A population-based case-control study of cancers of the nasal cavity and paranasal sinuses in Shanghai

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Sinonasal intestinal- and non-intestinal-type adenocarcinoma in China: a retrospective study of 14 cases

BACKGROUND

In China, reports on the epidemiology of adenocarcinomas of the nasal cavity and paranasal sinuses are limited.

AIM

This study aimed to describe the experience of a single institution in China in treating these malignant tumours.

MATERIALS AND METHODS

We conducted a retrospective chart review of patients with adenocarcinoma of the nasal cavity and paranasal sinuses admitted between January 2019 and December 2021. Tumour staging was based on the American Joint Committee on Cancer, 8th edition, for sinonasal malignancies.

RESULTS

The series included 10 men and 4 women (mean age, 54.5 [range, 14-80] years). Epistaxis and nasal obstruction were the most common clinical manifestations in 10 (71.4%) patients. Ten (71.4%) had stage T4 disease at diagnosis, but no patient had lymph node or distant metastasis. The posterosuperior septum (100.0%) and middle turbinate (92.8%) were the two sites most vulnerable to tumour invasion. All patients underwent endoscopic resection as the initial treatment; one patient died.

CONCLUSIONS AND SIGNIFICANCE

In China, these malignancies are related to exposure to certain substances; however, diagnosis can be delayed. Endoscopic resection is a suitable treatment option for adenocarcinomas of the nasal cavity and paranasal sinuses.

Exposures to IARC Carcinogenic Agents in Work Settings Not Traditionally Associated with Sinonasal Cancer Risk: The Experience of the Italian National Sinonasal Cancer Registry

The aim of this study is to highlight tasks and jobs not commonly considered at high risk for sinonasal cancer (SNC) identified by Regional Operating Centers currently active in the Italian National Sinonasal Cancer Registry (ReNaTuNS), which retrieve occupational histories through a standardized questionnaire. Data on exposures to IARC carcinogenic agents in work settings unknown to be associated with SNC risk were collected and analyzed. Out of 2,208 SNC cases recorded in the ReNaTuNS database, 216 cases and their worked exposure periods were analyzed. Unsuspected jobs with exposure to wood dust include construction-related tasks, production of resins, agriculture and livestock jobs (straw and sawdust), and heel factory work (cork dust). Other examples are hairdressers, bakers (formaldehyde), dressmakers, technical assistants, wool and artificial fiber spinners, and upholsterers (textile dusts). Moreover, settings with coexposure to different agents (e.g., wood with leather dusts and chromium–nickel compounds) were recognized. The study describes jobs where the existence of carcinogenic agents associated with SNC risk is unexpected or not resulting among primary materials employed. The systematic epidemiological surveillance of all epithelial SNC cases with a detailed collection of their work history, as performed by a dedicated population registry, is essential for detecting all potential occupational cases and should be considered in the context of forensic medicine and the compensation process.

Types of garlic and their anticancer and antioxidant activity: a review of the epidemiologic and experimental evidence

Garlic, an Allium vegetable, contains rich flavonoids organosulfur compounds (OSCs) that have potent anticancer properties. The aim of the review is to provide an overview of the different types of garlic, their active compounds, and the potential anticancer benefits with a focus on antioxidant activity. Animal and cell line studies have provided convincing evidence that garlic and its organosulfur compounds inhibit carcinogenesis through a number of events including induction of apoptosis, inhibiting cellular proliferation, scavenging radical oxygen species (ROS), increasing the activities of enzymes such as glutathione S-transferase, and reducing tumor size. Epidemiological studies showed compelling evidence that garlic consumption is associated with decreased risk of colorectal cancer, but inconsistent evidence for stomach, breast, and prostate cancers. Studies also suggest that the presence and potency of garlic OSCs varies with respect to the preparation and form of garlic. Further epidemiological studies with information on garlic form consumed or preparation methods and molecular studies regarding its antioxidant mechanisms, such as increasing enzymatic and nonenzymatic antioxidants levels, are warranted.

Sinonasal Squamous Cell Carcinoma: Etiology, Pathogenesis, and the Role of Human Papilloma Virus

PURPOSE OF REVIEW

Sinonasal squamous cell carcinoma (SNSCC) is a rare disease with considerable histologic diversity. Currently, there is a poor understanding of the etiology and pathogenesis of SNSCC. Here, we review recent literature to summarize what is known regarding (1) the etiology of SNSCC, (2) the role of Human Papilloma Virus (HPV) in SNSCC, and (2) the molecular underpinnings of SNSCC.

RECENT FINDINGS

1. High risk HPVappears to play a role in the pathogenesis of a subset of SNSCCs. SNSCCs with high risk HPV have improved survival compared with those without HPV and occur in patients who are younger, similar to HPV mediated oropharyngeal cancer. 2. A subset of inverted papillomas have transcriptionally active low-risk HPV and have a higher risk of transformation, while low risk HPV negative inverted papillomas frequently have EGFR mutations.

SUMMARY

SNSCC is a diverse disease with likely multiple etiologies including carcinogen, irritant exposure, and HPV. While not definitively proven, evidence supports a role for high-risk HPV in a subset of SNSCC, and low-risk HPV in a subset of inverted papillomas which transform to SNSCC. In-depth molecular and genomic studies are needed in SNSCC to better understand the genomic underpinnings and oncogenic drivers.

Nasal polyps and future risk of head and neck cancer: A nationwide population-based cohort study

BACKGROUND

Nasal polyps are a common condition with a significant effect on quality of life. The association between nasal polyps and future risk of head and neck cancer is unknown.

OBJECTIVE

We sought to investigate the relative risk of nasal cavity and paranasal sinus (NCPS) and nasopharyngeal cancers in a nationwide, population-based, longitudinal retrospective cohort of patients with nasal polyps and matched comparators.

METHODS

The 2005-2017 National Health Insurance claims and National Health Screening program databases were used to construct a cohort of patients with nasal polyps and matched comparators in Korea. The relative risk of NCPS and nasopharyngeal cancer in patients with nasal polyps was examined.

RESULTS

The study consisted of 453,892 patients with nasal polyps and 4,583,938 matched comparators. The mean duration of follow-up was 6.2 years (range, 2-13 years). The incidence rate ratios of patients with nasal polyps compared with the comparators was 7.00 (95% CI, 5.28-9.25) for NCPS cancer and 1.78 (95% CI, 1.28-2.42) for nasopharyngeal cancer. Increased risks of these cancers were only evident in older subjects (age ≥50 years). There were trends toward weaker associations of nasal polyps with these cancers in younger subjects with comorbid asthma or allergic rhinitis (<50 years).

CONCLUSION

Although the absolute cancer incidence is very low, the relative risk of NCPS or nasopharyngeal cancers was significantly greater in older patients with nasal polyps. Given the regional and pathologic heterogeneity of nasal polyps, further studies are needed to explore the underlying mechanisms and validate the relationships.

Relation of allium vegetables intake with head and neck cancers: evidence from the INHANCE consortium

SCOPE

Only a few studies analyzed the role of allium vegetables with reference to head and neck cancers (HNC), with mixed results. We investigated the potential favorable role of garlic and onion within the International Head and Neck Cancer Epidemiology (INHANCE) Consortium.

METHODS AND RESULTS

We analyzed pooled individual-level data from eight case-control studies, including 4590 cases and 7082 controls. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between garlic and onion intakes and HNC risk. Compared with no or low garlic use, the ORs of HNC were 0.95 (95% CI 0.71-1.27) for intermediate and 0.74 (95% CI 0.55-0.99) for high garlic use (p for trend = 0.02). The ORs of HNC for increasing categories of onion intake were 0.91 (95% CI 0.68-1.21) for >1 to ≤3 portions per week, and 0.83 (95% CI 0.60-1.13) for >3 portions per week (p for trend = 0.02), as compared to <1 portion per week. We found an inverse association between high onion intake and laryngeal cancer risk (OR = 0.69; 95% CI 0.54-0.88), but no significant association for other subsites.

CONCLUSION

The results of this pooled-analysis support a possible moderate inverse association between garlic and onion intake and HNC risk.

Nasal cytotoxic and carcinogenic activities of systemically distributed organic chemicals

Toxicity and carcinogenicity in the mucosa of the nasal passages in rodents has been produced by a variety of organic chemicals which are systemically distributed. In this review, 14 such chemicals or classes were identified that produced rodent nasal cytotoxicity, but not carcinogenicity, and 11 were identified that produced nasal carcinogenicity. Most chemicals that affect the nasal mucosa were either concentrated in that tissue or readily activated there, or both. All chemicals with effects in the nasal mucosa that were DNA-reactive, were also carcinogenic, if adequately tested. None of the rodent nasal cytotoxins has been identified as a human systemic nasal toxin. This may reflect the lesser biotransformation activity of human nasal mucosa compared to rodent and the much lower levels of human exposures. None of the rodent carcinogens lacking DNA reactivity has been identified as a nasal carcinogen or other cancer hazard to humans. Some DNA-reactive rodent carcinogens that affect the nasal mucosa, as well as other tissues, have been associated with cancer at various sites in humans, but not the nasal cavity. Thus, findings in only the rodent nasal mucosa do not necessarily predict either a toxic or carcinogenic hazard to that tissue in humans.

The Shanghai Women's Health Study: rationale, study design, and baseline characteristics

Although cancer is a major cause of morbidity and mortality in most nations, the spectrum of cancer occurrence varies substantially worldwide. Most previous epidemiologic studies investigating cancer etiology were conducted in North American and western European countries that are relatively homogenous in terms of cancer spectrums and many lifestyle exposures. These limitations may have hindered these studies from evaluating some important etiologic hypotheses. From 1996 to 2000, the Shanghai Women's Health Study recruited 74,942 adult Chinese women from selected urban communities, with a 92% response rate. All participants completed a detailed baseline survey and anthropometrics. Approximately 88% of cohort members donated a urine sample (n = 65,755) and a blood (n = 56,832) or exfoliated buccal cell (n = 8,934) sample. Noteworthy characteristics of this cohort include low consumption of alcohol (1.9%) and use of tobacco (2.4%); high intake of fish (mean, 50.8 g/day), soy foods (mean, 142.3 g/day), and certain vegetables; low prevalence of obesity (5.1%); and nearly 100% employment outside the home. Currently, this cohort of women is being followed via biennial in-person recontact and periodic linkage to cancer and vital statistics registries. The resources from the cohort will be valuable in future studies of environmental exposures and biomarkers for the risk of cancer and other chronic diseases.

After the Smoke Clears

Both environmental and occupational exposures are associated with the development of carcinomas of the upper aerodigestive tract, although most squamous cell carcinomas of the upper aerodigestive tract are related to smoking and drinking. This review discusses environmental and occupational risk factors, other than tobacco and alcohol, for carcinoma of the upper aerodigestive tract and the difficulties encountered when attempts are made to study these environmental and occupational exposures. However, this is not an all-inclusive review; rather, it is designed to give the reader an understanding of the topic, to allow for appropriate counseling of patients, and perhaps to advance public health initiatives.

The role of folates in squamous cell carcinoma of the head and neck

The primary objective of this review is to explore the hypothesis that folate insufficiency may be important in the pathogenesis of squamous cell carcinomas of the head and neck (SCCHN) and that folate repletion may be an effective component of chemoprevention. The main results are that folate insufficiency disrupts DNA global and specific gene methylation patterns such that the activity of certain tumor suppressor genes such as p16 and possibly p53 may be lost. Folate pool imbalance and impaired repair mechanisms may contribute to DNA instability and strand breaks. Sensitive methods exist for identification of individuals with folate insufficiency in contrast to the relatively insensitive conventional serum or red cell folate assays with broad "normal" ranges. The impact of folate supplementation can thus be quantified. Folate imbalance may result from alterations in folate cellular uptake by the reduced folate carrier (RFC) and/or the folate receptor (FR) and polymorphisms in enzymes important in folate retention such as folylpolyglutamate synthetase and in folate modification such as methylene tetrahydrofolate reductase (MTHFR). Known predisposing factors for SCCHN such as alcohol and tobacco carcinogens may influence folate balance. Folate supplementation may reduce primary or secondary risk of cancer. Formal studies of folate sufficiency in persons at risk for or diagnosed and treated for SCCHN are needed to define the role of folate supplementation in the prevention of these cancers.

Overview of smoking and all cancers

Tobacco consumption has been clearly implicated in the causation of many cancer types, with irrefutable evidence to support the association in multiple organ systems. Tobacco cessation leads to reduced cancer risk and improved survival of those under treatment for their already established cancers. As understanding of the mechanisms by which tobacco products cause cancer increases, clinicians may be able to identify those at highest risk for tobacco-related malignancies and allow for more focused interventions toward risk reduction among current tobacco users. This article reviews the carcinogens present in tobacco products, the mechanisms by which tobacco causes cancer, and the various tumor types causally related to tobacco use.

Decreasing incidence of malignant tumors of the paranasal sinuses in Sweden. An analysis of 141 consecutive cases at Karolinska Hospital from 1960 to 1980

We reviewed 141 cases of paranasal sinus tumors treated at Karolinska Hospital from 1960 to 1980. Of these tumors, 100 were located in the maxillary sinus, 32 in the ethmoidal sinuses, 8 in both the ethmoidal and maxillary regions, and 1 in the sphenoidal sinus. The male-to-female ratio was 2.1 to 1. Squamous cell carcinoma and adenocarcinoma were the most frequent types of tumors (55% and 13%, respectively). Treatment included surgery, irradiation, or both. The 5-year survival rate was 34% for squamous cell carcinomas and 64% for adenocarcinomas. When compared to a previous material of patients treated at the same hospital from 1940 to 1950, the proportion of poorly differentiated squamous cell carcinomas had increased significantly. The age-adjusted incidence rate decreased from 1.2 to 0.4 for male patients and from 0.7 to 0.3 for female patients between 1960 and 1980. We conclude that the incidence of malignant paranasal sinus tumors has decreased, and that squamous cell tumors now seem to be generally less differentiated than they were 50 years ago.

Smoking-induced squamous-cell cancer of the nose

Squamous-cell cancer (SCC) isolated to the anterior nose is uncommon. Numerous industrial and environmental contaminants have been implicated as causative factors in nasal carcinoma. The association between nasal cancer and smoking was recognized in the 1980s, but results have not been consistent and no possible mechanisms have been suggested. The case histories of 11 patients with SCC limited to the anterior nasal cavity were reviewed. The authors found no relationship with exposures to chemicals previously implicated in nasal cancer. Nine patients with SCC were exposed to cigarette smoke (mean = 103 pack-years). Cigarette smoke may induce cancer directly, thus affecting the mucosa, or by inducing genetic alterations. The authors favor the former mechanism.

Tobacco use and cancer causation: association by tumour type

In the second part of our review we describe the association between tobacco use and risk of specific cancer types. There is evidence for an established association of tobacco use with cancer of the lung and larynx, head and neck, bladder, oesophagus, pancreas, stomach and kidney. In contrast, endometrial cancer is less common in women who smoke cigarettes. There are some data suggesting that tobacco use increases the risk for myeloid leukaemia, squamous cell sinonasal cancer, liver cancer, cervical cancer, colorectal cancer after an extended latency, childhood cancers and cancer of the gall bladder, adrenal gland and small intestine. Other forms of cancer, including breast, ovarian and prostate cancer, are unlikely to be linked to tobacco use.

Case-control study evaluating the homogeneity and heterogeneity of risk factors between sinonasal and nasopharyngeal cancers

Sinonasal cancer and nasopharyngeal cancer may share some risk factors because both are located within the upper aerodigestive tract. They may also have different etiological profiles because of anatomic or pathologic differences. However, the similarities and differences in risk factors have rarely been studied within the same population. We assessed the risk factor profiles of sinonasal and nasopharyngeal cancers, using data from a case-control study. The 2 case groups consisted of men aged 31-59 and diagnosed pathologically with sinonasal cancer (n=70) and nasopharyngeal cancer (n=113), respectively. Controls were men without these cancers and selected from the same areas (n=1910). Logistic regression analysis showed that smoking was a risk factor for both sinonasal [odds ratio (OR)=2.5, 95% confidence interval (CI) 1.1-5.4] and nasopharyngeal cancer (OR=1.8, 95%CI 1.1-3.0). However, ever use of barbiturates without a prescription (OR=4.9, 95%CI 1.7-13.8), working with or around cutting oils on a job (OR=1.9, 95%CI 1.1-3.1) and ever having had sinus infections (OR=2.3, 95%CI 1.1-4.6) were associated with nasopharyngeal cancer only. Having received blood products other than a transfusion (OR=9.1, 95%CI 2.2-37.4) and exposure to a pesticide containing 2,4,5-T (OR=5.9, 95%CI 1.5-23.7) were related to sinonasal cancer only. When data analyses were confined to squamous cell type, smoking and exposure to chlorophenols were related to squamous cell tumors at both sites. However, use of barbiturates and sinus problems other than infection only increased the risk of nasopharyngeal carcinoma. Our study suggests that except for smoking and chlorophenol exposure, which are associated with both sites, the risk factor profiles may differ between sinonasal and nasopharyngeal cancers.

Study of ethmoidal mucosa in a population at occupational high risk of sinonasal adenocarcinoma

The occurrence of nasal adenocarcinomas was first described in 1965. Since 1988 these tumors have been accepted as an occupational disease for woodworkers in Italy. There are several underlying reasons why there is interest in studying the ways in which sinonasal adenocarcinomas occur. Often diagnosed at advanced stages of development because their symptoms are non-specific, these tumors are associated with a high mortality rate. A multidisciplinary study protocol was developed in this investigation. The aim was to identify the factors and conditions that promote sinonasal tumor growth in a population at risk due to occupational exposure to wood dust. Sixty-eight carpenters with a minimum of 10 years exposure to wood dust were studied. The control group comprised 81 volunteers. The patients underwent the following protocol: completion of a case report form, physical examination, evaluation of nasal cavity patency, clinical laboratory tests and histological study of the nasal mucosa. Our study provides significant evidence of the elevated incidence of pavimentous metaplasia in workers occupationally exposed to wood dust. In addition, it underscores a significant deficit of immunoglobulin A in such workers compared to the controls. However, we did not find, as reported elsewhere in the literature, a statistically significant difference between cases and controls as regards nasal symptoms and hyperemia of the nasal mucosa. Our study showed that, even in the absence of evident sinonasal lesions, it is still possible to determine an increased incidence of morphofunctional changes in subjects occupationally exposed to wood dust. Our findings may lead to the identification of occupational groups prone to elevated risk of the disease.

Potential pulmonary effects of man-made organic fiber (MMOF) dusts

In the first half of the twentieth century epidemiologic evidence linked elevated incidences of pulmonary fibrosis and cancer with inhalation of chrysotile and crocidolite asbestos, a family of naturally occurring inorganic fibrous materials. As the serpentine and amphibole forms of asbestos were phased out, synthetic vitreous fibers (SVFs; fiber glass, mineral wool, and refractory fiber) became increasingly utilized, and concerns were raised that they too might cause adverse health effects. Extensive toxicological research on SVFs has demonstrated that their pulmonary effects are directly related to fiber dose in the lung over time. This is the result of deposition (thin fibers deposit in the lower lung more efficiently than thick fibers) and lung-persistence ("biopersistence" is directly related to fiber length and inversely related to dissolution and fragmentation rates). In rat inhalation studies, asbestos was determined to be 7- to 10-fold more biopersistent in the lung than SVFs. Other than its effect on biopersistence, fiber composition did not appear to play a direct role in the biological activity of SVFs. Recently, the utilization of man-made organic fibers (MMOFs) (also referred to by some as synthetic organic fibers) has increased rapidly for a variety of applications. In contrast to SVFs, research on the potential pulmonary effects of MMOFs is relatively limited, because traditionally MMOFs were manufactured in diameters too thick to be respirable (inhalable into the lower lung). However, new developments in the MMOF industry have resulted in the production of increasingly fine-diameter fibers for special applications, and certain post-manufacturing processes (e.g., chopping) generate respirable-sized MMOF dust. Until the mid-1990s, there was no consistent evidence of human health affects attributed to occupational exposure to MMOFs. Very recently, however, a unique form of interstitial lung disease has been reported in nylon flock workers in three different plants, and respirable-sized nylon shreds (including fibers) were identified in workplace air samples. Whether nylon dust or other occupational exposures are responsible for the development of lung disease in these workers remains to be determined. It is also unknown whether the biological mechanisms that determine the respirability and toxicity of SVFs apply to MMOFs. Thus, it is appropriate and timely to review the current data regarding MMOF workplace exposure and pulmonary health effects, including the database on epidemiological, exposure assessment, and toxicology studies.

Organosulfur compounds from Allium and the chemoprevention of cancer

Allium vegetables and their associated organosulfur constituents are extensively studied for their chemopreventive potential against cancer. This article overviews their anticarcinogenic and antigenotoxic properties. Epidemiological studies (mostly case-control studies) provide strong evidence that Allium vegetable consumption reduces the incidence of gastric and colon cancer while the association between Allium vegetable consumption and other cancers is less convincing. Furthermore, many experimental studies have demonstrated that organosulfur compounds and Allium extracts have inhibitory effects on carcinogenesis in animals. These inhibitory effects are supported by many diverse mechanisms, including inhibition of carcinogen formation, modulation of carcinogen metabolism, inhibition of mutagenesis and genotoxicity, inhibition of cell proliferation and increase of apoptosis, inhibition of angiogenesis, and immune system enhancement. Before such constituents or extracts can be used in chemopreventive trials, it is important to verify their lack of toxicity and to investigate further their precise mechanisms of action throughout the whole process of carcinogenesis.

Garlic and cancer: a critical review of the epidemiologic literature

Animal and in vitro studies provide evidence of an anticarcinogenic effect of active ingredients in garlic. This review of the epidemiologic literature on garlic consumption addresses cancers of the stomach, colon, head and neck, lung, breast and prostate. Nineteen studies reported relative risk estimates for garlic consumption and cancer incidence. Site-specific case-control studies of stomach and colorectal cancer, in which multiple reports were available, suggest a protective effect of high intake of raw and/or cooked garlic. Cohort studies confirm this inverse association for colorectal cancer. Few cohort and case-control studies for other sites of cancer exist. Garlic supplements, as analyzed in four cohort studies and one case-control report, from two distinct populations, do not appear to be related to risk. Low study power, lack of variability in garlic consumption categorization within studies and poor adjustment for potential cofounders may limit the reliability of any conclusions regarding garlic supplements. However, an indication of publication bias was also found by visual inspection of a funnel plot and in a log-rank test (P = 0.004). Evidence from available studies nevertheless suggests a preventive effect of garlic consumption in stomach and colorectal cancers. The study limitations indicate the need for more definitive research and improved nutritional epidemiologic analyses of dietary data.

Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers

BACKGROUND

Animal and in vitro studies have provided evidence of an anticarcinogenic effect of active ingredients in garlic.

OBJECTIVE

The objective was to conduct meta-analyses of the epidemiologic literature on the association between garlic consumption and risk of stomach, colon, head and neck, lung, breast, and prostate cancers.

DESIGN

Meta-analyses were conducted for all cancers mutually and separately for colorectal and stomach cancers in relation to consumption of exclusively raw garlic, cooked garlic, or both (RC garlic). Eighteen studies reported a relative risk estimate for RC garlic consumption and cancer risk.

RESULTS

In the meta-analyses of colorectal and stomach cancer, the reference categories ranged from no consumption to consumption of 3.5 g/wk, whereas the highest categories ranged from any consumption to >28.8 g/wk. The average difference between the highest and lowest categories was 16 g/wk. The random-effects relative risk (RR) estimate of colorectal cancer and RC garlic consumption, excluding garlic supplements, was 0.69 (95% CI: 0.55, 0.89). For stomach cancer, the random-effects RR estimate was 0.53 (95% CI: 0.31, 0.92). The heterogeneity among studies for the latter outcome (P: = 0.0002) indicates the questionableness of the generalizability of this summary estimate. An indication of publication bias for all cancers combined is evident from a funnel plot of RC garlic consumption and cancer risk and from the results of the Begg and Mazumdar test (P: = 0.049).

CONCLUSIONS

High intake of RC garlic may be associated with a protective effect against stomach and colorectal cancers. Heterogeneity of effect estimates, differences in dose estimation, publication bias, and possible alternative hypotheses (eg, confounding by total vegetable consumption) preclude sole reliance on summary effect estimates.

Preventable risk factors for nasal cancer

PURPOSE

To determine preventable risk factors for cancers of the nasal cavity and paranasal sinuses in the United States, we analyzed data from the population-based, case-control Selected Cancers Study.

METHODS

Cases were men born between 1929 and 1953 who were diagnosed with primary nasal cancer between 1984 and 1988 and identified from population-based cancer registries; we narrowed the cohort to 70 subjects whose diagnosis of nasal cancer was confirmed by pathology review. All living controls interviewed for the Selected Cancers Study were included as the comparison group (n = 1910); they were recruited by random-digit dial telephone and were frequency-matched to the lymphoma cases of the Selected Cancers Study by geographic area and age. Both cases and controls were interviewed by telephone.

RESULTS

Logistic regression analyses showed that cases were 2.5 times more likely than controls to have smoked cigarettes [95% confidence interval (CI) = 1.1-5.3], and 2.2 times more likely to have worked in selected occupations, including lawn care, forestry, and maintenance of highway right-of-way areas (CI = 1.2-3.7). These occupations may cause workers to be exposed to pesticides or herbicides. The population attributable risk (PAR) was 53% for having ever smoked cigarettes.

CONCLUSIONS

The study results suggest that among U.S. men, some nasal cancer may be preventable by avoiding cigarette smoking.

The impact of cigarette smoking and environmental tobacco smoke on nasal and sinus disease: a review of the literature

Tobacco smoking and exposure to environmental tobacco smoke (ETS) have both been implicated in a number of acute and chronic medical problems including heart and lung disease and several cancers. The impact of tobacco smoke on disorders of the nose and paranasal sinuses is less well understood, although there is growing evidence that such exposure can have a significant impact on nasal and sinus function. A comprehensive review of the literature reveals that tobacco smoking is associated with acute and chronic rhinitis, but may actually be negatively correlated with the development of allergic rhinitis. In those patients with allergies, nasal and sinus symptoms may be exacerbated by tobacco smoking. ETS exposure is associated with acute and chronic nasal symptoms in adults and children, snoring in children and teenagers, and may be associated with an earlier onset and more significant symptoms for individuals with a predisposition to developing allergies. Both primary and environmental tobacco smoke are related to increases in nasal and sinus cancer. Tobacco smoking and ETS are associated with significant nasal and sinus disease and cancer.

Diet and nasopharyngeal cancer in a low-risk population

Asian studies have reported that risk of nasopharyngeal cancer (NPC) is increased in individuals who frequently consume salted fish, which contains high levels of N-nitroso compounds. As part of a collaborative, population-based, case-control study in the U.S., where the annual incidence of the disease is low, we investigated whether dietary intake of preformed nitrosamines or nitrosamine precursors, or of antioxidants including vitamin C and carotenoids, was associated with altered risk of NPC overall, or of specific histologic subtypes of disease. Cases (n = 133) identified at 5 population-based cancer registries and controls (n = 212) identified through random digit dialing completed a telephone interview and self-administered food frequency questionnaire. Dietary exposures were expressed as quartiles of intake, and odds ratios (ORs) calculated using the lowest quartile of intake as the reference category. Risk of non-keratinizing and undifferentiated tumors of the nasopharynx was increased in frequent consumers of preserved meats, which contain high levels of added nitrites. ORs in the 2nd, 3rd and highest quartile were 1.99, 4.35 and 4.59, although 95% confidence intervals did not exclude 1.0. Risk of differentiated squamous cell carcinoma, but not other histologic types, was significantly reduced in individuals with vitamin C intake above the lowest quartile (ORs 0.30, 0.33 and 0.30 in the 2nd, 3rd and highest quartiles, respectively). This association was markedly stronger among non-smokers and former smokers than among current smokers. Finally, individuals who reported consuming supplemental vitamins were at an approximately 50% reduced risk of NPC. Our results indicate that future studies should consider the effects of dietary risk factors on the risk of specific histologic subsets of NPC, and not assume that the disease is etiologically homogeneous.

Tobacco, alcohol, diet and risk of non-Hodgkin's lymphoma: a case-control study in Uruguay

To test whether high meat intake is associated with the development of non-Hodgkin lymphoma (NHL) in the Uruguayan population, a case-control study was performed at the Instituto Nacional de Oncologia, Montevideo, Uruguay. After controlling for age, sex, residence, education, urban/rural status and the habit of drinking the beverage 'mate', red meat intake was associated with an increased risk of NHL of 2.5. This finding was similar in both sexes separately. Odds ratios (OR) for the highest tertile of barbecued meat was 1.7 among men, whereas salted meat was associated with an increased risk of NHL (OR 4.9, 95% CI 1.4-17.7). The effect of processed and salted meat among women was of much less magnitude and the OR's were non-significant. Also, cumulative exposure to 'mate' drinking displayed an OR of 2.4 (95% CI 1.0-5.6). Smokers of black tobacco and hand-rolled cigarettes were associated with an increased risk of 3.5 (95% 1.1-10.9), whereas beer drinkers showed an increased OR of 5.5 (95% 1.1-26.7) in men. It could be concluded that red or salted meat intake, smoking of black tobacco, and beer and 'mate' drinking are risk factors for NHL in the Uruguayan population.

Cancer, cigarette smoking and premature death in Europe: a review including the Recommendations of European Cancer Experts Consensus Meeting, Helsinki, October 1996

Cigarette smoking has been clearly and unambiguously identified as a direct cause of cancers of the oral cavity, oesophagus, stomach, pancreas, larynx, lung, bladder, kidney and leukaemia, especially acute myeloid leukaemia. Additionally, cigarette smoking is a direct cause of ischaemic heart disease (the commonest cause of death in western countries), respiratory heart disease, aortic aneurysm, chronic obstructive lung disease, stroke, pneumonia and cirrhosis and cancer of the liver. Cigarette smoking can kill in 24 different ways and, although smoking protects against several fatal and non-fatal conditions, the adverse effect of smoking on health is largely negative. In developed countries as a whole, tobacco is responsible for 24% of all male deaths and 7% of all female deaths: these figures rise to over 40% in men in some countries of central and eastern Europe and to 17% in women in the United States. The average loss of life of smokers is 8 years. Among United Kingdom doctors followed for 40 years, overall death rates in middle age were about three times higher among doctors who smoked cigarettes as among doctors who had never smoked regularly. About half of all regular cigarette smokers will eventually be killed by their habit. The important information is that it is never too late to stop smoking: among United Kingdom doctors who stopped smoking, even in middle age, there was a substantial improvement in life expectancy. World-wide, smoking is killing three million people each year and this figure is increasing. In most countries the worst is yet to come, since by the time the young smokers of today reach middle or old age there will be about 10 million deaths/year from tobacco. Approximately 500 million individuals alive today can expect to be killed by tobacco, 250 million of these deaths will occur in middle age. Tobacco is already the biggest cause of adult death in developed countries. Over the next few decades tobacco could well become the biggest cause of adult death in the world. For men in developed countries, the full effects of smoking can already be seen. Tobacco now causes one-third of all male deaths in middle age (plus one fifth in old age). Tobacco is a cause of about half of all male cancer deaths in middle age (plus one-third in old age). Of those who start smoking in their teenage years and keep on smoking, about half will be killed by tobacco. Half of these deaths will be in middle age (35-69) and each will lose an average of 20-25 years of non-smoker life expectancy. In non-smokers in many countries, cancer mortality is decreasing slowly and total mortality rapidly. The war against cancer is being won slowly: the effects of cigarette smoking are holding back this victory. Lung cancer now kills more women in the United States each year than breast cancer. For women in developed countries, the peak of the tobacco epidemic has not yet arrived. Tobacco now causes almost one-third of all deaths in women in middle age in the United States. Although it has only 5% of the world's female population, the United States has 50% of the world's deaths from smoking in women. Tobacco smoking is a major cause of premature death. Throughout Europe, in 1990 tobacco smoking caused three quarters of a million deaths in middle age (between 35 and 69). In the Member States of the European Union in 1990 there were over one quarter of a million deaths in middle age directly caused by tobacco smoking: there were 219700 in men and 31900 in women. There were many more deaths caused by tobacco at older ages. In countries of central and eastern Europe, including the former USSR, there were 441200 deaths in middle age in men and 42100 deaths in women. There is a need for urgent action to help contain this important and unnecessary loss of life. In formulating Recommendations, the European Cancer Experts Consensus Committee recognised that Tobacco Control depends on various parts of society and not only on the individual.

Vegetables, fruit, and cancer prevention: a review

In this review of the scientific literature on the relationship between vegetable and fruit consumption and risk of cancer, results from 206 human epidemiologic studies and 22 animal studies are summarized. The evidence for a protective effect of greater vegetable and fruit consumption is consistent for cancers of the stomach, esophagus, lung, oral cavity and pharynx, endometrium, pancreas, and colon. The types of vegetables or fruit that most often appear to be protective against cancer are raw vegetables, followed by allium vegetables, carrots, green vegetables, cruciferous vegetables, and tomatoes. Substances present in vegetables and fruit that may help protect against cancer, and their mechanisms, are also briefly reviewed; these include dithiolthiones, isothiocyanates, indole-3-carbinol, allium compounds, isoflavones, protease inhibitors, saponins, phytosterols, inositol hexaphosphate, vitamin C, D-limonene, lutein, folic acid, beta carotene, lycopene, selenium, vitamin E, flavonoids, and dietary fiber. Current US vegetable and fruit intake, which averages about 3.4 servings per day, is discussed, as are possible noncancer-related effects of increased vegetable and fruit consumption, including benefits against cardiovascular disease, diabetes, stroke, obesity, diverticulosis, and cataracts. Suggestions for dietitians to use in counseling persons toward increasing vegetable and fruit intake are presented.

Wood dust and sino-nasal cancer: pooled reanalysis of twelve case-control studies

In order to examine the relationship between wood dust and sino-nasal cancer, data from 12 case-control studies conducted in seven countries were pooled and reanalyzed. The relative risks associated with wood-related jobs and with exposure to wood dust, measured using a job exposure matrix based on occupation and industry titles, were examined using logistic regression. The combined data set consisted of 680 male cases, 2,349 male controls, 250 female cases, and 787 female controls. A high risk of adenocarcinoma among men was associated with employment in wood-related occupations (odds ratio [OR] = 13.5, 95% confidence interval [CI] = 9.0-20.0) and the risk was greatest among men who had been employed in jobs with the highest wood dust exposure (OR = 45.5, 95% CI = 28.3-72.9) and increased with duration of exposure. The risk of adenocarcinoma also appeared elevated among women employed in wood-related jobs (OR = 2.5, 95% CI = 0.5-12.3), but the small number of exposed cases precluded detailed analysis. Women in wood dust-exposed jobs appeared to have an excess of squamous cell carcinoma (OR = 2.1, 95% CI = 0.8-5.5) which increased with duration of exposure. An increased risk of squamous cell carcinoma in men was seen only among those employed for 30 or more years in jobs with exposure to fresh wood (OR = 2.4, 95% CI = 1.1-5.0). The results of this analysis provide strong support to the association between exposure to wood dust in a variety of occupations and the risk of sino-nasal adenocarcinoma and are consistent with the results of individual participating studies, although the magnitude of the excess risk varied. The evidence in regard to squamous cell carcinomas was ambiguous and there was a great deal of heterogeneity observed in individual study results. This may be due to differences in risk associated with exposure to hardwoods and softwoods or with other, as yet to be identified, aspects of exposure.

Salted meat consumption and the risk of laryngeal cancer

A hospital-based, case-control study of laryngeal cancer was conducted in the Oncology Institute, Montevideo, Uruguay, during 1988-1992, in which 143 new cases and 460 controls were interviewed. The study was restricted to males. As in most previous studies tobacco smoking and alcohol drinking were the major risk factors. Past and current salted meat consumption was associated with increased risks of laryngeal cancer, after controlling for the effects of tobacco and alcohol. Cigarette smoking and consumption of salted meat appeared to increase the risk of laryngeal cancer in a multiplicative fashion. Fresh meat consumption (beef) was also associated with an increased risk of laryngeal cancer (OR 2.0). After controlling for fresh meat ingestion, the estimates for salted meat remained significant.