Radiation therapy is the most common treatment for prostate cancer regardless of cancer stage, prostate-specific antigen (PSA) level, and prognosis and risk rating
Earlier diagnosis and treatment advances have meant increased use of aggressive local treatments for prostate cancer, particularly radical prostatectomy and radiation therapy, which can result in adverse effects. And a study says patients must often consider the recommendations of physicians, the aggressiveness of their cancer, whether active surveillance is preferred over treatment, and health care costs.
Dr Jim C Hu, formerly of the David Geffen School of Medicine at UCLA, Los Angeles, and now of the Weill Cornell Medical College, New York, and co-authors examined predictors for treatment and use of watchful waiting or active surveillance (monitoring of the disease with the expectation to begin treatment if the cancer progresses) for indolent (less aggressive) prostate cancer. The research was conducted at UCLA and authors analysed Surveillance, Epidemiology and End Results (SEER)-Medicare linked data for a total of 37,621 men diagnosed with prostate cancer from 2004 to 2007.
The authors found radiation therapy (57.9%) was the most common treatment followed by radical prostatectomy (19.1%) and other treatments including watchful waiting or active surveillance (WW-AS 9.6%). Patient demographics and tumour characteristics account for 40% of patients undergoing prostatectomy, 12% choosing WW-AS, and 3% undergoing radiotherapy, according to the results.
While radiation treatment was the most common treatment (48% – 66%) regardless of stage, PSA level, and prognosis and tumour rating, radical prostatectomy was influenced by PSA level. WW-AS was guided by clinical stage, as well as prognosis and tumour rating, while androgen-deprivation therapy (ADT) was influenced by cancer stage, PSA level and prognosis and risk rating.
The authors also found WW-AS increased with advanced age and a consultation with a medical oncologist also increased use of WW-AS. Asian men and married men were associated with the least likely use of WW-AS. Increased radiation use was found among men with advancing age, more significant co-existing illnesses and tumour characteristics, and it was most likely used when men were referred to a radiation oncologist, according to the results.
"There remains an increased use of treatments in men diagnosed as having prostate cancer and under-use of active surveillance in men with low-risk disease. There is an increased use of radiotherapy among all risk groups and in particular patients with indolent disease with limited correlation according to tumour biological characteristics and patient health. Further research into identifying determinants that drive decision-making recommendations for patients diagnosed with low-risk prostate cancer are needed. These findings must be balanced when considering health care reform initiatives to improve quality of care," the study concludes.
Another study suggests active surveillance may be an initial approach for men with favourable intermediate-risk prostate cancer but further research results are needed. According to the US National Comprehensive Cancer Network (NCCN) guidelines, active surveillance is considered for patients with low-risk prostate cancer and a life expectancy of at least 10 years.
Active surveillance means monitoring the course of prostate cancer with the expectation to start treatment if the cancer progresses. No direct comparison has been made between favourable intermediate-risk and low-risk prostate cancer with regard to prostate cancer-specific mortality or all-cause mortality following high-dose radiotherapy such as brachytherapy (where radioactive seeds are placed near the tumour). The authors note such comparisons are clinically relevant because of the active surveillance guidelines for men with low-risk prostate cancer.
Dr Ann C Raldow, of Brigham and Women's Hospital, Boston, and co-authors studied 5,580 men (midpoint age, 68 years) with localised prostate cancer treated between 1997 and 2013. They estimated and compared the risk of prostate cancer-specific mortality and all-cause mortality following brachytherapy among men with low and favourable intermediate-risk prostate cancer.
After a median of nearly eight years of follow-up, 605 men died (10.84% of the total group) and, among those, 34 men died of prostate cancer (5.62% of total deaths). The authors found that men with favourable intermediate-risk prostate cancer did not have a significantly increased risk of prostate cancer-specific mortality and all-cause mortality compared with men with low-risk prostate cancer. Eight-year estimates for prostate cancer-specific mortality were low at 0.48% for men with favourable intermediate-risk prostate cancer and 0.33% for men with low-risk prostate cancer. The estimates for all-cause mortality were 10.45% for men with favourable intermediate-risk prostate cancer and 8.68% for men with low-risk prostate cancer, according to the results.
"Despite potential study limitations, we found that men with low-risk prostate cancer and favourable intermediate-risk prostate cancer have similar and very low estimates of prostate cancer-specific mortality and all-cause mortality during the first decade following brachytherapy. While awaiting the results of ProtecT, the randomised trial of active surveillance vs treatment, our results provide evidence to support active surveillance as an initial approach for men with favourable intermediate-risk prostate cancer," the study concludes.
[link url="http://media.jamanetwork.com/news-item/study-may-support-active-surveillance-for-favorable-intermediate-risk-prostate-cancer/"]JAMA press release[/link]
[link url="http://oncology.jamanetwork.com/article.aspx?articleid=2118571"]JAMA Oncology abstract[/link]
[link url="http://media.jamanetwork.com/news-item/radiation-therapy-most-common-treatment-for-prostate-cancer/"]JAMA release[/link]
[link url="http://oncology.jamanetwork.com/article.aspx?articleid=2118569&resultClick=3"]JAMA Oncology abstract[/link]