Last weekend, Dr. Himisha Beltran traveled to Washington, D.C. to speak at the “Best of ASCO” meeting. She hosted the session on prostate cancer and summarized some of the most important studies presented at the 2016 American Society of Clinical Oncology (ASCO) meeting in Chicago.
She also represented Weill Cornell Medicine and NewYork-Presbyterian on a panel of the nation’s leading experts. The panel answered questions regarding some of the most challenging cases in genitourinary (GU) cancer care.
What’s new in research and treatment?
For men with advanced (metastatic) prostate cancer, the class of chemotherapy that has consistently proven to improve survival is called “taxanes.”
There are two taxanes that have been FDA-approved to treat prostate cancer, docetaxel (brand name: Taxotere) and cabazitazel (brand name: Jevtana). While these drugs are similar, men whose tumors have grown despite taking one drug often respond to the other.
Much of the important research at this year’s ASCO meeting focused on some key questions related to these two treatment options:
1. What treatment dose is best to maximize response, but minimize side effects?
2. Does the order in which patients receive these treatments matter?
3. When should oncologists switch between treatments if one is not working?
4. What is the impact on quality of life?
Another hot topic was the value and cost of treatments, and the link between treatment cost and access to care, since there can be financial barriers associated with certain treatments.
Below, we’ve outlined some of the key studies and clinical takeaways for prostate cancer treatment that Dr. Beltran discussed at the Best of ASCO meeting:
- For patients with metastatic castration-resistant prostate cancer (cancer that grows despite initial hormonal therapy), we learned that a newer drug (cabazitaxel) was not better compared to the old standard (docetaxel) for men who had not previously received chemo. In addition, a slightly lower dose of cabazitaxel for men that had previously received docetaxel was just as good in controlling the cancer with fewer side effects. Combined, these studies point towards less toxicity for individual patients, a cost-savings for the healthcare system, and potentially a lower financial burden on patients. A smaller study pointed towards increased responses by switching between these two drugs at an early time point if PSA was not decreasing optimally, and demonstrated that a circulating biomarker (blood test) provides an opportunity for scientists to analyze the mechanism of action of chemotherapy and assess response or resistance to treatment.
- For patients with untreated metastatic prostate cancer, large studies have recently demonstrated the improved survival impact of using a combined treatment of both chemotherapy and hormonal therapy as opposed to only hormonal therapy for men with metastatic prostate cancer. A new research study examined the CHAARTED study data and evaluated the quality of life (QOL) of patients treated on the study. This research found that while the QOL was initially worse (at 3 months), there was no long-term negative impact, and QOL was better at 12 months for chemo patients relative to those who only received hormonal therapy. This has important implications for counseling patients, as some are worried about side effects. It is comforting to know that while side effects may occur, they are temporary and the longer-term benefit of cancer control leads to improved QOL in the longer term.
- A randomized trial examined radiation therapy for treating localized prostate cancer that had not spread beyond the prostate gland in men with intermediate risk disease. This study compared the standard eight-week course of treatment with a shorter course of four weeks, called hypofractionation. The shorter course of treatment did not see any reduction in treatment response and did not increase toxicity. The results from this study in combination with two other similar studies (RTOG 0415 and ChIPP) support using hypofractionation as a new standard for men with intermediate risk prostate cancer, as it is more convenient since it requires fewer visits to complete and is potentially less costly for patients.
- In a large multi-institutional study of nearly 700 patients (including Weill Cornell), over 11% of patients with metastatic prostate cancer had inherited mutations in DNA repair genes (such as BRCA2 or ATM). This has important family risk and treatment implications since these genes can be passed down through the family tree and are not only linked with prostate cancer, but other cancer risk, as well. This is practice changing and supports genetic counseling and testing for all men with metastatic prostate cancer. In addition, research is ongoing to utilize drugs that may work especially well in this situation.