One of the largest jumps in overall survival in advanced prostate cancer was described at this year’s annual meeting of the American Society of Clinical Oncology.
Hormone therapy is a standard treatment for men with advanced prostate cancer, but eventually resistance develops and the cancer progresses. Chemotherapy is a common second-line therapy. The question was posed that if chemotherapy was given earlier, during hormone therapy, would it improve survival.
Researchers found that adding docetaxel to hormone therapy improves survival by 10 months in patients with newly diagnosed, hormone-sensitive metastatic prostate cancer. (You can see the full abstract results here.) The trial studied 790 men, with about two-thirds having extensive metastases. Overall survival improved from 44 months to 57.6 months; men with extensive metastases saw an improvement from 32.2 months to 49.2 months–a 17-month improvement. Other than disease extent, the benefit was seen across many subgroups, including race, age and prior therapy for early-stage disease.
Michael Morris, of Memorial Sloan Kettering Cancer Center, provided commentary after the presentation and noted that no other large study in recent times in this patient group has seen such a large jump in survival, even with the new agents recently approved for prostate cancer. “If you look at every other drug trial that prolongs survival none even come close in terms of survival prolongation to 17 months. Our best therapies in castration-resistant disease are less than a third of that for the high-volume patients in ECOG3805 (study),” he said, adding that the combination uses a generic, older chemotherapy at a fraction of the cost of newer therapies.
Overall survival in men with less extensive metastases is not yet known, but researchers are continuing to follow the group to determine if there is a benefit of the combination.
Morris also commented that there should be a better definition of “extensive disease,” to help guide the medical community on who would benefit from this regimen. Currently, extensive disease is defined as four or more distant lesions. However, men with small lesions who are asymptomatic may not do as well on the combination as a man who has three large distant lesions.
The addition of chemotherapy resulted in one treatment-related death out of 397 patients, in addition to reports of allergic reaction, low white blood cell counts and fever, which could result in increased infection risk, and neuropathy.
“The benefit in patients with a high volume of metastases is clear and justifies the treatment burden,” said lead author and Dana Farber Cancer Institute oncologist, Christopher Sweeney, at the conclusion of the results presentation. “Longer follow up is required for patients with low volume metastatic disease.”