The stage of prostate cancer describes the extent of the disease, including how large the tumor is and whether it has spread to other parts of the body. Staging is determined by the TNM system, which stands for Tumor, Nodes, and Metastasis. Here's a breakdown:

1. Stage I
   • Tumor (T): Cancer is confined to one half of one side of the prostate or less.
   • Nodes (N): No spread to nearby lymph nodes.
   • Metastasis (M): No distant metastasis.
   • Gleason Score: Usually 6 or less.
   • PSA Level: Less than 10 ng/mL.
   • Characteristics: Cancer is not palpable on DRE or visible on imaging.
2. Stage II
   • IIA:
     • Tumor (T): Cancer is more than one half of one side of the prostate but not both sides.
     • Gleason Score: 6 or 7.
     • PSA Level: Between 10-20 ng/mL.
   • IIB:
     • Tumor (T): Cancer is in both sides of the prostate.
     • Gleason Score: 7.
     • PSA Level: Less than 20 ng/mL.
   • IIC:
     • Tumor (T): Cancer is still within the prostate but may be more extensive.
     • Gleason Score: 7 or 8.
     • PSA Level: Any level.
3. Stage III
   • IIIA:
     • Tumor (T): Cancer has spread beyond the prostate to nearby tissues.
     • PSA Level: More than 20 ng/mL.
     • Gleason Score: 7 or less.
   • IIIB:
     • Tumor (T): Cancer has spread outside the prostate to nearby tissues but not to lymph nodes.
     • Gleason Score: Any.
     • PSA Level: Any.
   • IIIC:
     • Tumor (T): Cancer has spread beyond the prostate to nearby tissues and may be to nearby lymph nodes.
     • Gleason Score: 8 or higher.
     • PSA Level: Any.
4. Stage IV
   • IVA:
     • Tumor (T): Cancer has spread to nearby lymph nodes but not to distant parts of the body.
     • Nodes (N): Regional lymph node involvement.
     • Gleason Score: Any.
     • PSA Level: Any.
   • IVB:
     • Tumor (T): Cancer has spread to distant parts of the body, such as bones or other organs.
     • Metastasis (M): Distant metastasis present.
     • Gleason Score: Any.
     • PSA Level: Any.

Grading of Prostate Cancer

The grade of prostate cancer describes how abnormal the cancer cells look under a microscope and how likely the cancer is to grow and spread. The most common grading system is the Gleason score, which ranges from 6 to 10.

1. Gleason Score 6 (Grade Group 1)
   • Characteristics: Low-grade cancer; cells look similar to normal prostate cells and are likely to grow slowly.
2. Gleason Score 7 (Grade Group 2 and 3)
   • Characteristics: Intermediate-grade cancer; cells look more abnormal and are more likely to grow and spread compared to low-grade cancer.
   • Gleason 3+4=7 (Grade Group 2): More cells look like Gleason grade 3.
   • Gleason 4+3=7 (Grade Group 3): More cells look like Gleason grade 4, indicating a higher risk of growth and spread.
3. Gleason Score 8 (Grade Group 4)
   • Characteristics: High-grade cancer; cells look very abnormal and are likely to grow quickly.
4. Gleason Score 9-10 (Grade Group 5)
   • Characteristics: Very high-grade cancer; cells look very abnormal and are highly likely to grow and spread rapidly.

Sources for Further Reading

• American Cancer Society: Prostate Cancer Stages
• National Cancer Institute: Prostate Cancer Treatment (PDQ®)–Patient Version
• Mayo Clinic: Prostate Cancer Staging
• American Urological Association: Gleason Grading