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DNA Repair Gene ERCC1 and ERCC2/XPD Polymorphisms and Risk of Squamous Cell Carcinoma of the Head and Neck
Erich M. Sturgis, MD;
Kristina R. Dahlstrom, BS;
Margaret R. Spitz, MD, MPH;
Qingyi Wei, MD, PhD
Arch Otolaryngol Head Neck Surg. 2002;128:1084-1088.
ABSTRACT
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Objective To determine the effect of the ERCC1 C8092A
polymorphism and the ERCC2/XPD G23591A polymorphism
on the risk of squamous cell carcinoma of the head and neck (SCCHN).
Design A hospital-based case-control study.
Subjects A total of 330 newly diagnosed case subjects with SCCHN and 330 cancer-free
control subjects matched on age (± 5 years), sex, smoking status, and
alcohol use. All subjects were non-Hispanic whites.
Methods After informed consent was obtained, blood was drawn for genotyping.
The ERCC1 C8092A polymorphism was typed by single-strand
conformational polymorphism analysis. The ERCC2/XPD
G23591A polymorphism was typed by polymerase chain reaction–based restriction
fragment length polymorphism analysis with the enzyme StyI. The  2 analysis was used to assess differences in
genotype and allele frequencies. Multivariate logistic regression analysis
was performed to estimate the risk of SCCHN for individuals having these genotypes
after adjustment for age, sex, tobacco smoking, and alcohol use.
Results The DNA was available and genotyping was ultimately successful for 313
case subjects and 313 control subjects. The ERCC1
8092CC genotype and the ERCC2/XPD 23591A allele were
associated with nonsignificantly increased risks of SCCHN: odds ratios, 1.15
(95% confidence interval [CI], 0.84-1.59) and 1.28 (95% CI, 0.93-1.76), respectively,
whereas having both risk genotypes was associated with an even higher risk
of SCCHN: odds ratio, 1.78 (95% CI, 0.99-3.17). When considering both polymorphisms,
we found a significant allele dose effect (P = .04).
Conclusions These 2 polymorphisms may contribute to the risk of SCCHN, but larger
studies are needed to confirm their role in SCCHN. Combining common DNA repair
gene polymorphisms into models of genetic risk of SCCHN may improve risk estimates.
INTRODUCTION
ANNUAL ESTIMATES show that the number of current smokers in the United
States has remained relatively stable at approximately 45 million over the
past 3 decades, and the absolute incidence of newly diagnosed cancers has
never exceeded 1.4 million.1-2
These facts suggest that most smokers never develop cancer and that genetic
differences probably influence individuals' responses to environmental carcinogens
and consequently their risk for cancer. Although the concept of genetic susceptibility
may seem intuitive, it is extremely complex and involves multiple cellular
systems regulated by hundreds of genes. It is unlikely that common genetic
variants, most of which are single nucleotide polymorphisms (SNPs), will significantly
influence risk without environmental exposures. Therefore, current efforts
have focused on determining genotype frequencies in the population and which
SNPs will be important to include in future, more complex, genetic models
of cancer risk assessment.
We have previously reported that the risk of squamous cell carcinoma
of the head and neck (SCCHN) was associated with poor DNA repair phenotype
in response to the classic tobacco carcinogen, benzo[a]pyrene diol epoxide.3-6 The damage
induced by it is repaired primarily by the nucleotide excision repair pathway.7 In 1998, Shen et al8
identified 31 SNPs of ERCC1, ERCC2/XPD, and ERCC4/XPF of the nucleotide excision
repair pathway. Because polymorphisms of the nucleotide excision repair genes
may be associated with differences in DNA repair capacity,9
we hypothesized that genetic variants in the nucleotide excision repair pathway
may influence risk of SCCHN. In the present study, we examine an SNP of the
3' untranslated region (UTR) of ERCC1 that
has been reported to be linked to adult-onset glioma,10
and an SNP of exon 10 of ERCC2/XPD that has been
linked to altered DNA repair capacity.9
SUBJECTS, MATERIALS, AND METHODS
STUDY SUBJECTS
Between May 1995 and March 2001, patients with incident (newly diagnosed)
SCCHN were recruited from patients seen in the Head and Neck Center at our
institution to participate in an ongoing molecular epidemiologic study. After
providing informed consent, all participating patients agreed to donate 30
mL of blood for biomarker testing and to complete a detailed questionnaire
eliciting demographic, exposure, and family history information. Cancer-free
control subjects were selected from a pool of healthy controls, identified
from enrollees in a local managed-care organization, to participate in ongoing
hospital-based case-control studies. The control subjects were matched to
the case subjects on age (± 5 years), sex, smoking status, and alcohol
use. To eliminate the possibility of racial confounders, only non-Hispanic
whites were included in this study. Smokers were defined as those who had
smoked more than 100 cigarettes in their lifetimes. Drinkers were defined
as those who had drunk alcoholic beverages at least once a week for more than
1 year.
GENOTYPING
We used leukocyte cell pellets obtained from the buffy coat by centrifugation
of 1 mL of whole blood for DNA extraction and performed polymerase chain reaction
(PCR) amplification as previously described.9-10
We used PCR assays to amplify the 3' UTR of ERCC1 and exon 10 of ERCC2/XPD, which contain the
polymorphisms of interest. The primers used were 5'-TGAGCCAATTCAGCCACT-3'
and 5'-TAGTTCCTCAGTTTCCCG-3', which generate a 255–base
pair (bp) fragment for the 3' UTR of ERCC1,
and 5'-CTGTTGGTGGGTGCCCGTATCTGTTGGTCT-3' and 5'-TAATATCGGGGCTCACCCTGCAGCACTTCCT-3',
which generate a 751-bp fragment for exon 10 of ERCC2/XPD. As previously described,10 we used
single-strand conformational polymorphism assay to type the ERCC1 3' UTR polymorphism. The restriction enzyme StyI (New England Biolabs, Beverly, Mass) was used to distinguish the
23591 polymorphism of exon 10 of ERCC2/XPD in which
the gain of a StyI restriction site occurs in the
polymorphic allele. The wild-type allele has a single StyI restriction site resulting in 2 bands (507 and 244 bp), and the polymorphic
allele has 2 StyI restriction sites and, therefore,
has 3 bands (474, 244, and 33 bp, not visible). The PCR product was digested
with 10 U of StyI, in the x10 buffer supplied
with the restriction enzyme and 2% bovine serum albumin at 37°C for 16
hours. The digestion products were separated on a 2% NuSieve 3:1 agarose gel
(FMC BioProducts, Rockland, Me) and photographed with Polaroid film (Cambridge,
Mass).
STATISTICAL ANALYSIS
We first performed univariate analysis to calculate the frequency of
each allele and genotype. By tabulation, we also examined the concordance
between the genotype frequencies of 2 polymorphisms. We compared the observed
genotype frequencies with those calculated from the Hardy-Weinberg equation
(p2 + 2pq + q2 = 1, where p is the frequency of the wild-type allele
and q is 1 - p). We calculated the odds ratios (ORs) and their 95% confidence
intervals (CIs) for the genotypes by logistic regression analysis with adjustment
for age, sex, smoking status, and alcohol use. All of the statistical analyses
were performed with Statistical Analysis System software (Version 6; SAS Institute
Inc, Cary, NC).
RESULTS
Initially, we identified 330 patients with SCCHN and 330 cancer-free
control subjects. Of these, DNA was unavailable or PCR was unsuccessful in
17 patients and 17 control participants. Consequently, the ultimate sample
size was 313 case subjects and 313 control subjects. The subjects were well
matched on age, sex, smoking status, and alcohol use (Table 1). All subjects were non-Hispanic whites. All cases were
incident squamous cell carcinomas of the oral cavity, oropharynx, hypopharynx,
or larynx (Table 1). Because only
19 patients with hypopharyngeal cancer were recruited, they were grouped with
oropharyngeal patients for subgroup analysis.
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Table 1. Frequency Distribution Analysis of Demographic and Risk Factors*
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Genotype distributions are summarized in Table 2. The ERCC1 8092 genotype distribution
for case and control subjects were in Hardy-Weinberg equilibrium (P = .88 and P = .54, respectively). The variant ERCC1 8092A allele was less frequent in the case subjects
(0.230) than in the control subjects (0.248), and the homozygous wild-type ERCC1 8092CC genotype was more common in the case group
(58.5%) than in the control group (55.0%), suggesting the ERCC1 A allele has a protective effect. The ERCC2/XPD 23591 genotype distribution in case and control subjects were in Hardy-Weinberg
equilibrium (P = .09 and P
= .94, respectively). The variant ERCC2/XPD 23591A
allele was more frequent in the case subjects (0.343) than in the control
subjects (0.331), and the homozygous wild-type ERCC2/XPD 23591GG genotype was less common in the case group (39.3%) than in
the control group (45.4%), suggesting that the ERCC2/XPD A allele increases risk.
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Table 2. ERCC1 8092 and ERCC2/XPD 23591 Genotype/Allele Frequencies and Concordance*
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Risk estimates are summarized in Table 3. The ERCC1 8092CC genotype was
associated with a borderline increased risk of SCCHN: adjusted OR, 1.15 (95%
CI, 0.84-1.59). The ERCC2/XPD 23591A allele was also
associated with a borderline increased risk of SCCHN: adjusted OR, 1.28 (95%
CI, 0.93-1.76). Furthermore, having both of these risk genotypes (ie, both ERCC1 8092CC and ERCC2/XPD 23591
GA/AA) was associated with a significantly increased risk of SCCHN, and having
only 1 risk genotype was associated with a borderline increased risk, suggesting
an allele dose effect (trend test, P = .04).
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Table 3. ERCC1 8092 and ERCC2/XPD 23591 Risk/Combination Genotype Frequencies and Risk Estimates*
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Subgroup analyses of the combined effect of ERCC1 8092CC and ERCC2/XPD 23591 GA/AA risk genotypes
are summarized in Table 4. In
smokers and drinkers, the risk estimates approached significance: adjusted
OR for smokers, 1.46 (95% CI 0.95-2.25) and for drinkers, 1.40 (95% CI; 0.94-2.10).
Furthermore, the combined risk genotype was associated with a significantly
increased risk for pharyngeal cancer: adjusted OR, 1.59 (95% CI, 1.02-2.49).
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Table 4. Stratification Analysis of Combination Risk Genotype Frequencies,
Odds Ratios, and 95% Confidence Intervals*
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COMMENT
In this study, we assessed the risk of SCCHN associated with ERCC1 8092 and ERCC2/XPD 23591 genotypes in
a hospital-based, case-control analysis of 626 non-Hispanic white subjects
closely matched on age, sex, smoking status, and alcohol use. Our findings
were consistent with the prior report by Chen et al10
of an association between ERCC1 8092CC and adult-onset
glioma. The frequency of the variant ERCC1 8092A
allele in our control subjects (0.248) was similar to the control group of
Chen and colleagues (0.270). However, in that study, a significant risk associated
with the ERCC1 8092CC genotype was found only in
a glioma histologic subgroup of 28 oligoastrocytomas.10
There are no other case-control data of tumor risk associated with the ERCC1 8092 genotype.
Our findings are also consistent with an association between the ERCC2/XPD 23591A allele and decreases in DNA repair capacity
reported in a case-control study of lung cancer risk.9
Although Lunn et al11 reported that the ERCC2/XPD 23591A allele is associated with better DNA repair
as measured by a cytogenetic assay of chromatid aberrations induced by 
irradiation, they assessed only 29 subjects, making genotyping subgroup analysis
particularly subject to chance findings. In fact, they reported an ERCC2/XPD 23591 variant A allele frequency of 0.420, which is much
higher than the 0.331 we found in our 313 control subjects. Furthermore, ERCC2/XPD is a component of the nucleotide excision repair
pathway, which is responsible for removal of tobacco-induced adducts and UV-induced
dimers but not the repair of chromatid breaks induced by irradiation.
In a study of 96 patients with lung cancer and 94 cancer-free controls,
Butkiewicz et al12 also suggested the ERCC2/XPD 23591A allele may have a potential protective
effect, but a case-control analysis of adult-onset glioma found no association
with the ERCC2/XPD 23591 genotype.13
In comparison, the study by Spitz et al9 of
more than 450 subjects found that in the case subjects the ERCC2/XPD 23591A allele was associated with suboptimal DNA repair function
as measured by the well-established host cell reactivation assay.9 Such suboptimal DNA repair is associated with increased
risk of lung cancer14 and SCCHN.3
These discrepancies in results between studies are obviously due to differences
in sample sizes and the assays used. However, these results also suggest that
these individual genotypes probably have only a modest effect on cancer risk,
if any, and that more studies with larger samples are needed to clarify the
role of these genotypes in cancer risk. Future genetic models will probably
include multiple genotypes to significantly and reliably predict cancer risk.
Furthermore, efforts to determine the effect of such polymorphisms on repair
function must be encouraged.
It is unlikely that such common genetic variants have a major effect
on cancer risk independent of environmental exposures. The increased risk
in those exposed to tobacco and alcohol suggests a potential gene-environment
effect. In other words, these genotypes may put individuals at increased risk
only if they are also exposed to a carcinogen. Some epidemiological data suggest
that tobacco and alcohol exposure may have a greater effect on pharyngeal
cancer risk than on oral cavity or laryngeal cancer risk.15
This may explain why we found these risk genotypes to be most common in the
pharyngeal cancer subgroup. Regardless, these findings in subgroup analyses
are preliminary, may be due to chance, and must be confirmed in larger studies.
AUTHOR INFORMATION
Accepted for publication February 13, 2002.
This study is supported in part by start-up funds from The University
of Texas M. D. Anderson Cancer Center (Dr Sturgis) and research grants CA
55769 (Dr Spitz), CA 70334, ES 11740 (Dr Wei), and CA 16672 (to M. D. Anderson
Cancer Center) from the National Institutes of Health, National Cancer Institute,
Bethesda, Md.
This work was presented in part at the annual meeting of the American
Head and Neck Society, Palm Desert, Calif, May 14-16, 2001.
We thank Margaret Lung, RN, for assistance with recruiting patients;
Maureen Goode, PhD, and Chris Yeager, BA, BS, for scientific editing; and
Deanna Thomas, BS, for manuscript preparation.
Corresponding author: Erich M. Sturgis, MD, Department of Head and
Neck Surgery, Box 441, The University of Texas M. D. Anderson Cancer Center,
1515 Holcombe Blvd, Houston, TX 77030-4009 (e-mail: esturgis{at}mdanderson.org).
From the Departments of Head and Neck Surgery (Dr Sturgis) and Epidemiology
(Drs Sturgis, Spitz, and Wei and Ms Dahlstrom), The University of Texas M.
D. Anderson Cancer Center, Houston.
REFERENCES
| |
1. Giovino GA, Schooley MW, Zhu BP, et al. Surveillance for selected tobacco-use
behaviors--United States, 1900-1994. Mor Mortal Wkly Rep CDC Surveill Summ. 1994;43:1-43.
2. Greenlee RT, Hill-Harmon MB, Murray T, Thun M. Cancer statistics, 2001. CA Cancer J Clin. 2001;51:15-36.
FREE FULL TEXT
3. Cheng L, Eicher SA, Guo Z, Hong WK, Spitz MR, Wei Q. Reduced DNA repair capacity in head and neck cancer patients. Cancer Epidemiol Biomarkers Prev. 1998;7:465-468.
FREE FULL TEXT
4. Wang LE, Sturgis EM, Eicher SA, Spitz MR, Hong WK, Wei Q. Mutagen sensitivity to benzo[a]pyrene diol epoxide and the risk of
squamous cell carcinoma of the head and neck. Clin Cancer Res. 1998;4:1773-1778.
ABSTRACT
5. Li D, Firozi PF, Chang P, et al. In vitro BPDE-induced DNA adducts in peripheral lymphocytes as a risk
factor for squamous cell carcinoma of the head and neck. Int J Cancer. 2001;93:436-440.
FULL TEXT
|
ISI
| PUBMED
6. Cheng L, Sturgis EM, Eicher SA, Spitz MR, Wei Q. Nucleotide excision repair gene expression and the risk for squamous
cell carcinoma of the head and neck. Cancer. 2002;94:393-397.
FULL TEXT
|
ISI
| PUBMED
7. Hoeijmakers JHJ. Genome maintenance mechanisms for preventing cancer. Nature. 2001;411:366-374.
FULL TEXT
| PUBMED
8. Shen MR, Jones IM, Mohrenweiser H. Nonconservative amino acid substitution variants exist at polymorphic
frequency in DNA repair genes in healthy humans. Cancer Res. 1998;58:604-608.
FREE FULL TEXT
9. Spitz MR, Wu X, Wang Y, et al. Modulation of nucleotide excision repair capacity by XPD polymorphisms
in lung cancer patients. Cancer Res. 2001;61:1354-1357.
FREE FULL TEXT
10. Chen P, Wiencke J, Aldape K, et al. Association of an ERCC1 polymorphism with
adult-onset glioma. Cancer Epidemiol Biomarkers Prev. 2000;9:843-847.
FREE FULL TEXT
11. Lunn RM, Helzlsouer KJ, Parsad R, et al. XPD polymorphisms: effects on DNA repair proficiency. Carcinogenesis. 2000;21:551-555.
FREE FULL TEXT
12. Butkiewicz D, Rusin M, Enewold L, Shield PG, Chorazy M, Harris CC. Genetic polymorphisms in DNA repair genes and risk of lung cancer. Carcinogenesis. 2001;22:593-597.
FREE FULL TEXT
13. Caggana M, Kilgallen J, Conroy JM, et al. Associations between ERCC2 polymorphisms and
gliomas. Cancer Epidemiol Biomarkers Prev. 2001;10:355-360.
FREE FULL TEXT
14. Wei Q, Cheng L, Amos CI, et al. Repair of tobacco carcinogen-induced DNA adducts and lung cancer risk:
a molecular epidemiologic study. J Natl Cancer Inst. 2000;92:1764-1772.
FREE FULL TEXT
15. Franceschi S, Talamini R, Barra S, et al. Smoking and drinking in relation to cancers of the oral cavity, pharynx,
larynx, and esophagus in northern Italy. Cancer Res. 1990;50:6502-6507.
FREE FULL TEXT
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