Patients newly diagnosed with metastatic prostate cancer may benefit from localized treatment, a new study suggests, showing that either removal of the prostate gland (radical prostatectomy) or a form of radiation therapy called intensity-modulated radiation therapy (IMRT) can markedly improve their survival chances.
The results, included in the abstract “Local Therapy Improves Overall Survival in Patients with Newly Diagnosed Metastatic Prostate Cancer,” were recently presented at the American Society for Radiation Oncology (ASTRO) 2016 Annual Meeting.
“While numerous treatment options exist for those with early stage prostate cancer, therapies are more limited for those with advanced disease that has spread beyond the prostate,” Rahul R. Parikh, MD, a Rutgers Cancer Institute radiation oncologist, and co-director of proton beam therapy at Rutgers Cancer Institute of New Jersey and its flagship hospital, Robert Wood Johnson University Hospital (RWJ), and study’s senior author, said in a press release.
Researchers sought to examine whether therapies that are often used in localized disease, such as radiation therapy or radical prostatectomy, could also be used to improve the the outcomes of patients with newly determined metastatic prostate cancer.
Using the National Cancer Database, which includes data from more than 1,500 accredited facilities, they identified 6,051 eligible patients, diagnosed with metastatic prostate cancer between 2004 and 2013. Eligibility criteria included adenocarcinoma histology, no chemotherapy or brachytherapy — a type of internal radiation therapy — and treatment within one year of diagnosis.
Of patients, 5,224 did not receive localized treatment, and more than 800 received therapy to treat the primary tumor in the prostate — 622 with a radical prostatectomy, 153 with conformational radiation therapy, and 52 with IMRT.
The researchers found that those who received localized treatment were more likely to be younger than 70, have fewer co-occurring diseases, have private or Medicare insurance, were treated at comprehensive cancer programs or academic/research centers, had higher incomes, and their disease had not spread to the lymph nodes.
Importantly, results showed that localized therapy significantly improved five-year overall survival compared to no local therapy (45.7% vs. 17.1%). After accounting for observed confounding factors, both radical prostatectomy and IMRT were still independently associated with an improvement in overall survival — 65 percent higher — compared to those who did not receive localized treatment.
“As radiation therapy and radical prostatectomy are not traditionally utilized in metastatic prostate cancer, we are hopeful that our findings will provide the foundation for new clinical research to further explore these therapies,” said John Byun, MD, the study’s lead investigator and a resident physician in the Department of Radiation Oncology at Rutgers Robert Wood Johnson Medical School.