"A new treatment protocol combining radionuclide therapy and chemotherapy may represent a distinct advantage over conventional protocols, especially when patients have metastatic (or spreading) prostate cancer that is not responding to hormonal therapy," said Giuliano Mariani, professor of nuclear medicine and director at the Regional Center of Nuclear Medicine at the University of Pisa Medical School in Italy. "Radionuclide therapy alleviated bone pain, but preliminary observations indicated that--if adequately combined with chemotherapy--it might produce clinical benefit in terms of regression and prolonged survival," added the co-author of "Early Response and Toxicity of 153Sm-EDTMP Combined With Docetaxel in Patients With Hormone-Refractory Metastatic Prostate Cancer."
All men are at risk of developing cancer in the prostate, a gland in the male reproductive system. Prostate cancer occurs when the cells of the prostate begin to grow uncontrollably, and these cells may spread--or metastasize--from the prostate to other parts of the body, especially the bones and lymph nodes, said Mariani. More than 234,000 men in the United States will be diagnosed with prostate cancer this year, and more than 27,000 will die of the disease, which is the second leading cause of cancer death in men.
"We explored combining radionuclide therapy based on the radioisotope Samarium-153 with carrier EDTMP and chemotherapy to achieve actual regression and prolonged survival," said Mariani. "Our research confirms the possibility of achieving tumor targeting of a radiopharmaceutical with such efficiency that it induces a definite therapeutic effect, and this shows the possibility of obtaining a synergistic therapeutic effect in combination with conventional chemotherapy," he explained.
"The blood toxic effects of our combination regimen were mild and comparable to those observed when the two therapies were used separately," said Mariani. In addition, researchers "observed significant reduction of PSA (prostate-specific antigen) levels in serum, a marker of the overall burden or severity of the disease," he added. "The majority of patients treated so far have either stable disease or regression of disease in a six-month follow-up," he noted.
"A major concern when attempting combination regimens of this type is to induce reciprocal augmentation of the possible toxic effects of the two therapies (radionuclide and chemotherapy), thus limiting applicability of the new protocol," said Mariani. "We are now evaluating our patients with an extended follow-up in order to assess the effect of the combined protocol on survival. Future investigations should explore the possibility of employing higher doses of the radiopharmaceutical in order to achieve the highest possible therapeutic effect--with the lowest possible toxic effect, he noted.
Abstract: G. Mariani, G. Boni, D. Genovesi, F. Pesella and G. Picchi, all at Regional Center of Nuclear Medicine, University of Pisa Medical School, Pisa, Italy, and I. Pastina, A. Chioni, C. Cianci and S. Ricci, all with the Division of Medical Oncology, University Hospital, Pisa, Italy, "Early Response and Toxicity of 153Sm-EDTMP Combined With Docetaxel in Patients With Hormone-Refractory Metastatic Prostate Cancer," SNM's 53rd Annual Meeting, June 3–7, 2006, Scientific Paper 297.
About SNM
SNM is holding its 53rd Annual Meeting June 3–7 at the San Diego Convention Center. Research topics for the 2006 meeting include molecular imaging in clinical practice in the fight against cancer; the role of diagnostic imaging in the management of metastatic bone disease; metabolic imaging for heart disease; neuroendocrine and brain imaging, new agents for imaging infection and inflammation; and an examination of dementia, neurodegeneration, movement disorders and thyroid cancer.
SNM is an international scientific and professional organization of more than 16,000 members dedicated to promoting the science, technology and practical applications of molecular and nuclear imaging to diagnose, manage and treat diseases in women, men and children. Founded more than 50 years ago, SNM continues to provide essential resources for health care practitioners and patients; publish the most prominent peer-reviewed journal in the field; host the premier annual meeting for medical imaging; sponsor research grants, fellowships and awards; and train physicians, technologists, scientists, physicists, chemists and radiopharmacists in state-of-the-art imaging procedures and advances. SNM members have introduced--and continue to explore--biological and technological innovations in medicine that noninvasively investigate the molecular basis of diseases, benefiting countless generations of patients. SNM is based in Reston, Va.; additional information can be found online at http://www.snm.org.