IMPORTANCE Prospective data on the risk of hepatocellular carcinoma (HCC) according to dose and duration of aspirin therapy are limited. OBJECTIVE To examine the potential benefits of aspirin use for primary HCC prevention at a range of doses and durations of use within 2 prospective, nationwide populations. DESIGN, SETTING, AND PARTICIPANTS Pooled analysis of 2 prospective US cohort studies: the Nurses' Health Study and the Health Professionals Follow-up Study. Data were accessed from November 1, 2017, through March 7, 2018. A total of 133 371 health care professionals who reported data on aspirin use, frequency, dosage, and duration of use biennially since 1980 in women and 1986 in men were included. Individuals with a cancer diagnosis at baseline (except nonmelanoma skin cancer) were excluded. MAIN OUTCOMES AND MEASURESCox proportional hazards regression models were used to calculate multivariable adjusted hazard ratios (HRs) and 95% CIs for HCC. RESULTSOf the 133 371 participants, 87 507 were women and 45 864 were men; in 1996, the median time of follow-up, the mean (SD) age was 62 (8) years for women and 64 (8) years for men. Over more than 26 years of follow-up encompassing 4 232 188 person-years, 108 incident HCC cases (65 women, 43 men) were documented. Compared with nonregular use, regular aspirin use (Ն2 standard-dose [325-mg] tablets per week) was associated with reduced HCC risk (adjusted HR, 0.51; 95% CI, 0.34-0.77). This benefit appeared to be dose related: compared with nonuse, the multivariable-adjusted HR for HCC was 0.87 (95% CI, 0.51-1.48) for up to 1.5 standard-dose tablets per week, 0.51 (95% CI, 0.30-0.86) for more than 1.5 to 5 tablets per week, and 0.49 (95% CI, 0.28-0.96) for more than 5 tablets per week (P for trend = .006). Significantly lower HCC risk was observed with increasing duration (P for trend = .03); this decrease was apparent with use of 1.5 or more standard-dose aspirin tablets per week for 5 or more years (adjusted HR, 0.41; 95% CI, 0.21-0.77). In contrast, use of nonaspirin nonsteroidal anti-inflammatory drugs was not significantly associated with HCC risk (adjusted HR, 1.09; 95% CI, 0.78-1.51). CONCLUSIONS AND RELEVANCEThis study suggests that regular, long-term aspirin use is associated with a dose-dependent reduction in HCC risk, which is apparent after 5 or more years of use. Similar associations were not found with nonaspirin NSAIDs. Further research appears to be needed to clarify whether aspirin use represents a feasible strategy for primary prevention against HCC.

These findings suggest that, in this relatively healthy population, smoking cessation and light-to-moderate drinking may reduce the risk of HCC.

These findings suggest that obesity and diabetes are associated with increased ICC risk, highlighting similar etiologies of hepatocellular carcinoma and intrahepatic cholangiocarcinoma. However, additional prospective studies are needed to verify these associations.

Background & Aims Patients with colorectal cancer (CRC) have high circulating levels of macrophage inhibitory cytokine-1 (MIC1 or GDF15), a marker of inflammation that might be involved in carcinogenesis. We analyzed blood samples collected from individuals before they were diagnosed with CRC to determine whether levels of MIC1 were associated with mortality. Methods We collected data on survival of 618 participants diagnosed with CRC who provided pre-diagnosis blood specimens in 1990 (Nurses’ Health Study) and 1994 (Health Professionals’ Follow-up Study) and were followed through 2010. Levels of MIC1 were measured by ELISA and then were categorized into quartiles based upon the known distribution of MIC1 levels among previously matched individuals without CRC (controls) within each cohort. We then examined the association of MIC-1 levels with overall and CRC-specific mortality using Cox proportional hazards models, with adjustments for mortality-associated risk factors and other plasma markers of inflammation. We also assessed the relationship between levels of MIC1 and levels of prostaglandin-endoperoxide synthase 2 expression (PTGS2 or COX2), measured in 245 tumor samples by immunohistochemistry. Results Compared to participants in the lowest quartile for plasma level of MIC1, the multivariate hazard ratio (HR) for CRC-specific death for participants in the highest quartile of MIC1 level was 2.40 (95% confidence interval, 1.33–4.34; P for linear trend=.009). The association of MIC1 with survival varied with level of PTGS2 expression in tumor samples (Pinteraction=.04). For individuals with PTGS2-positive tumors, the HR for CRC-specific death among those with high levels of MIC1 (equal to or greater than the median) was 2.13 (95% CI, 0.99–4.58) compared to participants with low levels of MIC1 (below the median). In individuals with PTGS2-negative CRC, a high level of MIC1 was not associated with an increased risk of CRC-specific death (multivariate HR=0.61; 95% CI, 0.13–2.93). Conclusions Based on an analysis of blood and colorectal tumor samples from 2 large studies, high plasma levels of MIC1 (GDF15) before diagnosis of CRC are associated with greater CRC-specific mortality, particularly in individuals with PTGS2-positive tumors.