The Seminal Vesicle and Its Role in Prostate Cancer

A seminal vesicle is one of a pair of small tubular glands. These glands are positioned inside the body: above the prostate, behind the bladder, and in front of the rectum. One sits toward the left and the other sits toward the right. Each is roughly two inches long, on average.

The primary function of the seminal vesicles involves the production of fluid that mixes with sperm and makes up a significant percentage of semen. The fluid that the seminal vesicles produce is rich in sugars because it's designed to feed sperm. It's also sticky, so that semen stays in the vagina long enough for a sperm to fertilize an egg.

If a man develops prostate cancer and it metastasizes (spreads), the disease will often spread to the seminal vesicles.

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What Is Prostate Cancer?

Prostate cancer develops in the prostate, a small gland that makes seminal fluid. It is one of the most common types of cancer in men. Prostate cancer usually grows over time and in the beginning, typically stays within the prostate gland, where it may not cause serious harm. While some types of prostate cancer grow slowly and may need only a minimal amount of treatment or no treatment at all, other types are aggressive and can spread quickly.

When prostate cancer is caught early, a person has a better chance of treating it successfully.


Prostate cancer that is more advanced may cause symptoms such as:

  • Trouble urinating
  • Decreased force in the stream of urine
  • Blood in the semen
  • Discomfort in the pelvic area
  • Bone pain
  • Erectile dysfunction

Risk Factors

Factors that can increase your risk of prostate cancer include:

  • Older age: Your risk of prostate cancer increases as you age.
  • Race: Black men have a greater risk of prostate cancer than men of other races. In black men, prostate cancer is also more likely to be aggressive or advanced.
  • A family history of prostate or breast cancer: If men in your family have had prostate cancer, your risk may be increased. Also, if you have a family history of genes that increase the risk of breast cancer (BRCA1 or BRCA2) or a very strong family history of breast cancer, your risk of prostate cancer may be higher.
  • Obesity: Obese men who are diagnosed with prostate cancer may be more likely to have advanced disease that's more difficult to treat.


Complications of prostate cancer and its treatments include:

  • Cancer that metastasizes (spreads): Prostate cancer can spread to nearby organs or through your bloodstream or lymphatic system to your bones or other organs. If prostate cancer travels to other areas of the body, it can be controlled but is unlikely to be cured.
  • Incontinence: Both prostate cancer and its treatment can cause urinary incontinence (accidental urination). Treatment options include medications, catheters, and surgery.
  • Erectile dysfunction: Erectile dysfunction can be a result of prostate cancer or its treatment, including surgery, radiation, or hormone treatments. Medications, vacuum devices that assist in achieving an erection, and surgery are available to treat erectile dysfunction.
2 Sources
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  1. American Cancer Society. Prostate cancer.

  2. Urology Care Foundation. What is prostate cancer?

By Matthew Schmitz, MD
Matthew Schmitz, MD, is a professional radiologist who has worked extensively with prostate cancer patients and their families.