ADVANCES IN CANCER EPIDEMIOLOGY: Understanding Causal Mechanisms and the Evidence for Implementing Interventions

Impaired lung function and lung cancer risk in 461 183 healthy individuals: a cohort study

BACKGROUND

It has been known that smoking and various lung diseases including lung cancer can cause lung function impairment. However, the impact of different types of lung function impairments, such as preserved ratio impaired spirometry (PRISm) and airflow obstruction (AO), on the incidence and mortality of lung cancer in both general and never-smoker populations remains unclear. We wished to examine the effect of lung function impairments on lung cancer risks.

METHODS

This was a retrospective cohort study (1 January 1994 to 31 December 2017) of individuals from a health surveillance programme in Taiwan who underwent baseline spirometry tests at the entry point. PRISm was defined as an FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) ratio >0.7 and FEV1 <0.8, while AO was defined as an FEV1/FVC ratio <0.7. Cox proportional hazards models and cubic spline curves were used to examine the associations between lung function impairments and lung cancer risks.

RESULTS

The study included 461,183 individuals, of whom 14.3% had PRISm and 7.9% had AO. A total of 4038 cases of lung cancer and 3314 lung cancer-related deaths were identified during the 23 years of follow-up. Individuals with PRISm and AO exhibited a higher risk of lung cancer incidence and mortality compared with those with normal lung function. The adjusted HRs and 95% CIs were 1.14 (1.03 to 1.26) and 1.23 (1.10 to 1.37) in the overall cohort, and 1.08 (0.93 to 1.24), and 1.23 (1.05 to 1.45) in the never-smoker cohort. The risks of both developing and dying of lung cancer increased with the severity levels of lung function impairments and lower FEV1 values.

CONCLUSION

Impaired lung function is associated with increased risks of developing lung cancer and subsequent mortality. The study highlights the importance of considering lung function in lung cancer screening for better candidate selection.

Sex differences in chronic obstructive pulmonary disease characteristics: the Korea National Health and Nutrition Examination Survey 2007-2018

BACKGROUND/AIMS

Chronic obstructive pulmonary disease (COPD) is less prevalent in females than males, but it affects mortality in females. There may be sex differences in the clinical characteristics of COPD.

METHODS

We analyzed the Korea National Health and Nutrition Examination Survey dataset from 2007 to 2018. We compared the clinical characteristics and comorbidities in subjects with COPD according to sex. We adjusted the multivariate logistic regression of lung cancer prevalence according to COPD and sex by age and smoking amount.

RESULTS

Females with COPD tended to be older than males with COPD (64.1 ± 0.4 yr vs. 62.3 ± 0.2 yr, respectively, p < 0.001). Approximately 89% of males with COPD had a smoking history, while 86% of females with COPD were non-smokers (p < 0.001). Household income was lower (p < 0.001) and asthma and overall malignancy were more prevalent in females with COPD than males with COPD (25.5 vs. 11.6%, respectively, p < 0.001; (6.3 vs. 5.4%, respectively, p < 0.001). However, lung cancer was more common in males with COPD than females with COPD (0.9 vs. 0.1%, respectively, p < 0.001). Lung cancer prevalence increased in males with moderate COPD compared to subjects without COPD (OR, 4.409; 95% CI, 1.741-9.419).

CONCLUSION

Females with COPD had a lower smoking rate, household income, and lung cancer prevalence than males with COPD. More active COPD screening is needed for women of low socioeconomic status, even if they do not smoke.

Resources for Human Health from the Plant Kingdom: The Potential Role of the Flavonoid Apigenin in Cancer Counteraction

Apigenin is one of the most widespread flavonoids in the plant kingdom. For centuries, apigenin-containing plant preparations have been used in traditional medicines to treat diseases that have an inflammatory and/or degenerative component. In the 1980s, apigenin was proposed to interfere with the process of carcinogenesis. Since then, more and more evidence has demonstrated its anticancer efficacy, both in vitro and in vivo. Apigenin has been shown to target signaling pathways involved in the development and progression of cancer, such as PI3K/Akt/mTOR, MAPK/ERK, JAK/STAT, NF-κB, and Wnt/β-catenin pathways, and to modulate different hallmarks of cancer, such as cell proliferation, metastasis, apoptosis, invasion, and cell migration. Furthermore, apigenin modulates PD1/PD-L1 expression in cancer/T killer cells and regulates the percentage of T killer and T regulatory cells. Recently, apigenin has been studied for its synergic and additive effects when combined with chemotherapy, minimizing the side effects. Unfortunately, its low bioavailability and high permeability limit its therapeutic applications. Based on micro- and nanoformulations that enhance the physical stability and drug-loading capacity of apigenin and increase the bioavailability of apigenin, novel drug-delivery systems have been investigated to improve its solubility.

Factors affecting HPV infection in U.S. and Beijing females: A modeling study

Background

Human papillomavirus (HPV) infection is an important carcinogenic infection highly prevalent among many populations. However, independent influencing factors and predictive models for HPV infection in both U.S. and Beijing females are rarely confirmed. In this study, our first objective was to explore the overlapping HPV infection-related factors in U.S. and Beijing females. Secondly, we aimed to develop an R package for identifying the top-performing prediction models and build the predictive models for HPV infection using this R package.

Methods

This cross-sectional study used data from the 2009-2016 NHANES (a national population-based study) and the 2019 data on Beijing female union workers from various industries. Prevalence, potential influencing factors, and predictive models for HPV infection in both cohorts were explored.

Results

There were 2,259 (NHANES cohort, age: 20-59 years) and 1,593 (Beijing female cohort, age: 20-70 years) participants included in analyses. The HPV infection rate of U.S. NHANES and Beijing females were, respectively 45.73 and 8.22%. The number of male sex partners, marital status, and history of HPV infection were the predominant factors that influenced HPV infection in both NHANES and Beijing female cohorts. However, condom application was not an independent influencing factor for HPV infection in both cohorts. R package Modelbest was established. The nomogram developed based on Modelbest package showed better performance than the nomogram which only included significant factors in multivariate regression analysis.

Conclusion

Collectively, despite the widespread availability of HPV vaccines, HPV infection is still prevalent. Compared with condom promotion, avoidance of multiple sexual partners seems to be more effective for preventing HPV infection. Nomograms developed based on Modelbest can provide improved personalized risk assessment for HPV infection. Our R package Modelbest has potential to be a powerful tool for future predictive model studies.

Impaired Lung Function and Lung Cancer Incidence: A Nationwide Population-Based Cohort Study

Background: It is unclear whether the presence of minimal lung function impairment is an independent risk factor for the development of lung cancer in general populations. Methods: We conducted a population-based cohort study using nationally representative data from the Korean National Health and Nutrition Examination Survey and the Korean National Health Insurance Service. Results: Of 20,553 participants, 169 were diagnosed with lung cancer during follow-up (median, 6.5 years). Participants with obstructive lung function impairment had increased risk of lung cancer (aHR: 2.51; 95% CI: 1.729–3.629) compared with those with normal lung function. The lower was the quartile or decile of forced expiratory volume in one second (FEV1) or the FEV1/forced vital capacity (FVC) ratio, the significantly higher was the incidence rate of lung cancer (p for trend < 0.0001). With FEV1 values in the lowest quartile (Q4), the incidence of lung cancer was significantly increased regardless of FVC (FEV1 Q4 and FVC values in the higher three quartiles Q1–3: aHR 1.754; 95% CI 1.084–2.847, FEV1 Q4 and FVC Q4: aHR 1.889; 95% CI 1.331–2.681). Conclusion: Our findings suggest that minimal lung function impairment, as expressed by lower FEV1 or FEV1/FVC value, may be associated with increased risk of lung cancer

Male papillomavirus infection and genotyping in the Qingyuan area

Background

This study aims to screen the male human papillomavirus (HPV) infection status and genotyping in Qingcheng District, Qingyuan City, Guangdong Province, China to provide a reference basis for formulating prevention strategies for HPV infection.

Methods

The present study collected urethral epithelium or scraped penile epidermis from high-risk male patients in Qingyuan People's Hospital during the last five years, extracted DNA fragments using the boiling method, and detected 23 types of HPV genotypes by PCR-reverse blot hybridization.

Results

The positive detection rate was 54.31% of 1044 males with high risk of HPV (567/1044). Among these males, the positive detection rate of HPV was the highest in patients initially diagnosed with warts, and the rate was 66.47%. Five main HPV types are identified as follows: HPV6 18.87% (197/1044), HPV11 10.25% (107/1044), HPV52 8.81% (92/1044), HPV16 6.90% (72/1044), and HPV51 5.08% (53/1044). Among these HPV-infected patients, single infection mainly by low-risk HPV6 and HPV11 accounted for 56.61% (321/567); high- and low-risk combined HPV co-infections accounted for 29.10% (165/567). The HPV infected patients was mainly between 21 and 40 years old, and the HPV infection rate was higher with increased age.

Conclusions

The HPV infection rate in the Qingyuan area is higher than in other areas and the main infection is single infection. Furthermore, HPV52, HPV16, and HPV51 are the main high-risk infection types, while HPV6 and HPV11 are the main low-risk infection types.

Economic burden of cancer in India: Evidence from cross-sectional nationally representative household survey, 2014

With the ongoing demographic and epidemiological transition, cancer is emerging as a major public health concern in India. This paper uses nationally representative household survey to examine the overall prevalence and economic burden of cancer in India. The age-standardized prevalence of cancer is estimated to be 97 per 100,000 persons with greater prevalence in urban areas. The evidence suggests that cancer prevalence is highest among the elderly and also among females in the reproductive age groups. Cancer displays a significant socioeconomic gradient even after adjusting for age-sex specifics and clustering in a multilevel regression framework. We find that out of pocket expenditure on cancer treatment is among the highest for any ailment. The average out of pocket spending on inpatient care in private facilities is about three-times that of public facilities. Furthermore, treatment for about 40 percent of cancer hospitalization cases is financed mainly through borrowings, sale of assets and contributions from friends and relatives. Also, over 60 percent of the households who seek care from the private sector incur out of pocket expenditure in excess of 20 percent of their annual per capita household expenditure. Given the catastrophic implications, this study calls for a disease-based approach towards financing such high-cost ailment. It is suggested that universal cancer care insurance should be envisaged and combined with existing accident and life insurance policies for the poorer sections in India. In concluding, we call for policies to improve cancer survivorship through effective prevention and early detection. In particular, greater public health investments in infrastructure, human resources and quality of care deserve priority attention.

Parthenolide induces apoptosis in colitis-associated colon cancer, inhibiting NF-κB signaling

Recently, the nuclear factor (NF)-κB inhibitor parthenolide (PT) was identified as a promising anticancer agent for the promotion of cancer cell apoptosis. Additionally, our previous study demonstrated that PT administration suppresses tumor growth in a xenograft model of colorectal cancer cells via regulation of the B-cell lymphoma-2 (Bcl-2) family. However, the role of PT in the development of colitis-associated colon cancer (CAC) is poorly understood. Therefore, the aim of the present study was to investigate the effects of PT administration on CAC using a murine model. Azoxymethane (AOM) and dextran sulfate sodium (DSS) were administered to induce experimental CAC in the following three groups of treated mice: i) AOM and DSS plus vehicle; ii) AOM, DSS and 2 mg/kg PT; and iii) AOM, DSS and 4 mg/kg PT. It was demonstrated that the histological acuteness of AOM/DSS-induced CAC was significantly reduced following the administration of PT, resulting in decreased NF-κB p65 expression levels via a blockade of phosphorylation and subsequent degradation of inhibitor of κB-α (IκBα). Furthermore, PT administration appeared to enhance the process of carcinogenesis via the downregulation of the antiapoptotic proteins Bcl-2 and Bcl-extra large, mediated by inhibition of NF-κB activation. Apoptosis and caspase-3 expression were markedly increased in the PT-treated group. These findings indicate that PT inhibits IκBα phosphorylation and NF-κB activation, resulting in the initiation of apoptosis and the eventual suppression of CAC development. The beneficial effects of PT treatment observed in the experimental CAC model indicate the potential chemopreventive and therapeutic role of PT in CAC.

Link between chronic inflammation and human papillomavirus-induced carcinogenesis (Review)

Inflammation is a defense strategy against invading agents and harmful molecules that is activated immediately following a stimulus, and involves the release of cytokines and chemokines, which activate the innate immune response. These mediators act together to increase blood flow and vascular permeability, facilitating recruitment of effector cells to the site of injury. Following resolution of the injury and removal of the stimulus, inflammation is disabled, but if the stimulus persists, inflammation becomes chronic and is strongly associated with cancer. This is likely to be due to the fact that the inflammation leads to a wound that does not heal, requiring a constant renewal of cells, which increases the risk of neoplastic transformation. Debris from phagocytosis, including the reactive species of oxygen and nitrogen that cause damage to DNA already damaged by the leukotrienes and prostaglandins, has an impact on inflammation and various carcinogenic routes. There is an association between chronic inflammation, persistent infection and cancer, where oncogenic action is mediated by autocrine and paracrine signals, causing changes in somatic cells under the influence of the microbial genome or of epigenetic factors. Among the infectious agents associated with cancer, certain genotypes of human papillomavirus (HPV) stand out. HPV is responsible for virtually all cases of cervical cancer and a lower proportion of cancers of the vagina, vulva, anus, penis and a number of extragenital cancers. In the present review, recent advances in the mechanisms involved in the inflammatory response are presented with their participation in the process of carcinogenesis, emphasizing the role of chronic inflammation in the development of HPV-induced cervical cancer.

Lysyl oxidase rs1800449 polymorphism and cancer risk among Asians: evidence from a meta-analysis and a case-control study of colorectal cancer

Growing evidence has indicated that lysyl oxidase (LOX) G473A polymorphism (rs1800449) is associated with cancer risk among Asians. However, results of single center and small sample study lack enough power. We first investigated the effect of LOX G473A polymorphism on cancer risk among Asians by a meta-analysis, and then further validated this association by a case-control study of colorectal cancer (CRC) with LOX G473A polymorphism in a Chinese population. STATA 12.0 software was used for the meta-analysis. The relationships were evaluated by calculating the pooled odds ratios (ORs) and their 95 % confidence intervals (CIs). In a case-control study comprising 577 CRC patients and 696 controls, LOX G473A polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Logistic regression was used to evaluate genetic associations with the occurrence of CRC. The results of our meta-analysis, including seven case-control studies with a total of 2,377 cancer patients and 2,499 controls, suggested that LOX G473A polymorphism might be associated with an increased risk of cancer among Asians. In addition, results of a case-control study indicated that individuals with the AA or AG genotype had a significantly increased susceptibility to CRC occurrence, compared with individuals who had GG genotype. Overall, this meta-analysis and case-control study of CRC observed convincing association of LOX G473A polymorphism with cancer risk in Asians; our study would contribute to complete elucidation of carcinogenesis.

Anti-proliferative effect of chalcone derivatives through inactivation of NF-κB in human cancer cells

To investigate the anti-proliferative effect of NF-κB inhibitor, a series of analogs of (E)-1-(2-hydroxy-6-(isopentyloxy)phenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one (5a) were prepared and evaluated for their NF-κB inhibition and anti-proliferative activity against various human cancer cell lines. Compounds (E)-1-(2-(3,3-dimethylbutoxy)-6-hydroxyphenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one (5e) and (E)-4-(3-(2-(3,3-dimethylbutoxy)-6-hydroxyphenyl)-3-oxoprop-1-enyl)benzenesulfonamide (5p) showed good NF-κB inhibition as well as potent anti-proliferative activity. SAR studies showed that all the compounds with potent or moderate NF-κB inhibition displayed good anti-proliferative activity. All the analogs (5b-r) maintained a good correlation between their NF-κB inhibition and anti-proliferative activity though the extent is not directly proportional to each other.

Cytochrome P450-isoenzyme 1A1 in susceptibility to tobacco-related lung cancer

BACKGROUND

Tobacco smoke contains many carcinogens that may mediate susceptibility to lung cancer. Cytochrome P450 isoenzyme 1A1 activity and expression increases several fold in lung cancer due to smoking. Finding the role of cytochrome P450 1A1 in susceptibility to tobacco-related lung cancer may be important to predict the outcome in early stage cancer, and may result in an improved survival rate.

PATIENTS AND METHODS

This study was carried on 2 groups of patients: group A was 20 patients with operable smoking-related lung cancer, who underwent surgery at the time of diagnosis; group B was 20 nonsmokers without lung cancer who underwent chest exploration following road traffic accidents. Specimens were obtained from tumor tissue and surrounding healthy tissue in group A patients, and from healthy lung tissue in group B patients. These specimens were sent for measurement of protein content and cytochrome P450 1A1 activity.

RESULTS

There was significantly greater tissue cytochrome P450 1A1 activity in group A compared to group B. Patients with stage II cancer showed significantly higher levels of tissue cytochrome P450 1A1 activity than those with stage I. There was also a significant difference in tissue cytochrome P450 1A1 activity between the tumor tissue and the tissue surrounding the tumor.

CONCLUSION

Carcinogens in smoke increase cytochrome P450 1A1 activity, which might be considered to play a role in cigarette smoking-induced lung cancer.

Study on anti-proliferative effect of benzoxathiole derivatives through inactivation of NF-κB in human cancer cells

To investigate the anti-proliferative effect of a newly discovered NF-kB inhibitor, 6,6-dimethyl-2-(phenylimino)-6,7-dihydrobenzo[d][1,3]oxathiol-4(5H)-one (1a), a series of its analogs (1b-n) were prepared and evaluated for their NF-κB inhibition and anti-proliferative activity against various human cancer cell lines. Slight variation of hydrophobicity by replacement of dimethyl group of 1a at 6-position with bulky isopropyl group and introduction of para-fluoro substitution on 2-phenyl group showed good NF-κB inhibitory activity and anti-proliferative activity. However, excessive increase in hydrophobicity with 2,4,6-trichloro substituents on phenyl group resulted in the loss of both the activities. From the SAR results, 2-phenylimino-6,7-dihydrobenzo[d][1,3]oxathiol-4(5H)-one was identified as the lead scaffold for investigating new anticancer agent through inactivation of NF-κB.

Role of cholesterol in the development and progression of breast cancer

Diet and obesity are important risk factors for cancer development. Many studies have suggested an important role for several dietary nutrients in the progression and development of breast cancer. However, few studies have specifically addressed the role of components of a Western diet as important factors involved in breast cancer initiation and progression. The present study examined the role of cholesterol in the regulation of tumor progression in a mouse model of mammary tumor formation. The results suggest that cholesterol accelerates and enhances tumor formation. In addition, tumors were more aggressive, and tumor angiogenesis was enhanced. Metabolism of cholesterol was also examined in this mouse model. It was observed that plasma cholesterol levels were reduced during tumor development but not prior to its initiation. These data provide new evidence for an increased utilization of cholesterol by tumors and for its role in tumor formation. Taken together, these results imply that an increase in plasma cholesterol levels accelerates the development of tumors and exacerbates their aggressiveness.

Occupational exposure to pesticides and bile tract carcinoma in men: results from a European multicenter case-control study

OBJECTIVES

To estimate the associations between occupational exposure to pesticides and extrahepatic biliary tract carcinoma in men, a population-based case-control study was carried out.

METHODS

Cases (n = 104), aged 35-70, diagnosed in 1995-1997, were sampled by active reporting systems from hospitals. Controls (n = 1,401) were a random sample of the general male population. Information on occupation and confounding factors was obtained by questionnaires. Exposures were quantified with respect to time, application methods, and use of personal protective equipment. Intensity was evaluated by using a published algorithm which weighted the exposure assigned according to the use of personal protective equipment and mode of application. Logistic regression analyses were conducted adjusted for gallstones, age, and country.

RESULTS

Being ever exposed to pesticides resulted in an odds ratio (OR) of 1.0 [95%-confidence interval (CI) 0.6-1.6]. A modestly elevated risk was found for backpack mounted sprayers OR = 1.4 [95% CI 0.7-2.6] and vine farmers OR = 2.5 [95% CI 0.9-7.2]. Using time periods and exposure frequency as intensity measure, no elevated risks were found. The only exception was year of maximum exposure which yielded an OR of 1.6 [95% CI 0.7-3.5]. However, no clear trend was observed in this analysis.

CONCLUSIONS

This study does not rule out that pesticide exposure represents an occupational risk factor for extrahepatic biliary tract carcinoma, but no indication of a strong association was observed. Some modes of exposure were weakly, albeit not significantly associated with carcinoma risk. The observed estimates of effects may be influenced by a lack of precise exposure assessment. Different chemical compositions of pesticides were utilized during a long time span of pesticide exposure, and it should be considered that the exposure is assessed with substantial uncertainty that could non-differential and bias results toward the null.

Silica exposure, smoking, silicosis and lung cancer--complex interactions

BACKGROUND

Establishing a clear relationship between workplace exposures and cancer is often difficult. The latent period for cancer development can make it difficult to establish a definite cause-effect relationship. The picture is further complicated by variable job histories, concomitant exposure to other carcinogens and other factors such as genetic susceptibility and poor nutrition. The lack of accurate and detailed record keeping may potentially mask informative differences among group of workers. Removing or reducing exposures to probable and known carcinogens, however, can prevent workplace cancer.

AIM

This paper gives an overview of the literature reporting investigations of the relationship between exposure to silica and development of lung cancer with a focus on the controversy concerning the roles of silicosis and smoking in the development of cancer.

METHOD

A literature search was conducted to identify epidemiologic papers on silica, silicosis and lung cancer using electronic databases (MEDLINE, PubMed, Web of Science) from 1996 onwards and paper bibliographies.

RESULTS

If silicosis were the necessary step leading to lung cancer, enforcing the current silica standards would protect workers against lung cancer risk as well. Alternatively, a direct silica-lung cancer association that has been suggested implies that regulatory standards should be revised accordingly.

CONCLUSION

Further research is needed in order to understand the complex pattern of interactions leading to lung cancer among silica-exposed workers (and cancers and workplace exposures in general) and to understand whether and to what extent other workplace lung carcinogens, total respirable dust and total surface size and age of silica particles affect the carcinogenic potential of silica. In addition, the apparent paradox of a lower lung cancer risk in some workplaces with high-level silica exposure needs further investigation.

Body composition and serum prostate-specific antigen: review and findings from Flint Men's Health Study

Recent studies have suggested that obesity is associated with lower serum prostate-specific antigen levels, perhaps influencing the recommendation for prostate biopsy and potentially explaining part of the observed poorer prognosis among obese men. African-American men have the greatest rates of prostate cancer and are more likely to die of the disease, making early detection a priority in this group. We present findings from the Flint Men's Health Study, a study of African-American men, that are consistent with most studies suggesting that overweight men have prostate-specific antigen levels that are 0.15 to 0.30 ng/mL lower than those who are not overweight. We have coupled our results with a systematic review of publications in this area.

Cancer registry policies in the United States and geographic information systems applications in comprehensive cancer control

OBJECTIVES

Through a long history of cancer policies, public health has a foundation for cancer research and data to use in applying technological advancements for U.S. cancer control efforts. Geographic information systems (GIS) are one technology enabling the visualization of cancer risk patterns associated with incidence, mortality, and accessibility to care.

METHODS

U.S. Comprehensive Cancer Control (CCC) program directors were interviewed from 49 of 50 states to assess use and function of GIS tools for mapping data related to cancer control policies and practices. Interviews were coded to obtain frequencies of response associated with content domains mapped using GIS tools and the perceived relative advantages.

RESULTS

Significant relationships were found between the mapping of behavioral risk factors, health care services, transportation access, and policy advantages identified by program managers. The mapping of cancer incidence, mortality, and staging, transportation access, and multiple layers of content were found to have significant associations with perceived research advantages.

CONCLUSIONS

U.S. CCC program managers recognize several important advantages relating to health policy and research for use of GIS tools in cancer control efforts. The application of GIS in U.S. cancer control efforts is employed unevenly, suggesting the need for innovative policies to support accessibility.

Alleviating the burden of cancer: a perspective on advances, challenges, and future directions

The control of the burden of cancer would be achievable by promoting health-maintaining lifestyle behavioral practices in conjunction with facilitated access to affordable and effective periodic screening and early detection examinations combined with comprehensive treatment services. In a global population exceeding six billion in the year 2002, there were approximately 10.9 million new cancer cases, 6.7 million cancer deaths, and 22.4 million persons surviving from cancer diagnosed in the previous 5 years. In 2020, the world's population is projected to increase to 7.5 billion and will experience 15 million new cancer cases and 12 million cancer deaths. This perspective on advances, challenges, and future directions in cancer epidemiology and prevention reviews the conceptual foundation for multistep carcinogenesis, causal mechanisms associated with chronic inflammation and the microenvironment of the cancer cell, and obesity, energy expenditure, and insulin resistance. Strategic priorities in global cancer control initiatives should embrace these fundamental concepts by targeting tobacco and alcohol consumption, the increasing prevalence of obesity and metabolic sequelae, and persistent microbial infections.

Utility of proxy versus index respondent information in a population-based case-control study of rapidly fatal cancers

PURPOSE

This work provides an empirical assessment of the usefulness of obtaining exposure data from proxy respondents.

METHODS

Two independent case groups were formed in data from a population-based case-control study. One case set was derived from proxy respondents. The second case series was derived from respondents who self-reported. The second case group was matched to the proxy case group for age, cancer site, and sex. These data were compared with a control group for completeness of information and identifying heterogeneity of risk estimates for a variety of variables. Index cases and controls were matched to the 829 available proxy respondents for sex, age (5-year groups), and cancer site.

RESULTS

Proxy respondents provided levels of complete information similar to index cases and controls for height and weight; occupational physical activity; consumption of coffee, alcohol, and cigarettes; and family history of cancer. Proxies had more missing responses for variables concerning recreational physical activity, clinical depression, age at first menstruation, use of oral contraceptives, and occupational exposure to pesticides. Polytomous logistic regression models found only a few examples of meaningful heterogeneity among all variables, limited to models for coffee consumption and cigarette smoking.

CONCLUSIONS

Our data suggest that proxy respondents, especially parents and spouses, provide adequately complete information for many, but not all, exposures common in epidemiologic studies.

Low number of donor activating killer immunoglobulin-like receptors (KIR) genes but not KIR-ligand mismatch prevents relapse and improves disease-free survival in leukemia patients after in vivo T-cell depleted unrelated stem cell transplantation

BACKGROUND

The effect of natural killer (NK) cell alloreactivity on outcome of unrelated stem cell transplantation (SCT) remains controversial. Killer immunoglobulin-like receptors (KIRs) recognize human leukocyte antigen C and B epitopes on target cells, thereby regulating NK cell activity. The KIR genes are polymorphic and two broad haplotypes exist: KIR-haplotype A mainly encode for inhibitory receptors and only for one activating (KIR2DS4), whereas the group B haplotype encodes more for activating KIRs (KIR2DS1, KIR2DS2, KIR2DS3, KIR2DS5 und KIR3DS1).

METHODS

The impact of KIR ligand mismatch on the number of activating and inhibitory donor KIR genes and on KIR-haplotype was studied on outcome of 142 patients with leukemia, who received standard myeloablative conditioning followed by in vivo T-cell depleted (ATG) unrelated SCT.

RESULTS

In a multivariate analysis KIR ligand mismatch had significantly higher treatment related mortality (RR 2.206, P = 0.03), resulting in reduced overall (RR 2.015, P = 0.02) and disease-free survival (RR 1.924, P = 0.03). In contrast, SCT from donors with group A haplotype (P = 0.003) or with low number of activating KIR genes (P = 0.005) resulted in reduced relapse rate with improved disease-fee survival (P = 0.04). This effect was seen only in acute myeloid leukemia/myelodysplastic syndrome and to a less extent in chronic myeloid leukemia. No effect was seen for acute lymphoblastic leukemia.

CONCLUSIONS

After in vivo T-cell depleted (ATG) unrelated stem cell transplantation with donors carrying low number of activating KIR genes (group A KIR haplotype), the risk of relapse is reduced and resulted in a significantly better disease-free survival.

Progress in chemoprevention drug development: the promise of molecular biomarkers for prevention of intraepithelial neoplasia and cancer--a plan to move forward

This article reviews progress in chemopreventive drug development, especially data and concepts that are new since the 2002 AACR report on treatment and prevention of intraepithelial neoplasia. Molecular biomarker expressions involved in mechanisms of carcinogenesis and genetic progression models of intraepithelial neoplasia are discussed and analyzed for how they can inform mechanism-based, molecularly targeted drug development as well as risk stratification, cohort selection, and end-point selection for clinical trials. We outline the concept of augmenting the risk, mechanistic, and disease data from histopathologic intraepithelial neoplasia assessments with molecular biomarker data. Updates of work in 10 clinical target organ sites include new data on molecular progression, significant completed trials, new agents of interest, and promising directions for future clinical studies. This overview concludes with strategies for accelerating chemopreventive drug development, such as integrating the best science into chemopreventive strategies and regulatory policy, providing incentives for industry to accelerate preventive drugs, fostering multisector cooperation in sharing clinical samples and data, and creating public-private partnerships to foster new regulatory policies and public education.

Impaired lung function and lung cancer incidence in a cohort of Swedish construction workers

BACKGROUND

Although impaired lung function in general has been associated with an increased risk of lung cancer, past studies typically have not attempted to investigate separately the obstructive and restrictive components of respiratory impairment. To deal with this question further, data from a large (n = 176 997) cohort of male Swedish construction workers, for whom spirometry measurements before follow-up were available, were analysed.

METHODS

Cancer incidence for 1971-2001 was obtained through linkage with the national cancer registry. Using a modification of the Global Initiative for Chronic Obstructive Lung Disease criteria for chronic obstructive pulmonary disease (COPD), subjects were classified into five categories of lung function: normal, mild COPD, moderate COPD, severe COPD and restrictive lung disease (RLD). Rate ratios (RR) and 95% confidence intervals (CI) for lung cancer across lung function categories were calculated using Poisson regression, adjusted for age and smoking. Other end points (histological types of lung cancer, non-lung tobacco-related cancers, other cancers, total mortality) were also investigated.

RESULTS

834 incident cases of lung cancer were identified. Increased rates of lung cancer were observed for both COPD (mild: RR 1.5, 95% CI 1.2 to 1.9; moderate/severe: RR 2.2, 95% CI 1.8 to 2.7) and RLD (RR 2.0, 95% CI 1.6 to 2.5) relative to normal lung function. These associations did not meaningfully change on applying follow-up lag times of 5, 10 and 15 years after spirometry. When analysed by histological type, associations with both COPD and RLD were stronger for squamous cell carcinoma and small cell carcinoma, and weaker for adenocarcinoma. Both COPD and RLD were associated with increased rates of total mortality.

CONCLUSIONS

Obstructive and restrictive impairments in lung function are associated with increased lung cancer risk.

Accelerated tumor formation in a fatless mouse with type 2 diabetes and inflammation

Epidemiologic studies show a positive association between obesity and cancer risk. In addition to increased body adiposity and secretion of fat-derived hormones, obesity is also linked to insulin resistance, type 2 diabetes, and chronic inflammation. We used the fatless A-ZIP/F-1 transgenic mouse to dissociate the relative role of each of these underlying factors in the development of cancer. These mice are unique in that they do not have white fat but do develop type 2 diabetes. In two cancer models, the classic two-stage skin carcinogenesis protocol and the C3(1)/T-Ag transgenic mouse mammary tumor model, A-ZIP/F-1 mice displayed higher tumor incidence, tumor multiplicity, and decreased tumor latency than wild-type mice. We examined circulating levels of adipokines, growth factors, and cytokines. As expected, adipokines (i.e., leptin, adiponectin, and resistin) were undetectable or found at very low levels in the blood of fatless mice. However, insulin, insulin-like growth factor-I, growth hormone, vascular endothelial growth factor, and proinflammatory Th2 cytokines, such as interleukin (IL)-1beta, IL-4, and IL-6, were elevated in A-ZIP/F-1 mice. Additionally, we examined multiple phosphorylated proteins (i.e., protein kinase B/Akt and ErbB2/HER-2 kinase) associated with cancer development. Results show that many of these phosphorylated proteins were activated specifically in the A-ZIP/F-1 skin but not in the wild-type skin. These findings suggest that adipokines are not required for the promotion of tumor development and thus contradict the epidemiologic data linking obesity to carcinogenesis. We postulate that insulin resistance and inflammation are responsible for the positive correlation with cancer observed in A-ZIP/F-1 mice.

The impact of variation at the KIR gene cluster on human disease

Leukocyte behavior is controlled by a balance of inhibitory and stimulatory signals generated on ligand binding to a complex set of receptors located on the cell surface. The killer cell immunoglobulin-like receptor (KIR) genes encode one such, family of receptors expressed by natural killer (NK) cells, key components of the innate immune system that participate in early responses against infected or transformed cells through production of cytokines and direct cytotoxicity. KIRs are also expressed on a subset of T cells, where they contribute to the intensity of acquired immune responses. Recognition of self HLA class I ligands by inhibitory KIR allows NK cells to identify normal cells, preventing an NK cell-mediated response against healthy autologous cells. Activation of NK cells through stimulatory receptors is directed toward cells with altered expression of class I, a situation characteristic of some virally infected cells and tumor cells. The "missing self" model for NK cell activation was proposed to explain killing of cells that express little or no class I, while cells expressing normal levels of class I are spared. Studies performed over the last several years have revealed extensive diversity at the KIR gene locus, which stems from both its polygenic (variable numbers of genes depending on KIR haplotype) and multiallelic polymorphism. Given the role of KIR in both arms of the immune response, their specificity for HLA class I allotypes, and their extensive genomic diversity, it is reasonable to imagine that KIR gene variation affects resistance and susceptibility to the pathogenesis of numerous diseases. Consequently, the evolution of KIR locus diversity within and across populations may be a function of disease morbidity and mortality. Here we review a growing body of evidence purporting the influence of KIR polymorphism in human disease.

Principles of Cancer Prevention

OBJECTIVE

To summarize the scientific principles underlying cancer prevention.

DATA SOURCES

Articles, text books, personal communications, and experience.

CONCLUSION

The scientific basis of cancer prevention is complex and involves experimental and epidemiologic approaches and clinical trials.

IMPLICATIONS FOR NURSING PRACTICE

As more information becomes available regarding proven and potential cancer-prevention strategies, oncology nurses are regularly called upon to guide patients and others in making choices regarding preventative options. It is important for oncology nurses to stay abreast of this growing body of knowledge.