Chemotherapy is any treatment involving the use of drugs to kill cancer cells. Cancer chemotherapy may consist of single drugs or combinations of drugs, and can be administered through a vein, injected into a body cavity, or delivered orally in the form of a pill. Chemotherapy is different from surgery or radiation therapy in that the cancer-fighting drugs circulate in the blood to parts of the body where the cancer may have spread and can kill or eliminate cancers cells at sites great distances from the original cancer. As a result, chemotherapy is considered a systemic treatment.
Chemotherapy is currently used mainly in men with advanced prostate cancer. The chemotherapy drug docetaxel was demonstrated to improve survival of men with metastatic prostate cancer in 2004 and has remained the mainstay of chemotherapy often utilized in combination with other chemotherapy drugs. For people who have cancers that respond well to chemotherapy, this approach helps treat their cancer effectively, enabling them to enjoy full, productive lives. Importantly, many side effects once associated with chemotherapy are now easily prevented, controlled, or avoided altogether by using targeted therapies allowing many people to work, travel, and participate in many of their other normal activities while receiving treatment.
A Targeted therapy is one that is designed to treat only the cancer cells and minimize damage to normal, healthy cells. Treatments that “target” cancer cells may offer the advantage of reduced treatment-related side effects and improved outcomes. Advances in science and technology have led to the development of several different drugs for the treatment of prostate cancer over the past few years and doctors are working to determine the best sequence, combinations, and timing of utilization.
Cabazitaxel is administered intravenously and has been demonstrated to improve time to cancer progression and overall survival in men with HRPC previously treated with docetaxel. Cabazitaxel’s primary side effect is neutropenia, and it is recommended that patients receive a white blood cell growth factor if they are at high risk of this complication.
Sipuleucel-T is actually an immunotherapy that prompts the body’s immune system to respond against the cancer. A Phase III clinical trial that contributed to the FDA approval of sipuleucel-T was a study known as IMPACT (Immunotherapy for Prostate AdenoCarcinoma Treatment) which demonstrated an improvement in overall survival for men treated with sipuleucel-T. The main side effects reported were chills, fever, and headache.
Patients with advanced prostate cancer can have cancer cells that have spread to their bones, called bone metastases. Bone metastases commonly cause pain, increase the risk of fractures, and can lead to a life-threatening condition characterized by an increased amount of calcium in the blood called hypercalcemia. Treatments for bone complications may include drug therapy or radiation therapy.
Zoledronic acid is a bisphosphonate drug and this class of drugs can effectively prevent loss of bone that occurs from cancer that has spread to the bones thereby reducing the risk of fractures, and decreasing pain. Bisphosphonate drugs work by inhibiting bone resorption, or breakdown. Zoledronic acid may be used to reduce the risk of complications from bone metastases or to treat cancer-related hypercalcemia,
Denosumab targets a protein known as the RANK ligand. This protein regulates the activity of osteoclasts (cells that break down bone). Studies have suggested that Denosumab may be more effective than Zoledronic acid at delaying bone complications in prostate cancer patients with bone metastases. Denosumab is associated with side effects including hypocalcemia (low levels of calcium in the blood) and osteonecrosis of the jaw (death of bone in the jaw).
Radium 223 is a targeted radiopharmaceutical agent that binds with minerals in the bone to deliver radiation directly to bone tumors, thereby limiting the damage to the surrounding normal tissues. The U.S. Food and Drug Administration (FDA) approved the drug in May 2013 after a trial known as Alpharadin in Symptomatic Prostate Cancer Patients (ALSYMPCA) was stopped early after an interim analysis showed that treatment with significantly improved survival.
Smith MR, Saad F, Coleman R et al. Denosumab and bone-metastasis-free survival in men with castration-resistant prostate cancer: results of a phase 3, randomised, placebo-controlled trial. Lancet. Early online publication November 16, 2011.
Basch E, Autio K, Ryan CJ, et al: Abiraterone acetate plus prednisone versus prednisone alone in chemotherapy-naive men with metastatic castration-resistant prostate cancer: patient-reported outcome results of a randomised phase 3 trial. The Lancet Oncology. 2013; 14(12):1193-1199.
Beer TM, Armstrong AJ, Sternberg CN, et al: Enzalutamide in men with chemotherapy-naive metastatic prostate cancer (mCRPC): Results of phase III PREVAIL study. Presented at the 2014 Genitourinary Cancers Symposium. Journal of Clinical Oncology. 2014; 32 (supplement 4; abstract LBA1).
Nelson J, Banato A, Battistini B, Nisen P. The endothelin axis: emerging role in cancer. Nat Rev Cancer2003;3(2):110-116.
Carducci M, Nelson JB, Saad F, et al. Effects of atrasentan on disease progression and biological markers in men with metastatic hormone-refractory prostate cancer: Phase 3 study. Journal of Clinical Oncology, 2004 Annual Meeting Proceedings (Post-meeting edition);22(14S), Abstract #4508.
Lipton A, Sleep DJ, Hulting SM, et al. Benefit of Atrasentan in Men with Hormone Refractory Prostate Cancer Metastatic to Bone. Journal of Clinical Oncology, 2004 ASCO Annual Meeting Proceedings (Post-Meeting Edition);22(14S), Abstract #4687.
Yount S, Cella D, Mulani P, et al. Impact of atrasentan on prostate-specific outcomes with hormone refractory prostate cancer patients. Journal of Clinical Oncology, 2004 ASCO Annual Meeting Proceedings (Post-Meeting Edition);22(14S), Abstract #4582.
Scher HI, Fizazi K, Saad F et al: Increased survival with enzalutamide in prostate cancer after chemotherapy. N Eng J Med 2012; 367: 1187.
de Bono JS, Logothetis CJ, Molina A et al: Abiraterone and increased survival in metastatic prostate cancer. N Engl J Med 2011; 364: 1995.
Kantoff PW, Higano CS, Shore ND et al: Sipuleucel-T immunotherapy for castration-resistant prostate cancer. N Engl J Med 2010; 363: 411.
de Bono JS, Oudard S, Ozguroglu M et al: Prednisone plus cabazitaxel or mitoxantrone for metastatic castration-resistant prostate cancer progressing after docetaxel treatment: a randomized open-label trial. Lancet 2010; 376: 1147.
Copyright © 2014 CancerConsultants. All Rights Reserved.