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22nd August 2022
A study has identified a higher male cancer risk in 19 out of 21 different cancers at shared anatomical sites which is only partially explained by known risk factors, underscoring the importance of sex-related biological features according to a study by a team of US researchers.
Cancer is a leading worldwide cause of deaths and which, according to the World Health Organisation, in 2020, was responsible for nearly one in six deaths. It is already recognised that there are sex-related differences in both the incidence and mortality from cancer. For example, the cancer incidence rate is 20% higher in men than in women though the male cancer death rate is 40% higher. Moreover, the reasons behind this disparity remain to be determined although traditional risk factor such as smoking and alcohol intake are clearly important. In fact, one European study found that smoking-related deaths accounted for around 40% to 60% of the gender gap and alcohol-related mortality for 20% to 30% in Eastern Europe and 10% to 20% elsewhere in Europe.
In an attempt to better understand the reasons for these sex-related differences in cancer, the US team estimated the risk for 21 solid tumours at shared anatomical sites and examined whether the higher male cancer incidence could be explained by known risk factors, such as smoking, diet, physical activity and alcohol use. They used data from the National Institutes of Health Diet and Health Study which began in 1995 and where a baseline questionnaire, asking about a wide range of issues including demographics, health status, co-morbidities and various lifestyle measures e.g., physical activity, levels of smoking, was mailed to over 3.5 million individuals aged 50 – 71 years of age. For the current study, the US team restricted their analysis to a smaller cohort who had completed both the baseline and follow-up questionnaire between 1996 and 1997. The main aim of the research was to estimate both crude and covariate adjusted male-to-female risk ratios of cancer incidence and to determine the extent to which these covariates and risk factors could account for the sex-related disparity in cancer risk.
Male cancer incidence and cancer disparities
The cohort included a total of 294,100 individuals with a median age of 63.5 years (41.7% female) with a mean of 11.5 person-years follow-up for men and 12.4 person-years for women.
Cancer incidence was recorded for 21 cancers and the biggest difference in the male-female incidence risk ratio (IRR) was for oesophageal adenocarcinoma (IRR = 12.19, 95% CI 8.32 – 17.86) and for gastric cardia cancer (IRR = 4.93, 95% CI 3.59 – 6.77). In fact, only thyroid and gall bladder cancer were more common in women than men.
After adjustment for covariates, oesophageal adenocarcinoma remained more common in men (Hazard ratio, HR = 10.80, 95% CI 7.33 – 15.90) as did gastric cardia cancer (HR = 3.49). Overall and after adjustment, the higher risk for men remained for 11 of the cancers.
When examining the effect of known risk factors, among 7 cancers (lung, colon, rectum, other biliary tract, skin, bladder and oesophageal adenocarcinoma), the distribution of risk factors and covariates explained some of the observed differences, ranging from 11.2% (oesophageal adenocarcinoma) to 49.4% (lung cancer). After adjusting for alcohol use, smoking status, body mass index and age groups, there was still no significant interaction effect for any of the cancer sites.
The authors concluded that sex-related biological factors appeared to represent major determinants of cancer incidence. The added that further analysis of physiologic, immunologic and genetic or genomic factors are needed across a wider range of cancers to better understand their contribution to the higher male cancer burden.
Jackson SS et al. Sex disparities in the incidence of 21 cancer types: Quantification of the contribution of risk factors Cancer 2022
4th August 2022
Daily insulin use increases the risk of developing cancer in patients with type 1 diabetes, with a greater risk among those who use a higher daily dose, according to findings of a study by US and Greek researchers.
Although diabetes and cancer are two heterogeneous, multifactorial, and chronic diseases, there are some epidemiological data indicating a higher risk of several types of cancer (including pancreas, liver, breast, colorectal, urinary tract, and female reproductive organs) in diabetic patients. Moreover, in an analysis of diabetic registries that specifically focused on patients with type 1 diabetes, a higher cancer risk was also identified for several types of cancer. However, whether this observed link is causal remains unclear. For example, in a 2016 meta-analysis of 16 observational studies in type 1 diabetics who used long-acting daily insulin, 13 studies reported no association between insulin glargine and detemir and any cancer and 4 studies reported an increased risk of breast cancer with insulin glargine. The authors concluded that observational studies examining the risk of cancer associated with long-acting insulin analogues have important methodological shortcomings that limit the conclusions that can be drawn. Nevertheless, whilst it is possible that the presence of type 1 diabetes is linked to an increased risk of cancer, no studies have examined potential patient risk factors. Consequently, for the present study, researchers turned to data from the Diabetes Control and Complications trial (DCCT) and the Epidemiology of Diabetes Interventions and Complications study (EDIC) to gain a better understanding of which, if any, factors increased the risk of cancer.
The DCCT enrolled patients between 1983 and 1989 and when the trial was completed in 1993, 1375 survivors continued in the EDIC study and follow-up data was available for 28 years. Daily insulin dose was categorised as low (< 0.5 units/kg), medium (> 0.5 and < 0.8 units/kg) and high (> 0.8 units/kg). The researchers used multivariable models to assess the association between several different factors and cancer incidence.
Daily insulin and cancer
Among a total of 1303 patients who were followed-up for 33,813 person-years, 93 (7%) developed cancer, giving an incidence rate of 2.8 (95% CI 2.2 – 3.3) per 1000 person-years. The mean age of participants at their cancer diagnosis was 50 years and the mean duration of diabetes was 25 years. Among the 93 who developed cancer, 61% were female. The majority of individuals (58%) developed their cancer after 21 and 28 years and the cancers affected the skin (27), breast (15) and digestive tract (6).
Factors associated with the development of cancer were age (hazard ratio, HR = 1.08, 95% CI 1.05 – 1.12) and female gender (HR = 1.74, 95% CI 1.15 – 2.64). Interestingly, participation moderate or strenuous exercise was associated with a reduced risk of cancer (HR = 0.31, 95% CI 0.16 – 0.59, p = 0.001).
In multivariable models, daily insulin use was associated with a 4-fold higher risk of cancer (HR = 4.13, 95% CI 1.13 – 15.17, p = 0.03). The cancer incidence was 2.11, 2.87 and 2.91 per 1000 person-years in the low, medium and high-dose daily insulin groups respectively.
Although the previous 2016 meta-analysis described earlier did not derive a clear association between type 1 diabetes and cancer, the authors of the current study suggested that this was because in the cohorts examined the doses of insulin used were low (< 0.3 units/kg) and many had discontinued treatment during follow-up.
The authors also felt that their observations may have been due to residual confounding and that potentially, the associations may not have been causal. They called for further studies to validate this association.
Zhong W, Moa Y. Daily Insulin Dose and Cancer Risk Among Patients With Type 1 Diabetes JAMA Oncol 2022
1st July 2022
Patient who have undergone bariatric surgery have a significantly lower risk of developing an obesity-related cancer as well as cancer-related mortality. This was the conclusion of a cohort study by a team of US researchers.
Individuals with a body mass index (BMI) above 25 are considered to be overweight but when the BMI exceeds 30, these individuals are deemed to be obese. Data from the World Health Organisation suggest that in 2016, 1.9 billion adults across the world were classed as overweight and 650 million obese. Although obesity increases the risk of cardiovascular disease, obesity has also been found to be associated with greater overall mortality in patients with cancer.
Whilst dieting helps many people to lose weight, one of the most effective weight loss strategies is surgery and in one follow-up study after a Roux-en-Y gastric bypass, the mean weight loss change from baseline was 35 kg at 12 years. Given the elevated risk of certain cancers in those who are obese, could weight loss reduce the risk of subsequently developing an obesity-related cancer? Unfortunately, the evidence base supporting this premise is limited apart from one study in patients who underwent bariatric surgery and which found that after a mean follow-up of 12.5 years, total cancer incidence was significantly lower in the surgical group compared to controls. Nevertheless, a limitation of the study was the absence of a matched control group, particularly in relation to possible cancer risk factors such as smoking history.
Consequently, there remains some uncertainty over whether weight loss can reduce the risk of cancer and this was the basis for the current study. The US team undertook the Surgical Procedures and Long-term Effectiveness in Neoplastic Disease Incidence and Death (SPLENDID) trial, which was a retrospective, observational, matched, cohort study in adults with obesity who either underwent bariatric surgery or who received usual care (i.e., no surgery). Participants were included if they had a BMI of between 35 and 80 and underwent either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). The primary endpoint of the study was the first occurrence of 1 of 13 types of obesity-associated cancers including oesophageal adenocarcinoma, renal cell carcinoma, colon, rectum, liver and pancreatic cancer. As a secondary endpoint, the team considered the incidence of all types of cancer and cancer-related mortality.
Bariatric surgery and cancer development
A total of 30,318 patients with a median age of 46 years (77% female) including 5,053 who underwent bariatric surgery, (RYGB 66%) were included in the analysis. After 10 years, participants in the bariatric surgery group had lost 27.5 kg compared to 2.7 kg in the control group (p <0.001).
During the period of follow-up, 96 patients in the bariatric surgery group and 780 in the control group developed one of the obesity-related cancers, giving an incidence rate of 3 vs 4.6 events (surgery vs control) per 1000 person-years.
The cumulative incidence of the primary endpoint at 10 years was 2.9% in the surgery group and 4.9% in the non-surgical (control group) and which was statistically significant (hazard ratio, HR = 0.68, 95% CI 0.53 – 0.87, p = 0.02). In addition, the cumulative incidence of cancer-related mortality at 10 years was 0.8% in the surgical group compared to 1.4% in the control group and which again, as statistically significant (HR = 0.52, 95% CI 0.31 – 0.88, p = 0.01).
Based on these findings, the authors concluded that bariatric surgery is associated with a significantly lower incidence of obesity-associated cancer and cancer-related mortality.
Aminian A et al. Association of Bariatric Surgery With Cancer Risk and Mortality in Adults With Obesity JAMA 2022
13th May 2022
Cancer is the second leading cause of death globally and in 2018, it accounted for approximately 9.6 million deaths. Although cancer can strike at any age, many types of cancer become more prevalent with increasing age. However, recent research has found that for most adults, cancer does not have to be an inevitable consequence of growing older. In fact, adoption of healthy lifestyle measures based on a combination of exercise, diet, smoking status, alcohol consumption, and anthropometry, in other words, simple behavioural modifications, have been shown to produce a sizeable reduction in the risk of some cancers. Among healthy interventions, there is evidence that physical activity is associated with a lower risk of several cancers. Equally, use of vitamin D supplements has some evidence to support its use in reducing the incidence of advanced (metastatic or fatal) cancer. Finally, an omega-3 fatty acid-rich diet, can significantly delay mouse tumour growth when compared with a monounsaturated fatty acid-rich diet. Nevertheless, whether a combination of exercise, vitamin D and omega-3 fatty acids provides a synergistic and preventative effect against cancer is less clear.
For the present study, the researchers undertook a randomised controlled trial, which sought to examine the combination of exercise, supplementation with vitamin D and omega-3 fatty acids in older adults and how this impacted on the subsequent development of cancer. Their DO-HEALTH trial examined the combined effect of simple home strength exercise (SHEP), vitamin D (2000 IU/day) and/or 1g/day of marine omega-3 fatty acids, in healthy adults 70 years of age and older. For the primary outcome, the team considered the time to the development of a verified invasive cancer.
Combination of exercise, omega-3 fatty acids, vitamin D and cancer development
A total of 2157 individuals with a mean age of 74.9 years (61.7% female) were included in the study and followed for a median of 2.99 years. During this period of time there were 81 invasive cancers diagnosed and verified.
For the three separate interventions, the adjusted hazard ratios (compared to controls) were 0.76 (95% CI 0.49 – 1.18) for vitamin D, 0.70 (95% CI 0.44 – 1.09) for omega-3 fatty acids and 0.74 (95% CI 0.48 – 1.15) for SHEP). In other words, while there were beneficial effects from the individual interventions, the effects were not statistically significant, but when two of the interventions were combined, the effect did become statistically significant. For instance, the combination of SHEP and omega-3 resulted in an adjusted hazard ratio of 0.52 (95% CI 0.28 – 0.97, p = 0.039). However, the greatest benefit was derived from the combination of exercise, vitamin D and omega-3 fatty acids, with an adjusted hazard ratio of 0.39 (95% CI 0.18 – 0.85, p = 0.017).
The authors calculated that the number needed to treat to prevent one incident case of cancer after three years with the three treatments combined was 35.
They concluded that future studies should focus on the benefit of combining interventions as a means of cancer prevention.
Bischoff-Ferrari HA et al. Combined Vitamin D, Omega-3 Fatty Acids, and a Simple Home Exercise Program May Reduce Cancer Risk Among Active Adults Aged 70 and Older: A Randomized Clinical Trial Am J Clin Nutr 2022
12th May 2022
A higher level of dairy consumption in Chinese adults has been found to be linked to an increased overall risk of developing cancer and in particular, liver and female breast cancers. This was the key finding of a prospective study by researchers from the UK and China.
Across the globe in 2020, it has been estimated that cancer was responsible for an estimated 19.3 million new cases and almost 10.0 million cancer deaths. Several dietary factors are linked with a reduced risk of developing cancer, including for example, a higher intake of fruit and vegetables, which is associated with a 17% lower cancer mortality. Another food linked with cancer is dairy products and a higher dairy consumption lowers the risk of developing colorectal cancer. However, intake of egg, fish and dairy consumption has remained at a low level among Chinese people with other work finding that dairy consumption was seriously inadequate in Chinese elderly and appears to be reducing. As a result, for the present study, researchers were interested in determining if, despite low levels of intake among the Chinese (compared to Westernised countries), dairy intake was associated with the incidence of cancer.
Turning to data held within the China Kadoorie Biobank, which represents a population-based prospective analysis with over 0.5 million adults across China, the researchers obtained information on the frequency of dairy consumption and which was categorised as daily, 4 – 6 day/week, 1 – 3 days/week, monthly or never/ready and which served as a baseline. The information on dairy intake was re-collected at two follow-up surveys and used to estimate mean intake of dairy foods. Cox regression analysis was used to link incident cancers with dairy consumption and adjusted for several covariates including a family history of cancer, alcohol intake and levels of smoking.
Dairy consumption and incident cancer
Among a population of 510,146 individuals with a mean age of 52 years (59% women), 20.4% reported intake of dairy foods at least once a week (subsequently referred to as ‘regular dairy consumers’) and which was largely for milk. Participants were followed for a mean of 10.8 years, during which time there were 29,277 incident cancer cases recorded. In the fully adjusted models, each 50g/day increase in dairy consumption was associated with a 7% increased risk of total cancer (hazard ratio, HR = 1.07, 95% CI 1.04 – 1.11) when compared to those who never consumed dairy foods. Furthermore, among regular dairy consumers, there was a significant increased risk of liver cancer (HR = 1.12, 95% CI 1.02 – 1.22) and for female breast cancer (HR = 1.17, 95% CI 1.07 – 1.29). There was no significant association for any other form of cancer including colorectal cancer.
The authors concluded that higher dairy consumption was associated with a greater risk of cancer among Chinese individuals even though levels of dairy intake are low compared to Westernised countries.
Kakkoura MG et al. Dairy consumption and risks of total and site-specific cancers in Chinese adults: an 11-year prospective study of 0.5 million people. BMC Med 2022
30th March 2022
The consumption of foods and beverages which contain artificial sweeteners has been found to be associated with a slight increased risk of cancer according to the results of a large, French cohort study by researchers from the Sorbonne Paris Nord University, University of Paris, France.
The World Health Organization recommends that both adults and children should reduce their intake of free sugars to less than 10% of total energy intake. Consequently, manufacturers developed alternatives to sugar and artificial sweeteners were developed, one of which is aspartame, that has been used since 1981 and is present in more than 6,000 products. Although aspartame contains the same number of calories as sugar, it is around 200 times sweeter than sugar. The potential carcinogenicity of artificial sweeteners like aspartame has always been controversial and one review in 2014 suggested that the studies performed in the 1970s did not provide adequate scientific support for the safety of aspartame and that more recent life-span carcinogenicity data undertaken with rodents provide consistent evidence of aspartame’s carcinogenic potential. Moreover, a 2021 review of aspartame and cancer concluded that new findings confirm that aspartame is a chemical carcinogen in rodents. Nevertheless, it has been unclear from studies in humans whether artificial sweeteners are associated with an increased risk of cancer. For example, one 2012 prospective study that evaluated whether the consumption of aspartame- and sugar-containing soda is associated with risk of haematopoietic cancers, concluded that the apparent cancer risk in individuals who consume regular soda do not permit the ruling out of chance as an explanation. In contrast, a second study concluded that higher levels of aspartame intake were not associated with the risk of overall hematopoietic cancer.
With some uncertainty over the association between cancer and intake of artificial sweeteners, for the present study, the French team prospectively followed participants in the NutriNet-Sante study. This prospective trial was designed to determine, among adults, any associations between nutrition and health. Nutritional intake information is collected at baseline and every year on various factors such as health status, physical activity, smoking status and diet using 24-hour dietary recall questionnaires through which the intake of artificial sweeteners can be assessed.
Artificial sweeteners and cancer risk
A total of 102,865 participants with a baseline mean age of 42.2 years (78.5% female) were followed for a median of 7.8 years and consumption of artificial sweeteners was recorded for 36.9% of participants.
A total of 3,358 incident cancers developed during the follow-up period. Compared those who did not consume artificial sweeteners, among high consumers, there was an increased risk of cancer development (hazard ratio, HR = 1.13, 95% CI 1.03 – 1.25, p-trend = 0.002). Two sweeteners in particular, aspartame (HR = 1.15, p = 0.002) and acesulfame-K (HR = 1.13, p = 0.007) were associated with higher cancer risks. In addition, aspartame was associated with an increased risk of breast cancer (HR = 1.22, 95% CI 1.01 – 1.48, p = 0.036).
Based on these findings, the authors concluded that while the study could not establish causal links, their findings did not support the use of artificial sweeteners as a safe alternative to sugar in food and beverages.
Debras C et al. Artificial sweeteners and cancer risk: Results from the NutriNet-Santé population-based cohort study PLoS Med 2022
21st March 2022
Individuals who are regular meat eaters have been found to be at a higher risk of all and some specific cancers compared to those who are either low meat eaters, pescatarians or vegetarians. This was the finding of a study of the UK Biobank database by researchers from the Cancer Epidemiology Unit, University of Oxford, Oxford, UK.
Cancer has been declared by the World Health Organization (WHO) as a leading cause of death worldwide accounting for nearly one in six of all deaths (10 million in 2020). Moreover, according to WHO, breast, lung, colorectal and prostate cancers are the most common forms of the disease. Understanding the causal relationship between dietary patterns or even particular dietary components and cancer aetiology and prevention is a challenge. For example, undertaking randomised controlled intervention trials to examine the association between diet and cancer outcomes are not feasible, for a number of reasons including cost, the difficulty of ensuring compliance among control and intervention groups as well as the long time-frame and exposure necessary to affect the carcinogenesis process. Although it has been shown that the risk of some cancers is lower in fish eaters and vegetarians than in meat eaters, it is not universally true with other work showing no statistically significant associations with dietary pattern and risk of premenopausal breast cancer.
For the present analysis, the Oxford team examined the relationship between those who ate meat at least 5 times a week, low meat consumers (< 5 times/week), pescatarians and vegetarians and the risk of all cancers and in particular, colorectal, postmenopausal breast and prostate cancers. They used data held in the UK Biobank and excluded individuals with a cancer diagnosis at recruitment. Participants completed an online questionnaire at recruitment into the database which asked about consumption and frequency of meat intake. The team also assessed whether specific hormones such as insulin-like growth factor-1 and testosterone as well as body mass index, might have potential mediator effects on the association between dietary patterns and cancer risk. The risks for the development of all and any of the specific cancers, were assessed using meat eaters as the reference group.
Meat eaters and cancer risk
A total of 247,571 individuals with a mean age of 56 years (46.4% female) were classed as meat eaters, 205,385 as low-meat eaters, 10,696 as pescatarians and 8,685 as vegetarians. After an average follow-up of 11.4 years, 54,861 incidence cases of cancer occurred; 5882 colorectal, 7537 women with postmenopausal breast cancer, 9501 men with prostate cancer.
After adjustment for several factors such as smoking status, physical activity etc, a vegetarian diet was associated with a 14% lower risk of all cancers compared to the reference group. (hazard ratio, HR = 0.86, 95% CI 0.80 – 0.93). This risk was also significantly reduced for breast cancer (HR = 0.82) and prostate cancer (HR = 0.69).
For pescatarians, there was also a lower risk of all cancers (HR = 0.90) compared to the reference meat group and for prostate cancer (HR = 0.80). For those categorised as low-meat eaters, the risks were only significantly lower for colorectal cancer (HR = 0.91).
After adjustment for possible mediators, only body mass index was found to be relevant and the risk of all cancers was slightly attenuated for vegetarians (HR = 0.88) and pescatarians (HR = 0.92) but remained significant. Furthermore, the reduced cancer risk remained significant among pescatarians and vegetarians but only for prostate cancer.
The authors concluded that being a pescatarian or vegetarian was associated with a lower risk of all cancers and that this might be attributable to differences in dietary factors in comparison to those who regularly eat meat. However, they added that it was unclear if these associations are causal or due to residual confounding, i.e., due to other, but unmeasured factors.
Watling CZ et al. Risk of cancer in regular and low meat-eaters, fish-eaters, and vegetarians: a prospective analysis of UK Biobank participants BMC Med 2022
18th March 2022
The angiotensin receptor blockers have been used clinically since 1995 and represent an effective class of antihypertensive agents with an excellent tolerability profile. Nevertheless, in 2018 the FDA in the US and the EMA in Europe, alerted health care professionals and patients of a voluntary recall of several drug products containing the active ingredient valsartan. This was due to the presence of an impurity, N-nitrosodimethylamine, which has been classified as a probable human carcinogen based on animal tests. After an initial evaluation, the EMA estimated that there could be one extra case of cancer for every 5000 patients taking the affected medicines at the highest valsartan dose (320 mg) every day for 7 years. Furthermore, the EMA has stated that there is a very low risk that nitrosamine impurities at the levels found in medicines could cause cancer in humans. However, a meta-analysis published in 2010, concluded that the use of an angiotensin receptor blocker is associated with a modestly increased risk of a new cancer diagnosis, though the authors also stated that it was not possible to draw conclusions about the exact risk of cancer associated with each particular drug.
For the present analysis, the author set out to re-examine the relationship between ARB use and the development of cancer, through an examination of information derived from randomised, controlled trials in which the drug class had been used. The study looked at cumulative exposure, i.e., the intensity and duration of exposure to the drug and specifically, the relationship with the development of lung cancer, which was found to be increased in the earlier meta-analysis.
Angiotensin receptor blocker use and cancer
A total of 15 randomised trials were included in the analysis with 74,021 patients given an ARB which included telmisartan (38.9%) and valsartan (33%).
In trials where the duration of use (reflecting cumulative exposure), exceeded 3 years, there was a statistically significant excess of new cancers in those assigned to an ARB (relative risk, RR = 1.12, 95% CI 1.02 – 1.24, p = 0.006). In contrast, this increased risk was absent trials where the drug was used for < 3 years. In relation to lung cancer, there was also an increased risk (RR = 1.21, 95% CI 1.02 – 1.44, p = 0.03) when the drugs were used for > 3 years but again, no increased risk when used for < 3 years.
Interestingly, there was also a higher cancer risk when an ARB was used alongside an angiotensin converting enzyme inhibitor for longer than 3 years (RR = 1.11, 95% CI 1.0 – 1.23, p = 0.05) and which, as before, was absent when used for a shorter period of time.
The author concluded that the risk of cancer and in particular lung cancer, increases with greater cumulative exposure to an angiotensin receptor blocker drug, adding that the widespread use of these drugs has profound implications for patients.
15th February 2022
Use of spironolactone does not appear to be linked with a higher incidence of any form of cancer and may even be protective against prostate cancer. This was the conclusion from a systematic review and meta-analysis by researchers from the University of Miami Miller School of Medicine, Florida, US.
Spironolactone is a potassium-sparing diuretic with a number of licensed indications including oedema, ascites, nephrotic syndrome and resistant hypertension. In addition, the drug is often prescribed ‘off-license’ for the treatment of acne in women, female pattern hair loss and hirsutism. In fact, a recent and retrospective analysis of 403 women concluded that spironolactone improves clinical outcomes and is well tolerated for many adult women with acne using it for an extended duration.
Despite being used for a wide range of indications, the US Food and Drug Administration carries a warning that spironolactone has been shown to be a tumourigen in chronic toxicity studies in rats and that it should be used only for licensed indications, adding that unnecessary use of this drug should be avoided. Similarly, the summary of product characteristics (SPC) for the drug states that spironolactone has been shown to produce tumours in rats when administered at high doses over a long period of time. While the SPC adds that the ‘significance of these findings with respect to clinical use is not certain‘, it does advise that the ‘long-term use of spironolactone in young patients requires careful consideration of the benefits and the potential hazard involved‘.
With some uncertainty over possible associations between the use of spironolactone and cancer, the US team undertook a systematic review and meta-analysis to synthesize the available evidence on the topic. They searched for studies that reported on the risk of cancer development in adults in both sexes who were exposed to spironolactone, irrespective of its primary use. The main outcome of interest was cancer occurrence.
Spironolactone use and incidence of cancer
A total of 7 observational studies including a total population of 4,528,332 individuals with a mean age of 62.6 to 72 years and between 17.2 and 54.4% women, were included in the analysis. These studies examined the incidence of breast, ovarian, bladder, kidney, gastric and oesophageal cancers. Furthermore, all of the studies were deemed to be at a low risk of bias.
There was a non-significant association between spironolactone use and breast cancer (risk ratio, RR = 1.04, 95% CI 0.86 – 1.22), bladder cancer (RR = 0.89, 95% CI 0.71 – 1.07) and kidney cancer (RR = 0.96, 95% CI 0.85 – 1.07). In addition, similar non-significant associations were calculated for the other cancer examined. However and contrast, in relation to prostate cancer and based on a total of 4 studies, there was a significantly reduced risk in those using spironolactone (RR = 0.79, 95% CI 0.68 – 0.90), although the certainty of evidence for this estimate was considered to be low.
Commenting on these findings, the authors considered their results to be reassuring and that treatment with spironolactone appeared unlikely to be associated with a meaningful increased risk of cancer when prescribed at typical clinical doses. Nevertheless, they concluded that the certainty of evidence was low and that future studies are needed to examine this relationship in more detail.
Bommareddy K et al. Association of Spironolactone Use With Risk of Cancer: A Systematic Review and Meta-analysis JAMA Dermatol 2022
28th January 2022
Heart failure (HF) patients have a higher risk of cancer and cancer-related mortality compared to matched-controls according to research by a team from the Cardiovascular Disease Unit, Genoa, Italy.
There is emerging evidence that the incidence of cancer is higher among those with cardiovascular disease and heart failure and this latter group frequently die from cancer. In fact, research has uncovered the increased risk of cancer among HF patients, persists beyond the first year after their HF diagnosis and that their prognosis is worse compared to non-heart failure patients with cancer. Despite this purported association, other work among 28,341 Physicians’ Health Study participants, has shown that HF is not associated with an increased risk of cancer among male physicians. It has also been suggested that while heart failure patients did have a slightly increased risk of various cancer subtypes, these increased risks were largely drive by comorbidities.
Given this potential uncertainty over the HF-cancer association, the Italian team attempted to provide greater clarity by undertaking a retrospective cohort study of healthcare records in Puglia, a region of southern Italy. They included patients aged 50 years and older, diagnosed with heart failure but without a history of cancer in the three years prior to their inclusion in the analysis. The team included a control group without HF who were matched on age and sex. The primary outcomes of the study were cancer incidence as well as mortality. In an effort to examine whether HF severity influenced the study outcomes, the researchers also explored patients use of doses in excess of 80 mg/day of furosemide and equivalents for longer than 30 days in the year before the index date.
Heart failure patients and cancer
A total of 104,020 HF patients with a mean age of 76 years were matched to an equal number of control patients. The researchers identified a total of 12,036 new diagnoses of cancer in HF patients and 7,045 in controls after a median follow-up period of 5 years. This gave an incidence cancer rate of 21.36 per 1000 person-years among those with HF and 12.42 in the control arm (Hazard ratio, HR = 1.76, 95% CI 1.71 – 1.81).
The cancer mortality rate was also higher among HF patients compared with controls (HR = 4.11, 95% CI 3.86 – 4.38). This difference was also seen among HF patients aged less than 70 years (HR = 1.66, 95% CI 1.58 – 1.75) and in those over 80 years of age (HR = 2.07).
High dose loop diuretics also showed an important effect with a higher cancer incidence (HR = 1.11, 95% CI 1.03 – 1.21) and cancer-related mortality (HR = 1.35).
The authors concluded that HF patients had both a higher incidence of cancer and cancer mortality than matched controls and speculated that given that the risk was elevated among those with high dose loop diuretics, it was possible that the overall cancer risks were potentially higher in those with decompensated, i.e., more severe HF.
Bertero E et al. Cancer Incidence and Mortality According to Pre-Existing Heart Failure in a Community-Based Cohort JACC CardioOncology 2022