Prostate Cancer: Definition, Types, Causes, Symptoms, Preventions, And Treatments

What is the Prostate?

The prostate is a small gland that is part of the male reproductive system. It is located just below the bladder and in front of the rectum. The prostate surrounds the urethra, which is the tube that carries urine and semen out of the body.

The prostate gland is responsible for producing some of the fluids that make up semen, which is the fluid that carries sperm during ejaculation. The gland is made up of both glandular tissue, which produces the fluids, and muscular tissue, which helps to expel the fluids during ejaculation.

Prostate cancer begins when healthy cells in the prostate change and grow out of control, forming a tumour. A tumor can be cancerous or benign. A cancerous tumour is malignant, meaning it can grow and spread to other parts of the body. A benign tumour means the tumour can grow but will not spread. The biology of adenocarcinomas of the prostate is strongly influenced by tumour grade. Low-grade tumours may remain localized for long periods of time. The disease locally invades along nerve sheaths and metastasizes through lymphatic chains. Lymphatic vessels produce cytokines that stimulate tumour cells promoting chemotactic diffusion of tumour cells into lymphatics. Additionally, prostate tumours can secrete growth factors, creating new lymphatic vessels in a process known as lymphangiogenesis.

Types of Prostate Cancer

There are several types of prostate cancer, which are classified based on the appearance of the cancer cells under a microscope. Almost all prostate cancers are adenocarcinomas (95%), which develop in the gland cells that produce the fluid that makes up semen. Other types of prostate cancer are less common and include –

Small cell carcinoma

This is a rare and aggressive type of prostate cancer that can grow and spread quickly.

Transitional cell carcinoma

This type of prostate cancer develops in the cells that line the urethra, which is the tube that carries urine and semen out of the body.

Sarcomas and carcinomas of the prostate gland

These are very rare types of prostate cancer that develop in the non-glandular tissues of the prostate gland.

Neuroendocrine tumours

These are rare tumours that develop in the hormone-producing cells of the prostate gland.

Most prostate cancers are adenocarcinomas, and they tend to grow slowly and respond well to treatment if detected early. Other types of prostate cancer are less common, but they may be more aggressive and require different treatment approaches. Your healthcare provider can help determine the type of prostate cancer you have and recommend the most appropriate treatment plan for your specific situation.

Risk Factors of Prostate Cancer

Although the cause of prostate cancer is still unknown, there are several risk factors associated with prostate cancer, including –

Demography

The risk of developing prostate cancer is highest in Sweden, intermediate in the United States and Europe (and Japanese men who migrated to the United States), and lowest in Taiwan and Japan. Blacks are afflicted 30% more often than whites and Hispanics, and they often present with higher PSA levels, higher Gleason scores, and more advanced stages.

Positive familial history of prostate cancer

Positive familial history of prostate cancer in the father or brother of a subject increases his risk sevenfold over the general population if the affected relative was diagnosed by 50 years of age. The relative risk declines fourfold if the diagnosis of the first-degree relative was made after 70 years of age.

BRCA1 or BRCA2 mutations

BRCA2 mutations in families have been associated with a five-fold increased risk of prostate cancer when compared with the general population. Additionally, it is associated with a higher Gleason score and poorer prognosis. BRCA1 mutations are associated with a younger age of diagnosis (age < 65) and have a twofold increased risk of prostate cancer.

Hormones

Altered estrogen and androgen metabolite levels have been suggested as a causative mechanism leading to prostate cancer occurrence and have provided a rationale for clinical trials such as the Prostate Cancer Prevention Trial, which used finasteride to block the conversion of testosterone to its more active form dihydrotestosterone.

Other suggested risk factors

Increased intake of vitamin A, decreased intake of vitamin D, obesity, increased intake of animal fats (alpha-linolenic acid component), and occupational exposure to cadmium. These risk factors are not fully established.

Having one or more of these risk factors does not mean that a man will definitely develop prostate cancer, and some men without any risk factors may still develop the disease. However, being aware of these risk factors can help men make informed decisions about their healthcare and whether or not to undergo regular prostate cancer screening.

Symptoms of Prostate Cancer

Currently, most patients with CAP are asymptomatic at diagnosis.

  1. Early prostatic cancer is usually asymptomatic and can be detected as a result of routine digital rectal examination (DRE). It is mainly discovered by serum PSA measurement or, rarely, during TURP for glandular hyperplasia. The presence of severe symptoms usually indicates advanced disease. Symptoms include hesitancy, urgency, nocturia, poor urine stream, dribbling, hematospermia, and terminal hematuria.
  2. The sudden onset and rapid progression of symptoms of urinary tract obstruction in men of the appropriate age are often caused by prostate cancer.
  3. Pain in the back, pelvis, or over multiple bony sites is the most common presenting complaint in patients with distant metastases.
  4. The sudden onset of neurologic deficiencies, such as paraplegia and incontinence resulting from extradural spinal metastases with cord compression, maybe a presenting feature or may develop during the course of the disease.

Diagnoses of Prostate Cancer

There are several procedures used to detect and diagnose prostate cancer, including –

Physical examination:

  • Check for asymmetrical induration or nodularity of the prostate, which often represents prostatic cancer. Frank nodules of prostatic cancer are typically stony hard and not tender.
  • Examine lateral sulci and palpable (abnormal) seminal vesicles.
  • Evaluate inguinal nodes for metastatic disease.
  • Evaluate for distant metastases by palpating the skeleton for tender foci and by performing an oriented neurologic examination looking for spinal cord compression.

Prostate-specific antigen (PSA) test:

PSA is a protein released by prostate tissue that is found in higher levels in the blood. Levels can be raised when there is abnormal activity in the prostate, including prostate cancer, benign prostatic hypertrophy (BPH), or inflammation of the prostate. Doctors can look at features of the PSA value to decide if a biopsy is needed, such as absolute level, change over time (also known as “PSA velocity”), and level in relation to prostate size.

Free PSA:

It is the fraction of PSA that is not bound to the plasma antiproteases a1-antichymotrypsin and a2-macroglobulin. A decreased ratio of free PSA to total PSA is associated with an increased probability of prostate cancer. For patients with elevated PSA and no abnormal findings on palpation of the prostate, conservative management with PSA monitoring is recommended after one negative biopsy if the free-to-total PSA ratio is >25%.

Biopsy techniques:

  • TRUS-guided true-cut biopsy is the standard method to diagnose prostate cancer. A six to twelve-core biopsy under local anaesthesia is taken by sampling the base, apex, and mid gland on each side of the gland along two parallel lateral lines. Some cancers have a hypoechoic appearance on TRUS, although the majority of cancers may be isoechoic. When the indication for TRUS-guided biopsy is a PSA > 4 ng/mL, the expected yield for diagnosing prostate cancer reaches 24%. When PSA is >4 ng/mL, the DRE is suspicious, and a hypoechoic lesion is imaged by TRUS, the yield rises to 45%.
  • TURP: Prostate cancer may be found in approximately 5% of TURP performed for benign hyperplasia.

CT scans and MRIs:

These are used to assess tumours spread into lymph nodes or the pelvis. These studies are warranted in high-risk patients who have a tumour that is confluent with the pelvic side wall on DRE, a high Gleason score (see tumour grading in Section IV.B.1), or PSA > 20 ng/mL.

Preventions and Treatments for Prostate Cancer

Preventions to be considered are as follows

There is no sure way to prevent prostate cancer, but there are some steps that may reduce the risk of developing the disease or help detect it at an early stage –

  • Eat a healthy diet: A diet that is low in fat and high in fruits and vegetables may help reduce the risk of prostate cancer.
  • Maintain a healthy weight: Obesity has been linked to an increased risk of prostate cancer, so maintaining a healthy weight may help reduce the risk.
  • Exercise regularly: Regular physical activity has been associated with a reduced risk of prostate cancer.
  • Don’t smoke: Smoking has been linked to an increased risk of prostate cancer, so avoiding tobacco products may help reduce the risk.
  • Get screened regularly: Regular screening for prostate cancer, including PSA tests and DREs, can help detect the disease at an early stage when it is more treatable.
  • Consider genetic counselling: Men with a family history of prostate cancer or certain genetic mutations may benefit from genetic counselling and testing to determine their risk of developing the disease.

Treatments required for Prostate Cancer

The treatment options for prostate cancer depend on several factors, including the stage and aggressiveness of cancer, the patient’s overall health, and their preferences. The main treatment options for prostate cancer include –

It implies that definitive local therapy is no longer under consideration as a management option. It is often the best option for patients with limited life expectancy. With watchful waiting, routine PSA tests, DRE, and biopsies are not usually done. If the prostate cancer causes symptoms, such as pain or blockage of the urinary tract, then treatment may be recommended to relieve those symptoms.

It also defers the application of definitive local therapy such as radical prostatectomy or radiation. However, a key difference from watchful waiting, is that the disease is actively monitored, and patients with signs of disease progression are treated with curative intent. It is generally used in younger men with low risk disease to defer treatment and their side effects. With active surveillance, PSAs can be monitored twice a year and tumor histology is re-evaluated with prostate biopsies every 1 to 3 years. Although the criteria for recommending active surveillance are evolving, there is a clear consensus that patients in the very low and low risk categories can safely undergo active surveillance. The latest version of the National Comprehensive Cancer Network guidelines recommends that some patients in the intermediate risk category can also undergo active surveillance.

Surgery involves the removal of the prostate and some surrounding lymph nodes during an operation. A surgical oncologist is a doctor who specializes in treating cancer using surgery. For prostate cancer, a urologist or urologic oncologist is the surgical oncologist involved in treatment. The type of surgery depends on the stage of the disease, the patient’s overall health, and other factors.

  • Radical (open) prostatectomy. A radical prostatectomy is the surgical removal of the entire prostate and the seminal vesicles. Lymph nodes in the pelvic area may also be removed. This operation has the risk of affecting sexual function. Nerve-sparing surgery, when possible, increases the chance that the patient can maintain sexual function after surgery by avoiding surgical damage to the nerves that allow erections and orgasm to occur. Orgasm can occur even if some nerves are cut because these are separate processes. Urinary incontinence is also a possible side effect of radical prostatectomy. To help resume normal sexual function, drugs, penile implants, or injections may be recommended. Sometimes, another surgery can fix urinary incontinence.
  • Robotic or laparoscopic prostatectomy. This type of surgery is less invasive than a radical prostatectomy and may shorten recovery time. A camera and instruments are inserted through small keyhole incisions in the patient’s abdomen. The surgeon then directs the robotic instruments to remove the prostate gland. In general, robotic prostatectomy causes less bleeding and less pain, but the sexual and urinary side effects are similar to those of a radical (open) prostatectomy. Talk with your doctor about whether your treatment center offers this procedure and how it compares with the results of the radical (open) prostatectomy.
  • Bilateral orchiectomy. Bilateral orchiectomy is the surgical removal of both testicles.
  • Transurethral resection of the prostate (TURP). TURP is most often used to relieve symptoms of a urinary blockage, not to treat prostate cancer. In this procedure, with the patient under full anaesthesia, which is medication to block the awareness of pain, a surgeon inserts a narrow tube with a cutting device called a cystoscope into the urethra and then into the prostate to remove prostate tissue.

Radiation therapy is the use of high-energy rays to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. Two types of radiation therapies for treating prostate cancer –

  • External-beam radiation therapy: This therapy includes hypo-fractionated radiation therapy. This is when a person receives a higher daily dose of radiation therapy given over a shorter period, instead of lower doses given over a longer period. Extreme hypo-fraction radiation therapy is when the entire treatment is delivered in 5 or fewer treatments. Moderate hypo-fraction radiation therapy regimens typically include 20 to 28 treatments. This is also called stereotactic body radiation therapy (SBRT) or stereotactic ablative radiation therapy (SABR).
  • Brachytherapy: Brachytherapy, or internal radiation therapy, is the insertion of radioactive sources directly into the prostate. These sources, called seeds, give off radiation just around the area where they are inserted and may be left for a short time (high-dose rate) or for a longer time (low-dose rate). Low-dose-rate seeds are left in the prostate permanently and work for up to 1 year after they are inserted. However, how long they work depends on the source of radiation. High-dose-rate brachytherapy is usually left in the body for less than 30 minutes, but it may need to be given more than once.

Focal therapies are less-invasive treatments that destroy small prostate tumours without treating the rest of the prostate gland. These treatments use heat, cold, and other methods to treat cancer, mostly for low-risk or intermediate-risk prostate cancer. Focal therapies are being studied in clinical trials. Most have not been approved as standard treatment options.

  • Cryosurgery: Cryosurgery, also called cryotherapy or cryoablation, involves freezing cancer cells with a metal probe inserted through a small incision in the area between the rectum and the scrotum, the skin sac that contains the testicles. It is not an established therapy or standard of care to treat newly diagnosed prostate cancer. Cryosurgery has not been compared with radical prostatectomy or radiation therapy, so doctors do not know if it is a comparable treatment option. Its effects on urinary and sexual function are also not well known.
  • High-intensity focused ultrasound (HIFU): HIFU is a heat-based type of focal therapy. During HIFU treatment, an ultrasound probe is inserted into the rectum and then sound waves are directed at parts of the prostate gland with cancer. This treatment is designed to destroy cancer cells while limiting damage to the rest of the prostate gland. The FDA approved HIFU for the treatment of prostate tissue in 2015. HIFU may be an attractive option for some people, but knowing who may benefit most from this treatment is still unknown. HIFU should only be performed by a specialist with a lot of expertise. You will need to carefully discuss with your doctor if HIFU is the best treatment for you.

References:

  • Manual of Clinical Oncology by Bartosz Chmeilowski and Mary Territo
  • cancer.net 

What is the Prostate?

The prostate is a small gland that is part of the male reproductive system. It is located just below the bladder and in front of the rectum. The prostate surrounds the urethra, which is the tube that carries urine and semen out of the body.

The prostate gland is responsible for producing some of the fluids that make up semen, which is the fluid that carries sperm during ejaculation. The gland is made up of both glandular tissue, which produces the fluids, and muscular tissue, which helps to expel the fluids during ejaculation.

Prostate cancer begins when healthy cells in the prostate change and grow out of control, forming a tumour. A tumor can be cancerous or benign. A cancerous tumour is malignant, meaning it can grow and spread to other parts of the body. A benign tumour means the tumour can grow but will not spread. The biology of adenocarcinomas of the prostate is strongly influenced by tumour grade. Low-grade tumours may remain localized for long periods of time. The disease locally invades along nerve sheaths and metastasizes through lymphatic chains. Lymphatic vessels produce cytokines that stimulate tumour cells promoting chemotactic diffusion of tumour cells into lymphatics. Additionally, prostate tumours can secrete growth factors, creating new lymphatic vessels in a process known as lymphangiogenesis.

Types of Prostate Cancer

There are several types of prostate cancer, which are classified based on the appearance of the cancer cells under a microscope. Almost all prostate cancers are adenocarcinomas (95%), which develop in the gland cells that produce the fluid that makes up semen. Other types of prostate cancer are less common and include –

Small cell carcinoma

This is a rare and aggressive type of prostate cancer that can grow and spread quickly.

Transitional cell carcinoma

This type of prostate cancer develops in the cells that line the urethra, which is the tube that carries urine and semen out of the body.

Sarcomas and carcinomas of the prostate gland

These are very rare types of prostate cancer that develop in the non-glandular tissues of the prostate gland.

Neuroendocrine tumours

These are rare tumours that develop in the hormone-producing cells of the prostate gland.

Most prostate cancers are adenocarcinomas, and they tend to grow slowly and respond well to treatment if detected early. Other types of prostate cancer are less common, but they may be more aggressive and require different treatment approaches. Your healthcare provider can help determine the type of prostate cancer you have and recommend the most appropriate treatment plan for your specific situation.

Risk Factors of Prostate Cancer

Although the cause of prostate cancer is still unknown, there are several risk factors associated with prostate cancer, including –

Demography

The risk of developing prostate cancer is highest in Sweden, intermediate in the United States and Europe (and Japanese men who migrated to the United States), and lowest in Taiwan and Japan. Blacks are afflicted 30% more often than whites and Hispanics, and they often present with higher PSA levels, higher Gleason scores, and more advanced stages.

Positive familial history of prostate cancer

Positive familial history of prostate cancer in the father or brother of a subject increases his risk sevenfold over the general population if the affected relative was diagnosed by 50 years of age. The relative risk declines fourfold if the diagnosis of the first-degree relative was made after 70 years of age.

BRCA1 or BRCA2 mutations

BRCA2 mutations in families have been associated with a five-fold increased risk of prostate cancer when compared with the general population. Additionally, it is associated with a higher Gleason score and poorer prognosis. BRCA1 mutations are associated with a younger age of diagnosis (age < 65) and have a twofold increased risk of prostate cancer.

Hormones

Altered estrogen and androgen metabolite levels have been suggested as a causative mechanism leading to prostate cancer occurrence and have provided a rationale for clinical trials such as the Prostate Cancer Prevention Trial, which used finasteride to block the conversion of testosterone to its more active form dihydrotestosterone.

Other suggested risk factors

Increased intake of vitamin A, decreased intake of vitamin D, obesity, increased intake of animal fats (alpha-linolenic acid component), and occupational exposure to cadmium. These risk factors are not fully established.

Having one or more of these risk factors does not mean that a man will definitely develop prostate cancer, and some men without any risk factors may still develop the disease. However, being aware of these risk factors can help men make informed decisions about their healthcare and whether or not to undergo regular prostate cancer screening.

Symptoms of Prostate Cancer

Currently, most patients with CAP are asymptomatic at diagnosis.

  1. Early prostatic cancer is usually asymptomatic and can be detected as a result of routine digital rectal examination (DRE). It is mainly discovered by serum PSA measurement or, rarely, during TURP for glandular hyperplasia. The presence of severe symptoms usually indicates advanced disease. Symptoms include hesitancy, urgency, nocturia, poor urine stream, dribbling, hematospermia, and terminal hematuria.
  2. The sudden onset and rapid progression of symptoms of urinary tract obstruction in men of the appropriate age are often caused by prostate cancer.
  3. Pain in the back, pelvis, or over multiple bony sites is the most common presenting complaint in patients with distant metastases.
  4. The sudden onset of neurologic deficiencies, such as paraplegia and incontinence resulting from extradural spinal metastases with cord compression, maybe a presenting feature or may develop during the course of the disease.

Diagnoses of Prostate Cancer

There are several procedures used to detect and diagnose prostate cancer, including –

Physical examination:

  • Check for asymmetrical induration or nodularity of the prostate, which often represents prostatic cancer. Frank nodules of prostatic cancer are typically stony hard and not tender.
  • Examine lateral sulci and palpable (abnormal) seminal vesicles.
  • Evaluate inguinal nodes for metastatic disease.
  • Evaluate for distant metastases by palpating the skeleton for tender foci and by performing an oriented neurologic examination looking for spinal cord compression.

Prostate-specific antigen (PSA) test:

PSA is a protein released by prostate tissue that is found in higher levels in the blood. Levels can be raised when there is abnormal activity in the prostate, including prostate cancer, benign prostatic hypertrophy (BPH), or inflammation of the prostate. Doctors can look at features of the PSA value to decide if a biopsy is needed, such as absolute level, change over time (also known as “PSA velocity”), and level in relation to prostate size.

Free PSA:

It is the fraction of PSA that is not bound to the plasma antiproteases a1-antichymotrypsin and a2-macroglobulin. A decreased ratio of free PSA to total PSA is associated with an increased probability of prostate cancer. For patients with elevated PSA and no abnormal findings on palpation of the prostate, conservative management with PSA monitoring is recommended after one negative biopsy if the free-to-total PSA ratio is >25%.

Biopsy techniques:

  • TRUS-guided true-cut biopsy is the standard method to diagnose prostate cancer. A six to twelve-core biopsy under local anaesthesia is taken by sampling the base, apex, and mid gland on each side of the gland along two parallel lateral lines. Some cancers have a hypoechoic appearance on TRUS, although the majority of cancers may be isoechoic. When the indication for TRUS-guided biopsy is a PSA > 4 ng/mL, the expected yield for diagnosing prostate cancer reaches 24%. When PSA is >4 ng/mL, the DRE is suspicious, and a hypoechoic lesion is imaged by TRUS, the yield rises to 45%.
  • TURP: Prostate cancer may be found in approximately 5% of TURP performed for benign hyperplasia.

CT scans and MRIs:

These are used to assess tumours spread into lymph nodes or the pelvis. These studies are warranted in high-risk patients who have a tumour that is confluent with the pelvic side wall on DRE, a high Gleason score (see tumour grading in Section IV.B.1), or PSA > 20 ng/mL.

Preventions and Treatments for Prostate Cancer

Preventions to be considered are as follows

There is no sure way to prevent prostate cancer, but there are some steps that may reduce the risk of developing the disease or help detect it at an early stage –

  • Eat a healthy diet: A diet that is low in fat and high in fruits and vegetables may help reduce the risk of prostate cancer.
  • Maintain a healthy weight: Obesity has been linked to an increased risk of prostate cancer, so maintaining a healthy weight may help reduce the risk.
  • Exercise regularly: Regular physical activity has been associated with a reduced risk of prostate cancer.
  • Don’t smoke: Smoking has been linked to an increased risk of prostate cancer, so avoiding tobacco products may help reduce the risk.
  • Get screened regularly: Regular screening for prostate cancer, including PSA tests and DREs, can help detect the disease at an early stage when it is more treatable.
  • Consider genetic counselling: Men with a family history of prostate cancer or certain genetic mutations may benefit from genetic counselling and testing to determine their risk of developing the disease.

Treatments required for Prostate Cancer

The treatment options for prostate cancer depend on several factors, including the stage and aggressiveness of cancer, the patient’s overall health, and their preferences. The main treatment options for prostate cancer include –

It implies that definitive local therapy is no longer under consideration as a management option. It is often the best option for patients with limited life expectancy. With watchful waiting, routine PSA tests, DRE, and biopsies are not usually done. If the prostate cancer causes symptoms, such as pain or blockage of the urinary tract, then treatment may be recommended to relieve those symptoms.

It also defers the application of definitive local therapy such as radical prostatectomy or radiation. However, a key difference from watchful waiting, is that the disease is actively monitored, and patients with signs of disease progression are treated with curative intent. It is generally used in younger men with low risk disease to defer treatment and their side effects. With active surveillance, PSAs can be monitored twice a year and tumor histology is re-evaluated with prostate biopsies every 1 to 3 years. Although the criteria for recommending active surveillance are evolving, there is a clear consensus that patients in the very low and low risk categories can safely undergo active surveillance. The latest version of the National Comprehensive Cancer Network guidelines recommends that some patients in the intermediate risk category can also undergo active surveillance.

Surgery involves the removal of the prostate and some surrounding lymph nodes during an operation. A surgical oncologist is a doctor who specializes in treating cancer using surgery. For prostate cancer, a urologist or urologic oncologist is the surgical oncologist involved in treatment. The type of surgery depends on the stage of the disease, the patient’s overall health, and other factors.

  • Radical (open) prostatectomy. A radical prostatectomy is the surgical removal of the entire prostate and the seminal vesicles. Lymph nodes in the pelvic area may also be removed. This operation has the risk of affecting sexual function. Nerve-sparing surgery, when possible, increases the chance that the patient can maintain sexual function after surgery by avoiding surgical damage to the nerves that allow erections and orgasm to occur. Orgasm can occur even if some nerves are cut because these are separate processes. Urinary incontinence is also a possible side effect of radical prostatectomy. To help resume normal sexual function, drugs, penile implants, or injections may be recommended. Sometimes, another surgery can fix urinary incontinence.
  • Robotic or laparoscopic prostatectomy. This type of surgery is less invasive than a radical prostatectomy and may shorten recovery time. A camera and instruments are inserted through small keyhole incisions in the patient’s abdomen. The surgeon then directs the robotic instruments to remove the prostate gland. In general, robotic prostatectomy causes less bleeding and less pain, but the sexual and urinary side effects are similar to those of a radical (open) prostatectomy. Talk with your doctor about whether your treatment center offers this procedure and how it compares with the results of the radical (open) prostatectomy.
  • Bilateral orchiectomy. Bilateral orchiectomy is the surgical removal of both testicles.
  • Transurethral resection of the prostate (TURP). TURP is most often used to relieve symptoms of a urinary blockage, not to treat prostate cancer. In this procedure, with the patient under full anaesthesia, which is medication to block the awareness of pain, a surgeon inserts a narrow tube with a cutting device called a cystoscope into the urethra and then into the prostate to remove prostate tissue.

Radiation therapy is the use of high-energy rays to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. Two types of radiation therapies for treating prostate cancer –

  • External-beam radiation therapy: This therapy includes hypo-fractionated radiation therapy. This is when a person receives a higher daily dose of radiation therapy given over a shorter period, instead of lower doses given over a longer period. Extreme hypo-fraction radiation therapy is when the entire treatment is delivered in 5 or fewer treatments. Moderate hypo-fraction radiation therapy regimens typically include 20 to 28 treatments. This is also called stereotactic body radiation therapy (SBRT) or stereotactic ablative radiation therapy (SABR).
  • Brachytherapy: Brachytherapy, or internal radiation therapy, is the insertion of radioactive sources directly into the prostate. These sources, called seeds, give off radiation just around the area where they are inserted and may be left for a short time (high-dose rate) or for a longer time (low-dose rate). Low-dose-rate seeds are left in the prostate permanently and work for up to 1 year after they are inserted. However, how long they work depends on the source of radiation. High-dose-rate brachytherapy is usually left in the body for less than 30 minutes, but it may need to be given more than once.

Focal therapies are less-invasive treatments that destroy small prostate tumours without treating the rest of the prostate gland. These treatments use heat, cold, and other methods to treat cancer, mostly for low-risk or intermediate-risk prostate cancer. Focal therapies are being studied in clinical trials. Most have not been approved as standard treatment options.

  • Cryosurgery: Cryosurgery, also called cryotherapy or cryoablation, involves freezing cancer cells with a metal probe inserted through a small incision in the area between the rectum and the scrotum, the skin sac that contains the testicles. It is not an established therapy or standard of care to treat newly diagnosed prostate cancer. Cryosurgery has not been compared with radical prostatectomy or radiation therapy, so doctors do not know if it is a comparable treatment option. Its effects on urinary and sexual function are also not well known.
  • High-intensity focused ultrasound (HIFU): HIFU is a heat-based type of focal therapy. During HIFU treatment, an ultrasound probe is inserted into the rectum and then sound waves are directed at parts of the prostate gland with cancer. This treatment is designed to destroy cancer cells while limiting damage to the rest of the prostate gland. The FDA approved HIFU for the treatment of prostate tissue in 2015. HIFU may be an attractive option for some people, but knowing who may benefit most from this treatment is still unknown. HIFU should only be performed by a specialist with a lot of expertise. You will need to carefully discuss with your doctor if HIFU is the best treatment for you.

References:

  • Manual of Clinical Oncology by Bartosz Chmeilowski and Mary Territo
  • cancer.net 

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