001). "American Cancer Society guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers. Also: update 2001--testing for early lung cancer detection". CA: a cancer journal for clinicians 51 (1): 38-75; quiz 77-80. PMID 11577479. [e]
  14. ↑ National Guideline Clearinghouse. Recommendations from the American Cancer Society Workshop on Early Prostate Cancer Detection. Retrieved on 2006-09-14.
  15. ↑ American Cancer Society. What the American Cancer Society Recommends. Retrieved on 2007-01-16.
  16. ↑ Nam RK, Toi A, Klotz LH, et al (2007). "Assessing individual risk for prostate cancer". J. Clin. Oncol. 25 (24): 3582–8. DOI:10.1200/JCO.2007.10.6450. PMID 17704405. Research Blogging.
  17. ↑ Thompson IM, Ankerst DP, Chi C, et al (2006). "Assessing prostate cancer risk: results from the Prostate Cancer Prevention Trial". J. Natl. Cancer Inst. 98 (8): 529–34. DOI:10.1093/jnci/djj131. PMID 16622122. Research Blogging. Online calculator
  18. ↑ 18.0 18.1 Sandblom G, Varenhorst E, Rosell J, Löfman O, Carlsson P (2011). "Randomised prostate cancer screening trial: 20 year follow-up.". BMJ 342: d1539. DOI:10.1136/bmj.d1539. PMID 21454449. Research Blogging.
  19. ↑ 19.0 19.1 Hugosson J, Carlsson S, Aus G, Bergdahl S, Khatami A, Lodding P et al. (2010). "Mortality results from the Göteborg randomised population-based prostate-cancer screening trial.". Lancet Oncol. DOI:10.1016/S1470-2045(10)70146-7. PMID 20598634. Research Blogging.
  20. ↑ 20.0 20.1 Andriole, Gerald L.; Robert L. Grubb, Saundra S. Buys, David Chia, Timothy R. Church, Mona N. Fouad, Edward P. Gelmann, Paul A. Kvale, Douglas J. Reding, Joel L. Weissfeld, Lance A. Yokochi, E. David Crawford, Barbara O'Brien, Jonathan D. Clapp, Joshua M. Rathmell, Thomas L. Riley, Richard B. Hayes, Barnett S. Kramer, Grant Izmirlian, Anthony B. Miller, Paul F. Pinsky, Philip C. Prorok, John K. Gohagan, Christine D. Berg, the PLCO Project Team (2009-03-18). "Mortality Results from a Randomized Prostate-Cancer Screening Trial". N Engl J Med: NEJMoa0810696. DOI:10.1056/NEJMoa0810696. Retrieved on 2009-03-19. Research Blogging.
  21. ↑ 21.0 21.1 Schröder FH, Hugosson J, Roobol MJ, Tammela TL, Ciatto S, Nelen V et al. (2009). "Screening and prostate-cancer mortality in a randomized European study.". N Engl J Med 360 (13): 1320-8. DOI:10.1056/NEJMoa0810084. PMID 19297566. Research Blogging. Review in: Ann Intern Med. 2009 Jun 16;150(12):JC6-5, JC6-4 Review in: Evid Based Med. 2009 Aug;14(4):104-5
  22. ↑ 22.0 22.1 Labrie F, Candas B, Dupont A, et al (February 1999). "Screening decreases prostate cancer death: first analysis of the 1988 Quebec prospective randomized controlled trial". Prostate 38 (2): 83–91. PMID 9973093. [e]
  23. ↑ 23.0 23.1 Labrie F, Candas B, Cusan L, et al (May 2004). "Screening decreases prostate cancer mortality: 11-year follow-up of the 1988 Quebec prospective randomized controlled trial". Prostate 59 (3): 311–8. DOI:10.1002/pros.20017. PMID 15042607. Research Blogging.
  24. ↑ Djulbegovic M et al (2010). Screening for prostate cancer: systematic review and meta-analysis of randomised controlled trials. BMJ DOI:10.1136/bmj.c4543
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