A systematic assessment of the association between frequently prescribed medicines and the risk of common cancers: a series of nested case-control studies

Oral prednisolone and warfarin and risk of oesophageal cancer: A case-control study

BACKGROUND

A recent epidemiological study systematically screened 250 prescription medications for associations with oesophageal cancer risk, using Scottish data, and identified an increased risk with use of prednisolone and warfarin. We investigated whether oral prednisolone or warfarin use was associated with increased oesophageal cancer risk.

METHODS

A case-control study was conducted within the Clinical Practice Research Datalink. In the primary analysis oesophageal cancer cases were identified from linked cancer registry records. Up to 5 cancer-free controls were matched to each case (based upon sex, birth year, GP practice and year of GP registration). Prednisolone and warfarin medications were identified from prescribing records. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression after adjusting for covariates including demographics, comorbidities and medication use.

RESULTS

There were 4552 oesophageal cancer cases and 22,601 matched control participants. Overall, there was no evidence of an increased risk of oesophageal cancer with oral prednisolone use (unadjusted OR=1.16 95% CI 1.06, 1.27 and adjusted OR=0.99 95% CI 0.89, 1.11) or warfarin use (unadjusted OR=1.12 95% CI 0.99, 1.28 and adjusted OR=1.08 95% CI 0.92, 1.27).

CONCLUSIONS

In this large population-based study, oral prednisolone and warfarin were not associated with oesophageal cancer risk.

Association between antihypertensive medicine use and risk of ovarian cancer in women aged 50 years and older

BACKGROUND

Epithelial ovarian cancer (EOC) has few modifiable risk factors. There is evidence that some antihypertensive medicines may have cancer preventive and/or therapeutic actions; therefore, we assessed the associations between use of different antihypertensive medicines and risk of specific EOC histotypes.

METHODS

Our nested case-control study of linked administrative health data included 6070 Australian women aged over 50 years diagnosed with EOC from 2004 to 2013, and 30,337 matched controls. We used multivariable conditional logistic regression to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for the association between ever use of each antihypertensive medicine group, including beta-adrenergic blockers, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, and alpha blockers, and the risk of EOC overall and separately for the serous, endometrioid, mucinous, clear cell and other histotypes.

RESULTS

We found that most antihypertensive medicines were not associated with risk of EOC. However, women who used calcium channel blockers had a reduced risk of serous EOC (OR= 0.89, 95 % CI:0.81,0.98) and use of combination thiazide and potassium-sparing diuretics was associated with an increased risk of endometroid EOC (OR= 2.09, 95 % CI:1.15,3.82).

CONCLUSION

Our results provide little support for a chemo-preventive role for most antihypertensives, however, the histotype-specific associations we found warrant further investigation.

Association between angiotensin-converting enzyme inhibitor-induced cough and the risk of lung cancer: a Mendelian randomization study

Background: Observational studies and meta-analyses have demonstrated a positive correlation between the use of angiotensin-converting enzyme inhibitors (ACEIs) and lung cancer. However, the findings remain controversial; furthermore, the relationship between ACEI-induced cough and lung cancer development remains unknown. We used Mendelian randomization (MR) to verify the association between ACEI use, ACEI-induced cough, and the risk of lung cancer. Methods: We performed a two-sample MR analysis to determine the unconfounded relationships between ACE inhibition, which mimics the effects of ACEIs, and genetic proxies for ACEI-induced cough and lung cancer. Single nucleotide polymorphisms that imitate ACE receptors and ACEI-induced cough were collected and integrated into a meta-analysis of existing genome-wide association studies for various lung cancers. The relationship was quantified using inverse variance weighting, weighted median, and MR-Egger methods. Results: A statistically significant association was observed between ACE inhibition and the risk of small cell lung cancer for Europeans (excluding rs118121655/rs80311894). Associations were identified between ACEI-induced cough and the risk of lung cancer for Europeans, although not for Asians, and between ACEI-induced cough and lung adenocarcinoma (excluding rs360206). Conclusion: Our findings reveal a relationship between ACE inhibition and lung cancer development, as well as a significant association between ACEI-induced cough and a higher risk of lung cancer for Europeans. Patients with hypertension who experience dry cough as a side effect of ACEI use should consider switching to an alternative antihypertensive treatment.

Identification of Drug-Cancer Associations: A Nationwide Screening Study

The main tool in drug safety monitoring, spontaneous reporting of adverse effects, is unlikely to detect delayed adverse drug effects including cancer. Hypothesis-free screening studies based on administrative data could improve ongoing drug safety monitoring. Using Danish health registries, we conducted a series of case-control studies by identifying individuals with incident cancer in Denmark from 2001 to 2018, matching each case with 10 population controls on age, sex, and calendar time. ORs were estimated using conditional logistic regression accounting for matching factors, educational level, and selected comorbidities. A total of 13,577 drug-cancer associations were examined for individual drugs and 8,996 for drug classes. We reviewed 274 drug-cancer pairs where an association with high use and a cumulative dose-response pattern was present. We classified 65 associations as not readily attributable to bias of which 20 were established as carcinogens by the International Agency for Research on Cancer and the remaining 45 associations may warrant further study. The screening program identified drugs with known carcinogenic effects and highlighted a number of drugs that were not established as carcinogens and warrant further study. The effect estimates in this study should be interpreted cautiously and will need confirmation targeted epidemiologic and translational studies.

Significance

This study provides a screening tool for drug carcinogenicity aimed at hypothesis generation and explorative purposes. As such, the study may help to identify drugs with unknown carcinogenic effects and, ultimately, improve drug safety as part of the ongoing safety monitoring of drugs.

Exposure to Ranitidine and Risk of Bladder Cancer: A Nested Case-Control Study

INTRODUCTION

Ranitidine has been shown to contain the carcinogen N-nitrosodimethylamine and increase urinary N-nitrosodimethylamine in humans. We investigated whether ranitidine use is associated with increased bladder cancer risk.

METHODS

A nested case-control study was conducted within the Primary Care Clinical Informatics Unit Research database which contains general practice records from Scotland. Bladder cancer cases, diagnosed between 1999 and 2011, were identified and matched with up to 5 controls (based on age, sex, general practice, and date of registration). Ranitidine, other histamine-2 receptor agonists, and proton pump inhibitors were identified from prescribing records. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression after adjusting for comorbidities and smoking.

RESULTS

There were 3,260 cases and 14,037 controls. There was evidence of an increased risk of bladder cancer in ranitidine users, compared with nonusers (fully adjusted OR = 1.22; 95% CI 1.06-1.40), which was more marked with use for over 3 years of ranitidine (fully adjusted OR = 1.43; 95% CI 1.05-1.94). By contrast, there was little evidence of any association between proton pump inhibitor use and bladder cancer risk based on any use (fully adjusted OR = 0.98; 95% CI 0.88-1.11) or over 3 years of use (fully adjusted OR = 0.98; 95% CI 0.80-1.20).

DISCUSSION

In this large population-based study, the use of ranitidine particularly long-term use was associated with an increased risk of bladder cancer. Further studies are necessary to attempt to replicate this finding in other settings.