Enlarged prostate or prostate cancer? Understanding the difference

A frequent and entirely understandable question I hear in clinic is whether an enlarged prostate means cancer. The short answer is no, the two are different conditions, although they can produce overlapping symptoms and can occasionally exist together. The longer answer is more useful and is what most men want to know.

This article explains what each condition is, how they differ, and how the diagnostic process is designed to tell them apart.

What an enlarged prostate actually is

The medical name for an enlarged prostate is benign prostatic hyperplasia, or BPH. The word "benign" is the important one. BPH is not cancer, has nothing to do with cancer, and does not turn into cancer over time. It is an extremely common, age-related growth of the prostate gland that affects most men to some degree past middle age.

The prostate sits just below the bladder and wraps around the upper part of the urethra, the tube through which urine leaves the body. As the gland enlarges, it can press on the urethra, which is what produces the symptoms most men associate with an enlarged prostate.

Typical symptoms include:

• Needing to pass urine more often, particularly at night
• A weaker or slower urinary stream
• Difficulty starting to pass urine
• A feeling that the bladder has not emptied completely
• Dribbling at the end of urination
• Urgency, or the feeling that you need to go quickly

These symptoms are uncomfortable and can be disruptive, but they are not in themselves a sign of cancer.

What prostate cancer is

Prostate cancer is an abnormal growth of cells within the prostate that, unlike BPH, has the potential to spread beyond the gland. The early stages of prostate cancer are typically asymptomatic, which is one of the central reasons the PSA blood test was developed: most men with early prostate cancer feel completely well.

When prostate cancer does produce symptoms, they can resemble those of BPH (changes in urinary flow, frequency, urgency) which is the source of the diagnostic confusion. Cancer can also produce blood in the urine or semen, persistent bone pain (if it has spread to bone), or unexplained weight loss in advanced disease.

The key point is that BPH and prostate cancer can each produce urinary symptoms, but the urinary symptoms themselves do not tell the doctor which is which. That work falls to the investigations described below.

How doctors tell them apart

In a man with new or worsening urinary symptoms, the investigation typically follows this sequence:

1. A careful history and examination. Many men are surprised by how much information emerges from a 20-minute conversation about exactly which symptoms started when. A digital rectal examination (DRE) can give the doctor a quick sense of the size and surface texture of the prostate.
2. A PSA blood test. A raised PSA suggests further investigation is needed. The interpretation of the number depends on age, prostate size, and previous trend. PSA is raised in BPH as well as in cancer, so a high PSA on its own does not distinguish the two.
3. A multiparametric MRI of the prostate (mpMRI). This is now the standard next step in most UK pathways. The MRI looks at the prostate in three dimensions and identifies any suspicious areas. A clear MRI gives strong reassurance. A suspicious MRI is what prompts a biopsy.
4. A targeted biopsy if the MRI shows suspicious areas. This is now usually performed transperineally rather than transrectally, with a lower infection risk.
5. Pathology and grading. Any tissue removed is examined under a microscope and graded for aggressiveness.

The point of this sequence is to investigate calmly and proportionally, not to leap from a single elevated number to a frightening conclusion. Most men with urinary symptoms turn out to have BPH. Of those who turn out to have prostate cancer, many have a low-grade disease for which active surveillance, rather than immediate treatment, is the right approach.

What an enlarged prostate is treated with

If symptoms of BPH are mild, no treatment may be needed. For more troublesome symptoms, the options include:

• Lifestyle adjustments: reducing fluid intake before bed, reducing caffeine and alcohol, addressing constipation.
• Medications: alpha-blockers such as tamsulosin (which relax the muscles around the bladder neck) and 5-alpha reductase inhibitors such as finasteride and dutasteride (which can shrink the prostate over months). The latter group reduces PSA, which the doctor must know about when interpreting your results.
• Minimally invasive procedures: UroLift, Rezum, and similar techniques offer alternatives to traditional surgery in selected men.
• Surgery: Transurethral resection of the prostate (TURP) remains the gold standard for men with significant symptoms not controlled by other means.

None of these are cancer treatments. They are designed to relieve the obstruction of the urethra and improve quality of life.

Common questions

Does an enlarged prostate mean I will get prostate cancer? No. BPH is not a precursor to prostate cancer. Men with BPH are no more likely to develop prostate cancer than men with normal-sized prostates of the same age.

Can I have both BPH and prostate cancer at the same time? Yes, because both are common. The presence of one does not exclude the other. This is part of why the diagnostic process is designed to evaluate both possibilities.

Will I need surgery for an enlarged prostate? Most men with BPH do not need surgery. Lifestyle changes and medication are usually tried first. Surgery is reserved for men with significant symptoms not controlled by other means, or with complications such as retention.

Does an enlarged prostate affect sexual function? It can do, particularly if the symptoms are significant or if treatment is needed. Tamsulosin can affect ejaculation; the 5-alpha reductase inhibitors can affect libido and erectile function in a minority of men. These effects should be discussed before any medication is started.

Should I have a PSA test if I have urinary symptoms? This is a conversation to have with your GP. New or changing urinary symptoms in a man over 50 (or younger in those with a family history or of Black African or Caribbean heritage) are a reasonable trigger for a discussion about PSA testing.

If you would like a private consultation to discuss your symptoms, please use the enquiries form.