How to Improve Prostate Cancer Chemotherapy

Next generation chemotherapy may offer effective earlier treatment for disease.

A member of the taxane chemotherapy family has properties that may make it effective for the treatment of some prostate cancer patients, according to a recent study.

The study, published online in Clinical Cancer Research, noted that a genomic marker may help physicians identify which prostate cancer patients may benefit the most from the FDA-approved drug cabazitaxel.

"It was surprising to find that cabazitaxel functions differently than docetaxel in killing cancer cells, even though they're both taxanes," study senior author Karen Knudsen, PhD, said in a press release. "It shows that we may not be taking full advantage of this next generation taxane in the clinic."

Docetaxel has previously been found to be the only effective chemotherapy for men with cancer that no longer responds to hormone treatments. Cabazitaxel, a next generation drug in the taxane family, was approved in 2010 for patients with cancer that no longer responds to hormone therapy or treatment with docetaxel.

The researchers found that cabazitaxel may be more effective sooner in treatment, however.

The study indicated that cabazitaxel works better than docetaxel in human prostate cancer cells lines with hormone treatment resistance. This result was achieved in terms of slowing the growth of cancer cells and the ability to kill cancer cells.

An analysis of tumor genes affected by both drugs showed that cabazitaxel has a greater effect on both cellular division and regulation of chromatin. Meanwhile, docetaxel was found to have a greater impact on DNA transcription and repair.

"This difference in mechanism suggests that we should treat these two drugs less like members of the same family, and more like two distinct therapies that may each have distinct benefits for certain patients," first author Renée de Leeuw said in a press release.

The researchers tested the 2 drugs in a model that more closely matched human disease and conducted tests of the drugs side-by-side on portions of tumors removed from patients during radical prostatectomy.

Cabazitaxel was found to provide greater efficacy in killing tumor cells than docetaxel. The study also found a molecular marker that would help to identify patients most likely to benefit from treatment with cabazitaxel.

Patients with tumors likely to become hormone resistant were more likely to respond to treatment with cabazitaxel.

"This gene could give us a way to identify patients who would benefit from cabazitaxel earlier and reduce the trial and error of treating a cancer patient," Dr. Knudsen said.