New combination therapy effective even for larger prostate cancers

Vienna: Chemotherapy is generally very effective for smaller prostate cancers. However, with larger tumors, more B-cells are produced and these suppress the body's immune response, thereby helping the cancer to grow, despite treatment. An international team of researchers including scientists from MedUni Vienna has now successfully demonstrated that even larger prostate cancers can be effectively combated with a new type of combination therapy – if the immunosuppressive cells are first of all blocked or removed. In a mouse model, advanced prostate cancer was almost completely cured using this "chemo-immunotherapy".

B-lymphocytes (or B-cells) occur much more frequently in metastasized prostate cancers than in small tumors and they also have an immunosuppressive effect. These cells suppress the immune system so that current treatments cannot work and malignant tumors are able to grow unchecked.

The international research group, which includes the Clinical Institute of Pathology, the Ludwig Boltzmann Institute for Cancer Research (LBI-CR), the Unit of Pathology of Laboratory Animals Laboratory, Vetmeduni Vienna, and the Department of Urology of MedUni Vienna, has now been able to show that, in combination with immunotherapy, a drug currently used in chemotherapy (oxaliplatin), can be effective even in otherwise therapy-resistant, advanced prostate cancers. This is achieved by blocking the activity and function of the B-cells beforehand. This work has now been published in the leading magazine "Nature" and was the result of a joint project conducted by MedUni Vienna, the University of California, the San Diego School of Medicine and Charité Berlin.

"An added bonus is that this therapy is effective even with low-dose chemotherapy and is therefore much less stressful to the patient," explains Lukas Kenner of the Institute of Clinical Pathology of MedUni Vienna. "It would also be reasonable to conclude that similar immunosuppressive B-cells are also present in other types of human cancer." This could therefore lead to new treatment options for other forms of cancer.

4,700 Austrians develop prostate cancer every year
Worldwide, prostate cancer is the third most frequent potentially terminal cancer in men and the sixth most frequent cause of death from cancer. According to Statistics Austria, around 4,700 men develop prostate cancer in Austria every year. Approximately 1,200 of those affected die during the same period. In the European Union, around 300,000 men are diagnosed with prostate cancer each year and there are around two million men living with this disease.