Prostate Cancer Screening: Outcomes Comparable to Breast Cancer Screening, Study Finds

Modern research presented at the European Association of Urology Congress suggests that prostate cancer screening can be as effective as breast cancer screening in identifying significant cancers, reducing mortality, and minimizing unnecessary harms. The findings, which are also slated for publication in European Urology, challenge the long-standing disparity in how these two common cancers are approached in terms of screening programs.

Similarities in Screening Effectiveness

For decades, organized breast cancer screening programs have been a standard practice across Europe. However, prostate cancer screening has lagged, largely due to concerns about the accuracy of the prostate-specific antigen (PSA) blood test and the potential for overdiagnosis and overtreatment. Despite these concerns, many men still pursue prostate cancer screening, often through self-referral. Recent prostate cancer screening trials in Europe have demonstrated a reduction in the risk of death from the disease, comparable to the risk reduction observed in breast cancer screening programs.

Researchers from the German Cancer Research Center in Heidelberg, Germany, compared prostate and breast cancer screening in terms of diagnostic test effectiveness and rates of overdiagnosis. They analyzed data from the PROBASE prostate cancer screening trial, involving over 39,000 men aged 45 or 50 who underwent initial PSA testing, and compared it to data from over 2.8 million women aged 50-69 participating in Germany’s organized breast cancer screening program using mammography.

The analysis revealed some key similarities and differences. PSA testing followed by MRI scans resulted in a higher rate of false positives (37–42%) compared to mammography (10%). However, the proportion of individuals referred for biopsy was similar for both cancers – 0.8–2.4% for men in the PROBASE trial and 1.1% for women. Here’s partly attributable to the use of risk stratification in the PROBASE trial, where men were assessed for their likelihood of having significant cancer before being referred for biopsy.

Importantly, biopsies were more likely to identify significant cancer in prostate screening (50–68%) than in breast screening (10%), suggesting fewer unnecessary biopsies among men. The percentage of invasive cancers identified was also similar across both screening programs (60–74% vs. 73%). Prostate cancer screening was slightly more likely to detect non-aggressive cancers (26–31% vs. 22%), but researchers note that active surveillance – a strategy of monitoring lower-grade cancers and delaying treatment until progression – is a well-established option, mitigating the risk of overtreatment.

Addressing Concerns About Overdiagnosis

Dr. Sigrid Carlsson, lead author of the research and head of Clinical Epidemiology of Early Cancer Detection at the German Cancer Research Center (DKFZ) in Heidelberg, emphasized that while a direct comparison is difficult without a population-based prostate cancer screening program, the data suggests that extending screening to the wider population would likely yield outcomes similar to those seen in breast cancer screening. “Until we have a population-based screening program for prostate cancer, we can’t produce an exact like-for-like comparison with breast cancer. But we can make some informed assumptions based on the data from our trial, which present that if prostate cancer screening were extended to the wider population, then the outcomes are likely to be very similar to breast cancer,” she stated.

The researchers acknowledge that their study utilized German data, but believe the findings are broadly applicable to other countries. A key question remains: what will be the cost-effectiveness of a widespread prostate cancer screening program compared to the current, more variable approach of opportunistic screening? This cost analysis is currently underway.

The Importance of Learning from Breast Cancer Screening

Tobias Nordström, a clinical urologist and Associate Professor at the Karolinska Institute in Sweden, and a member of the EAU Scientific Congress Office, highlighted the potential for prostate cancer screening to learn from the established practices of breast cancer screening. “There is much that prostate cancer screening can learn from breast cancer screening, and that is why this analysis is an important addition to our knowledge base,” he said. “As these kinds of comparisons are very challenging, the results do demand to be taken with a level of caution. That said, the clear overall similarities between the outcomes for breast and prostate cancer screening show that we are moving in the right direction, ensuring prostate cancer screening offers more benefits than harm.”

Understanding the PSA Test and MRI

The PSA (prostate-specific antigen) test measures the level of PSA in the blood. Elevated levels can indicate prostate cancer, but also other conditions like benign prostatic hyperplasia (BPH) or prostatitis. Because of this, a positive PSA test doesn’t automatically mean cancer is present. MRI scans provide more detailed images of the prostate and can support identify suspicious areas that may require biopsy. The combination of PSA testing and MRI, along with risk stratification, aims to improve the accuracy of prostate cancer detection and reduce unnecessary biopsies.

What Comes Next: Refining Screening Strategies

The European Association of Urology (EAU) guidelines, developed in collaboration with other leading European medical societies – including the European Association of Nuclear Medicine (EANM), the European Society for Radiotherapy and Oncology (ESTRO), and the European Society of Urogenital Radiology (ESUR) – are continually updated based on the latest evidence. These guidelines provide recommendations for the screening, diagnosis, and treatment of prostate cancer. You can find more information about the EAU guidelines on their website: Uroweb. The EAU-EANM-ESTRO-ESUR-ISUP-SIOG guidelines provide recommendations for the management of clinically localised prostate cancer, as detailed in a recent publication in PubMed.

Further research is needed to optimize prostate cancer screening strategies, including identifying the optimal age to begin screening, the frequency of screening, and the best combination of diagnostic tests. Ongoing trials and surveillance programs will continue to provide valuable data to inform these decisions and ensure that prostate cancer screening offers the greatest benefit with the least amount of harm.