Analgesic use and risk of renal cell carcinoma: A case-control, cohort and meta-analytic assessment

Analgesic use and the risk of renal cell carcinoma - Findings from the Consortium for the Investigation of Renal Malignancies (CONFIRM) study

PURPOSE

The incidence of renal cell carcinoma (RCC) is rising. Use of analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol may affect renal function. The aim of this study was to assess associations between analgesic use and risk of RCC.

METHODS

A population-based case-control family design was used. Cases were recruited via two Australian state cancer registries. Controls were siblings or partners of cases. Analgesic use was captured by self-completed questionnaire. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for RCC risk associated with regular analgesic use (at least 5 times per month for 6 months or more) and duration and frequency of use.

RESULTS

The analysis included 1064 cases and 724 controls. Regular use of paracetamol was associated with an increased risk of RCC (OR 1.41, 95%CI 1.13-1.77). Regular use of NSAIDs was associated with increased risk of RCC for women (OR 1.71, 95% CI 1.23-2.39) but not men (OR 0.83, 95% CI 0.58-1.18; p-interaction=0.003). There was no evidence of a dose-response for duration of use of paracetamol (linear trend p = 0.77) and weak evidence for non- aspirin NSAID use by women (linear trend p = 0.054).

CONCLUSION

This study found that regular use of paracetamol was associated with increased risk of RCC. NSAID use was associated with increased risk only for women.

A systematic assessment of the epidemiologic literature regarding an association between acetaminophen exposure and cancer

Introduced in the 1950s, acetaminophen is one of the most widely used antipyretics and analgesics worldwide. In 1999, the International Agency for Research on Cancer (IARC) reviewed the epidemiologic studies of acetaminophen and the data were judged to be "inadequate" to conclude that it is carcinogenic. In 2019 the California Office of Environmental Health Hazard Assessment initiated a review process on the carcinogenic hazard potential of acetaminophen. To inform this review process, the authors performed a comprehensive literature search and identified 136 epidemiologic studies, which for most cancer types suggest no alteration in risk associated with acetaminophen use. For 3 cancer types, renal cell, liver, and some forms of lymphohematopoietic, some studies suggest an increased risk; however, multiple factors unique to acetaminophen need to be considered to determine if these results are real and clinically meaningful. The objective of this publication is to analyze the results of these epidemiologic studies using a framework that accounts for the inherent challenge of evaluating acetaminophen, including, broad population-wide use in multiple disease states, challenges with exposure measurement, protopathic bias, channeling bias, and recall bias. When evaluated using this framework, the data do not support a causal association between acetaminophen use and cancer.

Quantifying bias in epidemiologic studies evaluating the association between acetaminophen use and cancer

Many observational studies explore the association between acetaminophen and cancer, but known limitations such as vulnerability to channeling, protopathic bias, and uncontrolled confounding hamper the interpretability of results. To help understand the potential magnitude of bias, we identify key design choices in these observational studies and specify 10 study design variants that represent different combinations of these design choices. We evaluate these variants by applying them to 37 negative controls - outcome presumed not to be caused by acetaminophen - as well as 4 cancer outcomes in the Clinical Practice Research Datalink (CPRD) database. The estimated odds and hazards ratios for the negative controls show substantial bias in the evaluated design variants, with far fewer of the 95% confidence intervals containing 1 than the nominal 95% expected for negative controls. The effect-size estimates for the cancer outcomes are comparable to those observed for the negative controls. A comparison of exposed and unexposed reveals many differences at baseline for which most studies do not correct. We observe that the design choices made in many of the published observational studies can lead to substantial bias. Thus, caution in the interpretation of published studies of acetaminophen and cancer is recommended.

Vitamin D binding protein and risk of renal cell carcinoma in the prostate, lung, colorectal and ovarian cancer screening trial

Our group has conducted two previous studies on the association between vitamin D binding protein (DBP) and renal cell carcinoma (RCC), the most common form of kidney cancer, finding strong inverse associations. We undertook the current analysis to replicate our findings in a different study population that included women and nonsmokers. We conducted a nested case-control study in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO). Cases (n = 323) were matched 1:1 to controls on age (±1 year), race/ethnicity, date of blood collection (±30 days) and sex. We performed conditional logistic regression to estimate the odds ratios and 95% confidence intervals for the association between quartiles of circulating DBP and risk of RCC. We observed a statistically significant positive association between DBP and RCC that persisted after adjustment for history of diabetes, history of hypertension, family history of renal cancer, body mass index and smoking status (mv-adj Q4 vs. Q1 OR = 4.1, 95% CI = 2.2-7.8; p-trend <0.0001). These findings were similar when we restricted to cases with at least 2 years of follow-up and no major weight loss, suggesting that our findings are not due to reverse causality. In the present study, those with higher serum concentrations of DBP were at increased risk of RCC, in contrast to previously published findings. Further research is necessary to determine the true association between DBP and risk of RCC, and whether different DBP phenotypes may have different associations with risk of RCC.

Epidemiology and screening for renal cancer

PURPOSE

The widespread use of abdominal imaging has affected the epidemiology of renal cell carcinoma (RCC). Despite this, over 25% of individuals with RCC have evidence of metastases at presentation. Screening for RCC has the potential to downstage the disease.

METHODS

We performed a literature review on the epidemiology of RCC and evidence base regarding screening. Furthermore, contemporary RCC epidemiology data was obtained for the United Kingdom and trends in age-standardised rates of incidence and mortality were analysed by annual percentage change statistics and joinpoint regression.

RESULTS

The incidence of RCC in the UK increased by 3.1% annually from 1993 through 2014. Urinary dipstick is an inadequate screening tool due to low sensitivity and specificity. It is unlikely that CT would be recommended for population screening due to cost, radiation dose and increased potential for other incidental findings. Screening ultrasound has a sensitivity and specificity of 82-83% and 98-99%, respectively; however, accuracy is dependent on tumour size. No clinically validated urinary nor serum biomarkers have been identified. Major barriers to population screening include the relatively low prevalence of the disease, the potential for false positives and over-diagnosis of slow-growing RCCs. Individual patient risk-stratification based on a combination of risk factors may improve screening efficiency and minimise harms by identifying a group at high risk of RCC.

CONCLUSION

The incidence of RCC is increasing. The optimal screening modality and target population remain to be elucidated. An analysis of the benefits and harms of screening for patients and society is warranted.

Associations between aspirin use and the risk of cancers: a meta-analysis of observational studies

Background

Epidemiological studies have clarified the potential associations between regular aspirin use and cancers. However, it remains controversial on whether aspirin use decreases the risk of cancers risks. Therefore, we conducted an updated meta-analysis to assess the associations between aspirin use and cancers.

Methods

The PubMed, Embase, and Web of Science databases were systematically searched up to March 2017 to identify relevant studies. Relative risks (RRs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

Results

A total of 218 studies with 309 reports were eligible for this meta-analysis. Aspirin use was associated with a significant decrease in the risk of overall cancer (RR = 0.89, 95% CI: 0.87–0.91), and gastric (RR = 0.75, 95% CI: 0.65–0.86), esophageal (RR = 0.75, 95% CI: 0.62–0.89), colorectal (RR = 0.79, 95% CI: 0.74–0.85), pancreatic (RR = 0.80, 95% CI: 0.68–0.93), ovarian (RR = 0.89, 95% CI: 0.83–0.95), endometrial (RR = 0.92, 95% CI: 0.85–0.99), breast (RR = 0.92, 95% CI: 0.88–0.96), and prostate (RR = 0.94, 95% CI: 0.90–0.99) cancers, as well as small intestine neuroendocrine tumors (RR = 0.17, 95% CI: 0.05–0.58).

Conclusions

These findings suggest that aspirin use is associated with a reduced risk of gastric, esophageal, colorectal, pancreatic, ovarian, endometrial, breast, and prostate cancers, and small intestine neuroendocrine tumors.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4156-5) contains supplementary material, which is available to authorized users.