A rise in the occurrence of untreatable cases of prostate cancer may indicate a need to reconsider Canada’s approach to screening for one of the most prevalent male diseases, as per recent findings. The latest research, detailed in Current Oncology, analyzed decades of prostate cancer instances and fatalities, revealing an increase in advanced cancer rates alongside a stabilization in mortality rates, which had been declining over time.
Dr. Anna Wilkinson, the lead author and a family physician at the University of Ottawa, noted that while it was challenging to determine who underwent screening, the sheer volume of cases allowed for certain conclusions regarding the outcomes of screening. However, some oncologists dispute the interpretation of the data, arguing that the prostate-specific antigen (PSA) test, a common screening tool, is unreliable and may result in unnecessary treatments and overdiagnosis.
The study observed shifts in screening practices, with the Canadian prevention task force historically not endorsing prostate cancer screening. Despite this, the approval of the PSA test in the U.S. in the early 1990s led to a significant adoption in Canada. Subsequently, both countries moved away from screening in the early 2010s, enabling researchers to analyze changes in case and mortality rates amidst evolving recommendations.
According to Wilkinson, since the shift against screening in the U.S., there has been a 50% increase in metastatic prostate cancer cases among men aged 50 to 74 and a 65% rise in older men. Conversely, mortality rates saw a decline during periods of widespread screening support but plateaued post the recommendation changes.
Bishal Gyawali, an oncologist at Queen’s University, views the mortality rate decline as a positive trend linked to advancements in prostate cancer treatment rather than screening practices. Disagreeing with the study’s interpretation is James Dickinson, a family medicine professor at the University of Calgary, attributing the rise in late-stage cancer cases to improved imaging technologies and reduced screening.
The controversy surrounding PSA screening revolves around its inherent inaccuracy, leading to potential false positives and subsequent invasive follow-up tests. Critics highlight the risks of unnecessary treatments resulting from such inaccuracies, advocating for more specific and refined screening methods to differentiate between aggressive and slow-growing prostate cancers.
Wilkinson acknowledges the need for progress in minimizing harms associated with screening, emphasizing the shift towards separating diagnosis from immediate treatment through active surveillance of low-risk prostate cancers. The article mentions the case of Denis Farbstein, who underwent screening and eventual surgery, underscoring the individual experiences that often influence broader screening decisions.
An overhaul in cancer screening guidelines, including prostate cancer, is expected next year following an external review that halted the work of the Canadian Task Force on Preventive Health Care. While organizations like the Canadian Cancer Society and Canadian Urological Association advocate for PSA screening, they emphasize the importance of discussing the risks and benefits with healthcare providers before proceeding.
