I happened to notice a slight disagreement between @KarlT and @adssx regarding the relationship between ARBs and cancer risk, so I reviewed studies from the past two years and found this question to be truly intriguing. It’s necessary to summarize these studies so that members can make better choices—clearly, this is a good example of weighing risks and benefits.
There is no evidence that ARBs increase cancer risk:
- Antihypertensive medications and cancer risk: Evidence from 0.27 million patients with newly diagnosed hypertension 2025: “There were no significant associations of angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, or thiazide diuretics (TDs) with cancer risk (p > 0.05). Compared with other antihypertensive treatments, the use of calcium channel blockers (CCBs) was significantly associated with a marginally mild increase in the risk of all cancers (hazard ratio, HR = 1.05; 95% CI: 1.01, 1.09; p = 0.017).”
- Long-term exposure to antihypertensive drugs and the risk of cancer occurrence: evidence from a large population-based study 2024: “There was no consistent significant association between the risk of cancer occurrence and angiotensin-converting-enzyme inhibitors, angiotensin-receptor blockers, or thiazides.”
- Antihypertensive treatment and risk of cancer: an individual participant data meta-analysis 2021, Lancet Oncology, University of Oxford + Johns Hopkins University: “In the individual participant data meta-analysis comparing each drug class with all other comparators, no associations were identified between any antihypertensive drug class and risk of any cancer (HR 0·99 [95% CI 0·95-1·04] for ACEIs; 0·96 [0·92-1·01] for ARBs; 0·98 [0·89-1·07] for β blockers; 1·01 [0·95-1·07] for thiazides), with the exception of calcium channel blockers (1·06 [1·01-1·11]). In the network meta-analysis comparing drug classes against placebo, we found no excess cancer risk with any drug class (HR 1·00 [95% CI 0·93-1·09] for ACEIs; 0·99 [0·92-1·06] for ARBs; 0·99 [0·89-1·11] for β blockers; 1·04 [0·96-1·13] for calcium channel blockers; 1·00 [0·90-1·10] for thiazides).”
- Systematic review and meta-analysis of randomised controlled clinical trial evidence refutes relationship between pharmacotherapy with angiotensin-receptor blockers and an increased risk of cancer 2019: “The results of our meta-analysis focusing only on high evidence levels and study designs (RCTs) did not reveal any relationship between pharmacotherapy with an ARB and an increased risk for cancer in general.”
For telmisartan specifically:
- The Use of Telmisartan and the Incidence of Cancer 2016: “Compared with other ARBs, telmisartan is not associated with an increased risk of cancer. This study provides reassurance as to the short-term safety of telmisartan.”
And published last month by the Dartmouth Cancer Center: New Study Finds Common Blood Pressure Drug Boosts Cancer Treatment
Telmisartan belongs to a class of medications called “angiotensin II receptor blockers” (ARBs), commonly prescribed to treat hypertension, or high blood pressure. But the DCC study found that the cancer-treatment-enhancing effects were unique to telmisartan among all of the ARBs tested.
Telmisartan also reduced levels of a protein inside tumor cells that cancers use to evade immune attack—further increasing its therapeutic potential.
“This study was about PARP inhibitors,” Curiel said. “But we also have a lot of evidence that telmisartan makes certain other chemotherapies and immunotherapies more effective through related mechanisms. Its potential could therefore extend to many other types of cancers and treatments.”
Telmisartan’s widespread use and high tolerability, even in people without high blood pressure, make it ideal for clinical use. Curiel’s team is already using the combination strategy in patients through two ongoing clinical trials at DCC.
In total, 133,539 cases and 257,849 controls were studied. Thiazide-containing combination treatments (OR 1.09), angiotensin II receptor blockers (OR 1.09), calcium channel blockers (OR 1.09), and beta-blockers (OR 1.07) were associated with an increased BCC risk. Use of single-agent thiazide treat-ment did not affect BCC risk.
In the adjusted model, the odds ratio (OR) for developing basal cell carcinoma (BCC) among those using ARBs was 1.09 (95% confidence interval [CI]: 1.06–1.11), indicating a significant increase in BCC risk. It is worth noting that when ACE inhibitors (ACEi) were considered as a whole, they showed a very slight decrease in BCC risk. The adjusted OR was 0.98 (95% CI: 0.96–1.00). However, when the two most commonly used ACEi drugs (enalapril and ramipril) were analyzed separately, neither showed a statistically significant association in the adjusted model. In the unadjusted crude model, the risk reduction associated with ACEi reached 9%. However, because the proportion of patients with diabetes and heart failure in the BCC case group was already lower than that in the control group, after adjusting for these comorbidities as confounders, the OR was pulled back to 0.98.
JCR Quartile (international evaluation standard): Q1. In Clarivate’s Dermatology subject ranking, it has long been positioned in the top 20%–25% globally, placing it among the international first-tier journals in this subfield.
AHTN use was associated with an increased risk of KC compared to no use, even after accounting for hypertension, with the highest risk observed for CCB. Our findings highlight the potential KC risks associated with different AHTN classes, with optimal cardiovascular care remaining an important consideration.
When not adjusting for hypertension variables: all classes of antihypertensive medications (AHTN) showed a statistically significant association with increased kidney cancer risk, with relative risks (RR) ranging from 1.48 to 1.75. After adjusting for hypertension variables: the risk for ACE inhibitors was no longer statistically significant (RR 1.19, 95% CI 0.93–1.52), while the risks for ARBs, beta-blockers (BB), and diuretics (DU) remained statistically significant, with RRs ranging from 1.09 to 1.36.
JCR Quartile: Consistently stable in Q2 (ranking between the top 25% and 50%) in the “Oncology” category.
Before I continue sharing multiple papers, let me mention something interesting. In the first two papers (from Sweden and China), I found that ACEi drugs are truly unique regarding cancer risk. While other antihypertensive drugs all show an increased cancer risk, ACEi not only does not increase the risk but also exhibits a slightly decreasing trend. This is indeed very interesting.
Wrong. The kidney cancer paper does not show a decreased risk with ACEI, it’s actually higher than for ARBs: “RR 1.19, 95% confidence interval (CI) 0.93-1.52 for angiotensin-converting enzyme inhibitor; RR 1.15, 95% CI 1.00-1.31 for angiotensin receptor blocker; RR 1.09, 95% CI 1.03-1.16 for beta-blocker, RR 1.40, 95% CI 1.12-1.75 for calcium channel blocker (CCB); RR 1.36, 95% CI 1.20-1.55 for diuretic”
I thought my words wouldn’t be misunderstood in context. An RR of 1.19 is obviously greater than 1, but its confidence interval indicates no statistical significance. Clearly, I was referring to the basal cell carcinoma study, which showed an OR of 0.98 (95% CI 0.96–1.00) — that clearly represents a slight but significant decrease.
Yes, the authors write “Indeed, our study showed a minimal, but statistically significant, decrease in BCC risk (OR 0.98).”
They don’t give the p-value, and 1.00 is in the confidence interval. So the effect is most likely null.
Also: are you writing your posts with AI @Cole?
emmmm,OFCOURSE…
I think it is very interesting that while other blood pressure-lowering drugs show an increase in cancer, ACEi remain unchanged, especially from two studies of different cancers in different countries.
Telmisartan may indeed be the optimal choice among ARBs.
In this large real-world matched cohort of over 83,000 patients, telmisartan was associated with superior cardiovascular and cerebrovascular outcomes compared to other ARBs, supporting its potential as a preferred antihypertensive agent in high-risk populations.
But that’s not the case. One study finds ACEi risk to be higher than ARB. Yes the BCC one finds a minimal decrease with ACEi. But that’s a single paper. Compared to dozens that found no differences between ACEi and other drug classes:
Yes, so I said that before continuing to share the papers, I found an interesting phenomenon based on these two papers from 2025. Of course I know that the cancer risk is controversial. Statements should be analyzed in context, right?
No.
You wrote: “I think it is very interesting that while other blood pressure-lowering drugs show an increase in cancer, ACEi remain unchanged, especially from two studies of different cancers in different countries”
That’s bullshit, as among the two papers you shared, one (KC) finds a higher risk with ACEi vs ARB.
So this is the point of confidence intervals—are you only looking at the risk without considering the confidence interval? That’s a factor in determining statistical significance.
The risks of other antihypertensive drugs are statistically significant, while ACEi are not. Moreover, the Swedish study even showed a decrease. Never mind — you’re just looking for an argument. I can’t be bothered to discuss whether 1+1 equals 2.
It’s unpleasant to feel like I’m talking to an AI.
But anyway you wrote: “In the first two papers (from Sweden and China), I found that ACEi drugs are truly unique regarding cancer risk. While other antihypertensive drugs all show an increased cancer risk, ACEi not only does not increase the risk but also exhibits a slightly decreasing trend.”
I just say that the above statement is CORRECT for the Swedish BCC study but INCORRECT for the Chinese KC one. Do you agree or not?
To sum up those two papers:
Swedish BCC (Basal Cell Carcinoma) study:
- ACEI: 0.98 (0.96–1.00)
- ARB: 1.09 (1.06-1.11)
- CCB: 1.09 (1.07–1.11)
- Thiazide: 1.02 (1.00–1.05)
- BB: 1.07 (1.05–1.09)
Kidney cancer meta-analysis (actually not Chinese btw but Stanford + UCSD):
- ACEI: 1.19 (0.93-1.52)
- ARB: 1.15 (1.00-1.31)
- BB: 1.09 (1.03-1.16)
- CCB: 1.40 (1.12-1.75)
- Diuretic (thiazide, loop, K): 1.36 (1.20-1.55)
- Other: 1.40 (1.13-1.75)
So yes, I now get your point: non-ACEI are associated with a higher risk of BCC and KC in those studies (although ARB is borderline in the KC one as 1.00 is within CI) while ACEI is not: minimal protective effect in BCC (but 1.00 within CI) and on the wrong side of null for KC with large CI that includes 1.00.
Is that relevant though? I don’t think so vs the other papers we have on the topic.
On BCC we have this paper as well by Tier 1 US + UK universities: Antihypertensive Medications and Risk of Melanoma and Keratinocyte Carcinomas: A Systematic Review and Meta-Analysis 2024
Increased risks were seen for basal cell carcinoma with calcium channel blockers (relative risk [RR] = 1.17, 95% confidence interval [CI] = 1.11–1.22), diuretics (RR = 1.06, 95% CI = 1.03–1.10), and thiazides (RR = 1.10, 95% CI = 1.04–1.16); for squamous cell carcinoma with calcium channel blockers (RR = 1.08, 95% CI = 1.01–1.14), diuretics (RR = 1.29, 95% CI = 1.17–1.43), and thiazides (RR = 1.36, 95% CI = 1.15–1.61); and for melanoma in angiotensin-converting enzyme inhibitors (RR = 1.09, 95% CI = 1.03–1.14), calcium channel blockers (RR = 1.08, 95% CI = 1.03–1.12), and thiazides (RR = 1.09, 95% CI = 1.02–1.17)
This one did not find an increased risk with ARBs, nor did it find a reduced risk with ACEIs. Worse, it found an INCREASED risk with ACEI for melanoma.
That’s why we cannot reach a conclusion based on a single study with a null hypothesis; we have to look at the whole body of evidence, which indicates that ARBs and ACEIs seem to carry a similar cancer risk.
Published this month: Abstract 1304: Cancer risk with initiation of angiotensin receptor blockers (ARBs) vs. angiotensin converting enzyme inhibitors (ACEIs).
It is an abstract so not yet peer-reviewed but high-quality journal (Cancer Research, published by the American Association for Cancer Research), good research team (University of Utah, University of Colorado, UPenn), massive cohort (2,658,758 veterans) and long follow-up (10 years).
Conclusion:
ARB initiation was associated with a lower 10-year risk of any cancer (RR, 0.79; 95% CI, 0.75-0.83) and a similar 10-year risk of non-cancer mortality (RR, 1.03; 95% CI, 0.88-1.07) compared with ACEI initiation. Associations were consistent across most cancer types, except for inconclusive findings for breast and renal cancers.
ARB initiators had a lower risk of developing any cancer compared with initiation of ACEIs, with no observed difference in non-cancer or all-cause mortality. We also reported stronger inverse association for ARBs in older adults in subgroup analyses. Further research should clarify underlying biological mechanisms, confirm causality in randomized trials, and evaluate personalized antihypertensive strategies that incorporate cancer risk considerations.
@Cole: what do you think about the above?
I am planning to categorize and share based on year and whether the evidence points to increased or decreased cancer risk, so the first two posts are both from 2025 and both show negative findings. Of course I know that drawing a firm conclusion requires synthesizing multiple studies, but others have already covered the older evidence. I’m simply aggregating research from the last two years — updating the “Bayesian priors” in people’s minds.
Since you enjoy playing this debating game, I can easily play along. You previously said: “The kidney cancer paper does not show a decreased risk with ACEI, it’s actually higher than for ARBs.” Anyone with a college education would conclude from the RR and CI that ACEI shows no statistically significant association with increased cancer risk — not “it’s actually higher than for ARBs.” In fact, ARBs’ RR might show a statistically significant association with increased cancer risk, whereas ACEI absolutely does not.