Statin use and the risk of kidney cancer: a population-based case–control study

Evaluation of statin use and renal cell carcinoma risk identifies sex-specific associations with RCC subtypes

Background: The association between statin use and risk of renal cell carcinoma (RCC) has been debated. We aimed to evaluate whether statin use is associated with RCC risk.Material and methods: We studied 100,195 women in the Nurses' Health Study (NHS) from 1994 to 2016; 91,427 women in the Nurses' Health Study II (NHS II) from 1999 to 2015; and 45,433 men in the Health Professionals Follow-up Study (HPFS) from 1990 to 2016. Statins and covariate data were collected at baseline and then biennially. Outcome was measured as incidence of total RCC and clinically relevant disease subgroups. Cox proportional hazards models estimated covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).Results: During follow-up, 661 participants developed RCC. There was no significant association between the use of statins and the risk of overall RCC, fatal RCC, or advanced or localized disease. Across cohorts, the adjusted HR for ever vs. never users was 0.97 (95% CI 0.81-1.16). Female ever users of statins were at increased risk of high-grade disease in the NHS only (HR 1.75, 95% CI 1.07-2.85). Among men only, ≥4 years of statin use was associated with an increased risk of clear cell RCC (HR 1.65, 95% CI 1.10-2.47).Conclusions: Statin use was not associated with the overall risk of RCC. However, it was associated with an increased risk of high-grade disease among women in the NHS cohort and an increased risk of clear cell RCC among men. The reasons for these inconsistent results by sex are unclear.

Association Between Statins and the Risk of Kidney Cancer Incidence and Mortality Using the Korean National Health Insurance Claims Database

BACKGROUND

Conflicting results have been reported regarding the potential preventive effects of statins on the risk of cancer. This study investigated the associations of statin use with the incidence and mortality of kidney cancer in South Korea.

METHODS

In this retrospective population-based cohort study using the National Health Insurance claims database, we compared patients aged 45-70 years who had used statins for at least 6 months to non-statin users matched by age and sex from 2005 to June 2013. The main outcomes were kidney cancer incidence and mortality according to statin use. Cox proportional hazard regression was used to calculate the adjusted hazard ratios (aHRs) and 95% confidence intervals (95% CIs).

RESULTS

In the cohort of 1 008 101 people, the aHRs for the association between statin use and the outcomes were .84 (95% CI: 0.71-.99) for kidney cancer incidence and .65 (95% CI: 0.41-.98) for kidney cancer mortality. In the matched cohort of 337 578, the risk per 1000 people of cancer incidence and mortality was 1.63, 1.07, and .24, .17 in statin users and non-users, respectively. In matched cohort, the risk of kidney cancer incidence and mortality decreased, but it is not statistically significant. Also, there was no linear relationship with increased doses.

CONCLUSION

Statin use might be associated with a decreased risk of kidney cancer incidence and mortality, but it showed no statistical significance. This study was a large-scale analysis, however, further studies that are larger and multinational in scope are needed to confirm the beneficial effects of statins on survival.

Statin use and the risk of renal cell carcinoma: national cohort study

Statins are a therapeutic drug with reducing plasma cholesterol levels and have been linked with potential antitumor effects. However, epidemiological studies on statin use and renal cell carcinoma (RCC) risk have been inconsistent. This cohort study aimed to examine this association in an Asian population. We identified patients who filled initial prescriptions for statins in the inpatient and ambulatory care order files from Taiwan’s National Health Insurance Research Database between January 1, 1998 and December 31, 2005 as the statin users cohort (n=14,067). The comparison cohort comprised of patients who had not taken any statin in the previous years prior to January 1, 1998 or had used statins for less than 28 cumulative defined daily doses between January 1, 1998 and December 31, 2005 (n=56 268). The outcome of interest was pathologically verified RCC occurred between January 1, 1999 and December 31, 2013. The Fine-Gray competing risk model was fitted to estimate HRs accompanying 95% CI. Patients with the use of statins had a significantly lower risk of RCC as compared with the non-users cohort, yielding an adjusted HR of 0.64 (95% CI, 0.38 to 0.87). Moreover, we found a significant inverse association between cumulative statin use and the risk of RCC. Further, the inverse association between statin use and risk of RCC was evident in both sexes. This population-based cohort study provides longitudinal evidence that the use of statins was associated with a reduced risk of RCC.

Long-term Use of Statins and Risk of Renal Cell Carcinoma: A Population-based Case-Control Study

BACKGROUND

Use of statins has been suggested to protect against renal cell carcinoma (RCC); however, studies have typically been underpowered, and the results are conflicting.

OBJECTIVE

To determine whether the use of statins is associated with a reduced risk of RCC using high-quality registry data.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a nationwide case-control study based on all histologically verified cases of RCC in Denmark between 2002 and 2012 (n=4606) matched 1:10 to cancer-free controls. Data on drug use, comorbidity, and educational level were obtained from Danish nationwide prescription, patient, and demographic registries.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Odds ratios (ORs) and 95% confidence intervals (CIs) for RCC associated with long-term use (≥5 yr) of statins were estimated using conditional logistic regression, adjusting for potential confounders.

RESULTS AND LIMITATIONS

The adjusted OR for RCC associated with long-term use of statins was 1.06 (95% CI, 0.91-1.23). Analyses stratified by duration of statin use, type of statin, and patient characteristics all yielded ORs close to unity, except for a slightly increased OR for RCC associated with long-term statin use among women (OR: 1.25; 95% CI, 0.96-1.62). The main limitation of our study was lack of information on lifestyle factors, notably obesity, which may have biased the risk estimates upward.

CONCLUSIONS

Our study does not support an important chemopreventive effect of long-term statin use against RCC. The marginally increased and statistically insignificant risk estimates can readily be interpreted as a null finding, considering the lack of control for obesity and other lifestyle risk factors.

PATIENT SUMMARY

Previous studies have shown that the use of cholesterol-lowering drugs (statins) may protect against renal cancer. In a large study including all Danish renal cancers during an 11-yr period, we found no evidence of such an effect.

Statins are potential anticancerous agents (review)

Statins are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), which is a rate-limiting enzyme in the mevalonate pathway. The pleiotropic effects of statins may be mediated by the inhibition of downstream products such as small GTP-binding proteins, Rho, Ras and Rac whose localization and function are dependent on isoprenylation. Preclinical studies of statins in different cancer cell lines and animal models showed antiproliferative, pro‑apoptotic and anti-invasive effects. Notably, statins showed targeted action in cancerous cell lines compared to normal cells. Previous studies have also shown the synergistic effects of statins with chemotherapeutic agents and radiotherapy. This effect of statins was also observed in chemotherapeutic-resistant tumors. Statins were reported to sensitize the cells to radiation by arresting them in the late G1 phase of the cell cycle. Similarly, population-based studies also demonstrated a chemopreventive and survival benefit of statins in various types of cancers. However, this benefit has yet to be proven in clinical trials. The inter-individual variation in response to statins may be contributed to many genetic and non-genetic factors, including single-nucleotide polymorphisms in HMGCR gene and the overexpression of heterogeneous nuclear ribonucleoprotein A1, which was reported to reduce HMGCR enzyme activity. However, more studies with large phase III randomized controlled trials in cancer patients should be conducted to establish the effect of stains in cancer prevention and treatment.

Statin use is associated with improved survival in patients undergoing surgery for renal cell carcinoma

PURPOSE

To determine whether statin use at time of surgery is associated with survival following nephrectomy or partial nephrectomy for renal cell carcinoma (RCC). Statins are thought to exhibit a protective effect on cancer incidence and possibly cancer survival in a number of malignancies. To date, no studies have shown an independent association between statin use and mortality in RCC.

METHODS

A retrospective cohort study of 916 patients who underwent radical or partial nephrectomy for RCC from 2000 to 2010 at a single institution was performed. Primary outcomes were overall (OS) and disease-specific survival (DSS). Univariable survival analyses were performed using the Kaplan-Meier and the log-rank methods. Multivariable analysis was performed using a Cox proportional hazards model. The predictive discrimination of the models was assessed using the Harrell c-index.

RESULTS

The median follow-up of the entire cohort was 42.5 months. The 3-year OS estimate was 83.1% (95% CI: 77.6%-87.3%) for statin users and 77.3% (95% CI: 73.7%-80.6%) for nonstatin users (P = 0.53). The 3-year DSS was 90.9% (95% CI: 86.3%-94.0%) for statin users and 83.5% (95% CI: 80.1%-86.3%) for nonstatin users (P = 0.015). After controlling for age, American Society of Anesthesiology class, pT category, pN category, metastatic status, preoperative anemia and corrected hypercalcemia, and blood type, statin use at time of surgery was independently associated with improved OS (hazard ratio = 0.62; 95% CI: 0.43-0.90; P = 0.011) and DSS (hazard ratio = 0.48; 95% CI: 0.28-0.83; P = 0.009). The multivariable model for DSS had excellent predictive discrimination with a c-index of 0.91.

CONCLUSIONS

These data suggest that statin usage at time of surgery is independently associated with improved OS and DSS in patients undergoing surgery for RCC.

Statin use and risk of kidney cancer: a meta-analysis of observational studies and randomized trials

AIM

Clinical studies have shown that statin use may modify the risk of kidney cancer. However, these studies yielded different results. To quantify the association between statin use and risk of kidney cancer, we performed a detailed meta-analysis of published studies regarding this subject.

METHODS

A literature search was carried out using MEDLINE, EMBASE and the Cochrane database between January 1966 and October 2012. Prior to performing a meta-analysis, the studies were evaluated for publication bias and heterogeneity. Fixed effect and random effect models were used to estimate summary relative risks (RR) and the corresponding 95% confidence intervals (CIs). Subgroup analyses and sensitivity analysis were also performed.

RESULTS

A total of 12 (two randomized controlled trials, five cohort, and five case-control) studies contributed to the analysis. There was heterogeneity among the studies but no evidence of publication bias. Pooled results indicated a non-significant decrease of total kidney cancer risk among all statin users (RR = 0.92, 95% CI 0.71, 1.19). Long term statin use did not significantly affect the risk of total kidney cancer (RR = 1.01, 95% CI 0.83, 1.22). In our subgroup analyses, the results were not substantially affected by study design, confounder adjustment and gender. Furthermore, sensitivity analysis confirmed the stability of the results.

CONCLUSION

The findings of this meta-analysis suggested that there was no association between statin use and risk of kidney cancer. More studies, especially randomized controlled trials and high quality cohort studies with larger sample size and well controlled confounding factors, are needed to confirm this association in the future.

The association between statin medication and progression after surgery for localized renal cell carcinoma

PURPOSE

Evidence suggests that statins may influence pathways of renal cell carcinoma proliferation, although to our knowledge no study has examined the influence of statin medications on the progression of renal cell carcinoma in humans.

MATERIALS AND METHODS

We identified 2,608 patients with localized renal cell carcinoma who were treated surgically between 1995 and 2010 at our tertiary referral center. Competing risks Cox proportional hazards models were used to evaluate the relationship between statin use and time to local recurrence or progression (metastases or death from renal cell carcinoma) and overall survival. Statin use was modeled as a time dependent covariate as a sensitivity analysis. Models were adjusted for clinical and demographic features.

RESULTS

Of 2,608 patients 699 (27%) were statin users at surgery. Statin users had similar pathological characteristics compared to nonusers. At a median followup of 36 months there were 247 progression events. Statin use was associated with a 33% reduction in the risk of progression after surgery (HR 0.67, 95% CI 0.47-0.96, p = 0.028) and an 11% reduction in overall mortality that was not significant (HR 0.89, 95% CI 0.71-1.13, p = 0.3). Modeling statin use as a time dependent covariate attenuated the risk reduction in progression to 23% (HR 0.77, p = 0.12) and augmented the risk reduction in overall survival (HR 0.71, p = 0.002).

CONCLUSIONS

In our cohort statin use was associated with a reduced risk of progression and overall mortality, although this effect was sensitive to the method of analysis. If validated in other cohorts, this finding warrants consideration of prospective research on statins in the adjuvant setting.

Common cancer risk and statins: a population-based case-control study in a Chinese population

OBJECTIVE

To investigate whether the use of statins is associated with common cancer risk.

METHODS

A population-based case-control study was conducted in Taiwan. Cases were defined as all patients who were aged 18 years and older and had received at least two statin prescriptions for use continuously for at least 6 months before a first-time diagnosis of studied cancers between the period of 2000 and 2008. The controls were matched to cases by age, sex, and index date. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by using the Cox proportional hazards model.

RESULTS

A total of 6841 cases and 27,364 matched controls were analyzed. The adjusted hazard ratio for any statin use and cancer at any site were 0.76 (95% 0.654, 0.891). There were a significant reduced risk of gastric cancer (HR: 0.26, 95% CI: 0.107, 0.588), liver cancer (HR: 0.44, 95% CI: 0.279, 0.723) and uterine cancer (HR: 0.44, 95% CI: 0.279, 0.723) associated with any statins.

CONCLUSION

Overall, the statins suggested a significant reduced risk of the most common cancers in a large Chinese population, particularly in gastric, liver, and uterine cancers.