Although prostate cancer is the second-most common cancer among men in the United States, with around 300,000 new cases diagnosed every year, early detection may drastically improve a patient’s prognosis. One way to look for and potentially help diagnose prostate cancer is by performing a magnetic resonance imaging (MRI) scan.
The results of a prostate MRI can play a vital role in diagnosing both cancer and non-cancerous conditions of the prostate. These results usually include a PIRADS score.
“A PIRADS score is a number given from 1 to 5 that tells us how suspicious a spot on a prostate MRI looks for cancer,” says Kevin King, M.D., D.A.B.R., assistant clinical professor of radiation oncology at City of Hope® Cancer Center Chicago.
While a higher PIRADS score suggests a higher risk for developing prostate cancer, it’s not always a cause for alarm. This article covers the basics on PIRADS scores and prostate cancer risk, including:
- What is PIRADS?
- How is PIRADS scoring done?
- PIRADS score chart
- What is “clinically significant prostate cancer?”
- Does a high PIRADS score always mean cancer?
- When should you worry about a high PIRADS score?
If you or a loved one has been diagnosed with prostate cancer and would like an initial appointment or a second opinion, call us 24/7 at (877) 834-8941.
What Is PIRADS?
PIRADS is short for prostate imaging reporting and data system. PIRADS scores are a way for cancer doctors and imaging specialists like Dr. King to turn the information gathered in an MRI into an overall score that explains how likely it is that the patient may have prostate cancer.
After a prostate MRI, the patient receives a report that includes a PIRADS score from 1 to 5.
“A score of 1 means it’s very unlikely to be cancer, while a score of 5 means it looks very concerning,” says Dr. King. “This score helps doctors decide whether a prostate biopsy is needed and where to check for cancer.”
A doctor may recommend a prostate MRI for several reasons:
- If the patient has a family or personal history of prostate cancer and is experiencing symptoms related to urinary or sexual health
- If tests show that the patient has higher-than-normal levels of prostate-specific antigen (PSA). An increase in PSA levels can be a sign of prostate cancer, but may also be caused by non-cancerous issues like prostatitis.
- If the doctor detects a lump on the prostate or an enlarged prostate during a routine digital rectal exam
A high PIRADS score on its own is not a prostate cancer diagnosis. However, patients with a score of 3 or above often undergo other tests to check for signs of cancer.
How Is PIRADS Scoring Done?
After a prostate MRI, expert radiologists use the results to assign a PIRADS score. When assigning this score, they look for:
- Signs of an enlarged prostate gland
- Signs of any unusual spots (or lesions) on the prostate
- How big these unusual lesions are
- Whether these lesions extend beyond the prostate gland itself
PIRADS Score Chart
| Score | Meaning |
|---|---|
| PIRADS 1 | Very low risk, prostate cancer unlikely |
| PIRADS 2 | Low risk, prostate cancer unlikely |
| PIRADS 3 | Intermediate risk, clinically significant prostate cancer may be present |
| PIRADS 4 | High risk, clinically significant prostate cancer is likely present |
| PIRADS 5 | Very high risk, clinically significant prostate cancer is most likely present |
What Is “Clinically Significant Prostate Cancer?”
A PIRADS score of 3 or above suggests that a patient is more likely to have “clinically significant prostate cancer.”
What does this term mean? “Clinically significant prostate cancer refers to types that are more likely to grow, spread or require treatment,” Dr. King explains, “but it does not necessarily mean that cancer has already spread beyond the prostate.”
Put simply, the term is used to distinguish between more aggressive prostate cancers and “those that are so slow-growing they might not cause harm during a patient’s lifetime,” he adds.
Does a High PIRADS Score Always Mean Cancer?
No, a high PIRADS score does not mean the patient definitely has cancer.
“A PIRADS score of 4 or 5 strongly suggests the possibility of clinically significant prostate cancer, but it is not diagnostic on its own,” says Dr. King. “Some patients with PIRADS scores of 4 or 5 may ultimately have benign findings or low-risk cancers that don’t require treatment. The score helps prioritize who should undergo a biopsy but is not a definitive diagnosis.”
Nonetheless, most patients with a high PIRADS score will undergo a prostate biopsy, which is a procedure that removes a small amount of tissue from the prostate so that it can be examined for cancer cells.
“Biopsy helps us confirm the presence of cancer and understand its grade and aggressiveness,” Dr. King says.
When Should You Worry About a High PIRADS Score?
While it is normal to have questions or concerns after receiving a high PIRADS score, it’s important to remember that this is only one part of a bigger picture when it comes to prostate cancer risk.
“A high PIRADS score simply indicates that further evaluation, typically a biopsy, is warranted. It does not mean cancer is confirmed, or that it is necessarily an aggressive form of prostate cancer,” Dr. King says.
Other factors that play a role in this bigger picture include:
- The results of other imaging tests
- Digital rectal exam findings
- The patient’s PSA levels
- A medical or family history of prostate cancer
- The results of a biopsy
Comprehensive screening for prostate cancer is the best way to detect the disease early – and make treatment more effective.
“Every patient should work closely with their cancer care team to determine the right course of action based on the details specific them,” he says.
If you or a loved one has been diagnosed with prostate cancer and would like an initial appointment or a second opinion, call us 24/7 at (877) 834-8941.