Low-dose aspirin has been hypothesized to prevent cancer risk by inhibiting platelet aggregation. However, the anti-cancer effect of low-dose aspirin has recently been questioned and its effect on breast cancer development remains unclear. The impact of other antiplatelet drugs on breast cancer risk has rarely been evaluated. Thus, this study aimed to investigate the associations between breast cancer risk and antiplatelet drug use in a nationwide nested case-control study. From the Danish healthcare registries, we identified as cases all women with invasive breast cancer diagnosis between 2001 and 2018 (n = 68 852). The date of diagnosis corresponded to the index date. We matched cases to 10 population controls on age and calendar time, using risk set sampling. Controls were assigned the same index date as their matched case. We used the prescription registry to identify exposure to low-dose aspirin, clopidogrel and dipyridamole. We defined ever use of antiplatelet drugs as at least two prescriptions filled up to 1 year before the index date. We applied conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for breast cancer associated with the use of antiplatelet drugs, overall, by breast cancer subtype and by cumulative dose. Twelve percent of women had ever been exposed to low-dose aspirin, 2% to clopidogrel and 2% to dipyridamole. In multivariable models, breast cancer risk was not associated with ever use of low-dose aspirin (OR = 1.00 [0.97-1.03]), clopidogrel (OR = 0.93 [0.87-1.00]), and dipyridamole (OR = 1.02 [0.94-1.10]), compared with never use, and there was no evidence of a dose-response relation. However, we found an inverse association between dipyridamole use and breast cancer risk among women aged <55 years old, with suggestion of a dose-response relationship (OR per 1000 Defined Daily Doses = 0.72 [0.54-0.95]). Associations did not differ by breast cancer histological type, estrogen receptor status or clinical stage at diagnosis. Overall, the findings from this study do not support the use of antiplatelet drugs for breast cancer prevention.

BACKGROUND: Low-dose aspirin and clopidogrel have demonstrated potential chemoprevention for colorectal cancer (CRC). Proton-pump inhibitors (PPI) are commonly prescribed with anticoagulation drugs, but the relationship between PPI and CRC is unclear. Moreover, evidence of CRC risk under direct oral anticoagulant (DOAC) is limited. This study aimed to investigate the effects of anticoagulation drugs combined with or without PPI on the risks of CRC in Taiwan.
METHODS: A retrospective case-control study of 1,024,227 cases based on the Chang Gung Research Database from 2010 to 2017 was performed. Clinical characteristics, indications, duration of anticoagulation and PPI use, and CRC occurrence data were collected. Logistic regression was employed to adjust for known confounders of CRC risk.
RESULTS: Monotherapy of clopidogrel decreased the risk of CRC (AOR 0.70; 95% CI 0.60-0.83), while no protective effect was observed in aspirin alone or aspirin plus clopidogrel. DOAC did not affect CRC significantly. The risk of CRC increased in patients with PPI (AOR 1.38; 95% CI 1.28-1.49) and PPI plus DOAC (OR 3.91; 95% CI 1.49-10.27), while PPI plus aspirin decreased the risk of CRC (OR 0.48; 95% CI 0.32-0.73). PPI plus clopidogrel showed no significant effect on the CRC.
CONCLUSIONS: This study suggests clopidogrel alone and PPI plus aspirin offer a preventative benefit against CRC in the Taiwanese population studied. The same effect was not observed in DOAC. Moreover, a significant increase in CRC was observed in patients on PPI monotherapy and PPI plus DOAC, suggesting a possible risk.

OBJECTIVE: In the present study, we evaluated the effect of systemic long-term, low-dose aspirin on the periodontal status and gingival crevicular fluid (GCF) concentrations of aspirin-triggered lipoxins (ATL) and soluble CD14 (sCD14).
METHODS: The study group consisted of 45 patients who were on long-term, low-dose aspirin therapy, and the control group included patients not on aspirin therapy. Mean bleeding index, plaque index (PI), probing depth (PD), and clinical attachment loss (CAL) were recorded. GCF samples were analyzed for concentrations of ATL, and sCD14 using enzyme-linked immunosorbent assay method.
RESULTS: The means of PI, PD, and CAL were higher for the control group compared to the study group. The mean concentration of ATL was significantly higher for the study group (49.13 ± 37.39 ng/mL). The mean concentration of sCD14 was higher in the control group (5.75 ± 3.91 μg/mL). There was a negative correlation in the study group between concentrations of ATL with PD (r = -0.54) and CAL (r = -0.123). There was a positive correlation between sCD14 and CAL (r = 0.047) in the study group. A negative correlation was also observed between concentrations of sCD14 and ATL (r = -0.134) in the study group.
CONCLUSIONS: The results indicate better periodontal status among long-term aspirin users compared to non-aspirin users.

OBJECTIVE: The aim of this study was to compare clinical characteristics and outcomes of bleeding gastroduodenal ulcer between patients taking antithrombotic medications and those not taking antithrombotic medications.
METHODS: We performed a case-control study of 346 patients with endoscopically verified bleeding gastroduodenal ulcer, which included 173 cases taking antithrombotic medications throughout peri-bleeding period and 173 age- and sex-matched controls not taking antithrombotic medications.
RESULTS: The cases showed less frequent Helicobacter pylori (H. pylori) infections (45.1% versus 60.7%, p = .005), more frequent duodenal location (31.8% versus 19.1%, p = .009), and more frequent rebleeding (13.9% versus 5.8%, p = .02) than the controls. Multivariate analysis revealed that duodenal location (odds ratio [OR] 3.01, 95% confidence interval [CI] 1.37-6.65) and use of antithrombotic medications (OR 2.47, 95% CI 1.13-5.77) were independent factors for rebleeding. However, there were no differences in clinical outcomes, including final successful endoscopic hemostasis, need for surgical intervention, and mortality between cases and controls. Thromboembolic events did not occur in any cases and controls during the periendoscopic period.
CONCLUSIONS: Low prevalence of H. pylori infection, frequent duodenal location, and high rebleeding rate are characteristics of patients with bleeding gastroduodenal ulcer under antithrombotic medications. Continuation of antithrombotic medications can be accepted for bleeding gastroduodenal ulcer.

Dual antiplatelet therapy consisting of low-dose aspirin (LDA) and other antiplatelet medications is recommended in patients with coronary heart disease, but it may increase the risk of esophageal lesion and bleeding. We describe a case of esophageal mucosal lesion that was difficult to distinguish from malignancy in a patient with a history of ingesting LDA and prasugrel after implantation of a drug-eluting stent. Multiple auxiliary examinations were performed to make a definite diagnosis. The patient recovered completely after concomitant acid-suppressive therapy. Based on these findings, we strongly argue for the evaluation of the risk of gastrointestinal mucosal injury and hemorrhage if LDA therapy is required, and we stress the paramount importance of using drug combinations in individual patients.