The current standard of care is for men with metastatic prostate cancer to begin with androgen-deprivation therapy (ADT), also known as hormone therapy, then progress to chemotherapy after ADT has stopped working. Previous clinical trials have shown that this increases overall median survival by about 2 to 5 months. ADT cuts the production of testosterone, which feeds the tumor. Doctors have been trying to determine the best time to begin chemotherapy if ADT stops being effective and the patientís tumor continues to grow.
Men typically put off starting chemotherapy because of its side effects and potential risks. The CHAARTED trial may convince some doctors to offer chemotherapy to their higher-risk patients sooner, as long as the patient is healthy enough for chemotherapy.
Effectiveness of Upfront Chemotherapy
The ECOG E3805 CHAARTED study aimed to assess the impact of upfront chemotherapy for men with metastatic prostate cancer. Researchers followed 790 men with metastatic prostate cancer who received androgen-deprivation therapy (ADT). Of these men, 397 were randomized within 4 months of starting ADT to receive docetaxel 75 mg/m2 every 3 weeks for 6 cycles. Patients who progressed with ADT alone could be given chemotherapy eventually, according to the current standard of care.
After a median follow-up of 29 months, ADT plus docetaxel improved survival by 39% for men in the study. Fewer men in the ADT plus docetaxel group died than those who received ADT alone (104 vs. 137), and the median overall survival was longer by 13.6 months (57.6 vs. 44.0 months). The combined treatment was especially effective in patients whose cancer had spread more extensively. In these men, overall survival was increased by an average of 17 months.
Docetaxel was approved for metastatic prostate cancer in 2004. Its brand name is Taxotere (by Sanofi), but generic options are also available.
Some guidelines for the detection of prostate cancer, such as those from the United States Preventive Services Task Force, discourage men from having PSA tests. Since routine PSA screening detects prostate cancer at an earlier stage, the findings from the CHAARTED are especially important. If fewer men are being screened early for prostate cancer, it is likely that in the future, more men will have metastatic cancer at the time of diagnosis.
The CHAARTED trial was highlighted at the American Society of Clinical Oncology annual meeting held in Chicago in June.