Hormone therapy plus chemotherapy may boost survival in men with advanced prostate cancer

By Charlie Schmidt

A team of Harvard-affiliated investigators made headlines recently when they reported that treating men with advanced prostate cancer using a two-drug combination significantly increased survival. One expert called the results potentially “transformative.”

When prostate cancer spreads beyond the prostate gland, the standard treatment is androgen-deprivation therapy (ADT). This treatment cuts off the body’s production of testosterone. Prostate cancer cells need testosterone (a type of hormone known as an androgen) to grow. ADT works for a time, but eventually cancer cells become resistant to it and begin to grow and spread again. At that point, doctors typically add a chemotherapy drug called docetaxel to ADT.

After scientists first reported in 2005 that docetaxel improved survival in men with advanced prostate cancer, some experts wondered if such men might live even longer if they got ADT and docetaxel at the same time.

Dr. Christopher Sweeney and his colleagues at the Dana-Farber Cancer Institute’s Lank Center for Genitourinary Oncology recruited 790 men with advanced prostate cancer and randomly divided them into two groups. One group was given ADT and six cycles of docetaxel over 18 weeks, then ADT alone. The other group was initially treated only with ADT, and then started on docetaxel if their cancer began to get worse.

The men who initially got the ADT/docetaxel combination lived an average of nearly 58 months, compared to 44 months for men who were treated initially only with ADT. Men with the most advanced cancers benefited most from the combination — they lived roughly 49 months, or 17 months longer than men who were started on ADT alone. The results were presented at the 2014 annual meeting of the American Society of Clinical Oncology in Chicago.

Sweeney emphasized that the combined treatment is suitable only for men who are “fit for chemotherapy,” meaning that they aren’t old, or frail, or sick with other potentially life-threatening conditions.

Keep in mind that these results have yet to be published in a peer-reviewed medical journal. Other scientists will need to evaluate the findings before they can be widely accepted. This is especially important because some men have difficulty tolerating docetaxel.

Clifford Hudis, M.D., president of the American Society of Clinical Oncology and chief of the Breast Cancer Medical Service at Memorial Sloan Kettering Cancer Center in New York, said the results revealed an “almost unprecedented improvement in survival” that could be “transformative” in prostate cancer care.

Doctors might also consider a multitude of other, potentially less toxic therapies that may not have been available when the study was launched, recommended prostate cancer specialist Dr. Marc B. Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center. “We still need to see detailed aspects of the study in a peer-reviewed publication,” Garnick said.