New Artificial Intelligence Program To Assist Pathologists Diagnosing Prostate Cancer May Help ‘Save Lives’, FDA Says

Paige Prostate uses artificial intelligence to help pathologists examine slides from biopsies for evidence of cancer, enabling them to read the slides with more accuracy, and to avoid relying on second opinions. The program uses a database of tissue patterns amassed by the Memorial Sloan Kettering Cancer Center to pinpoint formations in a slide that may be cancerous.

A prostate biopsy can be used to determine if cancer is present, how much cancer is present and how aggressive the cancer is.

Context and Implications

Speaking with SurvivorNet, Dr. Jeff Tosoian of Vanderbilt University Medical Center explained the process of a pathologist examination: “We perform a biopsy, and we send those tissue samples to the pathologists. Then, the pathologists look under the microscope and say, ‘cancer or no cancer,’ and if there is a cancer, what grade is it?” If a pathologist is unsure of their reading of a slide, they may seek a second opinion.

Paige CEO Leo Grady explained why it can be burdensome for pathologists to seek a second opinion: "You ship a glass slide to somebody else or you do another stain that’s really expensive or you do another molecular test.” With Paige Prostate, however, pathologists can digitally scan biopsy slides, upload them to a computer, and import them into a cloud-based program accessed through a web browser.

The software helps pathologists focus in on areas of concern and avoid overlooking any evidence. One study found that the detection of cancer in individual images improved by 7.3% with the help of Paige Prostate. According to Grady, this will give pathologists "a lot more confidence in their diagnosis without having to send it out for additional consultation."

Dr. Tosoian suggested that more research might be needed to determine how much of an impact this application of artificial intelligence can have. Prostate cancer is unique in that many low-grade prostate cancers are not fatal and therefore do not require direct treatment beyond active surveillance (monitoring for evidence of a more aggressive, higher grade cancer).

Of the cancers that Paige Prostate spotted after they had been overlooked by pathologists, few were cancers that would require treatment. “I think that is the next big question,” Dr. Tosoian said. “Is this helping us detect the harmful cancers?” Anything that can “improve the care we’re providing is very welcome,” he said, but there is still a question as to how significantly this will change current clinical practice.

Prostate Cancer Screening

In a previous interview with SurvivorNet, Dr. Edwin Posadas of the Cedars-Sinai Medical Center pointed out one of the key challenges of detecting prostate cancer: "Prostate cancer is a very odd disease in that it doesn't have a particular symptom," he said. Changes in urinary function can be a sign of the disease, but abnormal urinary behavior can also point to other conditions. Because prostate cancer is so elusive, screening should begin before any symptoms are identified.

According to Dr. Tosoian, the first step in screening for prostate cancer typically involves a PSA test (prostate-specific antigen). A PSA test is a straight-forward blood test that measures for a substance created by the prostate that is typically higher in men with prostate cancer. Unfortunately, PSA is not specific for prostate cancer. An elevated PSA can be the result of several conditions other than cancer, including benign enlargement of the prostate, a common condition in older men. Developing and validating more accurate biomarkers (substances like PSA that can be measured in blood or urine samples) to detect prostate cancer is a focus of Dr. Tosoian's research

A second test that has been used for prostate cancer screening is called a digital rectal exam (DRE), where a doctor feels manually for a mass in the prostate. Dr. Tosoian suggested that DREs are becoming less common, and will likely be phased out in the future. “As you can imagine,” he said, the DRE “has been shown to not be the most sensitive or accurate test for detecting cancer,” except for in cases where the tumor size is “grossly abnormal.”

Additional screening steps may include biomarker tests–there are two common blood tests and three common urine tests–and a prostate MRI. These additional steps are left up to doctors’ discretion, and decisions can be made based on the specific circumstances of a patient’s case and the patient’s preferences.

Prostate Cancer Diagnosis

The PSA and additional testing may warn your doctor of the possibility of prostate cancer, in which case you would have a biopsy to officially diagnose your condition. A biopsy, where a piece of prostate tissue is removed and sent to a lab for testing, is the only definitive way to diagnose prostate cancer.

After performing the biopsy, a tissue sample will be sent to a pathologist to determine if it contains cancer. If cancer is present, the pathologist will also analyze how aggressive the cancer is and rank it on a scale called the Gleason score. Grade groups are another ranking system that is beginning to be used more frequently than the Gleason score because it ranks cancers on a more intuitive 1 – 5 scale (instead of the Gleason score’s 6 – 10 scale). If cancer is present, doctors may request additional tests such as pelvic CT/MRI or a bone scan to complete the staging assessment.

The Gleason Score is used to determine how aggressive prostate cancer is, and whether to treat the disease or use the watch and wait approach.

Dr. Tosoian explained that if a pathologist has any  questions about their interpretation of the patient’s biopsy, they will often send the biopsy tissue to experts in the field for a second opinion. Even with a second opinion from the most respected doctors, however, there is still an element of subjectivity in reading and interpreting the biopsy tissue. The Paige Prostate software can help doctors by adding an element of objectivity to this assessment. It does so by using a record of prostate cancer tissue images to identify areas that are most likely to contain cancer, and directing doctors’ attention to these spots.

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