Recently, a team of researchers from the University of East Anglia found five strains of bacteria in the urine that are associated with aggressive prostate cancer. They examined prostate tissue and urine samples from men with and without prostate cancer. Men who had one or more of these bacteria—Fenollaria, Peptoniphilus, Anaerococcus, Porphyromonas or Fusobacterium—were about three times as likely than men without the bacteria to see their early-stage prostate cancer turn into an aggressive cancer.
“Prostate cancer is one of the most common cancers among men,” says Firas Abdollah, M.D., a urologist at Henry Ford Health. “But many people with slow-growing prostate cancer die with it—not of it. So if this study shows that we can use bacteria to predict who will develop aggressive or recurring prostate cancer, it could potentially help to save lives.
“Right now, however, it’s a ‘chicken or the egg’ scenario: does the presence of these bacteria cause cancer? Or does cancer cause these bacterial infections? We’re not sure. We don’t know much about these bacteria yet. Three of them were newly identified in the study, and a fourth isn’t something you usually see in clinical practice.”
That said, a few other types of cancers can be caused by bacterial infections. Having a long-term H. pylori stomach infection is a risk factor for gastric ulcers and gastric cancer. And having a chlamydia trachomatis infection is a risk factor for cervical cancer.
So if bacteria are contributing to prostate cancer, could treating the infection with antibiotics help treat the cancer? “That could be the case, but right now we just don’t know,” says Dr. Abdollah.
How Is Prostate Cancer Currently Diagnosed?
A blood test called the prostate-specific antigen blood test (PSA) is how patients are screened for prostate cancer. If test results are abnormal, further testing is done with a prostate biopsy, which involves obtaining a small sample of prostate tissue. Prostate MRI can also be used, which has been shown to help detect prostate cancers that are likely to be aggressive.
So using a urine test could be another great—and non-invasive—way to detect aggressive prostate cancers. “There are many studies on the microbiome, or the network of millions of bacteria that we have in our body, which we usually live in harmony with,” says Dr. Abdollah. “We have many beneficial bacterial, but there are also harmful bacteria. And studies have shown an association between harmful bacteria and cancer, along with other diseases.
“Although this study can’t really tell us if bacteria causes prostate cancer or if it's the other way around, I think in the future we’ll understand the role of bacteria in our body and how it causes certain cancers—and prostate cancer may be one of them.”
Firas Abdollah, M.D., is a urologist with Henry Ford Health. He specializes in robotic surgery for prostate cancer (as well as kidney, adrenal and bladder cancer) and is the vice-chair of academics and research for the department of urology. He sees patients at Henry Ford Cancer—Detroit, Henry Ford Hospital and Henry Ford Medical Center—Sterling Heights.