International renal-cell cancer study. II. Analgesics

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.

The associations between five polymorphisms of vascular endothelial growth factor and renal cell carcinoma risk: an updated meta-analysis

Background

Vascular endothelial growth factor (VEGF) is a key mediator that plays an important role in angiogenesis, tumor growth, and tumor metastasis. The associations between five polymorphisms of VEGF (rs3025039, rs699947, rs10434, rs1570360, and rs2010963) and renal cell carcinoma (RCC) risk have been extensively investigated, but the currently available results are inconsistent and inconclusive. To obtain a more accurate assessment of the associations, we conducted a meta-analysis in this study.

Materials and methods

Relevant studies were collected systemically from the following three electronic databases: MEDLINE, Web of Science, and CNKI (Chinese National Knowledge Infrastructure). Statistical analyses were performed using Review Manager 5.2 in a fixed- or random-effects model. Pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to establish the strength of associations.

Results

A total of eight case–control studies with 1,936 RCC cases and 2,770 controls fulfilling the inclusion criteria were selected for this meta-analysis. The pooled OR indicated that rs699947 polymorphism was significantly associated with RCC risk in all genetic models. A significant association was also found between the rs3025039 polymorphism and RCC risk in a homozygous model (TT vs CC: OR =1.38, 95% CI =1.11–1.72, P=0.004), a dominant model (CT+TT vs CC: OR =1.21, 95% CI =1.05–1.39, P=0.01), and a recessive model (TT vs CC+CT: OR =1.28, 95% CI =1.04–1.57, P=0.02). After a subgroup analysis of ethnicity in the allele contrast model of rs3025039 polymorphism, we found a significant relationship in the allele contrast model (T vs C: OR =1.21, 95% CI =1.05–1.40, P=0.007) in the Asian population. With regard to rs10434 polymorphism, significant association was observed only in a homozygous model (GG vs AA: OR =0.75, 95% CI =0.57–0.98, P=0.03). As to rs1570360 or rs2010963, we did not observe any relationship between the two polymorphisms and RCC risk in our study.

Conclusion

Our meta-analysis confirmed the fact that rs699947, rs3025039, and rs10434 polymorphisms were significantly relevant to elevated RCC risk. In the meanwhile, this study also demonstrated that the allele contrast model of rs3025039 polymorphism was likely to be associated with risk of RCC in the Asian population.

Use of acetaminophen in relation to the occurrence of cancer: a review of epidemiologic studies

Acetaminophen has several pharmacologic properties that suggest it could be carcinogenic in human beings. A number of epidemiologic studies have been conducted to examine whether use of acetaminophen actually predisposes to the occurrence of one or more forms of cancer. There are inherent limitations to many of these studies, including the inaccurate identification of users and nonusers of acetaminophen, relatively short follow-up for cancer incidence, and the potential for confounding by indication. The present manuscript reviews the results of epidemiologic studies of acetaminophen use in relation to cancer incidence published through the end of 2015. The limitations of the underlying studies notwithstanding, some interim conclusions can be reached. For all but several forms of cancer, there is no suggestion that persons who have taken acetaminophen are at altered risk, even persons who have consumed a large quantity of the drug or those who have taken it for an extended duration. While in some studies the incidence of renal cell carcinoma has been observed to be increased among acetaminophen users, several other studies have failed to observe any such association; the reason for the discrepant findings is unclear. Some of the small number of studies that have presented data on the incidence of lymphoma, leukemia, and plasma cell disorders have found the risk to be modestly higher in users than nonusers of acetaminophen, but the results of other studies of these malignancies will be needed to gauge the possible role of publication bias as the basis for the positive results.

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

Analgesics are the most commonly consumed drugs worldwide. Evidence that analgesics increase kidney cancer risk has been mixed. We investigated the association between renal cell carcinoma (RCC) and analgesic use in a large population-based case-control study and a post-trial observational cohort study. Findings were used to update a recent meta-analytic review. We analyzed data from 1,217 RCC cases and 1,235 controls in the US Kidney Cancer Study and 98,807 participants in the US Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO: n = 137 RCCs). Self-reported acetaminophen, aspirin and nonsteroid anti-inflammatory drug (NSAID) use and duration information was assessed in relation to RCC. For the US Kidney Cancer Study, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression. For PLCO, we computed hazard ratios (HRs) and 95%CIs using Cox regression. Among case-control participants, RCC risk was associated with over-the-counter acetaminophen use (OR = 1.35, 95%CI = 1.01-1.83). There was a positive trend with increasing duration (p-trend = 0.01), with a two-fold risk for use ≥10 years (OR = 2.01, 95%CI = 1.30-3.12). No association with prescription acetaminophen use was detected. In PLCO, acetaminophen use was also associated with increased RCC risk (HR = 1.68, 95%CI = 1.19-2.39), although elevated risk was absent among the few long-term users. No association with RCC risk was detected for aspirin or NSAIDs use in either study. An association between acetaminophen use and kidney cancer was supported by meta-analytic cohort (n = 4; summary relative risk = 1.34; 95%CI = 1.13-1.59; p-heterogeneity  = 0.40) and case-control (n = 9, summary OR = 1.20; 95%CI = 1.01-1.42; p-heterogeneity  = 0.05) findings. In brief, acetaminophen use may increase the risk of developing RCC.

Galangin inhibits cell invasion by suppressing the epithelial-mesenchymal transition and inducing apoptosis in renal cell carcinoma

Galangin, a flavonoid extracted from the root of the Alpinia officinarum Hence, has been shown to have anticancer properties against several types of cancer cells. However, the influence of galangin on human renal cancer cells remains to be elucidated. In the present study, proliferation of 786-0 and Caki-1 cells was suppressed following exposure to various doses of galangin. Cell invasion and wound healing assays were used to observe the effect of galangin on invasion and migration. The results demonstrated that Galangin inhibited cell invasion by suppressing the epithelial mesenchymal transition (EMT), with an increase in the expression of E-cadherin and decreased expression levels of N-cadherin and vimentin. The apoptosis induced by galangin was analyzed by flow cytometry. The results revealed that galangin induced apoptosis in a dose-dependent manner. The accumulation of reactive oxygen species (ROS) is an important contributing factor for the apoptosis of various types of cancer cell. The dichlorofluorescein-diacetate method was used to determine the level of ROS. Galangin induced the accumulation of intracellular ROS and malondialdehyde, and decreased the activities of total antioxidant and superoxide dismutase in renal cell carcinoma cells. Galangin exerted an antiproliferative effect and inhibited renal cell carcinoma invasion by suppressing the EMT. This treatment also induced apoptosis, accompanied by the production of ROS. Therefore, the present data suggested that galangin may have beneficial effects by preventing renal cell carcinoma growth, inhibiting cell invasion via the EMT and inducing cell apoptosis.

Renal cell carcinoma: links and risks

This review provides an overview of the incidence of renal cell carcinoma (RCC) and a summary of the most commonly associated risk factors. A literature review was performed with a focus on recent studies with a high level of evidence (large prospective cohort studies and meta-analyses). The incidence rate of RCC varies globally, with the rate rising rapidly in more developed regions, demonstrating the effects of increased use of diagnostic imaging and prevalence of modifiable risk factors. Based on the current evidence, cigarette smoking, obesity, and hypertension are the most well-established risk factors for sporadic RCC worldwide. Acquired cystic kidney disease is also a significant risk factor, specifically in dialysis patients. There is increasing evidence for an inverse association between RCC risk and moderate alcohol consumption. Certain analgesics and occupational exposure have been linked to an increased risk of RCC, although data are limited. Diets rich in fruits and vegetables may provide a protective effect.

Renal insufficiency is associated with an increased risk of papillary renal cell carcinoma histology

PURPOSE

End-stage renal disease (ESRD) and acquired renal cystic disease associated with dialysis are known risk factors of papillary renal cell carcinoma (pRCC); however, it is not known whether renal insufficiency alone is a risk factor for pRCC. Our aim was to test whether renal insufficiency is associated with an increased preponderance of pRCC.

METHODS

Retrospective review of institutional database to identify all patients who underwent extirpative renal surgery for renal cell carcinoma (RCC) with complete records from 1992 to 2012. We excluded those patients with preoperative ESRD as defined by GFR < 15 mL/min/1.73 m(2). The dependent variable was histologic RCC subtype. Independent variables included demographic data, comorbidities, and renal functional data. Multivariate analysis by binary logistic regression was used to determine factors that independently were associated with pRCC development.

RESULTS

A total of 1,226 patients met inclusion criteria, of which 15 % were pRCC. There was a positive association between likelihood of pRCC histology of RCC and increasing preoperative chronic kidney disease (CKD) stage (p = 0.021). Multivariate regression analysis indicated that male gender, race, and declining renal function categorized both by GFR and CKD stage were independently associated with a higher likelihood of pRCC histology as compared to other RCC histology.

CONCLUSIONS

Within a large cohort of patients with a diagnosis of RCC, declining renal function was independently associated with an increased likelihood of pRCC histology. This finding and the available molecular evidence indicating protein expression similarity between pRCC and resident stem cells, which appear to be upregulated with kidney damage, suggest a possible causal relationship between renal injury and pRCC.

Analgesic use and the risk of kidney cancer: a meta-analysis of epidemiologic studies

Analgesics are the most commonly used over-the-counter drugs worldwide with certain analgesics having cancer prevention effect. The evidence for an increased risk of developing kidney cancer with analgesic use is mixed. Using a meta-analysis design of available observational epidemiologic studies, we investigated the association between analgesic use and kidney cancer risk. We searched the MEDLINE and EMBASE databases to identify eligible case-control or cohort studies published in English until June 2012 for three categories of analgesics: acetaminophen, aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs). Study-specific effect estimates were pooled to compute an overall relative risk (RR) and its 95% confidence interval (CI) using a random-effects model for each category of the analgesics. We identified 20 studies (14 with acetaminophen, 13 with aspirin and five with other NSAIDs) that were performed in six countries, including 8,420 cases of kidney cancer. Use of acetaminophen and non-aspirin NSAIDs were associated with an increased risk of kidney cancer (pooled RR: 1.28; 95% CI: 1.15-1.44 and 1.25; 95% CI: 1.06-1.46, respectively). For aspirin use, we found no overall increased risk (pooled RR: 1.10; 95% CI: 0.95-1.28), except for non-US studies (five studies, pooled RR: 1.17; 95% CI: 1.04-1.33). Similar increases in risks were seen with higher analgesic intake. In this largest meta-analysis to date, we found that acetaminophen and non-aspirin NSAIDs are associated with a significant risk of developing kidney cancer. Further work is needed to elucidate biologic mechanisms behind these findings.

Acute generalized exanthematous pustulosis: A rare side effect of a common over-the-counter drug, Acetylsalicylic acid

Acute generalized exanthematous pustulosis is an uncommon cutaneous reaction characterized by sudden onset of generalized non-follicular aseptic pustules. It is most often secondary to drugs but causes as varied from viral infection to insect bites are reported. A case report of a 48-year-old male who developed pustular eruptions after taking acetylsalicylic acid is reported here. Clinicians need to be aware of this entity when dealing with pustular rash as this rare side effect of a very common drug is both, easy to miss and easy to manage.

A large cohort study of nonsteroidal anti-inflammatory drugs and renal cell carcinoma incidence in the National Institutes of Health-AARP Diet and Health Study

AIM

Existing epidemiologic evidence for the association between nonsteroidal anti-inflammatory drugs (NSAIDs) and renal cell carcinoma (RCC) risk is inconsistent.

METHODS

We investigated the association between the use of aspirin and nonaspirin NSAIDs and RCC risk in the National Institutes of Health-American Association of Retired Persons (AARP) Diet and Health Study, for which 298,468 AARP members free of cancer, aged 50-71 years, completed a survey on use of NSAIDs (1996-1997). Multivariate Cox proportional hazards models were used to estimate the hazard ratio (HR).

RESULTS

The state cancer registry and mortality index linkage identified 1,084 incident RCC cases through 31 December 2006. No statistically significant associations between the use of aspirin or nonaspirin NSAIDs and RCC risk were found. Compared to nonuse of any NSAIDs, the multivariate-adjusted HRs were 0.95 (95 % CI 0.75-1.21) and 0.93 (95 % CI 0.68-1.26) for monthly use of aspirin and nonaspirin NSAIDs, respectively, 0.92 (95 % CI: 0.69-1.23) and 1.11 (95 % CI: 0.76-1.62) for weekly use, 0.87 (95 % CI: 0.69-1.11) and 1.06 (95 % CI: 0.75-1.48) for daily use; and 0.95 (95 % CI 0.78-1.14) for the use of both aspirin and nonaspirin NSAIDs. We found some suggestions of an increased risk of RCC associated with frequent NSAID use among participants who were <63 years and a reduced risk associated with aspirin use among those ≥63 years. No significant associations were found in other stratified analyses by gender, BMI, smoking, history of diabetes, or history of hypertension.

CONCLUSION

RCC risk was not significantly associated with NSAID use overall. The difference in association by age needs to be explored further.

Update of carcinogenicity studies in animals and humans of 535 marketed pharmaceuticals

This survey is a compendium of information retrieved on carcinogenicity in animals and humans of 535 marketed pharmaceuticals whose expected clinical use is continuous for at least 6 months or intermittent over an extended period of time. Of the 535 drugs, 530 have the result of at least one carcinogenicity assay in animals, and 279 (52.1%) of them gave a positive response in at least one assay. Only 186 drugs (34.8%) have retrievable information on carcinogenicity in humans, and 104 of them gave to a variable extent evidence of a potential carcinogenic activity. Concerning the correlation between results obtained in animals and epidemiological findings, 58 drugs gave at least one positive result in carcinogenicity assays performed in animals and to a variable extent displayed evidence of carcinogenicity in humans, but 97 drugs tested positive in animals and were noncarcinogenic in humans or vice versa. Our findings, which are in agreement with previous studies, indicate that the evaluation of the benefit/carcinogenic risk ratio should be always made in prescribing a drug.

Environmental and modifiable risk factors in renal cell carcinoma

OBJECTIVES

Prevention of disease requires a firm understanding of the relevant environmental and modifiable risk factors. We present a comprehensive review of these factors in renal cell carcinoma.

MATERIALS AND METHODS

A literature search of the PubMed database was performed to identify clinical studies examining the relationship between environmental and modifiable factors in the development of renal cell carcinoma (terms utilized: kidney cancer; renal cell carcinoma; risk factors; environment; obesity; hypertension; trichloroethylene). An emphasis was placed on more recent studies.

RESULTS

Case control and large cohort studies have examined the relationship of numerous environmental and modifiable factors and the risk of renal cell carcinoma. Of particular note are dose-dependent increases in smokers, the obese, and hypertensive patients.

CONCLUSIONS

Environmental and modifiable risk factors contribute significantly to the risk of sporadic renal cell carcinoma. Emphasis should be placed on smoking cessation and hypertension control. Emerging evidence would suggest that dietary intake and quality impact renal cell carcinoma risk.

Prospective evaluation of analgesic use and risk of renal cell cancer

BACKGROUND

Epidemiologic data suggest that analgesic use increases the risk of renal cell cancer (RCC), but few prospective studies have been published. We investigated the association between analgesic use and RCC in 2 large prospective studies.

METHODS

We examined the relationship between analgesic use and RCC risk in the Nurses' Health Study and the Health Professionals Follow-up Study. Use of aspirin, other nonsteroidal anti-inflammatory drugs (NSAIDs), and acetaminophen was ascertained in 1990 in the Nurses' Health Study and in 1986 in the Health Professionals Follow-up Study, and every 2 years thereafter. We evaluated baseline and duration of use of analgesics.

RESULTS

During follow-up of 16 years among 77,525 women and 20 years among 49,403 men, we documented 333 RCC cases. Aspirin and acetaminophen use were not associated with RCC risk. However, regular use of nonaspirin NSAIDs was associated with an increased RCC risk; the pooled multivariate relative risk was 1.51 (95% confidence interval, 1.12-2.04) at baseline. The absolute risk differences for users vs nonusers of nonaspirin NSAIDs were 9.15 per 100 000 person-years in women and 10.92 per 100,000 person-years in men. There was a dose-response relationship between duration of nonaspirin NSAID use and RCC risk; compared with nonregular use, the pooled multivariate relative risks were 0.81 (95% confidence interval, 0.59-1.11) for use less than 4 years, 1.36 (0.98-1.89) for 4 to less than 10 years, and 2.92 (1.71-5.01) for use for 10 or more years (P < .001 for trend).

CONCLUSION

Our prospective data suggest that longer duration of use of nonaspirin NSAIDs may increase the risk of RCC.

Aspirin and risk of renal cell cancer in Italy

Aspirin and nonsteroidal anti-inflammatory drugs have been related to decreased risk of several cancers, but studies on the relation with the risk of renal cell cancer (RCC) are inconsistent. A case-control study of RCC was conducted in Italy between 1992 and 2004. Cases were 755 patients with incident, histologically confirmed RCC, and controls were 1297 patients in hospital for acute non-neoplastic conditions. Odds ratios (OR) and 95% confidence intervals (CI) for RCC were conditioned on center, sex, age, and year of interview, and adjusted for education, smoking, alcohol consumption, diabetes, and hypertension. Regular use of aspirin for at least 6 months was reported by 67 cases and 99 controls, corresponding to an OR of 0.98 (95% CI 0.69-1.38). The ORs were 0.91 (95% CI 0.55-1.50) in regular users for less than 3 years, and 1.04 (95% CI 0.67-1.63) in users for 3 years or longer; 0.47 (95% CI 0.20-1.12) when aspirin was used as analgesic and 1.10 (95% CI 0.75-1.62) when it was used for cardiovascular disease prevention. No significant heterogeneity was found for regular use of aspirin across strata of age and sex. This study, based on a large dataset, suggests that regular use of aspirin did not increase RCC risk.

Epidemiologic characteristics and risk factors for renal cell cancer

Incidence rates of renal cell cancer, which accounts for 85% of kidney cancers, have been rising in the United States and in most European countries for several decades. Family history is associated with a two- to four-fold increase in risk, but the major forms of inherited predisposition together account for less than 4% of renal cell cancers. Cigarette smoking, obesity, and hypertension are the most consistently established risk factors. Analgesics have not been convincingly linked with renal cell cancer risk. A reduced risk of renal cell cancer among statin users has been hypothesized but has not been adequately studied. A possible protective effect of fruit and vegetable consumption is the only moderately consistently reported dietary finding, and, with the exception of a positive association with parity, evidence for a role of hormonal or reproductive factors in the etiology of renal cell cancer in humans is limited. A recent hypothesis that moderate levels of alcohol consumption may be protective for renal cell cancer is not strongly supported by epidemiologic results, which are inconsistent with respect to the categories of alcohol consumption and the amount of alcohol intake reportedly associated with decreased risk. For occupational factors, the weight of the evidence does not provide consistent support for the hypotheses that renal cell cancer may be caused by asbestos, gasoline, or trichloroethylene exposure. The established determinants of renal cell cancer, cigarette smoking, obesity, and hypertension, account for less than half of these cancers. Novel epidemiologic approaches, including evaluation of gene–environment interactions and epigenetic mechanisms of inherited and acquired increased risk, are needed to explain the increasing incidence of renal cell cancer.

Lifestyle Factors, Exposures, Genetic Susceptibility, and Renal Cell Cancer Risk: A Review

Malignant kidney tumors account for approximately 2% of all new primary cancer cases diagnosed in the United States, with an estimated 30,000 cases occurring annually. Although a variety of agents, chemical and biological, have been implicated as causal agents in the development of renal cell carcinoma (RCC), the etiology remains enigmatic. The strongest association has been developed between cigarette smoking and renal cancer however consistent, positive associations between RCC and obesity, diabetes, and hypertension have also been reported. In addition, more recent investigations of familial kidney cancer syndromes indicate that a strong genetic component contributes to RCC development. Several genes have been identified through investigation of familial kidney cancer syndromes. This review article describes recent trends in RCC incidence and the currently identifiable etiological causes that account for approximately half of the RCC cases diagnoses. The remainder of this review then focuses on additional risk factors that have thus far not been well examined but may be helpful in explaining the increasing incidence trends and the geographic or racial variation observed nationally and worldwide.

Renal cell carcinoma

Considerable progress has been made in the treatment of patients with renal cell carcinoma, with innovative surgical and systemic strategies revolutionising the management of this disease. In localised disease, partial nephrectomy for small tumours and radical nephrectomy for large tumours continue to be the gold-standard treatments, with emphasis on approaches that have reduced invasiveness and preserve renal function. Additionally, cytoreductive nephrectomy is often indicated before the start of systemic treatment in patients with metastatic disease as part of integrated management strategy. The effectiveness of immunotherapy, although previously widely used for treatment of metastatic renal cell carcinoma, is still controversial, and is mainly reserved for patients with good prognostic factors. Development of treatments that have specific targets in relevant biological pathways has been the main advance in treatment. Targeted drugs, including inhibitors of the vascular endothelial growth factor and mammalian target of rapamycin pathways, have shown robust effectiveness and offer new therapeutic options for the patients with metastatic disease.

Aspirin and cancer risk: a summary review to 2007

Aspirin has been associated with a reduced risk of colorectal cancer and--based on limited evidence--to cancers of the oesophagus, stomach, breast, ovary and lung. The role of aspirin on other cancers, such as pancreatic, prostate and bladder cancer and non-Hodgkin's lymphomas and myeloma is less clear, and an increase of risk has been suggested for kidney cancer. For most cancer sites, however, significant heterogeneity between studies, and particularly between study design, was found, with a reduction in risk generally stronger in case-control studies than in cohort ones.

Epidemiology of kidney cancer

Some tumors are known to have a definite cause-effect etiology, but renal cell carcinoma (RCC) is not one of them precisely. With regard to RCC we can only try to identify some clinical and occupational factors as well as substances related to tumorigenesis. Smoking, chemical carcinogens like asbestos or organic solvents are some of these factors that increase the risk of the RCC. Viral infections and radiation therapy have also been described as risk factors. Some drugs can increase the incidence of RCC as well as other neoplasms. Of course, genetics plays an outstanding role in the development of some cases of kidney cancer. Chronic renal failure, hypertension, and dialysis need to be considered as special situations. Diet, obesity, lifestyle, and habits can also increase the risk of RCC. The aim of this review is to summarize the well-defined causes of renal cell carcinoma.

Genetics and epigenetics of renal cell cancer

Renal cell carcinoma (RCC) is not a single disease, but comprises a group of tumors of renal epithelial origin, each with a different histology, displaying a different clinical course and caused by different genetic alterations. Since cure rates are inversely associated with stage and response to the available treatment regimes is limited to a subgroup of patients, diagnostic methods facilitating early detection and new therapeutic modalities are necessary. Increased knowledge of the underlying pathophysiology of RCC has resulted in the identification of genetic alterations involved in renal cell cancer carcinogenesis. Promising agents to target these pathways, especially the angiogenesis pathway, are being developed, some of which are already standard of care. In addition to genetics, knowledge on epigenetics in the process of renal tumorigenesis has been significantly increased in the last decades. Epigenetics will play an increasing role in the development of new therapeutic modalities and may deliver new prognostic and early diagnostic markers. In this review we discuss the background of RCC and the clinical applications of RCC genetics and epigenetics.

Analgesic and anti-inflammatory drug use and risk of bladder cancer: a population based case control study

Background

Use of phenacetin and other analgesic and non-steroidal anti-inflammatory drugs (NSAIDs) potentially influences bladder cancer incidence, but epidemiologic evidence is limited.

Methods

We analyzed data from 376 incident bladder cancer cases and 463 controls from a population-based case-control study in New Hampshire on whom regular use of analgesic drugs and NSAIDs was obtained. Odds ratios and 95% confidence intervals were computed using logistic regression with adjustment for potentially confounding factors. Separate models by tumor stage, grade and TP53 status were conducted.

Results

We found an elevated odds ratio (OR) associated with reported use of phenacetin-containing medications, especially with longer duration of use (OR _{>8 years} = 3.00, 95% confidence interval (CI) = 1.4–6.5). In contrast, use of paracetamol did not relate overall to risk of bladder cancer. We also found that regular use of any NSAID was associated with a statistically significant decrease in bladder cancer risk (OR = 0.6, 95% CI = 0.4–0.9), and specifically use of aspirin. Further, the association with NSAID use was largely among invasive, high grade and TP53 positive tumors.

Conclusion

While these agents have been investigated in several studies, a number of questions remain regarding the effects of analgesic and NSAID use on risk of bladder cancer.

Cyclooxygenase-2 (cox-2) and the inflammogenesis of cancer

Cohesive scientific evidence from molecular, animal, and human investigations supports the hypothesis that aberrant induction of COX-2 and up-regulation of the prostaglandin cascade play a significant role in carcinogenesis, and reciprocally, blockade of the process has strong potential for cancer prevention and therapy. Supporting evidence includes the following: [1] expression of constitutive COX-2-catalyzed prostaglandin biosynthesis is induced by most cancer-causing agents including tobacco smoke and its components (polycylic aromatic amines, heterocyclic amines, nitrosamines), essential polyunsaturated fatty acids (unconjugated linoleic acid), mitogens, growth factors, proinflammatory cytokines, microbial agents, tumor promoters, and other epigenetic factors, [2] COX-2 expression is a characteristic feature of all premalignant neoplasms, [3] COX-2 expression is a characteristic feature of all malignant neoplasms, and expression intensifies with stage at detection and cancer progression and metastasis, [4] all essential features of carcinogenesis (mutagenesis, mitogenesis, angiogenesis, reduced apoptosis, metastasis, and immunosuppression) are linked to COX-2-driven prostaglandin (PGE-2) biosynthesis, [5] animal studies show that COX-2 up-regulation (in the absence of genetic mutations) is sufficient to stimulate the transformation of normal cells to invasive cancer and metastatic disease, [6] non-selective COX-2 inhibitors, such as aspirin and ibuprofen, reduce the risk of human cancer and precancerous lesions, and [7] selective COX-2 inhibitors, such as celecoxib, reduce the risk of human cancer and precancerous lesions at all anatomic sites thus far investigated. Results confirming that COX-2 blockade is effective for both cancer prevention and therapy have been tempered by observations that some COX2 inhibitors pose a risk to the cardiovascular system, and more studies are needed in order to determine if certain of these drugs can be taken at dosages that prevent cancer without increasing cardiovascular risk. It is emphasized that the "inflammogenesis model of cancer" is not mutually exclusive and may in fact be synergistic with the accumulation of somatic mutations in tumor suppressor genes and oncogenes or epigenetic factors in the development of cancer.

Risk factors, classification, and staging of renal cell cancer

Knowledge about renal cell carcinoma (RCC) has increased exponentially over the last decades. A clear understanding of RCC is of utmost importance to prevent the disease and improve the outcomes. Large epidemiologic studies have identified cigarette smoking, chemical agents, obesity, hypertension, and end-stage renal disease as risk factors associated with RCC. Identification and confirmation of risk factors may be projected into preventive strategies. Genetic studies of inherited disorders associated with an enhanced risk of RCC have elucidated many important targets for anticancer therapy. The World Health Organization (WHO) has recently developed a new histologic classification of renal cell tumors that has demonstrated prognostic utility. A refined clinical staging system is improving our ability to prognosticate the outcome of RCC patients. This article provides a practical yet comprehensive review of the risk factors, classification, and staging of RCC focusing on recent updates.

The epidemiology of renal cell carcinoma

PURPOSE

We identified and examined risk factors for renal cell cancer, some of which may explain in part the trends of steadily increasing incidence rates, particularly in black Americans.

MATERIALS AND METHODS

Epidemiological studies were identified through a MEDLINE(R) search of the literature through February 2006. A qualitative summary of the results of individual studies is presented.

RESULTS

Cigarette smoking and obesity are the most consistently established causal risk factors, accounting for about 20% and 30% of renal cell cancers, respectively. Hypertension appears to independently influence renal cell cancer risk. Neither acetaminophen nor other analgesics have been convincingly linked with renal cell cancer. With respect to diet a general protective effect of fruit and vegetable consumption is the only consistently reported finding. For occupational factors the weight of the evidence provides no consistent support for the hypotheses that renal cell cancer may be caused by asbestos, gasoline or trichloroethylene exposure. Self-reported family history is associated with 2 to 3-fold increases in risk and the major inherited forms of renal cell cancer together account for about 2% of this malignancy.

CONCLUSIONS

A further reduction in cigarette smoking, and a decrease in the rates of obesity and hypertension would likely moderate the increasing incidence of renal cell cancer. Epidemiological studies, including evaluation of gene-environment interactions, are needed to specifically identify reasons for the increasing incidence, particularly for assessing the roles of obesity and hypertension. Special attention should be focused on black Americans since their incidence rate recently increased to significantly surpass that in white Americans.

Use of analgesics and nonsteroidal anti-inflammatory drugs, genetic predisposition, and bladder cancer risk in Spain

BACKGROUND

We assessed use of nonaspirin nonsteroidal anti-inflammatory drugs (NSAID), aspirin, paracetamol (acetaminophen), phenacetin, and metamizol (dipyrone) and risk of bladder cancer and their interaction with polymorphisms in drug-metabolizing genes.

METHODS

We analyzed personal interview data from 958 incident bladder cancer cases and 1,029 hospital controls from a multicenter case-control study in Spain. A drug matrix was developed to estimate cumulative lifetime dose of active ingredients. Polymorphisms in GSTP1, SULT1A1, CYP2E1, CYP2C9, and NAT2 were examined.

RESULTS

A significant reduction in bladder cancer risk [adjusted odds ratio (OR), 0.4; 95% confidence interval (95% CI), 0.2-0.9] was observed for regular users of nonaspirin NSAIDs compared with never users. Regular users of aspirin experienced no reduction in risk (OR, 1.0; 95% CI, 0.7-1.5). Regular users of paracetamol had no overall increased risk of bladder cancer (OR, 0.8; 95% CI, 0.4-1.3), but our data suggested a qualitative interaction with the GSTP1 I105V genotype. Subjects with at least one copy of the 359L or 144C variant alleles in the NSAID-metabolizing gene CYP2C9 had a slightly decreased risk of bladder cancer (OR, 0.8; 95% CI, 0.7-1.0; P = 0.037); however, having at least one copy of the 359L or 144C variant alleles did not significantly modify the protective effect of nonaspirin NSAID use.

CONCLUSION

Regular use of nonaspirin NSAIDs was associated with a reduced risk of bladder cancer, which was not modified by polymorphisms in the NSAID-metabolizing gene CYP2C9. We found no evidence of an overall effect for paracetamol or aspirin use.

Aspirin and cancer risk: an updated quantitative review to 2005

Aspirin has been associated to a reduced risk of colorectal, and possibly of a few other common cancers. Epidemiological studies on aspirin and cancer risk published up to December 2005 have been reviewed, and pooled relative risks (RR) for several cancers have been provided. Besides a reduction in the risk of cancer of the colorectum (RR = 0.71, 95% confidence interval, CI: 0.67-0.75), there is evidence-although more limited, and mainly from case-control studies-that aspirin has a favourable effect on cancers of the esophagus (RR = 0.72, 95% CI: 0.62-0.84), stomach (RR = 0.84, 95% CI: 0.76-0.93), breast (RR = 0.91, 95% CI: 0.88-0.95), ovary (RR = 0.89, 95% CI: 0.78-1.02) and lung (RR = 0.94, 95% CI: 0.89-1.00). The role of aspirin on other cancers, such as pancreatic, prostate, bladder cancer, and non-Hodgkins' lymphomas is less clear, and an increase of risk has been suggested for kidney cancer. For most cancer sites, however, significant heterogeneity between studies, and particularly across study design, was found, with a reduction in risk generally stronger in case-control than in cohort studies. Further, notwithstanding the large amount of epidemiological evidence, substantial uncertainties remain about the proper aspirin dose and duration of treatment.

Risk factors for adult renal cell carcinoma

This study confirmed several independent risk and protective factors for RCC identified in the authors' previous study. Protective factors such as oral contraceptive use and moderate alcohol consumption were identified only in women. Tobacco consumption and severe obesity were the main independent risk factors. There were other modifiable risk markers, however, such as occupational exposure, thiazidic drug intake, and urinary tract infections. The associations between risk factors and RCC were weak, even for tobacco, for which the association was weaker than that for lung cancer. The identified risks involve a large proportion of the population, however, and the risk attributable to these types of exposure is high. The authors' recommendations for the prevention of RCC are therefore similar to those for the prevention of cardiovascular disease and cancer, and should be disseminated to the general population. The high-risk groups identified are too large for a specific early-screening program for RCC, but such screening might be appropriate if restricted to selected age groups.

Declining mortality from kidney cancer in Europe

Mortality rates from kidney cancer increased throughout Europe up until the late 1980s or early 1990s. Trends in western European countries, the European Union (EU) and selected central and eastern European countries have been updated using official death certification data for kidney cancer abstracted from the World Health Organisation (WHO) database over the period 1980-1999. In EU men, death rates increased from 3.92 per 100,000 (age standardised, world standard) in 1980-81 to 4.63 in 1994-95, and levelled off at 4.15 thereafter. In women, corresponding values were 1.86 in 1980-81, 2.04 in 1994-95 and 1.80 in 1998-99. Thus, the fall in kidney cancer mortality over the last 5 years was over 10% for both sexes in the EU. The largest falls were in countries with highest mortality in the early 1990s, such as Germany, Denmark and the Netherlands. Kidney cancer rates levelled off, but remained very high, in the Czech Republic, Baltic countries, Hungary, Poland and other central European countries. Thus, in the late 1990s, a greater than three-fold difference in kidney cancer mortality was observed between the highest rates in the Czech Republic, the Baltic Republics and Hungary, and the lowest ones in Romania, Portugal and Greece. Tobacco smoking is the best recognised risk factor for kidney cancer, and the recent trends in men, mainly in western Europe, can be related to a reduced prevalence of smoking among men. Tobacco, however, cannot account for the recent trends registered in women.

Effects of non-steroidal anti-inflammatory drugs on cancer sites other than the colon and rectum: a meta-analysis

Background

Observational studies have consistently shown that aspirin and non-steroidal anti-inflammatory drug (NSAID) use is associated with a close to 50% reduced risk of colorectal cancer. Studies assessing the effects of NSAIDs on other cancers have shown conflicting results. Therefore, we conducted a meta-analysis to evaluate the relationship between NSAID use and cancer other than colorectal.

Methods

We performed a search in Medline (from 1966 to 2002) and identified a total of 47 articles (13 cohort and 34 case-control studies). Overall estimates of the relative risk (RR) were calculated for each cancer site using random effects models.

Results

Aspirin use was associated with a reduced risk of cancer of the esophagus and the stomach (RR, 0.51; 95%CI (0.38–0.69), and 0.73; 95%CI (0.63–0.84)). Use of NSAIDs was similarly associated with a lower risk of esophageal and gastric cancers (RR,0.65; 95% CI(0.46–0.92) and RR,0.54; 95%CI (0.39–0.75)). Among other cancers, only the results obtained for breast cancer were fairly consistent in showing a slight reduced risk among NSAID and aspirin users (RR, 0.77; 95%CI (0.66–0.88), and RR, 0.77; 95%CI (0.69–0.86) respectively)).

Conclusions

The results of this meta-analysis show that the potential chemopreventive role of NSAIDs in colorectal cancer might be extended to other gastrointestinal cancers such as esophagus and stomach. Further research is required to evaluate the role of NSAIDs at other cancers sites.

Cancer risk in persons receiving prescriptions for paracetamol: a Danish cohort study

The use of paracetamol has been associated with increased risks for urinary tract cancers and decreased risk for ovarian cancer, although results have been inconsistent. We conducted a population-based cohort study using data from the Prescription Database of North Jutland County and the Danish Cancer Registry. Cancer incidence among 39,946 individuals receiving prescriptions for paracetamol was compared with expected incidence based on the North Jutland population who did not receive paracetamol prescriptions, during a 9-year follow-up period. Standardized incidence ratios (SIRs) with corresponding 95% confidence intervals (95% CIs) were calculated for cancers overall and at selected sites. Overall, 2,173 cancers were observed with 1,973 expected, yielding a SIR of 1.10 (95% CI, 1.06-1.15). Significantly elevated SIRs were found for cancers of the esophagus (1.9; 95% CI, 1.3-2.8) and lung (1.6; 95% CI, 1.4-1.7). Nonsignificantly increased SIRs were observed for cancers of the liver (1.5; 95% CI, 0.96-2.2), renal parenchyma (1.3; 95% CI, 0.9-1.7) and renal pelvis/ureter (1.6; 95% CI, 0.96-2.6), whereas the SIR for cancer of the urinary bladder was close to unity (1.1; 95% CI, 0.9-1.4). For ovarian cancer, the SIR was close to expectation (0.9; 95% CI, 0.6-1.2) with no evidence of trends with duration of follow-up or number of prescriptions. A similar risk pattern was observed after exclusion of person-time experience following prescription for aspirin or other nonsteroidal antiinflammatory drugs in the study cohort and reference population. Our results do not support a major role for paracetamol in the development of cancers of the urinary tract, and we found little evidence of a protective effect of paracetamol against ovarian cancer. The elevated risks for cancers of the esophagus, lung and liver are most likely a result of confounding variables, but may warrant further investigation.

VHL gene alterations in renal cell carcinoma patients: novel hotspot or founder mutations and linkage disequilibrium

Mutations in the von Hippel-Lindau (VHL) gene are frequently detected in human sporadic renal cell carcinoma (RCC). We analysed 102 Swedish RCCs for VHL mutations by PCR-SSCP and sequencing. In 47 patients (46.1%), 70 different mutations were found, and most of them represented novel variations of the VHL gene. Mutations in the VHL gene were found in 54% of clear cell renal cell carcinomas (CCRCC) and in 18% of chromophilic cancers but in no chromophobe cancers or oncocytomas (P=0.016). Three novel hotspot or founder mutations were detected in our study: four CCRCCs carried a missense mutation (glutamic acid to lysine) at codon 160 which is critical in the stabilization of the H1 helix of the alpha domain and the alpha-beta domain interface in the VHL protein. Five CCRCCs and one chromophilic RCC harbored a 15-nucleotide in-frame deletion (codons 41-45) at a duplex tandem repeat sequence site. Moreover, this deletion was in linkage disequilibrium with a C-->T transition in the promoter region. The frequency of linkage was 17 times more common than chance. Five patients with this linked mutation resided in the same hospital district and at least three of them showed the two sequence variants in the tumor-adjacent tissue. In 5/6 patients the wild-type allele was lost in the tumor samples, suggesting a causal role for the mutations in RCC. These linked mutations might be novel polymorphisms maintained in a relative isolated population. Multiple mutations in VHL were found in 17 tumors out of 47 tumors with the VHL mutation. A higher multiple mutation detected rate (33%) was observed in grade 3 CCRCCs than those in grade 1 (22%) and grade 2 (9%) (P=0.04). This is evidence on the association between VHL mutation and extent of nuclear atypia.

Regular use of analgesics is a risk factor for renal cell carcinoma

Phenacetin-based analgesics have been linked to the development of renal pelvis cancer and renal cell carcinoma (RCC). The relationship between non-phenacetin types of analgesics and kidney cancer is less clear, although laboratory evidence suggests that these drugs possess carcinogenic potential. A population-based case-control study involving 1204 non-Asian RCC patients aged 25-74 and an equal number of sex-, age- and race-matched neighbourhood controls was conducted in Los Angeles, California, to investigate the relationship between sustained use of analgesics and risk of RCC according to major formulation categories. Detailed information on medical and medication histories, and other lifestyle factors was collected through in-person interviews. Regular use of analgesics was a significant risk factor for RCC in both men and women (odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.4-1.9 for both sexes combined). Risks were elevated across all four major classes of analgesics (aspirin, non-steroidal anti-inflammatory agents other than aspirin, acetaminophen and phenacetin). Within each class of analgesics, there was statistically significant increasing risk with increasing level of exposure. Although there was some minor variability by major class of formulation, in general individuals in the highest exposure categories exhibited approximately 2.5-fold increase in risk relative to non- or irregular users of analgesics. Subjects who took one regular-strength (i.e. 325 mg) aspirin a day or less for cardiovascular disease prevention were not at an increased risk of RCC (OR = 0.9, 95% CI = 0.6-1.4).

Risk and prognosis in renal neoplasms. A pathologist's prospective

The incidence of renal carcinoma has increased in the United States over the last two decades. An increased rate of detection of incidental tumors and a variety of exogenous risk factors may be responsible for this increase. Pathologic stage and nuclear grade remain the most important and practical prognostic features, however, the specific tumor type has emerged as important as the cytogenetic validation of recent renal carcinoma classification. Proliferation markers, DNA ploidy, and morphometry have powerful predictive value but are handicapped by cost and complexity. The search continues for molecules of diagnostic and prognostic utility that may also impact invasive and metastatic capability for this group of neoplasms whose course is principally determined by the completeness of the original resection.

Renal cell carcinoma

Renal cell carcinoma (RCC) is characterized by (a) lack of early warning signs, which results in a high proportion of patients with metastases at the time of diagnosis; (b) protean clinical manifestations; and (c) resistance to radiotherapy and chemotherapy. The estimates of new diagnoses and deaths from kidney cancer in the United States during 1996 are 30,600 and 12,000, respectively. RCC occurs nearly twice as often in men as in women. The age at diagnosis is generally older than 40 years; the median age is in the midsixties. The incidence of RCC has been rising steadily. Between 1974 and 1990, there was a 38% increase in the number of patients who had a diagnosis of RCC. This increase was accompanied by a significant improvement in 5-year survival. Both trends are likely the result of improved diagnostic capability. Newer radiographic techniques, including ultrasonography, computed tomography, and magnetic resonance imaging, are detecting kidney tumors more frequently and at a lower disease stage, when tumors can be resected for cure. Surgical treatment is the only curative therapy for localized RCC. Radical nephrectomy remains the mainstay of surgical management, but techniques are being modified. These modifications include partial nephrectomy and resection of vena caval thrombi. In highly selected cases, surgical resection of locally recurrent RCC or of disease at a solitary metastatic site is associated with long-term survival. Metastatic RCC is highly resistant to the many systemic therapies that have been extensively investigated. A minority of patients achieve complete or partial response to interferon, interleukin-2, or both. Response can be dramatic but is rarely durable. Because most patients do not achieve response, these agents are not considered effective treatments for RCC, but the response in some patients indicates the need for continued research on their use. Identification of new agents with better antitumor activity against metastases remains a high priority in clinical investigation of therapy for this refractory disease.

Second primary cancers following cancers of the kidney and prostate in New South Wales (Australia), 1972-91

Data from the New South Wales (NSW) (Australia) Central Cancer Registry for the period 1972-91 were examined to determine the risk of second primary cancers following an initial invasive cancer of the renal parenchyma (ICD-9 code 189.0), renal pelvis (code 189.1), or prostate (code 185). Eligible cases were restricted to those who had survived for at least two months after diagnosis of the first primary cancer. Expected numbers of cancers were obtained by assuming that subjects experienced the same cancer incidence as prevailed in the corresponding general population and applying gender-, age-, and calendar-specific rates to the appropriate person-years at risk. The relative risk (RR) of a second primary cancer was taken to be the ratio of observed to expected numbers of second cancers. Following prostatic cancer, there was an overall deficit of cancers at all sites combined (RR = 0.79, 95 percent confidence interval [CI] = 0.75-0.84), and no site had a significantly raised RR. Taking this into consideration, there appeared to be a reciprocal relationship of increased risk of prostatic cancer (RR = 1.7, CI = 1.2-2.3) following an initial cancer of the renal parenchyma and of renal parenchymal cancer (RR = 1.2, CI = 0.8-1.7) after cancer of the prostate. An increased risk of bladder cancer occurred following renal parenchymal (RR = 3.4, CI = 1.1-8.0, for women only) as well as after renal pelvic cancer (men: RR = 8.7, CI = 5.4-13; women: RR = 39, CI = 26-56). A tobacco-related pattern of excess risk was seen after renal pelvic cancer but not after cancer of the renal parenchyma. These data illustrate that an excess of second primary cancers may reflect shared etiologic factors or increased medical surveillance.

Nutrition and renal cell cancer

Epidemiologic evidence on the relation between nutrition and renal cell cancer is reviewed. Kidney cancer, comprising 1.7 percent of all malignant diseases diagnosed worldwide, shows about a 20-fold international variation in the incidence in men and 10-fold in women. This substantial variation indicates an important causal role of environmental factors. Renal cell (parenchymal) cancer (RCC) accounts for about 80 percent of all kidney cancers. While the etiology of RCC is incompletely understood, analytic epidemiologic studies provide consistent support for a positive association of obesity with risk of RCC; the dose-response observed supports a causal relationship. Only a few prospective studies, all of them limited in size, have been published, while ecologic and case-control studies suggest that diet may be important in the etiology of RCC. However, contradictory results and methodologic limitations in some case-control studies prevent definite conclusions concerning diet and RCC. A positive association of protein and fat intake, as well as their main food sources (meat, milk, fats), with risk of RCC-as suggested by ecologic studies-has no clear support in analytic epidemiologic studies. A protective effect of vegetables and fruits has been observed in most case-control studies, while the majority do not show an association between alcohol, coffee, and risk of RCC. Recent reports indicated an increased risk of RCC associated with consumption of fried/sautéed meat and low intakes of magnesium or vitamin E. An apparent positive association with total energy intake, perhaps due to bias, needs further investigation.