Prostate cancer begins when cells in the prostate gland start to grow uncontrollably, forming a tumor. The prostate is a small, walnut-sized gland located below the bladder, playing a crucial role in producing semen. Most cases of prostate cancer are diagnosed during routine screening before symptoms appear, due to the disease's typically slow progression.

Gathering Medical History

The diagnostic process often begins with a review of the patient’s medical history. A healthcare provider will ask about any urinary or reproductive symptoms, their duration, and whether there is a family history of prostate cancer or exposure to chemicals. Risk increases with age, certain environmental exposures, and genetic predispositions.

Digital Rectal Examination (DRE)

A digital rectal exam is one of the first physical assessments used to detect prostate abnormalities. During this procedure, a gloved, lubricated finger is inserted into the rectum to feel for bumps, hard areas, or enlargement in the prostate. If abnormalities are detected, further investigation is needed.

Prostate-Specific Antigen (PSA) Test

PSA is a protein produced by the prostate. Elevated levels in the blood may indicate the presence of prostate cancer, though other conditions like benign prostatic hyperplasia or prostatitis can also raise PSA. PSA results are interpreted with consideration for age, prostate size, and previous levels. If levels are elevated or increasing rapidly, further testing is typically recommended.

Several types of PSA tests provide more insight:

  • Free vs. bound PSA: A lower percentage of free PSA may suggest a higher cancer risk.

  • PSA density: PSA level adjusted for prostate volume.

  • PSA velocity: The rate of change over time.

  • Prostate Health Index (PHI): A formula that incorporates total PSA, free PSA, and proPSA to improve the accuracy of cancer detection.

Transrectal Ultrasound (TRUS)

TRUS involves inserting a probe into the rectum to generate sound wave images of the prostate. It can reveal suspicious areas, and in many cases, is combined with a biopsy to obtain tissue samples for analysis.

Prostate Biopsy

If screening suggests the possibility of cancer, a biopsy is typically performed to confirm the diagnosis. Using a core needle, small samples are taken from various parts of the prostate, usually under local anesthesia. These samples are then examined under a microscope to look for cancer cells.

Biopsies may be conducted through the rectum (transrectal) or the skin between the anus and scrotum (transperineal), and often involve 10–12 core samples.

MRI Fusion Biopsy

MRI fusion biopsy combines detailed MRI images with ultrasound guidance to target specific areas of the prostate for sampling. This technique improves the accuracy of biopsies by focusing on suspicious regions identified during imaging.

Multiparametric MRI (mp-MRI)

This advanced imaging technique uses different types of MRI sequences to provide a detailed view of the prostate and surrounding tissues. mp-MRI can help identify the location, extent, and potential aggressiveness of cancer and is also useful in active surveillance.

Understanding Cancer Stage and Grade

Staging is the process of determining how far the cancer has progressed:

  • Clinical staging relies on exam findings, imaging results, and PSA levels.

  • Pathological staging is done after the prostate has been surgically removed and analyzed in the lab.

The Gleason score is used to grade the cancer based on how much the tumor tissue differs from normal prostate tissue. A lower score (6 or less) suggests a slow-growing cancer, while higher scores (8–10) indicate a more aggressive form.

Staging also follows the TNM system:

  • T: Size and extent of the primary tumor

  • N: Whether the cancer has spread to nearby lymph nodes

  • M: Whether the cancer has spread to other parts of the body

Cancer stages range from:

  • Stage 1: Localized, low-risk tumor not detectable by DRE.

  • Stage 2: Still confined to the prostate but more easily detected.

  • Stage 3: Spread outside the prostate to nearby tissues.

  • Stage 4: Spread to distant organs or lymph nodes.

Ruling Out Other Conditions

Because prostate cancer symptoms can mimic those of other disorders, it’s essential to differentiate between them. Conditions that may resemble prostate cancer include:

  • Benign prostatic hyperplasia (BPH)

  • Prostatitis

  • Bladder cancer

  • Prostatic stones

  • Urethritis

  • Urinary tract infections (UTIs)

Conclusion

Diagnosing prostate cancer involves multiple steps, from initial symptom assessment and PSA testing to advanced imaging and biopsy procedures. Early detection through routine screenings is vital, especially because prostate cancer often remains asymptomatic until it becomes advanced. A confirmed diagnosis enables precise staging and grading, helping clinicians choose the most effective treatment strategy tailored to the patient’s condition and overall health status.