Research Still Needed to Improve Prostate Cancer Outcomes

By Mike Bassett

Despite an impressive amount of science that has been accomplished in the area of prostate cancer, Colleen Lawton, MD, reminded her colleagues during Wednesday's Annual Oration in Radiation Oncology, "Prostate Cancer: Improving the Flow of Research," that a lot of research remains to be done.

RSNA President Richard L. Baron, MD, presents Colleen A. Lawton, MD, with a commemorative scroll of her Annual Oration in Radiation Oncology delivered Wednesday.

According to Dr. Lawton, vice chair of the Department of Radiation Oncology at the Medical College of Wisconsin, Milwaukee, prostate cancer in many ways resembles "an ugly stepsister" when it comes to the amount of funding and research that's been committed to the disease.

She noted, for example, that prostate cancer is diagnosed in over 200,000 men and is responsible for the deaths of 27,000 men annually in the United States. "Yet we think of it as a disease in our country that men don't really have to worry about."

By contrast, she pointed out, breast cancer is diagnosed in about the same number of women, kills over 40,000 women annually, and is thought of as an epidemic that must be stopped.

"We have a dichotomy here that needs to fixed," she said.

Screening Standards Still Lacking

She referred to what appears to be different approaches to screening breast and prostate cancer. While there has been much debate about both mammography and prostate cancer screening, there seems to be a consensus that women of a certain age should have yearly mammograms.

When it comes to prostate cancer, however, the test that was considered most appropriate — PSA screening — has been questioned over time, to the point that the United States Preventive Services Task Force now recommends against it.

"On the prostate cancer side, clearly we have much more work to do to come up with the best way to screen," Dr. Lawton said.

Dr. Lawton went on to discuss how research into, and the treatment of prostate cancer has evolved — from low-risk and intermediate-risk prostate cancer, to metastatic and post-operative disease.

She also described the significant role diagnostic radiology has played in helping radiation oncologists detect and treat prostate cancer.

Dr. Lawton said that the use of multiparametric MRI has been exceedingly helpful to radiation oncologists in several ways. For example, while low-risk patients who probably don't need treatment may follow an active surveillance approach to their prostate cancer, she pointed out that the use of MRI allows both the radiation oncologist and patient to be more comfortable with that approach.

"However, if you do an MRI and it shows a lesion likely to be in an area that was not biopsied, then a directed biopsy of those areas sometimes shows that it is a cancer that needs treatment, instead of surveillance," she said.

There has also been a lot of work going on in the ability to see lymph nodes, whether it's with MRI and nanoparticles, choline PET/CT, or PSMA (prostate specific cancer antigen), she said. "A number of these imaging agents that are being developed."

Collaboration Can Help Identify Solutions

Looking forward, Dr. Lawton suggested that there are several areas where diagnostic radiologists could help their radiation oncology colleagues "in specific areas we cannot understand."

One area involves the ability to see where the urethra traverses the prostate. "As we think about localized disease and our ability to increase radiation doses, and know that increasing doses cures more cancers, the organ at risk within the prostate becomes the urethra," she said.

If radiation oncologists could identify where the urethra traverses the prostate using imaging techniques, then they would know how to avoid it. "Currently the only way to do that is to put a Foley catheter in, and that is clearly undesirable," Dr. Lawton said.

"We also need to better understand where microscopic disease is," she said, adding that with the assistance of MR, other modalities, or new contrast agents, radiation oncologists can better understand if the prostate cancer is through the capsule, if the lymph nodes are involved — even on a microscopic level — and if the disease is in the bone or other areas of the body.

"Clearly we made strides in each of these areas, but we need more help," she said.

Dr. Lawton concluded her talk by lamenting the state of funding available for radiation oncology research.

"The reality is we have many more researchers and great ideas than funding," she said, pointing out that radiation oncology secures only about 1.6 percent of the funding that goes toward cancer research by the National Institutes of Health (NIH).

"So we still have much to do get the NIH or the [National Cancer Institute] to cough up more money to help us," Dr. Lawton said.

In the meantime, she noted that RSNA, through its Research & Education Foundation, and the American Society for Radiation Oncology, through its Radiation Oncology Institute, have been useful sources of research funding.

"It's important that if we want to keep the research flowing that all of us should donate to these important sources of funding," she said. "We have to be part of the solution."