Curbsiders Digest: Prostate Cancer Screening, Acetaminophen & Autism, COVID Vaccines & Cancer, Aspirin & Anticoagulants

Prostate Cancer Screening Study (ERSPC)

• 🔬 The European Study of Prostate Cancer Screening (ERSPC) published its 23-year follow-up, showing a 13% lower prostate cancer mortality in the screening group compared to the control group.
• 🎯 This translated to an absolute risk reduction of 0.22%, with a number needed to screen of 456 to save one life over 23 years.
• ⚠️ A significant concern raised is that for every one life saved from prostate cancer death, 11 out of 12 men diagnosed may experience harm due to overdiagnosis and overtreatment.
• 💡 The study's findings may be limited by changes in standard of care over time, including advancements in diagnostic imaging like MRI and the use of active surveillance.

Acetaminophen Use in Pregnancy and Neurodevelopmental Disorders

• ⚠️ A systematic review of 46 observational studies suggested an association between maternal acetaminophen use during pregnancy and an increased incidence of neurodevelopmental disorders (NDDs), including ADHD and autism.
• 🎯 However, the review's conclusions were criticized for using causal language based on associational data and for not adequately considering alternatives or confounding factors like maternal fever.
• 🧩 A sibling-controlled analysis of a large Swedish cohort found that the association between in utero acetaminophen exposure and autism was completely attenuated, suggesting unmeasured genetic and environmental confounders.
• ❓ Key limitations include the heterogeneity of studies, the small effect sizes observed (hazard ratios often < 1.2), and the significant issue of confounding by indication, where the reason for taking acetaminophen (e.g., fever) may be the true risk factor.

COVID-19 Vaccination and Cancer Risk

• 📈 A South Korean cohort study suggested an association between COVID-19 vaccination and an increased risk of six cancer types, with hazard ratios ranging from 1.2 to 1.7.
• 🧐 However, the study is heavily criticized for obvious methodological flaws, including a lack of biological plausibility, an immediate separation of risk curves, and a failure to account for healthy user bias.
• 🔍 The observed increased cancer incidence is likely due to differences in healthcare-seeking behavior and screening practices between vaccinated (who are more likely to see doctors and get screened) and unvaccinated individuals, rather than a direct effect of the vaccine.
• ⚠️ The authors recommend ignoring this paper and using it primarily as a teaching tool for identifying flawed research.

Aspirin and Oral Anticoagulation in Chronic Coronary Syndrome

• 📉 The AQUATIC trial, a randomized controlled trial, found that adding aspirin to oral anticoagulation in patients with chronic coronary syndrome and high thrombotic risk led to a 50% relative increase in major adverse cardiovascular events (driven by cardiovascular death) and a tripling in bleeding risk.
• 🎯 This suggests that combination therapy with aspirin and oral anticoagulants in this population causes more harm than good, and the practice should be stopped.
• ❓ A key question remains about the mechanism behind the increased cardiovascular death, as bleeding alone may not fully explain it.
• 💡 The findings highlight the importance of data trumping theory and the need to de-escalate dual therapy sooner rather than later, especially in lower-risk populations.