by Stahl RJ
(Cancer of the Prostate; Prostatic Carcinoma)

Definition

Prostate cancer is a disease in which cancer start in the prostate gland. The prostate is a walnut-sized gland in men. It surrounds the urethra, the tube that carries urine out of the body.

Prostate Cancer
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Causes

Cancer occurs when cells in the body divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant growths. These growths can invade nearby tissues. Cancer that has invaded nearby tissues can then spread to other parts of the body.

It is not clear exactly what causes these problems in the cells, but it is probably a combination of genetics and environment.

Risk Factors

Prostate cancer is more common in men who are aged 55 and older. Other factors that may increase your chances of prostate cancer:

  • Family history of prostate cancer, especially in father or brother
  • Family history of prostate cancer diagnosed at a young age
  • A high-fat diet

Symptoms

Prostate cancer may cause:

  • A need to urinate frequently, especially at night
  • Difficulty starting urination or holding back urine
  • Inability to urinate
  • Weak or interrupted urine flow
  • Painful or burning urination
  • Difficulty having an erection
  • Painful ejaculation
  • Blood in urine or semen
  • Frequent pain or stiffness in the lower back, hips, or upper thighs

These symptoms may be caused by other conditions, such as benign prostatic hyperplasia (BPH) or an infection. If you have any of these symptoms, promptly see your doctor.

Diagnosis

Many prostate cancers are found through prostate-specific antigen (PSA) screening. It can find cancer before symptoms start.

Prostate cancer may also be found after symptoms start. The doctor will ask about symptoms and past health. A physical and digital rectal exam will be done. The doctor can feel an enlarged prostate through the wall of the rectum. Blood and urine tests may be done to rule out other things that cause increased prostate size.

A sample of the prostate will be removed for a biopsy. This will confirm cancer. Images of the prostate and area can show size of growth. Tests that may be done include:

Test results will be used to find important details of the cancer such as the type and stage of cancer. Staging is used to guide your treatment plan. Prostate cancer is staged from 1 to 4. Stage 1 cancer has only affected nearby tissue. Stage 4 cancer has spread to other parts of the body.

Treatment

Cancer treatment varies depending on the stage of prostate cancer. Treatment may include:

Watchful Waiting

Early stage cancer may not cause problems. Some cancer is also slow growing and may not need immediate treatment. The prostate will be monitored over time. You will need to track any changes in symptoms. The doctor will do tests or other follow up appointments. Watchful waiting may be appropriate for:

  • Early stage prostate cancer that is growing slowly
  • People of an advanced age
  • People with serious health problems where the risks of treatment outweigh the benefits

Surgery

Types of surgery that may be needed include:

Prostate cancer surgery may cause side effects, like erectile dysfunction, problems controlling urine flow, or control of stool. Special surgery techniques may decrease the risk of these side effects in some. Some examples include nerve-sparing surgery, robotic surgery, and laparoscopic surgery.

Radiation Therapy

Radiation therapy can kill cancer cells and shrink tumors. Examples include:

  • Conformal radiation therapy—Conformal radiation therapy uses 3-dimensional radiation beams that are conformed into the shape of the diseased prostate. This treatment spares nearby tissue the damaging effects of radiation.
  • Intensity-modulated radiation therapy (IMRT)—IMRT uses radiation beams of different intensities to deliver higher doses of radiation therapy to the tumor and lower doses to nearby tissues at the same time.

Hormone Therapy

Hormone therapy may be used if prostate cancer has spread or has returned after being treated. The goal of hormone therapy is to lower the levels of male hormones called androgens. The main androgen is testosterone. Lowering androgen levels can cause prostate cancer to shrink or slow its growth.

Hormone therapy may include:

  • Luteinizing hormone-releasing hormone (LHRH) analogs
  • Luteinizing hormone-releasing hormone (LHRH) antagonists
  • Anti-androgens
  • Estrogen therapy—rarely used now unless other treatments are not working
  • Antifungal medications
  • Antineoplastic agents

A type of surgery called orchiectomy may be done to help control hormones. The testicles makes androgens. This surgery removes the testicles.

Other Treatment Options

Other options may include:

  • Cryosurgery—this involves using an instrument to freeze and destroy prostate cancer cells
  • Chemotherapy—mainly used to relieve symptoms of metastatic cancer
  • Immunotherapy—a drug treatment that builds your immune system so that you can better fight cancer cells
  • Targeted therapies—focus on the cancer cells, rather than attacking both the cancer cells and the healthy cells
  • High-intensity focused ultrasound—an endorectal probe (a probe that is inserted into the rectum) is used to destroy cancer cells with ultrasound energy

Prevention

To help reduce your chances of prostate cancer:

  • Eat a healthful diet. Your diet should be high in fruits, vegetables, and fish, and low in red meat.
  • Ask your doctor about taking certain medications. For example, daily aspirin therapy and 5-alpha reductase inhibitors may reduce your risk of prostate cancer.

RESOURCES

National Cancer Institute  https://www.cancer.gov 

Urology Care Foundation  http://www.urologyhealth.org 

CANADIAN RESOURCES

Health Canada  https://www.canada.ca 

Prostate Cancer Canada  http://www.prostatecancer.ca 

References

Angiogenesis inhibitors. National Cancer Institute website. Available at: https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/angiogenesis-inhibitors-fact-sheet. Accessed October 9, 2020.

Biological therapies for cancer. National Cancer Institute website. Available at: http://www.cancer.gov/about-cancer/treatment/types/immunotherapy/bio-therapies-fact-sheet. Accessed October 9, 2020.

Chemotherapy & targeted therapy. Texas Oncology website. Available at: https://www.texasoncology.com/types-of-cancer/prostate-cancer/targeted-therapy-for-prostate-cancer. Accessed October 9, 2020.

Enzalutamide. EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T904251/Enzalutamidw. Accessed October 9, 2020.

Evolution of cancer treatments: targeted therapy. American Cancer Society website. Available at: https://www.cancer.org/cancer/cancer-basics/history-of-cancer/cancer-treatment-targeted-therapy.html. Accessed October 9, 2020.

FDA approval for sipuleucel-T. National Cancer Institute website. Available at: https://www.cancer.gov/about-cancer/treatment/drugs/fda-sipuleucel-t. Accessed October 9, 2020.

Mohler JL, Kantoff PW, Armstrong AJ, et al. Prostate Cancer. Version 2.2014. In: National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology (NCCN Guidelines). NCCN 2014 Apr from NCCN website.

National Institute for Health and Care Excellence (NICE). Prostate cancer: diagnosis and treatment. NICE 2014 Jan:CG175.

Prostate cancer. American Cancer Society website. Available at: https://www.cancer.org/cancer/prostate-cancer.html. Accessed October 9, 2020.

Prostate cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/prostate-cancer. Accessed October 9, 2020.

Prostate cancer screening. EBSCO DynaMed website. Available at: https://www.dynamed.com/prevention/prostate-cancer-screening. Accessed October 9, 2020.

Prostate cancer staging and imaging. EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T905769/Prostate-cancer-staging-and-imaging. Accessed October 9, 2020.

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