What is prostate cancer?
Prostate cancer is a disease in which cells in the prostate gland — a walnut-sized gland in the male reproductive system that resides below the bladder and surrounds the upper part of the urethra (i.e., the tube that carries urine from the bladder) and makes seminal fluid — start to grow out of control.[1] It is the second most common cancer in men worldwide and is most prevalent in men over the age of 65;[2] The majority of prostate cancers grow very slowly and are unlikely to cause serious problems. When the cancer is confined to the prostate, long-term prognosis is excellent, but if the cancer begins to grow quickly and spreads to distant organs, it becomes dangerous, and current therapies cannot cure it.
What are the main signs and symptoms of prostate cancer?
The signs and symptoms of prostate cancer are nonspecific and tend to be more indicative of benign prostatic hyperplasia (i.e., noncancerous enlargement of the prostate) than cancer. They’re mainly related to problems with urinating and include:[1]
- Decreased urinary stream that’s hard to start, or starts and stops
- Frequent urination, especially at night
- Suddenly needing to urinate right away
- Incomplete bladder emptying
- Pain or burning while urinating
- Blood in the urine or semen Although rare in the current era of widespread screening, people with prostate cancer may also present with symptoms of metastatic disease (i.e., the spread of cancer cells to other parts of the body), such as bone pain or fractures.
How is prostate cancer diagnosed?
A doctor can use different tests to screen for prostate cancer, such as a digital (finger) rectal exam, a prostate-specific antigen (PSA, a protein secreted by prostate cells) blood test, and imaging tests (e.g., ultrasound, magnetic resonance imaging).[1] A prostate biopsy is then used to confirm the presence of prostate cancer and determine the severity of the disease.
What are some of the main medical treatments for prostate cancer?
The treatment selected depends on a variety of factors, including age, comorbidities, expected lifespan, the stage (i.e., the size of the tumor and whether the cancer has spread to other parts of the body) and grade (i.e., how abnormal the cancer cells and tissue look under a microscope and how quickly the cancer cells are likely to grow and spread) of the cancer, and patient preferences.[3] Common treatment options include watchful waiting or active surveillance, surgery, radiation therapy, hormone therapy, chemotherapy, targeted therapy, and immunotherapy.
Watchful waiting or active surveillance is typically reserved for older men without symptoms and prostate cancer that isn’t likely to grow or with comorbidities that would affect their immediate lifespan.[4] Surgery or radiation therapy are used in the early stages of prostate cancer to try and cure the disease.
How could diet affect prostate cancer?
A Western dietary pattern rich in animal-based protein, dairy products, and refined carbohydrates tends to be associated with an increased risk of prostate cancer, whereas a healthy plant-based dietary pattern (e.g., the Mediterranean diet) tends to be associated with a decreased risk of prostate cancer.[7][8] Concerning specific dietary factors, a notable body of evidence indicates that a high intake of dairy products is associated with an increased risk of prostate cancer,[7] while fairly consistent evidence indicates a high intake of lycopene from tomato products is associated with a decreased risk of prostate cancer.[9][10] Also, obesity increases the risk of advanced prostate cancer, so a hypocaloric diet that facilitates weight loss is often beneficial in this population.
Are there any other treatments for prostate cancer?
What causes prostate cancer?
The precise causes of prostate cancer are unclear, but they involve changes in the DNA of a normal prostate cell, which are either inherited or acquired throughout life. Several genes have been linked to prostate cancer (e.g., TMPRSS2-ERG, SPOP, FOXA1, BRCA1, BRCA2).[12] Additionally, the risk of prostate cancer is approximately doubled in men who are Black or have a first-degree relative with prostate cancer compared to the general population.[4] Acquired gene mutations are the result of errors in the DNA replication process, which occur at random or via the influence of other factors (e.g., diet, hormone levels, exposure to cancer-causing chemicals).[13]
Examine Database: Prostate Cancer
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Frequently asked questions
Prostate cancer is a disease in which cells in the prostate gland — a walnut-sized gland in the male reproductive system that resides below the bladder and surrounds the upper part of the urethra (i.e., the tube that carries urine from the bladder) and makes seminal fluid — start to grow out of control.[1] It is the second most common cancer in men worldwide and is most prevalent in men over the age of 65;[2] The majority of prostate cancers grow very slowly and are unlikely to cause serious problems. When the cancer is confined to the prostate, long-term prognosis is excellent, but if the cancer begins to grow quickly and spreads to distant organs, it becomes dangerous, and current therapies cannot cure it.
The signs and symptoms of prostate cancer are nonspecific and tend to be more indicative of benign prostatic hyperplasia (i.e., noncancerous enlargement of the prostate) than cancer. They’re mainly related to problems with urinating and include:[1]
- Decreased urinary stream that’s hard to start, or starts and stops
- Frequent urination, especially at night
- Suddenly needing to urinate right away
- Incomplete bladder emptying
- Pain or burning while urinating
- Blood in the urine or semen Although rare in the current era of widespread screening, people with prostate cancer may also present with symptoms of metastatic disease (i.e., the spread of cancer cells to other parts of the body), such as bone pain or fractures.
Prostate-specific antigen (PSA) is a protein produced by the cells of the prostate gland. Levels of PSA in the blood are used to detect early prostate cancer (which is usually asymptomatic) as higher PSA levels are associated with a greater likelihood of prostate cancer.[14]
However, the PSA test has poor specificity. Infection, trauma, inflammation (i.e., prostatitis), and benign prostatic hyperplasia can all increase PSA levels. A PSA level ≥ 4.0 ng/mL is generally the threshold for which further evaluation for prostate cancer should occur,[15] but prostate cancer has been detected in men with PSA levels as low as 1.1 ng/mL[16] and not every man with very high PSA levels will have prostate cancer.
Although PSA testing appears to have a small potential benefit on reducing the risk of death from prostate cancer,[17] there are potential harms of testing due to frequent occurrence of false-positive results,[18] including psychological distress, additional testing and prostate biopsy, and treatment complications (e.g., incontinence, erectile dysfunction).[19] Many men with prostate cancer never become symptomatic and wouldn’t know they have the disease if they weren’t screened for it. In these cases, treatment would only result in harm without benefit.
For these reasons, it’s recommended that, in men aged 55–69, undergoing PSA testing should be a personal choice, rather than a blanket recommendation.[19]
A doctor can use different tests to screen for prostate cancer, such as a digital (finger) rectal exam, a prostate-specific antigen (PSA, a protein secreted by prostate cells) blood test, and imaging tests (e.g., ultrasound, magnetic resonance imaging).[1] A prostate biopsy is then used to confirm the presence of prostate cancer and determine the severity of the disease.
The treatment selected depends on a variety of factors, including age, comorbidities, expected lifespan, the stage (i.e., the size of the tumor and whether the cancer has spread to other parts of the body) and grade (i.e., how abnormal the cancer cells and tissue look under a microscope and how quickly the cancer cells are likely to grow and spread) of the cancer, and patient preferences.[3] Common treatment options include watchful waiting or active surveillance, surgery, radiation therapy, hormone therapy, chemotherapy, targeted therapy, and immunotherapy.
Watchful waiting or active surveillance is typically reserved for older men without symptoms and prostate cancer that isn’t likely to grow or with comorbidities that would affect their immediate lifespan.[4] Surgery or radiation therapy are used in the early stages of prostate cancer to try and cure the disease.
“Watchful waiting” involves closely monitoring the patient’s condition and only using treatment to relieve symptoms and improve quality of life, without any intention of curing the disease. This option is typically reserved for older men who do not present with signs or symptoms. “Active surveillance” also involves closely monitoring the patient’s condition, but tests (e.g., PSA test, digital rectal exam, prostate biopsy) are frequently conducted, and treatment is given to try and cure the disease when test results change unfavorably. Active surveillance is typically utilized for men with very-low- to low-risk prostate cancer without serious health conditions.[20]
In men, especially younger men, with intermediate- to high-risk prostate cancer, either radiation (external or interstitial) therapy or surgery (radical prostatectomy being the most common) are used to try and cure the disease. Surgery is reserved for patients with cancer confined to the prostate gland. Radiation therapy may be used as the first treatment for cancers that spread into nearby tissues, in patients who are not good candidates for surgery or whose cancer has come back after surgery, or to control advanced cancer.[21] Potential complications after surgery include those typical of any major surgery (e.g., infection at surgery site), as well as erectile dysfunction, urinary incontinence, bowel problems, shortening of the penis, and inguinal hernia. Radiation shares the same potential complications as surgery, plus an increased risk of bladder and gastrointestinal cancer.[22]
Other treatment options are not intended to cure prostate cancer and are typically reserved for advanced cancers. They include the following:
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Hormone therapy: uses surgery or drugs to reduce testosterone levels, which fuel prostate cancer cells. It may be used if radical prostatectomy or radiation cannot be used or were ineffective.[23] Hormone therapy can also be used before radiation therapy to enhance treatment effectiveness. Potential side effects include reduced or absent sexual desire, erectile dysfunction, shrinkage of testicles and penis, hot flashes, breast tenderness and growth, and reduced bone mineral density.
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Chemotherapy: uses anti-cancer drugs injected into a vein or taken by mouth. It is sometimes used if cancer has spread outside the prostate gland and hormone therapy isn’t working.[24] Potential side effects include hair loss, mouth sores, loss of appetite, nausea, vomiting, diarrhea, increased risk of infections, and fatigue.
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Targeted therapy: uses anti-cancer drugs or other substances to attack cancer cells while doing little damage to normal cells, typically less than chemotherapy or radiation.[25] Potential side effects are similar to chemotherapy.
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Immunotherapy: aims to enhance the ability of the individual’s immune system to recognize and destroy cancer cells.[26] Most commonly, a vaccine (Sipuleucel-T) is used to treat cancer that has spread to other parts of the body and is no longer responding to hormone therapy.
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Bisphosphonates: drugs that slow down the activity of osteoclasts (cells that break down bone) with the aim of reducing bone disease when the cancer has spread to other parts of the body. These drugs can also help to lessen the risk of bone fracture with hormone therapy.[25]
A Western dietary pattern rich in animal-based protein, dairy products, and refined carbohydrates tends to be associated with an increased risk of prostate cancer, whereas a healthy plant-based dietary pattern (e.g., the Mediterranean diet) tends to be associated with a decreased risk of prostate cancer.[7][8] Concerning specific dietary factors, a notable body of evidence indicates that a high intake of dairy products is associated with an increased risk of prostate cancer,[7] while fairly consistent evidence indicates a high intake of lycopene from tomato products is associated with a decreased risk of prostate cancer.[9][10] Also, obesity increases the risk of advanced prostate cancer, so a hypocaloric diet that facilitates weight loss is often beneficial in this population.
The precise causes of prostate cancer are unclear, but they involve changes in the DNA of a normal prostate cell, which are either inherited or acquired throughout life. Several genes have been linked to prostate cancer (e.g., TMPRSS2-ERG, SPOP, FOXA1, BRCA1, BRCA2).[12] Additionally, the risk of prostate cancer is approximately doubled in men who are Black or have a first-degree relative with prostate cancer compared to the general population.[4] Acquired gene mutations are the result of errors in the DNA replication process, which occur at random or via the influence of other factors (e.g., diet, hormone levels, exposure to cancer-causing chemicals).[13]
Benign prostatic hyperplasia (BPH) refers to a noncancerous enlargement of the prostate gland. The prevalence of BPH and prostate cancer both increase with advancing age, and there are a number of overlapping features between these conditions, including hormone-dependent growth and increased PSA levels. Moreover, inflammation and metabolic syndrome are common risk factors and variants of several genes are associated with an increased risk of both conditions.[27][28]
The relationship between BPH and prostate cancer is not fully understood. Conflicting findings are common, but meta-analyses of observational studies tend to report an increased risk of prostate cancer with BPH.[29][30] However, a causal link between these conditions is far from established, and the association may be explained by the mere coexistence of two very common conditions,[31] rather than BPH being a risk factor for prostate cancer.
References
Examine Database References
- Prostate Cancer Risk - C J Paller, X Ye, P J Wozniak, B K Gillespie, P R Sieber, R H Greengold, B R Stockton, B L Hertzman, M D Efros, R P Roper, H R Liker, M A CarducciA randomized phase II study of pomegranate extract for men with rising PSA following initial therapy for localized prostate cancerProstate Cancer Prostatic Dis.(2013 Mar)
- Prostate Cancer Risk - Pantuck AJ, Leppert JT, Zomorodian N, Aronson W, Hong J, Barnard RJ, Seeram N, Liker H, Wang H, Elashoff R, Heber D, Aviram M, Ignarro L, Belldegrun APhase II study of pomegranate juice for men with rising prostate-specific antigen following surgery or radiation for prostate cancerClin Cancer Res.(2006 Jul 1)
- Prostate Cancer Risk - Heinonen OP, Albanes D, Virtamo J, Taylor PR, Huttunen JK, Hartman AM, Haapakoski J, Malila N, Rautalahti M, Ripatti S, Mäenpää H, Teerenhovi L, Koss L, Virolainen M, Edwards BKProstate cancer and supplementation with alpha-tocopherol and beta-carotene: incidence and mortality in a controlled trialJ Natl Cancer Inst.(1998 Mar 18)
- Prostate Cancer Risk - Lippman SM, Klein EA, Goodman PJ, Lucia MS, Thompson IM, Ford LG, Parnes HL, Minasian LM, Gaziano JM, Hartline JA, Parsons JK, Bearden JD 3rd, Crawford ED, Goodman GE, Claudio J, Winquist E, Cook ED, Karp DD, Walther P, Lieber MM, Kristal AR, Darke AK, Arnold KB, Ganz PA, Santella RM, Albanes D, Taylor PR, Probstfield JL, Jagpal TJ, Crowley JJ, Meyskens FL Jr, Baker LH, Coltman CA JrEffect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)JAMA.(2009 Jan 7)
- Prostate Cancer Risk - Klein EA, Thompson IM Jr, Tangen CM, Crowley JJ, Lucia MS, Goodman PJ, Minasian LM, Ford LG, Parnes HL, Gaziano JM, Karp DD, Lieber MM, Walther PJ, Klotz L, Parsons JK, Chin JL, Darke AK, Lippman SM, Goodman GE, Meyskens FL Jr, Baker LHVitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)JAMA.(2011 Oct 12)
- Prostate Cancer Risk - Choi YH, Han DH, Kim SW, Kim MJ, Sung HH, Jeon HG, Jeong BC, Seo SI, Jeon SS, Lee HM, Choi HYA randomized, double-blind, placebo-controlled trial to evaluate the role of curcumin in prostate cancer patients with intermittent androgen deprivationProstate.(2019 May)
- Prostate Cancer Risk - Hurst R, Hooper L, Norat T, Lau R, Aune D, Greenwood DC, Vieira R, Collings R, Harvey LJ, Sterne JA, Beynon R, Savovic J, Fairweather-Tait SJSelenium and prostate cancer: systematic review and meta-analysisAm J Clin Nutr.(2012 Jul)
- Prostate Specific Antigen - Ya-Feng Yang, Preety Babychen Mattamel, Tanya Joseph, Jian Huang, Qian Chen, Babatunde O Akinwunmi, Casper J P Zhang, Wai-Kit MingEfficacy of Low-Carbohydrate Ketogenic Diet as an Adjuvant Cancer Therapy: A Systematic Review and Meta-Analysis of Randomized Controlled TrialsNutrients.(2021 Apr 21)
- High-density lipoprotein (HDL) - Amanollahi A, Khazdouz M, Malekahmadi M, Klement RJ, Lee D, Khodabakhshi AEffect of Ketogenic Diets on Cardio-Metabolic Outcomes in Cancer Patients: A Systematic Review and Meta-Analysis of Controlled Clinical Trials.Nutr Cancer.(2023)
- Weight - Marzieh Taftian, Sara Beigrezaei, Vahid Arabi, Amin Salehi-AbargoueiThe Effect of Ketogenic Diet on Weight Loss in Adult Patients with Cancer: A Systematic Review and Meta-Analysis of Controlled Clinical TrialsNutr Cancer.(2022 Feb 7)
- Prostate Specific Antigen - lker Durak, PhD, Erdal Yılmaz, MD, Erdinç Devrim, MD, Hakkı Perk, MD, Murat Kaçmaz, MDConsumption of aqueous garlic extract leads to significant improvement in patients with benign prostate hyperplasia and prostate cancerNutrition Research.()