MDNews - San Antonio

A PPROXIMATELY FOUR OUT of fi ve cases of prostate cancer are now diagnosed before the dis- ease spreads to outlying tissue, organs or bone. Many physicians consider screening for prostate-specifi c antigens (PSA) — proteins often found at elevated levels in those with prostate cancer — the reason behind both enhanced early diagnosis and improved survival rates. Despite this, in 2012 the U.S. Preventive Services Task Force (USPSTF) published an offi cial recommendation discouraging physicians from using PSA screening, citing concerns about overtreatment and harmful side effects. That recommendation sparked a ques- tion: If PSA screening is not responsible for reducing prostate cancer mortality, what is? A Late-Stage Treatment Link? Recent research conducted at the UC Davis Comprehensive Cancer Center examined the possible link between improved late-stage treatment and reduced prostate cancer-related mortality. "We already knew that the average lifespan of people [with prostate cancer] is being extended," says Marc Dall'Era, MD, lead author of the article "No Improvement Noted in Overall or Cause-specifi c Survival for Men Presenting with Metastatic Prostate Cancer over a 20-year Period" and Assistant Professor and Vice Chair of Urology at UC Davis Comprehensive Cancer Center. "Assuming PSA screening has little benefi t changing prostate cancer mortality, what else can account for the dramatic changes we've seen in mortality over the past 25 years? Perhaps in men with metastatic prostate cancer, we've just done that good of a job at extending their lives. So we asked that question." Ultimately, the answer was no. The study, which appeared in the November 2013 issue of the online journal Cancer, examined the records of 19,336 men with prostate cancer from the California Cancer Registry. While overall prostate cancer mortality rates have declined and the number of men initially diagnosed with metastatic prostate cancer has decreased by 65 percent, Dr. Dall'Era and his associates found the likelihood of a patient with metastatic prostate cancer surviving had not increased. In fact, they found that patients initially diagnosed with metastatic prostate cancer between 1988 and 1998 actually had slightly higher survival rates than those diagnosed between 2004 and 2009. Making a Case for PSA "It's indisputable that the incidence of men walking in the door with metastatic prostate cancer has dropped since the invention of PSA screening," Dr. Dall'Era says. "Screening has led to profound stage migration. You could argue that PSA is still the best way to follow [the condition of] men with prostate cancer. We can pick up recurrences and gauge responses to secondary treatments better [with PSA]. It may lead to improvements in survival." Heavy hitters in the prostate cancer world, such as the American Cancer Society and the Prostate Cancer Research Institute, have spoken out against the USPSTF's stance against PSA, recommending smarter screening instead of no screening and urg- ing an individual approach to treatment to help prevent unnecessary therapies. "There is a need to separate treat- ment from diagnosis," Dr. Dall'Era says. "Treatments need to be risk-based, not one-size-fi ts-all." Advancing Care The UC Davis Comprehensive Cancer Center study also highlights the need for improved treatment options for patients with metastatic prostate cancer. There is no cure for metastatic prostate cancer, but new treatments may offer additional options to slow progression and improve life expectancy. The study reviewed patient data through 2009. Since that time, there have been several advances in care, especially for metastatic castration-resistant pros- tate cancer, which does not respond to routine hormone therapy, such as androgen deprivation. One such advance, abiraterone, was recently approved for asymptomatic patients with metastatic castration- resistant prostate cancer before physicians resort to chemotherapy. It and enzalu- tamide, which is expected to be approved soon, are so-called "super-antiandrogens," medications that suppress testosterone production from multiple sources in the body at once, reducing cancer-fueling testosterone levels better than any other current medication in some patients. Enzalutamide, an androgen receptor inhibitor, has been shown to reduce the hazard ratio of prostate cancer patients by 81 percent, may be taken in pill form and causes fewer side effects than chemotherapy. Abiraterone is prescribed alongside prednisone and blocks testosterone syn- thesis in the testes, adrenal glands and prostate cancer cells. "As a class, these new medications are very exciting," Dr. Dall'Era says. "I think future research will look at patterns of resistance to these medications, into why some patients respond well and why some rapidly develop resistance. [It's possible] we can circumvent some of that resistance [using these medications] concurrently or in succession." ■ STI C KI N G WITH TH E PL AN ONE AREA OF general agreement about prostate-specifi c antigen screening is that men should be provided ample information regarding its risks and benefi ts. Yet that may not alter their decisions. A total of 1,879 men ages 45–70 were provided print- and Web-based decision aids as part of a study published in JAMA Internal Medicine in July 2013. The materials enhanced patients' knowledge and assuaged their uncertainty, "but in fact, the men didn't change their screening plans," notes Kathryn Taylor, PhD, Professor in the Cancer Prevention and Control Program at Georgetown Lombardi Comprehensive Cancer Center. By Valerie Lauer IN 1975, APPROXIMATELY 66 PERCENT OF PATIENTS WITH PROSTATE CANCER COULD EXPECT TO LIVE FIVE YEARS OR MORE. IN THE DECADES THAT FOLLOWED, THE NUMBER OF LONG-TERM SURVIVORS INCREASED MORE THAN 40 PERCENT, AND TODAY, NEARLY 100 PERCENT OF PATIENTS WHO HAVE LOCAL OR REGIONAL PROSTATE CANCER AT THE TIME OF DIAGNOSIS LIVE FIVE YEARS OR MORE. PATIENTS WITH METASTATIC PROSTATE CANCER HAVE NOT SEEN SIMILAR PROGRESS, HOWEVER. Fuel for Debate: Study Raises New Questions about PSA Screening Recommendation CORE CORE 1 8 | San Antonio MD NEWS ■ M D N E W S . CO M

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