Prostate cancer and combined therapy

“Prostate cancer patients and their doctors may want to think twice about the best timing for chemotherapy or radiation therapy in conjunction with a common nonsurgical treatment, based on international research findings led by UT Southwestern Medical Center investigators.”

Scientists found out that usual medical androgen deprivation therapies (ADTs) like chemotherapy or radiotherapy deprive also patient´s adaptive immune system and any subsequent immunotherapy will be then compromised. The surgical ADT- castration- works in combination with immunotherapy.

The ADTs are used for 50 years. Progress in immunotherapy led to some promising candidates and as a logical step, combination of ADTs and immunotherapy for prostate cancer started to be used. However, using medical ADT in this combination order leads to the relapses in prostate cancer commonly seen in clinical trials.

Reduction of T-cell response against the prostate cancer induced by some androgen receptor antagonists was found by researchers as a main mechanism of this effect.

As a take-home message from this scientific work is that physicians will have to carefully think about possible combination strategies in advance before starting radiotherapy or chemotherapy for prostate cancer. And if immunotherapy is an option, one should consider timing and method of the ADT to be used.

Sources:

1. News source: Common prostate cancer treatments suppress immune response and may promote relapse, Eurekalert.
2. Scientific paper: Androgen receptor antagonists compromise T cell response against prostate cancer leading to early tumor relapse. DOI: 10.1126/scitranslmed.aad5659