Introduction: Advances in the Management of Prostate Cancer: The Emerging Role of ProstaScint and Quadramet

INTRODUCTION Advances in the Management of Prostate Cancer: The Emerging Role of ProstaScint® and Quadramet® Michael K. Brawer, MD Northwest Prostate Institute, Northwest Hospital, Seattle, WA [Rev Urol. 2004;6(suppl 10):S1–S2] © 2004 MedReviews, LLC rostate cancer remains the second most common malignancy and cause of death from cancer among men in the United States, despite the profound changes in the epidemiology and management of the disease that have occurred over the past few decades.1 The progress in our understanding of the disease has led to significant advances in our therapeutic, diagnostic, and prognostic abilities. Although effective therapies continue to evolve and improve, there is yet a long way to go before we can claim victory in our war against prostate cancer.1 Prostate cancer is relatively unique in terms of its pattern of metastasis. Each year approximately 100,000 new cases of bony metastasis are diagnosed in the United States, with prostate, lung, and breast cancers accounting for close to 80% of incident cases.2,3 The prevalence of skeletal metastasis, however, is particularly high for prostate cancer patients; not only is the bone to soft tissue ratio disproportionately high vis-á-vis other solid tumors, but the length of survival is also relatively longer. The median survival for men with prostate cancer and bony metastasis is more than 24 months, in comparison with 3.6 months for lung cancer patients.4,5 The complications of metastasis to the bone are well known and include pain, pathologic fractures, anemia, hypercalcemia, and spinal cord compression. Such anticipated sequelae of the disease have increased the clinician’s and patient’s interest in therapies that improve quality of life along with possibly further increasing longevity. In November 2004, we convened a roundtable in New Orleans, Louisiana, to discuss advances in the treatment and diagnosis of prostate cancer, with an emphasis on the development and proliferation of radiopharmaceutical agents. Four opinion leaders from major medical institutions around the country met to share their clinical expertise and research results surrounding treatment advances and new therapeutic approaches to men with advanced prostate cancer. These experts debated P VOL. 6 SUPPL. 10 2004 REVIEWS IN UROLOGY S1 Introduction continued the current and future management and diagnosis of advanced prostate cancer. The presentations and discussions from this roundtable form the basis of this supplement to Reviews in Urology. Oliver Sartor, MD, begins this supplement with an overview of samarium Sm 153 lexidronam and metastatic bone disease, a provocative area for research as well as patient care. The role of radiopharmaceuticals is well established in the palliative care milieu, and it is believed that combinations of bone-targeted agents, bisphosphonates, radiopharmaceuticals, and agents designed to target key growth factor and signaling pathway will be a mechanism whereby we can make continued progress in our understanding and treatment of the disease. Sam S. Chang, MD, follows with a discussion of prostate-specific membrane antigen (PSMA), a glycoprotein expressed by prostate tissue, and its prognostic capabilities or potential as a therapeutic marker for prostate cancer. The US Food and Drug Ad- ministration-approved diagnostic tool, ProstaScint® scan (Cytogen Corporation, Princeton, NJ), is described, as are the potential uses of PSMA as an effective therapy beyond its use for a diagnostic target. As a companion piece, Samir S. Taneja, MD, presents the contemporary uses of this sitespecific radiolabeled monoclonal antibody that is reactive with PSMA. Its conventional uses for staging and relapse detection are described, and a number of future clinical applications are presented. The supplement concludes with a review by David I. Quinn, MD, PhD, of future therapies for men with prostate cancer refractory to standard androgen ablation treatment. The potential therapeutic advances associated with targeted therapies and response prediction are discussed, and the need for well-designed clinical trials to integrate the recent results of laboratory, translational, and clinical studies is outlined. Although significant strides have been made in our understanding and S2 VOL. 6 SUPPL. 10 2004 REVIEWS IN UROLOGY treatment of men with advanced prostate cancer, many areas and questions remain to be explored and answered. I hope this supplement answers a number of questions currently facing clinicians and their patients with refractory prostate cancer and raises issues in need of further study. Further, I hope and anticipate that the directions and research efforts currently under investigation will result in significant improvement in pain management and quality of life of increasing numbers of men with this disease. References 1. 2. 3. 4. 5. Bailer JC III, Gornik HL. Cancer undefeated. N Engl J Med. 1997;336:1569–1574. Jemal A, Tiwari RC, Murray T, et al. Cancer statistics, 2004. CA Cancer J Clin. 2004;54:8–29. Galasko CSB. The anatomy and pathways of skeletal metastases. In: Weiss L, Gilbert HA, eds. Bone Metastasis. Volume 6. Boston, MA: GK Hall; 1981:49–63. Kato I, Severson RK, Schwartz AG. Conditional median survival in patients with advanced carcinoma: surveillance, epidemiology and end results data. Cancer. 2000;92:2211–2219. American Cancer Society. Survival from advanced cancer increases with each passing year. 2001;11. Available at: http://www.cancer.org/ docroot/NWS/content/NWA.html. Accessed November 18, 2004.