La Jolla area researchers work to extend prostate cancer options

By Lynne Friedmann

Prostate cancer is the second most common cancer in men. It will affect one in six U.S. men in their lifetime; African-American men are more than twice as likely to die from it.

Diagnosis involves a simple blood test and, if caught early effective treatments are available. Yet only 36 percent of men, age 50 to 64, receive regular prostate cancer screening; compared to more than 70 percent of women, in the same age group, who receive regular mammogram screening for breast cancer, according to the American Cancer Society.

While there are new drugs and more targeted therapy available than ever, basic research being done within labs in Torrey Pines Mesa may eventually lead to other forms of treatment and maybe even a vaccine.

The chestnut-size prostate gland is part of the male reproductive system. The American Urological Association recommends that all men age 40 and over talk with their doctor about prostate cancer screening, particularly if there is a family history of prostate cancer. Screening involves a blood test to measure PSA (prostate-specific antigen) levels together with a digital rectal exam.

The good news is cancer caught before it has spread beyond the prostate gland can often be successfully treated with surgery or radiation therapy.

“Radiation can be made to conform to the shape of the tumor, allowing us to avoid damaging the bladder and colon,” said John P. Einck, M.D., assistant clinical professor, department of radiology, UCSD School of Medicine, in a public health seminar presented Sept. 13 at the UCSD Moores Cancer Center as part of Prostate Cancer Awareness Month.

For more aggressive forms of prostate cancer, several new FDA-approved drugs shown to improve survival have recently come on the market.

“There are more drugs available now than ever, with an additional 15 or 20 agents in the (drug-development) pipeline,” said Christopher J. Kane, M.D., F.A.C., professor of surgery/urology, and chief of urology at UCSD School of Medicine.

In May, The Scripps Research Institute and the Moffitt Cancer Center (Tampa, Fla.) were awarded more than $2 million to study the origins of prostate cancer and the role that inflammation plays in tumor development and growth.

Researchers at the UCSD Moores Cancer Center hope to develop a low-cost immunotherapy for prostate carcinoma based on a decade of research that has shown the immune system’s “killer” T-cells — thought to recognize only peptides or pieces of proteins — can also recognize sugars on the surface of tumor cells. The next step is to utilize the T-cells’ recognition ability to attach and kill the cancer cell.

“If ultimately proven successful, this could be used in a first attempt to try to address vaccination on a large scale to prevent cancer,” said immunologist Alessandra Franco, M.D., Ph.D., adjunct assistant professor of pediatrics at the UCSD School of Medicine in a news release announcing additional funding for the research.

Some types of prostate tumors are more aggressive and more likely to metastasize than others. Nearly one-third of these aggressive tumors contain a small nest or else are entirely made up of especially dangerous cells known as neuroendocrine-type cells. In July, a team of investigators at Sanford-Burnham Medical Research Institute reported the identification of a series of proteins that could provide doctors with an early warning sign for tumors that are likely to metastasize.

“In identifying this protein pathway, we’ve identified new markers that can be used to distinguish the dangerous cells and find new targets for therapy,” according to Ze’ev Ronai, Ph.D., associate director of Sanford-Burnham’s National Cancer Institute-designated cancer center.

Sanford-Burnham researchers also study the impact of nutrition on cancer using mass spectrometry to track stable isotopes incorporated into nutrients taken up and metabolized by cells. The result is a step-by-step snapshot of how cancer cells defy poor nutritional environments, what happens to the nutrients they take in, and how to pinpoint and exploit vulnerabilities in cancer cells.

While prostate cancer is a relatively common type of cancer in men, it tends to grow very slowly. This being the case, often the best course of action is simple observation, known as “active surveillance” without the surgery or radiation that can unnecessarily diminish the quality of life for men.

“I can guarantee no side effects with active surveillance,” said J. Kellogg Parsons, M.D., M.H.S., associate professor of surgery, UCSD Medical Center.

In March, a new clinical trial at UCSD Moores Cancer Center was launched. Known as the MEAL (Men’s Eating And Living) study, it is the first to evaluate whether lifestyle changes can delay the progression of prostate cancer.

“We focus on more vegetables, less meat, and comprehensive counseling which encourages a more active lifestyle,” said J. Kellogg Parsons, M.D., M.H.S., urologic oncologist at the Moores Center.