Combining an older chemotherapy drug with standard hormone treatment early on helped men with advanced prostate cancer live more than a year longer, according to a study that may change medical practice.
For decades, hormone therapy has been the standard as a first treatment for metastatic prostate cancer. Chemotherapy and other drugs are usually reserved for when hormone therapy fails. The new trial, which included 790 patients, showed that joining the two treatments right away could dramatically improve survival. The chemotherapy drug used was docetaxel, which is available as a generic.
More than 29,000 Americans will die from prostate cancer this year, according to the American Cancer Society. Patients who got the combination treatment as a first-line therapy lived a median of 57.6 months, compared with 44 months for those with hormone treatment alone, according to data reported yesterday at the American Society of Clinical Oncology meeting in Chicago.
“It is a big deal,” the first regimen to increase survival significantly in newly diagnosed patients since hormone suppression was shown to be an active therapy in the 1940s, said Christopher Sweeney, a medical oncologist at Dana-Farber Cancer Institute who was lead author on the study.
Docetaxel is the generic name for the chemotherapy drug Taxotere, made by Paris-based Sanofi. Because docetaxel is off patent, an 18 week course of treatment costs just $9,000, far less than for most new cancer drugs, said Michael Morris, an oncologist at Memorial Sloan Kettering Cancer Center.
“This is what we would call a high value proposition,” Morris said in a telephone interview. “It doesn’t cost that much and it produces a lot of survival benefit.”
The year-plus gain “is a big difference,” compared to other prostate cancer drug trials, Morris said. Trials of other drugs, including docetaxel itself, have found survival gains of between two to five months when the drugs were used after hormone therapy stopped working.
The survival difference was most pronounced in the 520 men whose tumors had spread extensively to numerous sites in the bone or other organs. They lived 17 months longer if they were treated with the combination, according to the data. It is not yet clear whether initial chemotherapy use extended survival in men with lower amounts of disease, Sweeney said.
Side effects of the chemotherapy include fatigue, numbness in the fingers and toes, and lowered white blood cell counts, said Sweeney, who has served as a consultant to Sanofi.
The findings show the importance of matching the aggressiveness of prostate cancer therapy to the likelihood a man is going to die from the disease soon. The current trial focused on advanced patients with extensive disease spread who were at high risk of dying relatively soon.
By contrast, an earlier European trial combining docetaxel with hormone therapy that failed to show a survival advantage was smaller and studied advanced prostate patients with lower-risk disease, Morris said.
Most patients are diagnosed in early-stage disease that’s curable with surgery or radiation, and some early-stage cases are so slow growing they may not need immediate treatment. In a small percentage of cases, the disease spreads to distant sites such as the bones, and these tumors are life threatening.
“If you think of it as a huge funnel, at the top end there are a lot of cancers we don’t need to worry about,” said Sweeney. “At the bottom there are these aggressive cancers that may compromise a man’s life.”