NEW data generated by The UK Genetic Prostate Cancer Study suggests a strong family history of prostate cancer is linked to a decreased risk of prostate cancer-related death. Researchers at the Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, both in London, UK, attribute this improved prognosis to an increased awareness of prostate cancer and subsequent early diagnosis and treatment.
Prostate cancer is a polygenic disease with large heritability. Thus, the risk of developing prostate cancer is more than doubled in males with a brother or father with prostate cancer. However, conflicting evidence was previously reported when examining clinical and survival outcomes for prostate cancer patients with a known family history.
This longitudinal observational study, which was established in 1992, examined 16,340 males across the UK. Patients were categorised according to the strength of their family history. Results suggested a stronger family history was inversely associated with the risk of prostate cancer-related mortality. The association was strongest in those with increasing number and closeness of the relatives. The research team attribute the reduced likelihood of prostate cancer-related death almost completely to a greater awareness of the disease and subsequent screening attendance. Therefore, ‘the research highlights the importance of awareness and screening programmes,’ says Kristian Helin, Chief Executive, Institute of Cancer Research.
The authors note a few limitations. Firstly, despite most co-founders being accounted for, they are missing data on other epidemiological risk factors associated with mortality, such as smoking, and information on comorbidities. Furthermore, the population is predominantly of European ancestry (90%), meaning the data is not representative of other ethnicities. Finally, the analysis did not compare those diagnosed before and after the widespread uptake of protein-specific antigen testing. Further analysis of this kind would provide valuable insight into the implications of screening.
Despite these limitations, study leader Ros Eeles, Institute of Cancer Research, concluded that the improved outcomes for prostate cancer patients with a strong family history is: ‘Likely to be explained by an “awareness” effect, which seems to lead to earlier diagnosis, and as a consequence, better survival.’