What is Prostate Cancer? Causes and Treatment Explained

Prostate cancer is a disease where abnormal cells grow uncontrollably in the prostate gland, a walnut-sized organ in men that produces fluid for semen. It is one of the most common cancers in men, with more than 288,000 new cases diagnosed in the United States each year. Most prostate cancers grow slowly and remain confined to the prostate, though some can spread aggressively to other parts of the body.

What Causes Prostate Cancer?

The exact cause of prostate cancer is not fully understood, but it begins when cells in the prostate develop mutations in their DNA. These mutations cause cells to grow and divide faster than normal cells, and they continue living when other cells would die.

Age is the strongest risk factor. About 60% of prostate cancers are diagnosed in men over 65. Family history matters too — having a father or brother with prostate cancer more than doubles your risk. Black men develop prostate cancer at higher rates than other racial groups and are more likely to have aggressive forms of the disease.

Obesity appears to increase the risk of aggressive prostate cancer specifically, not all types. Studies have found that men with higher body mass index are more likely to develop cancer that spreads beyond the prostate.

What Are the Early Signs of Prostate Cancer?

Early-stage prostate cancer usually causes no symptoms at all. This is why screening tests exist — the disease often grows silently for years.

When symptoms do appear, they typically involve urination changes: difficulty starting to urinate, weak urine flow, frequent urination especially at night, or a feeling that the bladder does not empty completely. Blood in urine or semen can also occur. Pain in the hips, back, or pelvis may signal that cancer has spread to bones.

Here is the frustrating part: these symptoms can also be caused by benign prostatic hyperplasia, a non-cancerous enlargement of the prostate that happens in most aging men. You cannot diagnose prostate cancer based on symptoms alone. Testing is required.

How Is Prostate Cancer Diagnosed?

The PSA blood test measures prostate-specific antigen, a protein produced by the prostate. Elevated PSA levels can indicate cancer, but they can also be caused by infection, inflammation, or benign enlargement. A PSA above 4 ng/mL typically triggers further investigation, though some doctors use age-adjusted ranges.

If PSA levels are concerning, the next step is usually a digital rectal exam where a doctor feels the prostate for hard or irregular areas. If either test raises suspicion, a biopsy is performed. During a prostate biopsy, small tissue samples are removed with a needle and examined under a microscope for cancer cells.

Newer tests like MRI imaging can help target biopsies more accurately. Some men also get genomic tests that analyze tumor DNA to predict how aggressive the cancer is likely to be. The Gleason score, assigned after biopsy, grades cancer cells from 1 to 5 based on how abnormal they look. Two grades are added together for a final score between 6 and 10, with higher scores indicating more aggressive cancer.

What Are the Treatment Options for Prostate Cancer?

Treatment depends heavily on whether the cancer is confined to the prostate and how fast it appears to be growing. For very slow-growing cancers detected early, active surveillance is often recommended. This means regular monitoring with PSA tests, exams, and sometimes repeat biopsies instead of immediate treatment.

Surgery called radical prostatectomy removes the entire prostate gland and some surrounding tissue. Radiation therapy uses high-energy beams to kill cancer cells and can be delivered externally or through radioactive seeds implanted in the prostate. Both approaches have similar cure rates for localized cancer.

Hormone therapy blocks testosterone, which fuels prostate cancer growth. It is typically used when cancer has spread beyond the prostate or in combination with radiation for high-risk cases. Chemotherapy and newer targeted drugs are reserved for advanced cancers that no longer respond to hormone therapy. Immunotherapy has shown promise in some cases as of 2026, though it is not yet standard treatment.

What Does Research Show About Prostate Cancer Survival Rates?

The five-year survival rate for prostate cancer caught early is nearly 100%. Even when cancer has spread to nearby tissues, the five-year survival rate is close to 100%. The numbers drop significantly when cancer spreads to distant organs, where the five-year survival rate falls to about 32%.

These statistics explain why early detection matters and why some doctors push PSA screening aggressively. They also explain the ongoing debate about screening. Because most prostate cancers grow so slowly, many men die with prostate cancer rather than from it. Some will never know they had it. Aggressive screening finds cancers that would never have caused problems, leading to unnecessary treatment and side effects.

The US Preventive Services Task Force recommends that men ages 55 to 69 make an individual decision about PSA screening after talking with their doctor. They do not recommend routine screening for men 70 and older. Different medical organizations have different guidelines, which tells you this is genuinely unsettled.

Can Diet or Lifestyle Changes Prevent Prostate Cancer?

No diet or supplement has been proven to prevent prostate cancer in rigorous clinical trials. Studies on vitamin E, selenium, and saw palmetto have all failed to show benefit. Some even found increased risk with high-dose vitamin E.

Some evidence suggests that eating tomatoes and tomato products may be associated with lower prostate cancer risk, possibly due to lycopene, though results are mixed. A diet high in processed meat and high-fat dairy has been linked to increased risk in some studies.

Regular exercise appears protective. Men who exercise vigorously have lower rates of aggressive prostate cancer and better outcomes if diagnosed. Maintaining a healthy weight matters more for preventing aggressive disease than preventing cancer altogether.

Things that do not prevent prostate cancer despite common claims:

• Frequent ejaculation — some studies suggested a link, but evidence is weak and inconsistent
• Avoiding vasectomy — early concerns have been thoroughly debunked
• Taking finasteride or dutasteride for prevention — reduces total cancer incidence but may increase high-grade cancers
• Drinking green tea — population studies show associations but controlled trials do not support it

What Are the Long-Term Side Effects of Prostate Cancer Treatment?

Surgery and radiation both carry significant risks to sexual function and urinary control. Erectile dysfunction occurs in 30-70% of men after radical prostatectomy depending on age, baseline function, and whether nerve-sparing techniques were used. Urinary incontinence affects 10-20% of men long-term after surgery, though most regain control within a year.

Radiation causes erectile dysfunction at similar rates though often more gradually. It also increases the risk of bowel problems including rectal bleeding and urgency. Hormone therapy causes hot flashes in most men, often severely. It also leads to muscle loss, weight gain, diabetes risk, and bone density loss that can result in fractures.

These side effects are not rare complications. They are expected outcomes that every man considering treatment should understand clearly. The decision between treatment and active surveillance for low-risk cancer often comes down to weighing these guaranteed quality-of-life impacts against uncertain cancer progression risk.