1: Baseline PSA levels predict for future development of lethal prostate cancer
An American study published in the Journal of Clinical Oncology has shown that baseline PSA levels taken in midlife were strongly associated with future risk of lethal prostate cancer (PCa). Researchers measured baseline PSA levels in blood samples, collected between 1982 and 1984, from men then aged 40-59 years. Men were divided into two categories: 234 cases (men who were diagnosed with PCa between 1982 and 1993) and 711 matched controls. During follow up, 60 out of the 234 men (26%) originally diagnosed with PCa died of the disease, whereas 11 out of 711 men (2%) selected as controls also developed lethal PCa.
Across all age groups, men with baseline PSA levels above the age-specific median had increased risk of developing PCa compared to men with PSA levels at or below the median. The ORs were 7.3 (95% CI, 2.4 to 21.8) for 40-49 years, 7.6 (95% CI 3.4-17.2) for 50-54 years and 10.1 (95% CI, 5.2 to 19.6) for 55-59 years. The risk of developing lethal PCa was also strongly associated with baseline PSA levels, with 86% of lethal cases occurring in men with PSA measurements above the median level. These results are consistent with previous research and suggest that there may be limited benefit in re-testing men who have no additional risk factors and a PSA less than 1.0ng/ml at 60 years. While significant, this was a small study and future research will be important to confirm these results. For more information about Prostate Cancer UK's position on PSA testing please see our PSA Consensus Statements.
2: Androgen deprivation treatments associated with higher risk of dementia
A retrospective analysis of 9272 men with prostate cancer found that men who received androgen deprivation treatment (ADT) had a small but significant increased rate of dementia at 5 years. Men who received ADT had a 7.9% absolute risk of developing dementia compared to 3.5% for men who were not treated with ADT. Men receiving ADT were significantly older and had more co-morbidities. These factors were adjusted for in the analysis, however do raise the possibility that there may be other aspects of poor health that were not accounted for in the ADT treatment group. This data is consistent with previous research from the same group showing a link between ADT treatment and Alzheimer’s disease, as well as work suggesting that lower levels of testosterone in men may be predictive for developing dementia.
Despite the possible increased dementia risk, ADT remains a highly effective treatment. Therefore, while these risks may form part of a risk-benefit conversation, the study does not support changing current clinical practice.
3: Chemotherapy-naive patients may have greater benefit from treatment than post-chemotherapy patients
Preliminary data from Janssen EMEA’s Prostate Cancer Registry was presented this month at the annual European Society for Medical Oncology Congress (ESMO 2016). The early data (Abstact# 746P) from men with metastatic castration-resistant prostate cancer (mCRPC) shows that chemotherapy-naïve men have a longer time to next treatment when treated with androgen receptor-targeted agents than post-chemotherapy patients. Median time to next therapy for chemotherapy-naïve men was 601 days for abiraterone acetate and 503 days for enzalutamide compared to 428 days for abiraterone acetate and 366 days for enzalutamide for post-chemotherapy patients. The Prostate Cancer Registry has enrolled over 3000 patients across 16 countries and ongoing data collection aims to provide insights into real world management of mCRPC.