A clinical trial reported on at the 2017 American Society of Clinical Oncology (ACSO) Annual Meeting found that advanced prostate cancer patients whose tumors have a certain combination of mutations may significantly benefit from treatment with platinum chemotherapy.
Not all “chemotherapy” is the same. Taxane chemotherapy (docetaxel, cabazitaxel) which works by blocking cells from multiplying, is a standard of care for advanced prostate cancer. Platinum chemotherapy (carboplatin, oxaliplatin, cisplatin, others), which works by damaging the cancer cell’s DNA, is standard of care in other cancer types, but is primarily used in prostate cancer patients who have no other treatment options left – not all of whom benefit.
Dr. Ana Aparicio, a medical oncologist at the University of Texas MD Anderson Cancer Center, is a world’s expert on identifying which of the end-stage prostate cancer patients she sees is most likely to benefit from platinum chemotherapy, based on clinical features. Typically, these patients have fast-growing cancers that do not respond to hormone therapy, and have a distinct growth pattern and pattern of metastasis.
Dr. Aparicio conducted a study to improve the ability to identify which patients might benefit from the addition of platinum chemotherapy. She examined 160 advanced prostate cancer patients who were treated with taxane chemotherapy (cabazitaxel) alone or with the addition of platinum chemotherapy (carboplatin). The study identified a unique mutation pattern in tumors from patients who significantly benefitted from the addition of carboplatin to cabazitaxel. Patients whose tumors did not have this mutation pattern benefited from cabazitaxel, but were not helped further by the addition of carboplatin.
This study demonstrates that precision medicine can be used to stratify patients with advanced prostate cancer into two groups – those for whom platinum chemotherapy is a life-extending treatment, and those who should receive standard of care taxane chemotherapy. Dr. Aparicio is now working to establish a blood test that can be used to easily identify these groups of patients – so that precision medicine – and the best treatment possible — can be accessible to every patient.
