A rise in the frequency of untreatable cases of prostate cancer may signal a need to reconsider Canada’s approach to screening for one of the most prevalent diseases affecting men, as per recent findings. The recent study, published in Current Oncology, analyzed decades of prostate cancer incidences and fatalities. It revealed an increase in the rates of advanced-stage cancers alongside a stabilization in mortality rates, which had previously been declining.
Dr. Anna Wilkinson, the lead author and a family physician at the University of Ottawa, highlighted that while it was not possible to identify the individuals who underwent screening, the substantial number of cases allowed for drawing some inferences regarding the outcomes of screening or lack thereof. However, some oncologists differ in their interpretation of the data, arguing that the screening tool, known as the prostate-specific antigen (PSA) test, is unreliable and could result in unnecessary treatment and overdiagnosis.
The study observed shifts in screening practices over the years. Although the Canadian prevention task force has historically not endorsed prostate cancer screening, the approval of the PSA test in the U.S. in the early 1990s led to widespread adoption in Canada as well. Subsequently, both countries moved away from screening in the early 2010s, enabling researchers to study the impact of changing recommendations on case and mortality rates. Wilkinson pointed out that the incidence of metastatic or stage four prostate cancer surged by 50% in men aged 50 to 74 and by approximately 65% in men in their late 70s post the shift away from screening in the U.S.
Furthermore, the research indicated a decline in mortality rates during periods of increased screening support, followed by a plateau after the shift against screening recommendations. Despite differing opinions on the data interpretation, experts like Bishal Gyawali, an oncologist at Queen’s University, view this as a sign of ongoing advancements in prostate cancer treatment over the years. He emphasized that the decreasing mortality rates are likely attributed to progress in cancer treatment rather than screening practices.
The debate revolves around the PSA test, a simple yet controversial screening method that measures a protein produced by the prostate. Critics argue that the test’s lack of precision may lead to false-positive results, necessitating further invasive diagnostic procedures. Concerns about the harms associated with acting on PSA results, such as surgeries leading to incontinence or sexual dysfunction, have been raised, emphasizing the need for a more specific and reliable screening test.
While acknowledging the benefits of screening, experts caution against overreliance on individual success stories to justify population-level decisions. They stress the importance of distinguishing between aggressive prostate cancer that requires immediate intervention and indolent cases that may not necessitate treatment. As discussions on cancer screening guidelines, including those for prostate cancer, undergo review, the Canadian Task Force on Preventive Health Care is expected to provide updated guidance next year. Both the Canadian Cancer Society and Canadian Urological Association recommend PSA screening but advise patients to weigh the potential benefits and risks in consultation with their healthcare providers.