BU Today: Could you explain the Gleason score? The statement from Biden’s office says his cancer is characterized by a “Gleason score of 9 (Grade Group 5).” What does this mean?

Gleason score is a system used by pathologists to visually grade how prostate tissue looks under the microscope. There are uniformly agreed upon standards that harmonize interpretation so that a pathologist in Boston is likely to come to the same conclusion as a pathologist in Los Angeles upon viewing the same specimen.

Grade 1 is assigned if the cancer looks a lot like normal prostate tissue. Grade 5 is assigned if the cancer looks very abnormal. Grades 2 through 4 have features in between these extremes.

Since prostate cancers often have areas with different grades, a grade is assigned to the two areas that make up most of the cancer. These two grades are added to yield the Gleason score.

Cancers with Gleason scores of 8 to 10 may be called poorly differentiated or high-grade. So the pathologists’ interpretation of former President Biden’s cancer (Gleason 9) is that it appears to be highly aggressive. This is not encouraging news.

BU Today: The statement also notes that his cancer “appears to be hormone-sensitive, which allows for effective management.” What does that mean, in regard to treatment?

“Hormone-sensitive” means that the cancer still relies on male sex hormones (testosterone and dihydrotestosterone) to grow. So, cutting off the supply of these hormones, usually by specialized drugs, reduces the hormone levels in the body and slows the growth of the tumor. Over time, prostate cancers usually learn to live without the hormones and grow independently, so that these therapies (called androgen deprivation) lose effectiveness. Former President Biden’s cancer, despite its apparently aggressive presentation, appears still to be at this hormone-sensitive stage. Generally speaking, there are many treatment options available to strengthen bones and slow tumor growth and spread, even if the bones are involved. In short, he can still be treated, and the progress of the cancer slowed, even if it is regarded as incurable.

BU Today: How common is prostate cancer in the United States? How treatable is it, generally?

Prostate cancer affects 13 out of every 100 American men. About 112 men are diagnosed out of every 100,000 annually. It is highly treatable and slow-growing in many cases. And, in certain situations, it is wiser to do nothing except monitor the slow growth, rather than start aggressive treatment, because many treatments have difficult side effects. We worry about prostate cancer in younger men, say age 40 years, because although they are rare, these cases are often more aggressive. About 10 percent of men newly diagnosed with prostate cancer are under the age of 55 years.

I’ll add, a strong relationship between patient and clinician is absolutely essential—trusting your oncology team is an important part of any treatment. At Boston Medical Center, we pride ourselves on building strong relationships like that.

BU Today: Is the Shipley Center spearheading any new research on prostate cancer, broadly?

We are designing a clinical trial to combine blood biomarkers with physical activity for prostate cancer patients at BMC—however, the study has not been evaluated or funded yet. Previous studies have shown that vigorous physical exercise, such as fast walking, is associated with lower risk for cancer progression or death from prostate cancer. The mechanisms are not fully understood and are in need of deeper study.

BU Today: What do we know already about the benefits of exercise for folks with prostate cancer?

Our lab at Boston University has shown that uncontrolled diabetes likely drives prostate cancer progression (undermining the androgen deprivation therapy I mentioned above) through new kinds of signal systems, called exosomes, that we are studying intensively. Exercise that lowers blood glucose likely improves these systems and reduces the risk of progression.

BU Today: The National Institutes of Health—specifically, the National Cancer Institute—is the largest funder of cancer research in the United States. Do recent cuts to the NIH and the federal Department of Health and Human Services affect this research?

Cancer research, hospitals, and research universities are [all being impacted by budget cuts from] the federal government, and many studies have been suddenly stopped or withdrawn. Morale at the National Cancer Institute is very low. Students, faculty, and trainees nationwide are seeking other careers and leaving cancer research, or leaving the country, because their futures have suddenly become bleak. I am concerned that the American people are not fully aware of the irreversible damage that is rapidly accumulating and will destroy research on many cancer types, including research at Boston University.

Unfortunately, this funding crisis also means that many prostate cancer patients who we treat will not benefit from the new therapies that we are hoping will be developed. The pipeline of ideas and funding has suddenly run dry.