Comment: This is another in a growing group of studies showing a correlation between levothyroxine (synthetic T4) use and increased cancer risk. What makes this analysis particularly compelling is the direct comparison between treated and untreated patients with hypothyroidism. While we must respect the limitations of observational data, we must also be pragmatic: we are […]
Comment: This is a fascinating review of a complex topic. The key clinical pearl here is the paradoxical finding that treatment-induced hypothyroidism (from TKIs/ICPis) often correlates with a favorable prognosis. It underscores the need to closely monitor thyroid function in these patients—not just as a side effect to be managed, but as a potential prognostic […]
Comment: This massive Swedish cohort study serves as a critical update for anyone managing contraception. While the absolute risk remains low—approximately 1 extra case per 7,752 users per year—the relative increase in breast cancer risk is substantial, driven largely by specific hormonal components. The overall Hazard Ratio of 1.24 suggests a 24% increase in relative […]
Comment: While this ecological study is, as detailed in the appraisal, deeply flawed and certainly cannot be used to draw any causal conclusions, it raised a provocative, hypothesis-generating question. Further studies have substantiated that there are links between levothyroxine use and cancer. The proposed mechanism—oxidative stress—is biologically plausible. We know that thyroid hormones are powerful […]
Comment: While this is an observational study and cannot prove causation, the findings are nonetheless concerning, especially as it’s not the only study showing an association of levothyroxine use and cancer. A nation-wide study identifying a 24% increase in the odds of breast cancer associated with levothyroxine use (AOR 1.24) warrants serious attention from the […]
Comment: This is an important, large-scale population study, even with the weaknesses of the study design. An adjusted odds ratio of 1.50 for any cancer is a significant signal that cannot be easily dismissed, particularly given the strong associations noted for brain (AOR 1.90) and breast (AOR 1.24) cancers. While the authors rightly point out […]
Comment: Another study showing that animal protein intake does not increase death rates. In fact, this study links higher animal protein intake to a reduced risk of cancer, albeit small. This study was designed specifically to revisit the controversial 2014 Levine findings that suggested a four-fold cancer risk from animal protein. By applying more sophisticated statistical […]
