Geographic variation of mutagenic exposures in kidney cancer genomes

International differences in the incidence of many cancer types indicate the existence of carcinogen exposures that have not yet been identified by conventional epidemiology make a substantial contribution to cancer burden1. In clear cell renal cell carcinoma, obesity, hypertension and tobacco smoking are risk factors, but they do not explain the geographical variation in its incidence2. Underlying causes can be inferred by sequencing the genomes of cancers from populations with different incidence rates and detecting differences in patterns of somatic mutations. Here we sequenced 962 clear cell renal cell carcinomas from 11 countries with varying incidence. The somatic mutation profiles differed between countries. In Romania, Serbia and Thailand, mutational signatures characteristic of aristolochic acid compounds were present in most cases and but these were rare elsewhere. In Japan, a mutational signature of unknown cause was found in more than 70% of cases but in less than 2% elsewhere. A further mutational signature of unknown cause was ubiquitous but exhibited higher mutation loads in countries with higher incidence rates of kidney cancer. Known signatures of tobacco smoking correlated with tobacco consumption, but no signature was associated with obesity or hypertension, suggesting that non-mutagenic mechanisms of action underlie these risk factors. The results of this study indicate the existence of multiple, geographically variable, mutagenic exposures that potentially affect tens of millions of people and illustrate the opportunities for new insights into cancer causation through large-scale global cancer genomics.

Smoking Cessation After Diagnosis of Kidney Cancer Is Associated With Reduced Risk of Mortality and Cancer Progression: A Prospective Cohort Study

PURPOSE

To investigate whether postdiagnosis smoking cessation may affect the risk of death and disease progression in patients with renal cell carcinoma (RCC) who smoked at the time of diagnosis.

METHODS

Two hundred twelve patients with primary RCC were recruited between 2007 and 2016 from the Urological Department in N.N. Blokhin National Medical Research Center of Oncology, Moscow, Russia. Upon enrollment, a structured questionnaire was completed, and the patients were followed annually through 2020 to repeatedly assess their smoking status and disease progression. Survival probabilities and hazards for all-cause and cancer-specific mortality and disease progression were investigated using extended the Kaplan-Meier method, time-dependent Cox proportional hazards regression, and Fine-Gray competing-risk models.

RESULTS

Patients were followed for a median of 8.2 years. During this time, 110 cases of disease progression, 100 total deaths, and 77 cancer-specific deaths were recorded. Eighty-four patients (40%) quit smoking after diagnosis. The total person-years at risk for this analysis were 748.2 for continuing smoking and 611.2 for quitting smoking periods. At 5 years of follow-up, both overall survival (85% v 61%) and progression-free survival (80% v 57%) rates were higher during the quitting than continuing smoking periods (both P < .001). In the multivariable time-dependent models, quitting smoking was associated with lower risk of all-cause mortality (hazard ratio [HR], 0.51; 95% CI, 0.31 to 0.85), disease progression (HR, 0.45; 95% CI, 0.29 to 0.71), and cancer-specific mortality (HR, 0.54; 95% CI, 0.31 to 0.93). The beneficial effect of quitting smoking was evident across all subgroups, including light smokers versus moderate-heavy smokers and those with early-stage versus late-stage tumors.

CONCLUSION

Quitting smoking after RCC diagnosis may significantly improve survival and reduce the risk of disease progression and cancer mortality among patients who smoke.

Risk factors for head and neck cancer in more and less developed countries: Analysis from the INHANCE consortium

OBJECTIVE

We analyzed the pooled case-control data from the International Head and Neck Cancer Epidemiology (INHANCE) consortium to compare cigarette smoking and alcohol consumption risk factors for head and neck cancer between less developed and more developed countries.

SUBJECTS AND METHODS

The location of each study was categorized as either a less developed or more developed country. We compared the risk of overall head and neck cancer and cancer of specific anatomic subsites associated with cigarette smoking and alcohol consumption. Additionally, age and sex distribution between categories was compared.

RESULTS

The odds ratios for head and neck cancer sites associated with smoking duration differed between less developed and more developed countries. Smoking greater than 20 years conferred a higher risk for oral cavity and laryngeal cancer in more developed countries, whereas the risk was greater for oropharynx and hypopharynx cancer in less developed countries. Alcohol consumed for more than 20 years conferred a higher risk for oropharynx, hypopharynx, and larynx cancer in less developed countries. The proportion of cases that were young (<45 years) or female differed by country type for some HNC subsites.

CONCLUSION

These findings suggest the degree of industrialization and economic development affects the relationship between smoking and alcohol with head and neck cancer.

Application of Genomic Sequencing to Refine Patient Stratification for Adjuvant Therapy in Renal Cell Carcinoma

PURPOSE

Patients with resected localized clear-cell renal cell carcinoma (ccRCC) remain at variable risk of recurrence. Incorporation of biomarkers may refine risk prediction and inform adjuvant treatment decisions. We explored the role of tumor genomics in this setting, leveraging the largest cohort to date of localized ccRCC tissues subjected to targeted gene sequencing.

EXPERIMENTAL DESIGN

The somatic mutation status of 12 genes was determined in 943 ccRCC cases from a multinational cohort of patients, and associations to outcomes were examined in a Discovery (n = 469) and Validation (n = 474) framework.

RESULTS

Tumors containing a von-Hippel Lindau (VHL) mutation alone were associated with significantly improved outcomes in comparison with tumors containing a VHL plus additional mutations. Within the Discovery cohort, those with VHL+0, VHL+1, VHL+2, and VHL+≥3 tumors had disease-free survival (DFS) rates of 90.8%, 80.1%, 68.2%, and 50.7% respectively, at 5 years. This trend was replicated in the Validation cohort. Notably, these genomically defined groups were independent of tumor mutational burden. Amongst patients eligible for adjuvant therapy, those with a VHL+0 tumor (29%) had a 5-year DFS rate of 79.3% and could, therefore, potentially be spared further treatment. Conversely, patients with VHL+2 and VHL+≥3 tumors (32%) had equivalent DFS rates of 45.6% and 35.3%, respectively, and should be prioritized for adjuvant therapy.

CONCLUSIONS

Genomic characterization of ccRCC identified biologically distinct groups of patients with divergent relapse rates. These groups account for the ∼80% of cases with VHL mutations and could be used to personalize adjuvant treatment discussions with patients as well as inform future adjuvant trial design.

Abstract LB113: Genomic classification to refine prognosis in clear cell renal cell carcinoma

Renal cell carcinomas (RCC) are characterized by their heterogenous clinical outcomes, and due to their indeterminate behavior and the absence of routine biomarkers, it is difficult to identify patients who are at high-risk for relapse after curative nephrectomy. To identify genomic biomarkers for clear cell RCC (ccRCC) risk-stratification we interrogated somatic mutation status of 12 RCC-relevant genes using next-generation sequencing (NGS) in tumor-normal pairs from 943 patients with matched follow up data from the Cancer Genomics of the Kidney (CAGEKID) study. We examined associations between genomically-defined patient groups, explained below, and disease-free as well as RCC-specific survival independently in two cohorts of patients (N=469 for cohort 1; 474 for cohort 2). We used the Kaplan-Meier method with log-rank tests to compare survival functions, and Cox proportional hazards models to stratify for patient stage and age to estimate association of each group with survival. RCC-specific survival was assessed with a competing-risks method to include deaths from other causes. Within these cohorts, 76.4% of patients harbored somatic mutations in VHL, the most common driver gene in ccRCC. The most commonly mutated genes within VHL-mutated tumors were PBRM1 (39.7%), SETD2 (19%), BAP1 (14.3%), and KDM5C (8.3%). Less frequently mutated genes included ATM, COL11A1, DMD, TP53, and TRRAP (~3-5%).Among VHL-driven tumors, we identified a new genomic classifier on the basis of the number of mutations in additional RCC driver genes in the panel examined. Patients were classified based on the presence of mutations only in VHL (VHL+0), those with mutations in VHL and one other driver gene (VHL+1), two other driver genes (VHL+2), and 3 or more other driver genes (VHL≥3). We observed within both cohorts that both the risk of disease recurrence as well as RCC-specific death were associated with an increased number of mutations within this classification. When stratified for patient stage and age, the hazard-ratio for 5-year disease-free survival for VHL≥3 patients was 6.69 (p=0.000212), 4.31 for VHL+2 (p=0.000862), and 2.43 for VHL+1 (p=0.035662), compared to patients with only mutations in VHL. These observations were replicated in the second patient cohort, with hazards ratios of 4.55, 2.49, and 1.40, for VHL≥3, VHL+2, and VHL+1 classified patients respectively, indicating that risk of disease recurrence increases with the number of driver mutations. Notably, tumor mutational burden (TMB) was not significantly different between the aforementioned groups, demonstrating that our classifier is independent of TMB. We created a model based on a set of 12 RCC-relevant genes, which can predict risk of relapse for the ~80% of patients with ccRCC that are VHL-driven. This classification can be defined based on a small panel of genes, making it easily applicable to the clinic, in the context of tumor or liquid biopsy analysis.

Citation Format: Kate I. Glennon, Naveen S. Vasudev, Ghislaine Scelo, Michelle Wilson, Louis Letourneau, Robert Eveleigh, Nazanin Nourbehesht, Madeleine Arseneault, Antoine Paccard, Lars Egevad, Juris Viksna, Edgars Celms, Sharon M. Jackson, Behnoush Abedi-Ardekani, Anne Y. Warren, Peter J. Selby, Sebastian Trainor, Michael Kimuli, Naeem Soomro, Adebanji Adeyoju, Poulam Patel, Magdalena B. Wozniak, Ivana Holcatova, Antonin Brisuda, Vladimir Janout, Estelle Chanudet, David Zaridze, Anush Moukeria, Oxana Shangina, Lenka Foretova, Marie Navratilova, Dana Mates, Viorel Jinga, Ljiljana Bogdanovic, Bozidar Kovacevic, Anne Cambon-Thomsen, Guillaume Bourque, Alvis Brazma, Jörg Tost, Paul Brennan, Mark Lathrop, Yasser Riazalhosseini, Rosamonde E. Banks. Genomic classification to refine prognosis in clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB113.

Postdiagnosis Smoking Cessation and Reduced Risk for Lung Cancer Progression and Mortality : A Prospective Cohort Study

BACKGROUND

Lung cancer is the leading cause of cancer death worldwide, and about one half of patients with lung cancer are active smokers at diagnosis.

OBJECTIVE

To determine whether quitting smoking after diagnosis of lung cancer affects the risk for disease progression and mortality.

DESIGN

Prospective study of patients with non-small cell lung cancer (NSCLC) who were recruited between 2007 and 2016 and followed annually through 2020.

SETTING

N.N. Blokhin National Medical Research Center of Oncology and City Clinical Oncological Hospital No. 1, Moscow, Russia.

PATIENTS

517 current smokers who were diagnosed with early-stage (IA-IIIA) NSCLC.

MEASUREMENTS

Probabilities of overall survival, progression-free survival, and lung cancer-specific mortality and hazard ratios (HRs) for all-cause and cancer-specific mortality.

RESULTS

During an average of 7 years of follow-up, 327 (63.2%) deaths, 273 (52.8%) cancer-specific deaths, and 172 (33.7%) cases of tumor progression (local recurrence or metastasis) were recorded. The adjusted median overall survival time was 21.6 months higher among patients who had quit smoking than those who continued smoking (6.6 vs. 4.8 years, respectively; P = 0.001). Higher 5-year overall survival (60.6% vs. 48.6%; P = 0.001) and progression-free survival (54.4% vs. 43.8%; P = 0.004) were observed among patients who quit than those who continued smoking. After adjustments, smoking cessation remained associated with decreased risk for all-cause mortality (HR, 0.67 [95% CI, 0.53 to 0.85]), cancer-specific mortality (HR, 0.75 [CI, 0.58 to 0.98]), and disease progression (HR, 0.70 [CI, 0.56 to 0.89]). Similar effects were observed among mild to moderate and heavy smokers and patients with earlier and later cancer stages.

LIMITATION

Exposure measurements were based on self-reported questionnaires.

CONCLUSION

Smoking cessation after diagnosis materially improved overall and progression-free survival among current smokers with early-stage lung cancer.

PRIMARY FUNDING SOURCE

International Agency for Research on Cancer.

Age at start of using tobacco on the risk of head and neck cancer: Pooled analysis in the International Head and Neck Cancer Epidemiology Consortium (INHANCE)

BACKGROUND

Tobacco use is a well-established risk factor for head and neck cancer (HNC). However, less is known about the potential impact of exposure to tobacco at an early age on HNC risk.

METHODS

We analyzed individual-level data on ever tobacco smokers from 27 case-control studies (17,146 HNC cases and 17,449 controls) in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using random-effects logistic regression models.

RESULTS

Without adjusting for tobacco packyears, we observed that younger age at starting tobacco use was associated with an increased HNC risk for ever smokers (OR<10 years vs. ≥30 years: 1.64, 95% CI: 1.35, 1.97). However, the observed association between age at starting tobacco use and HNC risk became null after adjusting for tobacco packyears (OR<10 years vs. ≥30 years: 0.97, 95% CI: 0.80, 1.19). In the stratified analyses on HNC subsites by tobacco packyears or years since quitting, no difference in the association between age at start and HNC risk was observed.

CONCLUSIONS

Results from this pooled analysis suggest that increased HNC risks observed with earlier age at starting tobacco smoking are largely due to longer duration and higher cumulative tobacco exposures.

Joint effects of intensity and duration of cigarette smoking on the risk of head and neck cancer: A bivariate spline model approach

OBJECTIVES

This study aimed at re-evaluating the strength and shape of the dose-response relationship between the combined (or joint) effect of intensity and duration of cigarette smoking and the risk of head and neck cancer (HNC). We explored this issue considering bivariate spline models, where smoking intensity and duration were treated as interacting continuous exposures.

MATERIALS AND METHODS

We pooled individual-level data from 33 case-control studies (18,260 HNC cases and 29,844 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. In bivariate regression spline models, exposures to cigarette smoking intensity and duration (compared with never smokers) were modeled as a linear piecewise function within a logistic regression also including potential confounders. We jointly estimated the optimal knot locations and regression parameters within the Bayesian framework.

RESULTS

For oral-cavity/pharyngeal (OCP) cancers, an odds ratio (OR) >5 was reached after 30 years in current smokers of ∼20 or more cigarettes/day. Patterns of OCP cancer risk in current smokers differed across strata of alcohol intensity. For laryngeal cancer, ORs >20 were found for current smokers of ≥20 cigarettes/day for ≥30  years. In former smokers who quit ≥10  years ago, the ORs were approximately halved for OCP cancers, and ∼1/3 for laryngeal cancer, as compared to the same levels of intensity and duration in current smokers.

CONCLUSION

Referring to bivariate spline models, this study better quantified the joint effect of intensity and duration of cigarette smoking on HNC risk, further stressing the need of smoking cessation policies.

Genome-wide association analyses identify new susceptibility loci for oral cavity and pharyngeal cancer

We conducted a genome-wide association study of oral cavity and pharyngeal cancer in 6,034 cases and 6,585 controls from Europe, North America and South America. We detected eight significantly associated loci (P < 5 × 10-8), seven of which are new for these cancer sites. Oral and pharyngeal cancers combined were associated with loci at 6p21.32 (rs3828805, HLA-DQB1), 10q26.13 (rs201982221, LHPP) and 11p15.4 (rs1453414, OR52N2-TRIM5). Oral cancer was associated with two new regions, 2p23.3 (rs6547741, GPN1) and 9q34.12 (rs928674, LAMC3), and with known cancer-related loci-9p21.3 (rs8181047, CDKN2B-AS1) and 5p15.33 (rs10462706, CLPTM1L). Oropharyngeal cancer associations were limited to the human leukocyte antigen (HLA) region, and classical HLA allele imputation showed a protective association with the class II haplotype HLA-DRB1*1301-HLA-DQA1*0103-HLA-DQB1*0603 (odds ratio (OR) = 0.59, P = 2.7 × 10-9). Stratified analyses on a subgroup of oropharyngeal cases with information available on human papillomavirus (HPV) status indicated that this association was considerably stronger in HPV-positive (OR = 0.23, P = 1.6 × 10-6) than in HPV-negative (OR = 0.75, P = 0.16) cancers.

Low frequency of cigarette smoking and the risk of head and neck cancer in the INHANCE consortium pooled analysis

BACKGROUND

Cigarette smoking is a major risk factor for head and neck cancer (HNC). To our knowledge, low cigarette smoking (<10 cigarettes per day) has not been extensively investigated in fine categories or among never alcohol drinkers.

METHODS

We conducted a pooled analysis of individual participant data from 23 independent case-control studies including 19 660 HNC cases and 25 566 controls. After exclusion of subjects using other tobacco products including cigars, pipes, snuffed or chewed tobacco and straw cigarettes (tobacco product used in Brazil), as well as subjects smoking more than 10 cigarettes per day, 4093 HNC cases and 13 416 controls were included in the analysis. The lifetime average frequency of cigarette consumption was categorized as follows: never cigarette users, >0-3, >3-5, >5-10 cigarettes per day.

RESULTS

Smoking >0-3 cigarettes per day was associated with a 50% increased risk of HNC in the study population [odds ratio (OR) = 1.52, 95% confidence interval (CI): (1.21, 1.90). Smoking >3-5 cigarettes per day was associated in each subgroup from OR = 2.01 (95% CI: 1.22, 3.31) among never alcohol drinkers to OR = 2.74 (95% CI: 2.01, 3.74) among women and in each cancer site, particularly laryngeal cancer (OR = 3.48, 95% CI: 2.40, 5.05). However, the observed increased risk of HNC for low smoking frequency was not found among smokers with smoking duration shorter than 20 years.

CONCLUSION

Our results suggest a public health message that low frequency of cigarette consumption contributes to the development of HNC. However, smoking duration seems to play at least an equal or a stronger role in the development of HNC.

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.

Risk factors for head and neck cancer in young adults: a pooled analysis in the INHANCE consortium

BACKGROUND

Increasing incidence of head and neck cancer (HNC) in young adults has been reported. We aimed to compare the role of major risk factors and family history of cancer in HNC in young adults and older patients.

METHODS

We pooled data from 25 case-control studies and conducted separate analyses for adults ≤ 45 years old ('young adults', 2010 cases and 4042 controls) and >45 years old ('older adults', 17700 cases and 22 704 controls). Using logistic regression with studies treated as random effects, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The young group of cases had a higher proportion of oral tongue cancer (16.0% in women; 11.0% in men) and unspecified oral cavity / oropharynx cancer (16.2%; 11.1%) and a lower proportion of larynx cancer (12.1%; 16.6%) than older adult cases. The proportions of never smokers or never drinkers among female cases were higher than among male cases in both age groups. Positive associations with HNC and duration or pack-years of smoking and drinking were similar across age groups. However, the attributable fractions (AFs) for smoking and drinking were lower in young when compared with older adults (AFs for smoking in young women, older women, young men and older men, respectively, = 19.9% (95% CI=9.8%, 27.9%), 48.9% (46.6%, 50.8%), 46.2% (38.5%, 52.5%), 64.3% (62.2%, 66.4%); AFs for drinking=5.3% (-11.2%, 18.0%), 20.0% (14.5%, 25.0%), 21.5% (5.0%, 34.9%) and 50.4% (46.1%, 54.3%). A family history of early-onset cancer was associated with HNC risk in the young [OR=2.27 (95% CI=1.26, 4.10)], but not in the older adults [OR=1.10 (0.91, 1.31)]. The attributable fraction for family history of early-onset cancer was 23.2% (8.60% to 31.4%) in young compared with 2.20% (-2.41%, 5.80%) in older adults.

CONCLUSIONS

Differences in HNC aetiology according to age group may exist. The lower AF of cigarette smoking and alcohol drinking in young adults may be due to the reduced length of exposure due to the lower age. Other characteristics, such as those that are inherited, may play a more important role in HNC in young adults compared with older adults.

Estimating and explaining the effect of education and income on head and neck cancer risk: INHANCE consortium pooled analysis of 31 case-control studies from 27 countries

Low socioeconomic status has been reported to be associated with head and neck cancer risk. However, previous studies have been too small to examine the associations by cancer subsite, age, sex, global region and calendar time and to explain the association in terms of behavioral risk factors. Individual participant data of 23,964 cases with head and neck cancer and 31,954 controls from 31 studies in 27 countries pooled with random effects models. Overall, low education was associated with an increased risk of head and neck cancer (OR = 2.50; 95% CI = 2.02 - 3.09). Overall one-third of the increased risk was not explained by differences in the distribution of cigarette smoking and alcohol behaviors; and it remained elevated among never users of tobacco and nondrinkers (OR = 1.61; 95% CI = 1.13 - 2.31). More of the estimated education effect was not explained by cigarette smoking and alcohol behaviors: in women than in men, in older than younger groups, in the oropharynx than in other sites, in South/Central America than in Europe/North America and was strongest in countries with greater income inequality. Similar findings were observed for the estimated effect of low versus high household income. The lowest levels of income and educational attainment were associated with more than 2-fold increased risk of head and neck cancer, which is not entirely explained by differences in the distributions of behavioral risk factors for these cancers and which varies across cancer sites, sexes, countries and country income inequality levels.

Adult height and head and neck cancer: a pooled analysis within the INHANCE Consortium

Several epidemiological studies have shown a positive association between adult height and cancer incidence. The only study conducted among women on mouth and pharynx cancer risk, however, reported an inverse association. This study aims to investigate the association between height and the risk of head and neck cancer (HNC) within a large international consortium of HNC. We analyzed pooled individual-level data from 24 case-control studies participating in the International Head and Neck Cancer Epidemiology Consortium. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated separately for men and women for associations between height and HNC risk. Educational level, tobacco smoking, and alcohol consumption were included in all regression models. Stratified analyses by HNC subsites were performed. This project included 17,666 cases and 28,198 controls. We found an inverse association between height and HNC (adjusted OR per 10 cm height = 0.91, 95% CI 0.86-0.95 for men; adjusted OR = 0.86, 95% CI 0.79-0.93 for women). In men, the estimated OR did vary by educational level, smoking status, geographic area, and control source. No differences by subsites were detected. Adult height is inversely associated with HNC risk. As height can be considered a marker of childhood illness and low energy intake, the inverse association is consistent with prior studies showing that HNC occur more frequently among deprived individuals. Further studies designed to elucidate the mechanism of such association would be warranted.

Cigarette, cigar, and pipe smoking and the risk of head and neck cancers: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

Cigar and pipe smoking are considered risk factors for head and neck cancers, but the magnitude of effect estimates for these products has been imprecisely estimated. By using pooled data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium (comprising 13,935 cases and 18,691 controls in 19 studies from 1981 to 2007), we applied hierarchical logistic regression to more precisely estimate odds ratios and 95% confidence intervals for cigarette, cigar, and pipe smoking separately, compared with reference groups of those who had never smoked each single product. Odds ratios for cigar and pipe smoking were stratified by ever cigarette smoking. We also considered effect estimates of smoking a single product exclusively versus never having smoked any product (reference group). Among never cigarette smokers, the odds ratio for ever cigar smoking was 2.54 (95% confidence interval (CI): 1.93, 3.34), and the odds ratio for ever pipe smoking was 2.08 (95% CI: 1.55, 2.81). These odds ratios increased with increasing frequency and duration of smoking (Ptrend ≤ 0.0001). Odds ratios for cigar and pipe smoking were not elevated among ever cigarette smokers. Head and neck cancer risk was elevated for those who reported exclusive cigar smoking (odds ratio = 3.49, 95% CI: 2.58, 4.73) or exclusive pipe smoking (odds ratio = 3.71, 95% CI: 2.59, 5.33). These results suggest that cigar and pipe smoking are independently associated with increased risk of head and neck cancers.

An examination of male and female odds ratios by BMI, cigarette smoking, and alcohol consumption for cancers of the oral cavity, pharynx, and larynx in pooled data from 15 case-control studies

BACKGROUND

Greater tobacco smoking and alcohol consumption and lower body mass index (BMI) increase odds ratios (OR) for oral cavity, oropharyngeal, hypopharyngeal, and laryngeal cancers; however, there are no comprehensive sex-specific comparisons of ORs for these factors.

METHODS

We analyzed 2,441 oral cavity (925 women and 1,516 men), 2,297 oropharynx (564 women and 1,733 men), 508 hypopharynx (96 women and 412 men), and 1,740 larynx (237 women and 1,503 men) cases from the INHANCE consortium of 15 head and neck cancer case-control studies. Controls numbered from 7,604 to 13,829 subjects, depending on analysis. Analyses fitted linear-exponential excess ORs models.

RESULTS

ORs were increased in underweight (< 18.5 BMI) relative to normal weight (18.5-24.9) and reduced in overweight and obese categories (≥ 25 BMI) for all sites and were homogeneous by sex. ORs by smoking and drinking in women compared with men were significantly greater for oropharyngeal cancer (p < 0.01 for both factors), suggestive for hypopharyngeal cancer (p = 0.05 and p = 0.06, respectively), but homogeneous for oral cavity (p = 0.56 and p = 0.64) and laryngeal (p = 0.18 and p = 0.72) cancers.

CONCLUSIONS

The extent that OR modifications of smoking and drinking by sex for oropharyngeal and, possibly, hypopharyngeal cancers represent true associations, or derive from unmeasured confounders or unobserved sex-related disease subtypes (e.g., human papillomavirus-positive oropharyngeal cancer) remains to be clarified.

A genome-wide association study of upper aerodigestive tract cancers conducted within the INHANCE consortium

Genome-wide association studies (GWAS) have been successful in identifying common genetic variation involved in susceptibility to etiologically complex disease. We conducted a GWAS to identify common genetic variation involved in susceptibility to upper aero-digestive tract (UADT) cancers. Genome-wide genotyping was carried out using the Illumina HumanHap300 beadchips in 2,091 UADT cancer cases and 3,513 controls from two large European multi-centre UADT cancer studies, as well as 4,821 generic controls. The 19 top-ranked variants were investigated further in an additional 6,514 UADT cancer cases and 7,892 controls of European descent from an additional 13 UADT cancer studies participating in the INHANCE consortium. Five common variants presented evidence for significant association in the combined analysis (p ≤ 5 × 10⁻⁷). Two novel variants were identified, a 4q21 variant (rs1494961, p = 1×10⁻⁸) located near DNA repair related genes HEL308 and FAM175A (or Abraxas) and a 12q24 variant (rs4767364, p =2 × 10⁻⁸) located in an extended linkage disequilibrium region that contains multiple genes including the aldehyde dehydrogenase 2 (ALDH2) gene. Three remaining variants are located in the ADH gene cluster and were identified previously in a candidate gene study involving some of these samples. The association between these three variants and UADT cancers was independently replicated in 5,092 UADT cancer cases and 6,794 controls non-overlapping samples presented here (rs1573496-ADH7, p = 5 × 10⁻⁸); rs1229984-ADH1B, p = 7 × 10⁻⁹; and rs698-ADH1C, p = 0.02). These results implicate two variants at 4q21 and 12q24 and further highlight three ADH variants in UADT cancer susceptibility.

Body mass index, cigarette smoking, and alcohol consumption and cancers of the oral cavity, pharynx, and larynx: modeling odds ratios in pooled case-control data

Odds ratios for head and neck cancer increase with greater cigarette and alcohol use and lower body mass index (BMI; weight (kg)/height(2) (m(2))). Using data from the International Head and Neck Cancer Epidemiology Consortium, the authors conducted a formal analysis of BMI as a modifier of smoking- and alcohol-related effects. Analysis of never and current smokers included 6,333 cases, while analysis of never drinkers and consumers of < or =10 drinks/day included 8,452 cases. There were 8,000 or more controls, depending on the analysis. Odds ratios for all sites increased with lower BMI, greater smoking, and greater drinking. In polytomous regression, odds ratios for BMI (P = 0.65), smoking (P = 0.52), and drinking (P = 0.73) were homogeneous for oral cavity and pharyngeal cancers. Odds ratios for BMI and drinking were greater for oral cavity/pharyngeal cancer (P < 0.01), while smoking odds ratios were greater for laryngeal cancer (P < 0.01). Lower BMI enhanced smoking- and drinking-related odds ratios for oral cavity/pharyngeal cancer (P < 0.01), while BMI did not modify smoking and drinking odds ratios for laryngeal cancer. The increased odds ratios for all sites with low BMI may suggest related carcinogenic mechanisms; however, BMI modification of smoking and drinking odds ratios for cancer of the oral cavity/pharynx but not larynx cancer suggests additional factors specific to oral cavity/pharynx cancer.

Total exposure and exposure rate effects for alcohol and smoking and risk of head and neck cancer: a pooled analysis of case-control studies

Although cigarette smoking and alcohol consumption increase risk for head and neck cancers, there have been few attempts to model risks quantitatively and to formally evaluate cancer site-specific risks. The authors pooled data from 15 case-control studies and modeled the excess odds ratio (EOR) to assess risk by total exposure (pack-years and drink-years) and its modification by exposure rate (cigarettes/day and drinks/day). The smoking analysis included 1,761 laryngeal, 2,453 pharyngeal, and 1,990 oral cavity cancers, and the alcohol analysis included 2,551 laryngeal, 3,693 pharyngeal, and 3,116 oval cavity cancers, with over 8,000 controls. Above 15 cigarettes/day, the EOR/pack-year decreased with increasing cigarettes/day, suggesting that greater cigarettes/day for a shorter duration was less deleterious than fewer cigarettes/day for a longer duration. Estimates of EOR/pack-year were homogeneous across sites, while the effects of cigarettes/day varied, indicating that the greater laryngeal cancer risk derived from differential cigarettes/day effects and not pack-years. EOR/drink-year estimates increased through 10 drinks/day, suggesting that greater drinks/day for a shorter duration was more deleterious than fewer drinks/day for a longer duration. Above 10 drinks/day, data were limited. EOR/drink-year estimates varied by site, while drinks/day effects were homogeneous, indicating that the greater pharyngeal/oral cavity cancer risk with alcohol consumption derived from the differential effects of drink-years and not drinks/day.

Interaction between tobacco and alcohol use and the risk of head and neck cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

BACKGROUND

The magnitude of risk conferred by the interaction between tobacco and alcohol use on the risk of head and neck cancers is not clear because studies have used various methods to quantify the excess head and neck cancer burden.

METHODS

We analyzed individual-level pooled data from 17 European and American case-control studies (11,221 cases and 16,168 controls) participating in the International Head and Neck Cancer Epidemiology consortium. We estimated the multiplicative interaction parameter (psi) and population attributable risks (PAR).

RESULTS

A greater than multiplicative joint effect between ever tobacco and alcohol use was observed for head and neck cancer risk (psi = 2.15; 95% confidence interval, 1.53-3.04). The PAR for tobacco or alcohol was 72% (95% confidence interval, 61-79%) for head and neck cancer, of which 4% was due to alcohol alone, 33% was due to tobacco alone, and 35% was due to tobacco and alcohol combined. The total PAR differed by subsite (64% for oral cavity cancer, 72% for pharyngeal cancer, 89% for laryngeal cancer), by sex (74% for men, 57% for women), by age (33% for cases <45 years, 73% for cases >60 years), and by region (84% in Europe, 51% in North America, 83% in Latin America).

CONCLUSIONS

Our results confirm that the joint effect between tobacco and alcohol use is greater than multiplicative on head and neck cancer risk. However, a substantial proportion of head and neck cancers cannot be attributed to tobacco or alcohol use, particularly for oral cavity cancer and for head and neck cancer among women and among young-onset cases.

Family history of cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

Alcohol and tobacco consumption are well-recognized risk factors for head and neck cancer (HNC). Evidence suggests that genetic predisposition may also play a role. Only a few epidemiologic studies, however, have considered the relation between HNC risk and family history of HNC and other cancers. We pooled individual-level data across 12 case-control studies including 8,967 HNC cases and 13,627 controls. We obtained pooled odds ratios (OR) using fixed and random effect models and adjusting for potential confounding factors. All statistical tests were two-sided. A family history of HNC in first-degree relatives increased the risk of HNC (OR=1.7, 95% confidence interval, CI, 1.2-2.3). The risk was higher when the affected relative was a sibling (OR=2.2, 95% CI 1.6-3.1) rather than a parent (OR=1.5, 95% CI 1.1-1.8) and for more distal HNC anatomic sites (hypopharynx and larynx). The risk was also higher, or limited to, in subjects exposed to tobacco. The OR rose to 7.2 (95% CI 5.5-9.5) among subjects with family history, who were alcohol and tobacco users. A weak but significant association (OR=1.1, 95% CI 1.0-1.2) emerged for family history of other tobacco-related neoplasms, particularly with laryngeal cancer (OR=1.3, 95% CI 1.1-1.5). No association was observed for family history of nontobacco-related neoplasms and the risk of HNC (OR=1.0, 95% CI 0.9-1.1). Familial factors play a role in the etiology of HNC. In both subjects with and without family history of HNC, avoidance of tobacco and alcohol exposure may be the best way to avoid HNC.

Multiple ADH genes are associated with upper aerodigestive cancers

Alcohol is an important risk factor for upper aerodigestive cancers and is principally metabolized by alcohol dehydrogenase (ADH) enzymes. We have investigated six ADH genetic variants in over 3,800 aerodigestive cancer cases and 5,200 controls from three individual studies. Gene variants rs1229984 (ADH1B) and rs1573496 (ADH7) were significantly protective against aerodigestive cancer in each individual study and overall (P = 10(-10) and 10(-9), respectively). These effects became more apparent with increasing alcohol consumption (P for trend = 0.0002 and 0.065, respectively). Both gene effects were independent of each other, implying that multiple ADH genes may be involved in upper aerodigestive cancer etiology.

Oral health and risk of squamous cell carcinoma of the head and neck and esophagus: results of two multicentric case-control studies

Poor oral health has been reported as a risk factor in the etiology of head and neck cancer. Data on oral health were ascertained as part of two multicenter case-control studies comprising 924 cases and 928 controls in central Europe and 2,286 cases and 1,824 controls in Latin America. Incident cases of squamous cell carcinoma of the head and neck (oral cavity, pharynx, larynx) and esophagus, as well as age (in quinquennia)- and sex frequency-matched controls, were enrolled from 1998 to 2003. Poor condition of the mouth (central Europe: odds ratio (OR) = 2.89, 95% confidence interval (CI): 1.74, 4.81; Latin America: OR = 1.89, 95% CI: 1.47, 2.42), lack of toothbrush use (Latin America: OR = 2.36, 95% CI: 1.28, 4.36), and daily mouthwash use (Latin America: OR = 3.40, 95% CI: 1.96, 5.89) emerged as risk factors for head and neck cancer, independent of tobacco use and alcohol consumption. Missing between six and 15 teeth was an independent risk factor for esophageal cancer (central Europe: OR = 2.84, 95% CI: 1.26, 6.41; Latin America: OR = 2.18, 95% CI: 1.04, 4.59). These results indicate that periodontal disease (as indicated by poor condition of the mouth and missing teeth) and daily mouthwash use may be independent causes of cancers of the head, neck, and esophagus.

Contribution of tobacco and alcohol to the high rates of squamous cell carcinoma of the supraglottis and glottis in Central Europe

Incidence rates for laryngeal cancer in Central Europe are among the highest in the world. The authors recruited cases and controls between 2000 and 2002 for the Central and Eastern Europe Multicenter Study to investigate the role of tobacco and alcohol as causes of laryngeal cancer in this region. A total of 384 incident squamous cell cases were included, comprising 254 glottic and 108 supraglottic cancers. Hospital controls were chosen from within the same catchment area, from diseases unrelated to tobacco or alcohol (n = 918). Significant dose-response trends for frequency and duration of tobacco use were observed for both supraglottic and glottic cancers, with potentially a more important effect for supraglottic cancer. Quitting smoking was protective against laryngeal cancers after 5 years. Any increases in risk for alcohol drinking were generally moderate and nonsignificant. A greater than multiplicative interaction was observed between tobacco and alcohol on the risk of laryngeal cancer (p = 0.04). Approximately 87% of laryngeal cancer cases in Central Europe are attributable to tobacco use, of which 75% and 12% are due to current and past smoking, respectively. Approximately 39% are attributable to the interaction between alcohol and tobacco. Preventive efforts to encourage current smokers to quit are likely to be the most effective way to reduce the incidence of laryngeal cancer in this region.

Esophageal cancer in Central and Eastern Europe: Tobacco and alcohol

Esophageal cancer mortality rates in Central and Eastern Europe have been increasing steadily and are expected to increase further in the future. To evaluate the role of risk factors for esophageal cancer in this population, a multicenter study was conducted, with investigation of tobacco and alcohol as one of the principal aims. We have included 192 squamous cell carcinoma (SCC) and 35 adenocarcinoma cases of the esophagus diagnosed at designated hospitals in 5 centers from Romania, Russia, the Czech Republic and Poland. Controls were frequency matched from patients in the same hospital as the cases (n=1,114). Our results showed that the risk of esophageal SCC may be increased by approximately 7-fold for current smokers (OR=7.41, 95% CI 3.98-13.79) and by 3-fold for ever alcohol drinkers (OR=2.86, 95% CI 1.06-7.74). Dose-response relations were evident for both the frequency and duration of tobacco and of alcohol on the risk of esophageal SCC. Risk estimates for tobacco smoking were highest for lower esophageal SCCs, while risk estimates for alcohol drinking were highest for upper esophageal SCCs; though differences were not statistically significant. For adenocarcinoma of the esophagus, our results suggested a more modest increase in risk because of tobacco smoking than that for SCC of the esophagus and no association with alcohol consumption, although our sample size was small. A synergistic interaction between tobacco and alcohol was observed for the risk of esophageal SCC, highlighting the importance of both factors for esophageal cancers in Central and Eastern Europe.

The association of sequence variants in DNA repair and cell cycle genes with cancers of the upper aerodigestive tract

Cancers of the upper aerodigestive tract (UADT), comprising the oral cavity, pharynx, larynx and oesophagus, account for 5.2% of all cancers cases worldwide. The major risk factors, tobacco and alcohol can directly or indirectly generate DNA damage, which if unrepaired can give rise to mutations, unregulated cell growth and apoptosis induction. To clarify the role of DNA repair and cell cycle control proteins in UADT cancer susceptibility, we studied the risk in relation to 28 SNPs in 18 DNA repair enzymes and 9 SNPs in 7 cell cycle control genes. A case-control study was conducted from 2000 to 2002 in six centers from Romania, Poland, Russia, Slovakia and the Czech Republic. Patients diagnosed with squamous cell carcinoma of the UADT (n=811) and controls with a recent diagnosis of diseases unrelated to tobacco and alcohol (n=1083) were recruited. For UADT cancer risk, associations were observed for the homozygous carriers of the variant alleles of MGMT L84F [odds ratio (OR) 2.35, 95% confidence interval (CI) 1.32-4.20], MGMT 171C > T (OR 2.24, 95% CI 1.20-4.17) and OGG1 S326C (OR 2.07, 95% CI 1.15-3.73) whilst three variants were associated with a protective effect (XPA 23G > A, P for trend 0.022, APEX Q51H, P for trend 0.036, CHEK2 intron 9-200T > C, P for trend 0.009). Several other sequence variants showed associations with specific cancers without an overall association with UADT cancer. While some of these associations are consistent with previous studies, we cannot rule out the possibility of false-positive associations. The positive findings should be explored in another large-scale study on UADT cancers.

Occupational exposure and laryngeal and hypopharyngeal cancer risk in central and eastern Europe

A multicenter case-control study was conducted during 1999-2002 in four European countries (Poland, Romania, Russia, and Slovakia) to evaluate the role of occupational exposures in risk of laryngeal/hypopharyngeal cancer. Male cancer cases (34 hypopharyngeal, 316 laryngeal) with full data on occupational history and nonoccupational factors were compared with 728 hospital controls for occupational exposure to 73 suspected carcinogens. Occupational history was evaluated by industrial hygienists blinded to case/control status. Elevated risks for ever exposure to coal dust were found for both hypopharyngeal (odds ratio (OR) = 4.19, 95% confidence interval (CI): 1.18, 14.89) and laryngeal (OR = 1.81, 95% CI: 0.94, 3.47) cancer, with clear dose-response patterns. Inclusion of a 20-year lag in the analysis strengthened these associations. Hypopharyngeal cancer risk was also significantly associated with exposure to mild steel dust (OR = 3.04, 95% CI: 1.39, 6.64) and iron compounds and fumes (OR = 2.74, 95% CI: 1.29, 5.84), without clear dose-response relations. Laryngeal cancer was significantly associated with exposure to hard-alloys dust (OR = 2.23, 95% CI: 1.08, 4.57) and chlorinated solvents (OR = 2.18, 95% CI: 1.03, 4.61), without dose-response relations. A possible link between high formaldehyde exposure and laryngeal cancer was suggested. No association was found for exposure to asbestos or inorganic acid mists. These data indicate that occupational exposure to coal dust may play a role in laryngeal and hypopharyngeal cancer. Other possible relations need further evaluation.

Evidence for an Important Role of Alcohol- and Aldehyde-Metabolizing Genes in Cancers of the Upper Aerodigestive Tract

BACKGROUND

Incidence and mortality rates of upper aerodigestive tract cancers in Central Europe are among the highest in the world and have increased substantially in recent years. This increase is likely to be due to patterns of alcohol and tobacco consumption. Genetic susceptibility to upper aerodigestive tract cancer in relation to such exposures is an important aspect that should be investigated among populations in this region.

METHODS

A multicenter case-control study comprising 811 upper aerodigestive tract cancer cases and 1,083 controls was conducted in: Bucharest (Romania), Lodz (Poland), Moscow (Russia), Banska Bystrika (Slovakia), and Olomouc and Prague (Czech Republic). We analyzed six SNPs in three genes related to ethanol metabolism: alcohol dehydrogenase 1B and 1C (ADH1B, ADH1C) and aldehyde dehydrogenase 2 (ALDH2).

RESULTS

The ADH1B histidine allele at codon 48 was associated with a decreased risk of upper aerodigestive tract cancer; odds ratios (OR) were 0.36 [95% confidence interval (95% CI), 0.17-0.77] for medium/heavy drinkers and 0.57 (95% CI, 0.36-0.91) for never/light drinkers. Moderately increased risks were observed for the ADH1C (350)Val allele (OR, 1.19; 95% CI, 0.98-1.55) and ADH1C (272)Gln allele (OR, 1.24; 95% CI, 0.98-1.55). Medium/heavy drinkers who were heterozygous or homozygous at ALDH2 nucleotide position 248 were at a significantly increased risk of upper aerodigestive tract cancer (OR, 1.76; 95% CI, 1.13-2.75; OR, 5.79; 95% CI, 1.49-22.5, respectively), with a significant dose response for carrying variant alleles (P = 0.0007). Similar results were observed for the ALDH2 +82A>G and ALDH2 -261C>T polymorphisms. When results were analyzed by subsite, strong main effects were observed for squamous cell carcinoma of the esophagus for all six variants. Among the 30% of the population who were carriers of at least one ALDH2 variant, the attributable fraction among carriers (AF(c)) was 24.2% (5.7-38.3%) for all upper aerodigestive tract cancers, increasing to 58.7% (41.2-71.0%) for esophageal cancer. Among carriers who drank alcohol at least thrice to four times a week, the AF(c) for having at least one ALDH2 variant was 49% (21.3-66.8%) for all upper aerodigestive tract cancers, increasing to 68.9% (42.9-83.1%) for esophageal cancer.

CONCLUSIONS

Polymorphisms in the ADH1B and ALDH2 genes are associated with upper aerodigestive tract cancer in Central European populations and interact substantially with alcohol consumption.