BERKELEY, CA (UroToday.com) - Approximately 50% of prostate cancer patients develop bone metastases which are predominantly osteoblastic – a type that has a tendency towards fractures, resulting in serious morbidity.
This type of bone metastasis often leads to chronic pain syndrome in prostate cancer patients. Up to 50 % of prostate cancer patients with chronic pain syndrome are reported to receive inadequate pain treatment - which makes them candidates for radionuclide therapy.
Our study reviewed cases of 60 patients with hormone-refractory prostate cancer. The patients, all of whom had more than 5 lesions documented by a bone scan, were divided into 3 groups – those who received 1 therapy, 2 therapies, or 3 or more therapies.
Radionuclide therapy of bone metastases has been used for several decades for bone pain palliation. These isotopes include 32P, 89Sr, 153Sm-EDTMP, or 186Re-HEDP. Pain palliation using these radiopharmaceuticals was observed in approximately 70% of patients receiving them.
For this study, we developed 188Re-HEDP as a novel radiopharmaceutical which, due to its short half life of 19 hours, makes sequential therapy possible. Data were obtained from a questionnaire that asked for the survival time after the last 188Re-HEDP therapy (and if the pain had decreased), the prostate specific antigen (PSA level) and the physician’s objective impression about pain palliation.
Another radiopharmaceutical which was also administered in different doses is 153Sm-EDTMP. With increasing doses, a decrease in pain scores was observed in up to 80 % after 3 administrations. Only minor decreases in platelets and white blood cell counts were seen. However, no data on the survival of the patients were available.
This new study, using 188Re-HEDP, is an extension of our trials that were first published in 2003. That paper had shown that in 39% of patients with repeated treat-ments, a decrease in prostate specific antigen levels of more than 50 % for at least 3 weeks was observed. It could be shown that the survival of respective patients could significantly be improved. In our new study, we found an improvement of survival from 4.5 to 15.7 months after multiple injections of 188Re-HEDP.
In conclusion, for patients failing chemotherapy or hormone treatment, this new radiopharmaceutical is a promising therapy that can both extend the number of survival months and help relieve pain from bone metastases. With respect to the unpredictable course of the disease, randomized prospective studies are needed to achieve a comparable database in these patients and to define the benefits of repeated therapy.
Hans-Jürgen Biersack, MD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.