What Is Prostate Cancer?

Prostate cancer develops in the prostate gland when healthy cells change (mutate) and begin to grow and divide uncontrollably, forming a tumor. The prostate gland is an organ present in people assigned male at birth that helps with the production of semen. It is located below the bladder and in front of the rectum.

Researchers don’t know the exact cause of prostate cancer, but certain risk factors like age, family history, race, and geographical location can increase your odds of developing the disease. About 1 in 8 people assigned male at birth will develop prostate cancer in their lifetime. 

Early-stage prostate cancer does not usually cause symptoms. However, as the disease progresses, urinary symptoms such as frequent urination and a weak urine stream can occur. Prostate cancer is often detected through routine screening tests and diagnosis is confirmed through imaging tests and biopsy procedures. Treatment options for prostate cancer vary based on the type and stage of the disease. There are a number of treatment options available for early- and advanced-stage prostate cancer. 

This article discusses what we know about prostate cancer types, symptoms, diagnosis, and treatments. 

Types of Prostate Cancer

Prostate cancers are grouped based on the type of cell they start in. After a biopsy procedure, doctors examine the cancer cells under a microscope to learn the type of prostate cancer a person has. This information helps your cancer care team determine the best course of treatment. Prostate cancer types include: 

• Adenocarcinoma: The vast majority of prostate cancers are adenocarcinomas. These tumors form in the glandular cells that make prostate fluid. There are two types of adenocarcinoma: acinar adenocarcinoma and ductal adenocarcinoma. Acinar adenocarcinoma develops in the glandular cells that line the prostate. Ductal adenocarcinoma develops in the cells that line the tubes of the prostate and usually grows and spreads more quickly than acinar adenocarcinoma. 
• Transitional cell carcinoma: Also known as urothelial carcinoma, this type of tumor begins in the urethra (the tube that carries urine from the bladder to outside of the body) and spreads to the prostate gland. It can also begin in the prostate itself, but this is more rare. Between 2-4% of all prostate cancers are transitional cell carcinomas. 
• Small cell carcinoma: Small cell prostate cancer is a rare and aggressive form of prostate cancer that starts in the neuroendocrine cells of the prostate. Less than 2% of prostate cancers are small cell carcinomas. 
• Squamous cell carcinoma: Squamous cell carcinoma is an aggressive type of prostate cancer that starts in the flat cells that line the prostate gland. Less than 1% of prostate cancers are squamous cell carcinomas.

Symptoms

Most prostate cancers do not cause symptoms in the early stages. Many symptoms of prostate cancer are related to the urinary tract because of where the prostate is located in the body—just below the bladder in the lower pelvis, wrapped around the first part of the urethra.

When prostate cancer does cause symptoms, they can include: 

• Frequent urination: Urinating more often than usual
• Nocturia: Excessive nighttime urination 
• Urinary urgency: A sudden, urgent need to pee 
• Difficulty urinating: A weak or interrupted urine stream 
• Erectile dysfunction: Difficulty getting or maintaining an erection 
• Painful ejaculation: Mild to severe pain may be felt in the penis, rectum, testes, or lower abdomen 
• Blood in the urine or semen: Occurs when the prostate gland puts pressure on the urethra and nearby blood vessels

If prostate cancer metastasizes (spreads) to other parts of the body, additional symptoms can occur:

• Pain in the back, hips or chest: Occurs when prostate cancer spreads to the bones
• Swelling in the legs or feet: Occurs when prostate cancer spreads to the pelvic lymph nodes 
• Unintentional weight loss: Cancer cells burn more of the body’s energy
• Numbness and weakness in the limbs: Occurs when prostate cancer spread to the spine and compresses the spinal cord 

What Causes Prostate Cancer?

Prostate cancer occurs when healthy cells in the prostate gland mutate (change), causing the cells to behave abnormally. The cells begin to grow and divide out of control and form a tumor. Some gene mutations are acquired, meaning they happen at random and are not passed down through families. Most gene mutations linked to prostate cancer are acquired, but the reason why these mutations occur is not fully understood. 

Some gene mutations are inherited, meaning they are passed down from generation to generation. Inherited gene mutations account for about 10% of all prostate cancers. Lynch syndrome, for example, is an inherited cancer syndrome that increases the risk of prostate cancer and many other types of cancer. Prostate cancer is linked to inherited mutations on several different genes, including BRCA1 and BRCA2, RNASEL, HOXB13, MSH2, MSH6, MLH1, and PMS2. 

Prostate Cancer Risk Factors

Not everyone with inherited or acquired gene mutations will develop prostate cancer. Certain risk factors are known to increase the risk of the disease, including:

• Age: Prostate cancer is more common in older adults 
• Race and ethnicity: The incidence of prostate cancer is higher in African Americans and in Caribbeans with African ancestry. It is less common in Asian Americans and Hispanics/Latinos compared to non-Hispanic whites. The reasons for these differences has not yet been identified.
• Geographical location: The incidence of prostate cancer is higher in some parts of the world, including North and Western Europe, Australia, North America, the Caribbean islands, and South Africa. 
• Family history: Having a relative with a history of prostate cancer is associated with a higher risk of the disease.

How Is Prostate Cancer Diagnosed?

Prostate cancer is often detected before it causes symptoms through routine screening tests:

• Prostate-specific antigen (PSA) blood test: Measures the amount of PSA in the blood, which is a protein made by cells in the prostate gland. Cancer cells produce more PSA than noncancerous cells, so higher levels may be a sign of prostate cancer. 
• Digital rectal exam (DRE): Healthcare providers perform a DRE during routine check-ups in people with a prostate after age 50, or sooner in those with known risk factors. During the exam, the provider inserts a gloved, lubricated finger into the anus to feel the prostate and check for lumps and hard areas. 

If your healthcare provider suspects you may have prostate cancer or you have symptoms of the disease, further tests and procedures may be ordered: 

• Transrectal ultrasound (TRUS): This is an imaging test that uses sound waves to take pictures of the prostate to look for signs of cancer.
• Prostate biopsy: A small tissue sample is removed from the prostate and examined under a microscope in the lab to check for cancer cells.
• MRI fusion biopsy: Combines a magnetic resonance imaging (MRI) scan, transrectal ultrasound (TRUS), and biopsy into one procedure to take pictures of the prostate and surrounding tissues and obtain a tissue sample that will be analyzed in the lab to look for cancer cells. 
• Multiparametric MRI (mp-MRI): A standard MRI is performed in combination with another type of MRI (e.g., diffusion weighted imaging) to take pictures of the prostate and nearby tissues. Pictures from both scans are compared to look for signs of cancer. 

Stages of Prostate Cancer 

After evaluating your tests and biopsies, an oncologist (a doctor who specializes in cancer) will stage the disease. Prostate cancer is staged based on where the cancer is located, the size of the tumor, whether it has spread, and how far in the body it has spread.

There are two types of prostate cancer staging: 

• Clinical: Done at the time of diagnosis and is based on the results of your tests and procedures.
• Pathologic: After the prostate is removed during surgery, it is examined in the lab so the oncologist can learn more about your specific type of prostate cancer and recommend the most effective treatments. 

There are 4 stages of prostate cancer, and each stage is further divided into substages. The main stages of prostate cancer include: 

• Stage 1: Cancer is confined to one half of one side of the prostate and is low-risk (slow growing). 
• Stage 2: Cancer is confined to the prostate and the tumor is small but is at risk of growing and spreading. 
• Stage 3: Cancer has spread outside of the prostate gland into nearby tissues or organs (e.g., bladder, rectum, pelvic lymph nodes). 
• Stage 4: Cancer is advanced and has spread beyond the prostate to other, more distant areas of the body.

Treatments 

Prostate cancer is highly curable when detected in its early stages. If prostate cancer is diagnosed in later stages or has returned (recurrence), treatments may be focused on preventing the growth and spread of cancer cells to prolong life and manage symptoms. 

Treatments for prostate cancer depend on the type and stage of the disease, your overall health, and personal preferences.

Active Surveillance 

Active surveillance is a treatment approach that may be recommended for prostate cancers that are slow-growing and considered low-risk. This involves holding off on treatment until the disease progresses. Regular examinations, imaging tests, and biopsies will be performed to check for signs that the disease has advanced.

Surgery 

Surgery to remove the prostate gland—and sometimes the seminal vesicles and pelvic lymph nodes—is a common treatment for prostate cancer. 

There are several types of surgical procedures that may be performed, depending on the stage of the disease and your overall health. These procedures include open surgery (making an incision in the abdomen) and laparoscopic (making several small incisions). Laparoscopic procedures are less invasive and recovery is usually faster.

Radiation Therapy 

Radiation therapy uses high-energy X-rays (radiation) to kill cancer cells and prevent them from growing and spreading. There are different types of radiation therapy used to treat prostate cancer, including external-beam radiation therapy and internal radiation. 

• External-beam radiation therapy uses a machine outside of the body to focus radiation directly on the tumor. 
• Internal radiation involves placing radioactive ‘seeds’ into the prostate gland to destroy cancer cells.

Hormone Therapy 

Prostate cancer cells use sex hormones, such as testosterone, as fuel to grow and spread. Hormone therapy blocks the production of sex hormones or reduces levels of these hormones to ‘starve’ the cancer cells so they die. 

Hormone therapy may be given as an oral medication or placed in the body through an injection. More rarely, surgical castration removes the testicles to cease all hormone production.

Chemotherapy

Chemotherapy (often called “chemo”) uses anti-cancer drugs to destroy cancer cells anywhere in the body. Chemo is not a curative treatment for prostate cancer, and may be recommended as an option for more advanced prostate cancers to stop the growth of cancer cells to prolong a person’s life and manage symptoms.

Immunotherapy

Immunotherapy, also known as biological therapy, uses medicines tailored for each individual person to stimulate the body’s immune system to fight cancer cells. Advanced prostate cancer that causes few symptoms and has stopped responding to hormone therapy is sometimes treated with Provenge (sipuleucel-T), a type of vaccine immunotherapy.

Targeted Therapy 

Targeted therapy uses drugs that identify and kill specific cancer cells without damaging healthy cells. poly (ADP-ribose) polymerase inhibitors, or PARP inhibitors, are a targeted therapy used to treat prostate cancers linked to BRCA gene mutations. These drugs prevent cancer cells from repairing their damaged DNA, which leads to death of the cells.

How to Prevent Prostate Cancer 

There is no guaranteed way to prevent prostate cancer. Like all cancers, there are certain risk factors for prostate cancer that cannot be changed, like your age, family history, and ethnicity. However, adopting healthy lifestyle habits may help lower your risk.

• Eat a healthy diet: Research on the link between diet and prostate cancer is inconclusive, but some studies suggest that eating a diet high in calcium (which is found in many forms of dairy), red meats, and processed foods may increase the risk of prostate cancer. Aim to eat a nutritious, balanced diet rich in fruits, vegetables, and whole grains. 
• Get regular exercise: Staying physically active can improve immune function and reduce inflammation, which may lower the risk of prostate cancer. 
• Maintain a healthy body weight: Obesity has been linked to more aggressive forms of prostate cancer and an increased risk of death. Maintaining a healthy body weight may help lower your chances of developing the disease. 

Comorbid Conditions

Having prostate cancer can increase the risk of developing other health conditions, including:

• Other cancers: People who have had prostate cancer are at an increased risk of small intestine cancer, soft tissue cancer, bladder cancer, thyroid cancer, thymus cancer, and melanoma (skin cancer). 
• Osteoporosis: Bone loss is a common side effect of hormone therapy treatment for prostate cancer. This can lead to an increased risk of osteoporosis and bone fractures. 
• Heart disease: Research shows that cancer survivors are at a significantly increased risk of cardiovascular (heart) disease, particularly heart failure and stroke. 
• Diabetes: Hormone therapy used to treat prostate cancer can elevate the risk of diabetes. 

Living With Prostate Cancer

When you’re living with prostate cancer, every part of your life can be affected—relationships, career, finances, and more. To help yourself cope, you may want to learn as much as you can about treatments and side effects so you can take an active role in your care. Sharing your concerns with your healthcare providers and leaning on family and friends for support can help, too. Some people with prostate cancer find it helpful to join prostate cancer support groups to talk with others who understand what living with the disease is like. 

Thanks to advancements in screening tests and treatments, most people with prostate cancer survive. In fact, the 5-year survival rate for early-stage prostate cancers is 100%, and almost 97% overall (including advanced prostate cancers). Most prostate cancer survivors—and even people living with the disease—are able to have fulfilling lives.