A groundbreaking new study from Norway sheds compelling light on the potential role of low-dose aspirin therapy in enhancing survival outcomes for patients diagnosed with epithelial ovarian cancer (EOC). Published in the reputable journal BMC Cancer, this rigorous registry-based cohort analysis meticulously tracked over four thousand women diagnosed with invasive EOC between 2004 and 2018, leveraging extensive health registries to evaluate the impact of aspirin and non-aspirin non-steroidal anti-inflammatory drugs (NA-NSAIDs) on survival rates.
Ovarian cancer remains a formidable challenge in oncology, often diagnosed at advanced stages due to subtle symptomatology and a lack of effective early detection methods. Despite therapeutic advances, five-year survival rates remain disappointingly low, prompting relentless research into adjuvant therapies that might improve outcomes. The anti-inflammatory properties of aspirin and other NSAIDs have garnered interest for their potential to modulate cancer progression, yet epidemiological findings to date have been inconsistent and, at times, contradictory.
This Norwegian cohort study employed a refined methodological framework by analyzing both “fixed” and “time-varying” post-diagnostic usage patterns of these drugs. Fixed post-diagnosis exposure was assessed within the initial 305 days after diagnosis, categorizing individuals simply as users or non-users. However, to capture the dynamic nature of medication use, the researchers also utilized a time-varying exposure model accounting for changes over time, including current, past, or never use, and calculated cumulative drug doses through the defined daily dose metric (DDD). Importantly, the study evaluated not only post-diagnostic but also pre-diagnostic exposure, aiming to disentangle potential timing effects on survival.
Survival outcomes were analyzed via multivariable Cox proportional hazards models, allowing adjustment for potential confounders and yielding hazard ratios that quantify the impact of drug use on cause-specific mortality risk. Complementing this, the researchers applied restricted mean survival time (RMST) analyses to estimate survival time differences between exposure groups over a five-year follow-up period, providing clinically interpretable magnitudes of benefit or harm.
Crucially, the study found no survival benefit associated with aspirin use when assessed at the fixed early post-diagnosis time window; hazard ratios hovered near unity, indicating no clear effect. However, when utilizing the more nuanced time-varying exposure model, current aspirin use after diagnosis correlated with a notably improved survival profile. The hazard ratio of 0.68 and a 95% confidence interval spanning 0.57 to 0.81 signals a statistically significant 32% reduction in ovarian cancer-specific mortality among current aspirin users relative to non-users.
Moreover, the observed survival advantage exhibited a dose-response relationship, with higher cumulative aspirin intake correlating with greater survival benefits. Such findings bolster the biological plausibility of aspirin’s protective effects and highlight the importance of sustained post-diagnostic usage. Contrastingly, evidence for non-aspirin NSAIDs was inconsistent, underscoring potential differences in pharmacological mechanisms or patient adherence patterns.
Interestingly, analyses failed to reveal any significant survival associations for pre-diagnostic aspirin or NA-NSAID use, suggesting that the window immediately following diagnosis may be critical for leveraging aspirin’s anticancer effects. This temporal specificity invites further exploration into the biological underpinnings of aspirin’s action on residual tumor cells or the tumor microenvironment during early treatment phases.
The study’s cause-specific survival findings mirrored overall survival trends, reinforcing the robustness of the observed associations. Using RMST analysis, researchers quantified that post-diagnosis low-dose aspirin users experienced an average increase of approximately 2.67 months in survival time over a five-year period compared to never users. While modest, these gains are impactful considering the aggressive nature of EOC and the urgent need for improving therapeutic outcomes.
Mechanistically, aspirin’s anti-cancer properties may stem from its well-documented anti-inflammatory effects, inhibition of cyclooxygenase enzymes, and subsequent modulation of prostaglandin biosynthesis, a pathway implicated in tumor growth, angiogenesis, and metastasis. Additionally, aspirin may exert antiplatelet effects that reduce metastatic dissemination. These biological effects have fostered hypotheses positioning aspirin as a candidate adjunct therapy in various malignancies, with this study lending weight specifically to ovarian cancer.
Despite its strengths, including a large sample size and robust registry data facilitating real-world evidence generation, the study acknowledges inherent limitations typical of observational research, such as residual confounding by indication and the inability to establish causality definitively. The authors call for prospective randomized controlled trials to validate aspirin’s role as an adjuvant treatment in ovarian cancer, including optimal dosing, timing, and patient selection criteria.
The findings invigorate a broader discourse on repurposing well-established medications like aspirin in oncology, a strategy that promises cost-effective improvements in cancer care. Given aspirin’s accessibility and established safety profile at low doses, its integration into post-diagnosis clinical management could represent a paradigm shift pending confirmatory evidence.
This nuanced investigation harmonizes with emerging research suggesting that persistent inflammation contributes to ovarian cancer progression and resistance mechanisms. As such, targeting inflammatory pathways pharmacologically is an appealing avenue, with aspirin standing out as a promising agent.
Importantly, these results extend beyond mere statistical associations, hinting at tangible clinical benefits that might translate into longer survival and better quality of life for thousands of women afflicted by this deadly disease worldwide. The potential public health implications are substantial, especially in regions where access to advanced therapeutics is limited.
Further scrutiny is warranted into aspirin’s interactions with conventional chemotherapies and targeted agents, safety considerations in the oncology population, and patient adherence determinants. Furthermore, molecular studies probing biomarkers predictive of aspirin responsiveness could personalize therapy and maximize benefit.
In conclusion, this landmark Norwegian registry study substantially enriches our understanding of aspirin’s potential utility in extending survival among epithelial ovarian cancer patients. It emphasizes the critical importance of timing and dosage in therapeutic effectiveness, providing a solid foundation for future interventional trials that could transform current treatment paradigms. As the oncology community continues to grapple with ovarian cancer’s lethality, this research offers a beacon of hope anchored in accessible, low-cost pharmaceutical intervention.
Subject of Research: The impact of post-diagnosis use of low-dose aspirin and non-aspirin non-steroidal anti-inflammatory drugs (NA-NSAIDs) on survival in patients with epithelial ovarian cancer.
Article Title: Low-dose aspirin and non-aspirin non-steroidal anti-inflammatory drugs and epithelial ovarian cancer survival: a registry-based cohort study in Norway.
Article References:
Støer, N.C., Botteri, E., Lindemann, K. et al. Low-dose aspirin and non-aspirin non-steroidal anti-inflammatory drugs and epithelial ovarian cancer survival: a registry-based cohort study in Norway. BMC Cancer 25, 807 (2025). https://doi.org/10.1186/s12885-025-14168-y
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