Elevated CRP Levels Linked to Poor Prognosis in Prostate Cancer

From the Prostate Cancer Symposium

ORLANDO—Elevated levels of C-reactive protein (CRP) indicate inflammation and have been associated with cardiovascular disease. Now new findings show that CRP is also associated with prostate cancer and may be used as a new marker for assessing patient survival.

At the recent Prostate Cancer Symposium, sponsored by the American Society of Clinical Oncology, Tomasz Beer, MD, director of the Prostate Cancer Research Program at the Oregon Health and Science University Cancer Institute, reported that elevated CRP levels are strongly associated with poor survival in men with advanced prostate cancer.

“We looked at a series of inflammatory markers in patients with metastatic prostate cancer who had progressed on hormonal therapy and were starting docetaxel [Taxotere]-based chemotherapy,” Dr Beer said.

The ASCENT (Androgen Independent Prostate Cancer Study of Calcitriol Enhancing Taxotere) study included 160 men with metastatic prostate cancer that continued to progress despite hormonal therapy.

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The study investigated whether large doses of calcitriol, the active form of vitamin D, would help reduce prostate-specific antigen (PSA) levels and improve patient survival. It compared a combination of docetaxel and DN-101 (high-dose calcitriol) with docetaxel and placebo, Dr Beer told .

An increasing body of evidence suggests that cancer can take advantage of the inflammatory response, and that the inflammatory cytokines released by the immune reaction may in fact fuel cancer progression. To the extent that this hypothesis proves true, CRP may be reflecting the overall intensity of the inflammation.

“We found that elevated CRP levels were associated with shorter survival and a lower probability of response to chemotherapy. Specifically, having an abnormally elevated CRP was associated with a 3-fold increase of the risk of death. Likewise, a doubling of CRP levels was associated with a 27% increase in the risk of death and a 19% decrease in the probability of response to chemotherapy as measured by PSA reduction,” Dr Beer said.

Although recent studies have reported similar findings in other types of tumors, this is the first study to show the role of CRP in prostate cancer. If confirmed, CRP testing could be used to determine the patient’s prognosis and probability of response to treatment. These results also indicate that inflammation may be an important mediator of prostate cancer progression and resistance to therapy and thus identify a potential avenue for therapeutic innovation.

Dr Beer is optimistic about these results, but he cautions, “Right now, to be fair, we ought to have one of my colleagues confirm this in another sample set before we recommend going forward using this test in the clinic. Because it is a readily measurable test, I would hope that these data get looked at in another sample set soon and, if confirmed, I would say that we have a new prognostic marker that can be helpful to physicians and patients right away.”

Dean Bajorin, MD, of Memorial Sloan-Kettering Cancer Center in New York City, says this is “an interesting study that looks at multiple factors, trying to predict how patients will do on treatment. CRP is a prognostic factor that has been helpful in predicting how men and women will do regarding heart disease. So it looks like this factor, which is associated with inflammation, might be able to predict how well we will do with prostate cancer. Once we get more in the way of that factor, along with PSA, etc, we might be able to give more information to men with metastatic prostate cancer, to give them an idea of just what their survival is expected to be.”