ORLANDO, Fla.—The time to prostate cancer (PCa) metastasis in treatment-naïve patients and after patients have started androgen-deprivation therapy is associated with overall survival (OS), according to the findings of separate studies presented at the 2015 Genitourinary Cancers Symposium.

In a study of 92 PCa patients with metastatic disease, Shusuke Akamatsu, MD, PhD, of the Vancouver Prostate Centre and Department of Urologic Sciences at the University of British Columbia in Vancouver, and colleagues found that patients who have metastatic PCa at the time of their diagnosis have significantly shorter OS than PCa patients who develop metastases while their tumors are sensitive to castration or after they become castration resistant. 

Of the 92 patients, 35 had metastases at diagnosis (de novo-M), 26 developed metastases while the cancer was still castration-sensitive (CSPC-M), and 31 developed metastases after their cancer became castration-resistant (CRPC-M). The median time to death from diagnosis was 12.3, 15.8, and 3.7 years in the CSPC-M, CRPC-M, and de novo-M groups, respectively.

The median time to death from metastasis was 5, 2.6, and 3.7 years, respectively, and the median time to death from CRPC was 2.7, 3, and 0.9 years, respectively. 

The median time to metastasis in the CSPC-M and CRPC-M groups was 4.4 and 11.4 years, respectively. 

“Regardless of the timing of metastasis,” Dr. Akamatsu and colleagues concluded, “survival of more than 10 years after initial diagnosis is possible in cases that did not have metastasis at initial presentation.”

In the other study, Loana Valenca, MD, of the Dana-Farber Cancer Institute, Harvard Medical School, Boston, and colleagues explored the association between time to PCa metastasis and overall survival after the start of androgen-deprivation therapy (ADT) in 415 PCa patients who experienced biochemical recurrence after primary local therapy but had non-metastatic disease. The median follow-up was 6.4 years. 

Patients who had metastases identified 1, 2, and 3 years after the start of ADT had a significant 7.6 times, 5.7 times, and 5.8 times greater risk of death, respectively, than patients who did not have metastases at those time points. 

The study also showed that the time to metastasis from identification of castration-resistant disease is significantly associated with OS. Patients who had metastases identified 1, 2, and 3 years after ADT initiation had a significant 4.4, 4.6, and 5.2 times greater risk of death, respectively, than patients who did not have metastases identified at those time points, according to the investigators. 

Of the 415 patients in the study, 217 (52%) underwent radical prostatectomy with or without radiation therapy and 198 (48% underwent radiation therapy alone as their primary treatment.

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