Biomedical subjects

J R Daling

Publications and source records attributed to J R Daling.

At least 55 records · Page 3Linked to original sources

PubMed1999

Effect of cervical carcinoma in situ and its management on pregnancy outcome.

OBJECTIVE: To assess the effect of cervical carcinoma in situ (CIS) and its management on subsequent pregnancy outcome. METHODS: We used a population-based retrospective cohort design that included record linkage between cancer data and birth records. The Cancer Surveillance System records of women with CIS (n = 1851, 312 diagnosed during pregnancy) diagnosed between 1984 and 1992, were linked to birth certificates of their first subsequent deliveries after CIS diagnosis. The comparison group (n = 9201) was a random sample of women without CIS who gave birth during the same years. The outcome measures were preterm and low birth weight infants subsequent to CIS diagnosis and treatment. Treatments included no therapy, dilation and curettage or endocervical curettage, cryosurgery or laser vaporization, and conization. RESULTS: Women with CIS who were not treated with conization had a small increased risk of preterm delivery (odds ratio [OR] 1.4, 95% confidence interval [CI] 1.0, 2.0) and no increased risk of low birth weight infant (OR 1.0, 95% CI 0.7, 1.6), compared with women without CIS, after adjusting for maternal smoking, race, parity, marital status, and history of induced pregnancy termination. Women with CIS who had conization were more likely to deliver premature infants (OR 1.6, 95% CI 1.2, 2.0) than women without CIS, after adjusting for the same confounding factors. The apparently increased risk of low birth weight (OR 1.8, 95% CI 1.4, 2.4) seemed to be a reflection of premature delivery. CONCLUSION: The risk of prematurity increased after conization for CIS and did not increase when women with CIS had other procedures.

Adult↗

PubMed1999

Hair product use and the risk of breast cancer in young women.

OBJECTIVES: The reported mutagenic and carcinogenic effects of some chemicals present in hair dyes have raised concern that hair dye use could increase breast cancer risk. This case-control study evaluated how detailed aspects of hair coloring and hair spray application by reproductive-age women may affect breast cancer risk. METHODS: Cases were white female residents of three counties of western Washington state 45 years of age or less, who were diagnosed with breast cancer between 1983 and 1990 (n = 844). A sample of similarly aged women residing in the same counties served as controls (n = 960). Information on hair coloring and hair spray use, as well as other exposures, was ascertained during in-person interviews. RESULTS: Breast cancer cases were slightly more likely than controls to report ever having used some type of hair coloring application, including use of rinses, semi-permanent or permanent dyes, as well as bleaching then dyeing or frosting their hair (relative risk [RR] = 1.3, 95% CI = 1.0-1.6, adjusted for age, fullterm pregnancies, family history of breast cancer, and weight). In subgroup analyses, women with exclusive use of just one of these methods of hair coloring application had no elevation in risk (similarly adjusted RR = 1.1, 95% CI = 0.9-1.3), whereas women who used two or more of these methods did have an elevated risk (RR = 1.9, 95% CI = 1.4-2.5). Hair spray use was not related to the risk of breast cancer (ever versus never users: RR = 1.0, 95% CI = 0.8- 1.3). CONCLUSION: The lack of an association between exclusive use of a single type of hair coloring application and breast cancer risk argues that hair coloring application does not influence breast cancer risk among reproductive-age women. Thus, the results of the present study, as well as negative ones from most (but not all) prior studies, are most consistent with the conclusion that neither hair coloring application nor hair spray application influences breast cancer risk.

Adult↗

PubMed1999

Risk of breast cancer in young women in relation to body size and weight gain in adolescence and early adulthood.

Findings have been inconsistent on effects of adolescent body size and adult weight gain on risk of breast cancer in young women. These relations were examined in a population-based case control study of 1590 women less than 45 years of age newly diagnosed with breast cancer during 1990-1992 in three areas of the US and an age-matched control group of 1390 women. Height and weight were measured at interview and participants asked to recall information about earlier body size. Logistic regression was used to estimate the relative risk of breast cancer adjusted for other risk factors. Women who were either much heavier or lighter than average in adolescence or at age 20 were at reduced risk. Weight gain after age 20 resulted in reduced risk, but the effect was confined to early-stage and, more specifically, lower grade breast cancer. Neither the risk reduction nor the variation by breast cancer stage or grade was explained by the method of cancer detection or by prior mammography history. These findings suggest that relations between breast cancer risk in young women and body weight at different ages is complex and that the risk reduction with adult weight gain is confined to less aggressive cancers.

Adolescent↗

PubMed1999

Comparison of self-report data and medical records data: results from a case-control study on prostate cancer.

BACKGROUND: Self-report and review of medical records are the most common methods for the assessment of past exposures. However, information obtained from self-reports and medical records may not be consistent. This study compared information provided in a self-administered questionnaire with medical records data. METHODS: Self-report and medical records data came from a case-control study on prostate cancer. Cases were 181 patients with primary prostate cancer and controls were 297 men without the disease, enrolled in Group Health Cooperative (GHC) in Seattle. The consistencies between the two data sources were examined. RESULTS: In general, agreement between the two data sources was almost perfect for demographic and anthropometric variables, substantial for the history of inguinal hernia and kidney stones, and moderate for vasectomy, family history of prostate cancer, smoking and alcohol consumption. However, the two data sources generally were poorly concordant for prior genitourinary diseases that have less explicit diagnostic criteria such as benign prostatic hyperplasia and prostatitis. Analyses of discordant data showed that men were more likely to report an exposure or medical condition that could not be verified from medical records. No discernible patterns in the difference of agreement were found according to age, GHC membership length or case-control status. CONCLUSIONS: This study suggests that agreement between self-reported data and medical records data varies depending upon the study variables. While both data sources are subject to some problems, self-report may provide more complete and comparable information, at least for variables unrelated to diagnosis.

Adult↗

PubMed1999

Integrated designs for gene discovery and characterization.

Recent advances, including near completion of the human genome map, ever improving high-throughput technologies, and successes in discovering chronic disease-related genes, have stimulated the further development of genetic epidemiology. The primary mission of genetic epidemiology is to discover and characterize genes, whether independent of or interactive with environmental factors, that cause human diseases. To accomplish such a mission, genetic epidemiology needs to integrate both genetic and epidemiologic approaches. One of the challenges facing such an integrated approach is the identification of study designs that are efficient for both gene discovery and characterization. Because designs for gene discovery alone and designs for gene characterization alone have been elaborated in the other two panels, the focus of this paper is to describe those designs that may be useful for discovery and characterization jointly, including case-family and case-control-family designs. Examples of integrated designs are described, and studies of breast cancer conducted at the Fred Hutchinson Cancer Research Center are used for illustration. Finally, related analytic issues are also discussed.

Breast Neoplasms↗

PubMed1999

CYP2D6 genotype and the incidence of anal and vulvar cancer.

The risks of anal and vulvar cancer are strongly related to cigarette smoking. Smokers are exposed to a substantial quantity of tobacco-specific nitrosamines, including 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). NNK is present in the mucus of the female genital tract. The enzyme debrisoquine 4-hydroxylase (CYP2D6) activates NNK and is present in foreskin kerotinocytes and cervical epithelial cells. A polymorphism for the gene CYP2D6 exists, and persons who possess alleles that are associated with reduced levels of CYP2D6 activity might be expected to be at a relatively lower risk of cancers arising from NNK exposure. To test this hypothesis, we conducted a case-control study to examine the association of CYP2D6 genotype and the incidence of anal and vulvar cancer among cigarette smokers in western Washington State. We tested for 14 alleles (*1-*12, *14, and *17) among cases (25 men and 43 women with anal cancer, 64 women with vulvar cancer) and controls (30 men and 110 women). Contrary to the hypothesis, cases were not less likely than controls to have one (43.9 versus 40.7%) or two (6.8 versus 4.3%) inactivating alleles (*3, *4, *5, *6, *7, *8, *11, or *12). There was a suggestion that, if anything, the combined anal and vulvar cancer risk increased (rather than decreased) with an increasing number of CYP2D6 inactivation alleles: odds ratio = 1.2, 95% confidence interval = 0.7-2.0 with one inactivating allele; odds ratio = 1.8, 95% confidence interval = 0.6-5.4 with two inactivating alleles. These results provide no support for the hypothesis that cigarette smokers who carry the CYP2D6 alleles that result in a low activity phenotype have a decreased risk of anogenital cancer.

Adolescent↗

PubMed1999

Vasectomy and risk of prostate cancer.

Most studies do not support an association between vasectomy and prostate cancer, but a few have suggested a link. Vasectomy is a common birth control method, and prostate cancer is the most frequently diagnosed solid tumor in men, making this a major public health question. This study was specifically designed to determine whether or not vasectomy is associated with risk of prostate cancer. To examine this issue, we conducted a population-based case-control study in King County, Washington. Interviews were completed with men ages 40-64 years newly diagnosed with prostate cancer between January 1993 and December 1996 who were ascertained through the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry (n = 753) and with comparison men without prostate cancer identified from the same general population (n = 703). The odds ratio (OR) for prostate cancer in relation to vasectomy was assessed. The prevalence of vasectomy was similar in cases (39.4%) and controls (37.7%), resulting in no association (adjusted OR, 1.10; 95% confidence interval, 0.9-1.4). There was no consistent evidence that risk varied by the age at which vasectomy was performed, the time since vasectomy, or the calendar period when the vasectomy was performed. The OR in relation to vasectomy was higher in men with less aggressive prostate cancer. Risk estimates did not differ according to age, race, or family history of prostate cancer. This study suggests that vasectomy is not associated with the risk of developing prostate cancer. It also provides evidence that vasectomized men may be more likely to present with earlier-stage, lower-grade prostate tumors.

Adult↗

PubMed1999

Prostate cancer in relation to the use of electric blanket or heated water bed.

Using data from a case-control study conducted in Group Health Cooperative (GHC) of Puget Sound, we examined the relation between the use of electric blankets or heated water beds and the risk of prostate cancer. Cases were 175 prostate cancer patients ages 40-69 years. Controls were 258 male GHC members frequency matched to cases. The odds ratio (OR) for prostate cancer associated with the use of an electric blanket or heated water bed was 1.4 (95% confidence interval (CI) 0.9-2.2). The risk, however, did not tend to be higher with increasing months per year or years of use. This study did not provide clear evidence on the hypothesized association.

Adult↗

PubMed1998

Oral cancer risk in relation to sexual history and evidence of human papillomavirus infection.

BACKGROUND: Experimental models and analyses of human tumors suggest that oncogenic, sexually transmittable human papillomaviruses (HPVs) are etiologic factors in the development of oral squamous cell carcinoma (SCC). We conducted a population-based, case-control study to determine whether the risk of this cancer is related to HPV infection and sexual history factors. METHODS: Case subjects (n = 284) were 18-65-year-old residents of three counties in western Washington State who were newly diagnosed with oral SCC from 1990 through 1995. Control subjects (n = 477) similar in age and sex were selected from the general population. Serum samples were tested for HPV type 16 capsid antibodies. Exfoliated oral tissue collected from case and control subjects and tumor tissue from case subjects were tested for HPV DNA. Odds ratios (ORs) were calculated after adjusting for age, sex, cigarette smoking, and alcohol consumption. RESULTS: Among males only, oral SCC risk increased with self-reported decreasing age at first intercourse, increasing number of sex partners, and a history of genital warts. Approximately 26% of the tumors in case subjects contained HPV DNA; 16.5% of the tumors contained HPV type 16 DNA. The prevalence of oncogenic HPV types in exfoliated oral tissue was similar in case and control subjects. The ORs for HPV type 16 capsid seropositivity were 2.3 (95% confidence interval [CI] = 1.6-3.3) for all oral SCCs and 6.8 (95% CI = 3.0-15.2) for oral SCCs containing HPV type 16 DNA. The joint association of cigarette smoking and HPV type 16 capsid seropositivity with oral SCC (OR = 8.5; 95% CI = 5.1-14.4) was stronger than predicted from the sum of individual associations with current smoking (OR = 3.2; 95% CI = 2.0-5.2) and seropositivity (OR = 1.7; 95% CI = 1.1-2.6). CONCLUSIONS: HPV type 16 infection may contribute to the development of a small proportion of oral SCCs in this population, most likely in combination with cigarette smoking.

Adult↗

PubMed1998

BRCA1 mutations and breast cancer in the general population: analyses in women before age 35 years and in women before age 45 years with first-degree family history.

CONTEXT: Studies of high-risk families with multiple early-onset cases of breast cancer have been useful for assessing the type and spectrum of germline mutations on the BRCA1 gene, but do not provide guidance to women with modest family history profiles. Thus, studies of women from the general population are needed to determine the BRCA1 mutation frequency in women perceived to be at high risk, and to develop profiles of those most likely to be carriers. OBJECTIVE: To characterize frequency and spectrum of germline BRCA1 mutations in 2 categories of women identified via population-based studies hypothesized to be at increased risk of carrying such mutations: those diagnosed as having breast cancer before age 35 years and those diagnosed before age 45 years who have first-degree breast cancer family history. DESIGN: Study subjects were drawn from 2 population-based case-control studies of breast cancer in young women on the basis of their family history or their age of diagnosis. Cases were younger than 35 years or were younger than 45 years with first-degree family history at the time of breast cancer diagnosis and were ascertained via a population-based cancer registry, and controls (women without breast cancer) were identified via random-digit dialing. SETTING: Three counties in western Washington State. MAIN OUTCOME MEASURE: BRCA1 germline mutations in study subjects identified in DNA from peripheral blood lymphocytes by single-strand conformation polymorphism analysis using primer pairs that span the BRCA1 coding region and intron-exon boundaries. RESULTS: Of 193 women diagnosed as having breast cancer before age 35 years, none of whom were selected on the basis of family history status, 12 (6.2%, 95% confidence interval [CI], 3.2%-10.6%) had germline BRCA1 mutations. In 208 women diagnosed before age 45 years who had first-degree breast cancer family history, 15 (7.2%, 95% CI,4.1%-11.6%) had germline mutations in BRCA1. In both groups, there were variations in mutation frequency noted by age and by family history. Mutation frequency decreased with increasing age of diagnosis. Higher proportions of mutations were seen in cases with at least 1 relative diagnosed as having breast cancer before age 45 years, in cases with greater numbers of affected relatives, and those with ovarian cancer family history. Mutation frequency did not vary by bilateral breast cancer family history. No frameshift or nonsense mutations were observed in 71 control women with a first-degree family history, although missense changes of unknown significance were seen in cases and controls. CONCLUSIONS: Women with BRCA1 germline mutations lacked a common family history profile. Also, a large proportion of the women with a first-degree breast cancer family history and women diagnosed as having breast cancer before age 35 years did not carry germline BRCA1 mutations. Hence, while early-onset disease and a strong breast cancer family history may be useful guidelines for checking BRCA1 status, these findings on women drawn from the general population suggest that it may be difficult to develop BRCA1 mutation screening criteria among women with modest family history profiles.

Adult↗

PubMed1998

Recreational physical activity and breast cancer risk among women under age 45 years.

To evaluate whether recreational physical activity is associated with breast cancer among young women, the authors analyzed data from a population-based case-control study. Cases (n = 1,668) were women under age 45 years who had been newly diagnosed with breast cancer between 1990 and 1992 in Atlanta, Georgia, central New Jersey, or Seattle, Washington. Controls (n = 1,505) were frequency-matched to cases by 5-year age group and geographic area of residence. Breast cancer was not associated with recreational activity in any of the three time periods assessed (highest quartile of activity vs. lowest: age- and center-adjusted odds ratio (OR) = 0.94 (95% confidence interval (CI) 0.77-1.15) at ages 12-13 years, OR = 1.08 (95% CI 0.88-1.32) at age 20 years, and OR = 1.18 (95% CI 0.97-1.44) during the past year), with the average of the three time periods (OR = 1.02, 95% CI 0.84-1.25), or with daily climbing of at least two flights of stairs (without stopping) during the past year (daily climbing vs. never climbing: OR = 1.03, 95% CI 0.86-1.23). Estimates were not modified or confounded by body mass index, menopausal status, or caloric intake during the past year. These results do not support a protective role for physical activity in the risk of breast cancer among young women.

Adolescent↗

PubMed1998

Validity and reliability of subject and mother reporting of perinatal factors.

The authors used data from a population-based case-control study of breast cancer in women aged < or = 44 years (cases, n = 975; controls, n = 866) conducted between 1994 and 1996 in three counties of western Washington state to assess the validity and reliability of reported perinatal factors. For a sample of participants, exposure information from self-administered questionnaires was validated with information from birth certificates (cases, n = 378; controls, n = 283). Detailed information regarding perinatal characteristics of their daughters was also collected from subjects' mothers (case mothers, n = 510; control mothers, n = 436) to assess the reliability of subjects' reporting of these events. Although reporting of birth weight by subjects (cases, r = 0.83; controls, r = 0.80) and their mothers (case mothers, r = 0.89; control mothers, r = 0.84) was highly correlated with the birth certificates, there was differential measurement error by subjects; cases reported birth weight accurately on average, but controls tended to underestimate their birth weight. Agreement between the subject and mother report was excellent for birth weight (cases, r = 0.85; controls, r = 0.87) and good for other perinatal factors, but birth order and maternal diethylstilbestrol use were underreported among cases and reported accurately among controls. Differential measurement error of birth weight by case-control status resulted in biased odds ratios for breast cancer risk.

Birth Weight↗

PubMed1998

Characteristics of women who use perineal powders.

OBJECTIVE: To examine demographic and behavioral factors related to perineal application of powders. METHODS: Controls from three case-control studies (N = 1206) were asked identical questions about the use of genital powders by direct perineal application. The relationship of perineal powder application with demographic factors, reproductive factors, body mass index (BMI), douching, and alcohol and tobacco use was assessed. Data were analyzed by multiple logistic regression. RESULTS: Women who douched (prevalence odds ratio [prevalence OR] 2.0, 95% confidence interval [CI] 1.0, 3.9), drank alcohol (prevalence OR 1.8, 95% CI 1.2, 2.8), smoked cigarettes (prevalence OR 1.3, 95% CI 1.0, 1.8), or were in the highest BMI quartile were more likely to engage in perineal use of powder (prevalence OR 1.6, 95% CI 1.1, 2.6). There appeared to be a close response relationship between the number of perineal applications of powder and BMI (P < .002). CONCLUSION: Body mass index might confound the relationship between perineal powder application and the development of ovarian cancer. Other factors, such as alcohol and tobacco use and douching, are related to perineal use of powder and may represent similar behavioral characteristics.

Alcohol Drinking↗

PubMed1998

Use of exogenous hormones hormones and risk of papillary thyroid cancer (Washington, United States).

OBJECTIVES: Greater incidence of thyroid cancer in women than men, particularly evident during the reproductive years, has led to the suggestion that female hormones may increase risk of this disease. We conducted a population-based case-control study in women aged 18 to 64 years in three counties of western Washington State (United States) to assess the relation of use of exogenous hormones, including oral contraceptives (OC) and hormone replacement therapy (HRT), to risk of papillary thyroid cancer. METHODS: Of 558 women with thyroid cancer of the follicular epithelium diagnosed during 1988-94 who were identified as eligible, 468 (83.9 percent) were interviewed; this analysis was restricted to women with papillary histology (n = 410). Controls (n = 574) were identified by random digit dialing, with a response proportion of 73.6 percent. Logistic regression was used to calculate odds ratios (OR) and associated 95 percent confidence intervals (CI) estimating the relative risk of papillary thyroid cancer among users of exogenous hormones. RESULTS: Among women aged 45 to 64 years, we observed no association of use of OCs or HRT with risk of papillary thyroid cancer. Among women less than 45 years of age, risk of papillary thyroid cancer was reduced in women who had ever used OCs (OR = 0.6, CI = 0.4-0.9); beyond the relation with ever-use, there was no further association with specific aspects of exposure such as estrogenic potency, latency, recency, age at first or last use, or use at the reference date. CONCLUSIONS: Our data do not support the hypothesis that use of exogenous estrogens increases the risk of female thyroid cancer.

Adolescent↗

PubMed1998

Maternal factors and breast cancer risk among young women.

The results from previous studies have provided evidence to support the hypothesised association between intrauterine oestrogen exposure and subsequent risk of breast cancer. Information has not been available to study this relationship for several perinatal factors thought to be related to pregnancy oestrogen levels. Data collected from the mothers of women in two population-based case-control studies of breast cancer in women under the age of 45 years (510 case mothers, 436 control mothers) who were diagnosed between 1983 and 1992 in three western Washington counties were used to investigate further the relationship between intrauterine oestrogen exposure and risk of breast cancer. A pregnancy weight gain of 25-34 pounds was associated with breast cancer risk (odds ratio [OR] = 1.5; 95% confidence interval [CI] 1.1, 2.0); however, women whose mothers gained 35 pounds or more were not at increased risk. Use of antiemetic medication in women with any nausea and vomiting (OR = 2.9; 95% CI 1.1, 8.1) and use of diethylstilboestrol (DES) (OR = 2.3; 95% CI 0.8, 6.4) appeared to be positively associated with breast cancer risk. The results from this study provide limited support for the hypothesis that in utero oestrogen exposure may be related to subsequent breast cancer risk among young women.

Adult↗

PubMed1998

Risk factors for incident and recurrent condylomata acuminata among men. A population-based study.

BACKGROUND AND OBJECTIVES: The rapid increase in the number of physician office visits for condylomata acuminata and the association of human papillomavirus and cancer has prompted renewed interest in the epidemiology of this sexually-transmitted disease. Few epidemiologic studies have examined what risk factors are associated with condylomata acuminata in men. GOAL: To determine what factors may predispose a man to the occurrence of condylomata acuminata. STUDY DESIGN: A population-based case-control study was conducted among male members of a health maintenance organization. Patients were men 18 years or older who were seen for condyloma at one of four primary care clinics of Group Health Cooperative of Puget Sound between April 1, 1987 and September 30, 1991. Control subjects were frequency matched to the patients on clinic site, race, and age. In-person interviews were used to ascertain exposure histories from both patients and control subjects. RESULTS: Recurrent condyloma was reported by about one third of our patients. Patients with multiple partners were strongly associated with developing the disease. Several factors were either more strongly or only associated with recurrent disease. Other behavioral measures, such as recreational drug use, were also related the occurrence of condyloma. CONCLUSION: These results confirm the sexual-transmitted mechanism of condyloma in men. Exposure to multiple partners was associated with elevated risk of both recurrent and incident disease. Other cofactors may be involved in the etiology of condyloma.

Adolescent↗

PubMed1998

Risk factors for incident and recurrent condylomata acuminata among women. A population-based study.

BACKGROUND: Condylomata acuminata is one of the most common sexually transmitted diseases (STDs) diagnosed in the United States, yet relatively little research has been conducted on the determinants of this disease in well-defined populations. GOAL: To determine the exposures that predispose a woman to the development of condylomata acuminata or genital warts. STUDY DESIGN: A population-based case-control study was conducted among enrollees of Group Health Cooperative of Puget Sound. Patients (94 women with incident and 55 women with recurrent condyloma) were diagnosed between April 1, 1987 and September 30, 1991. Control subjects were 133 women without a history of genital warts. An in-person interview was conducted to collect information on subject characteristics, exposures, and on all episodes of genital warts. RESULTS: Women with five or more partners within the 5 years before reference date were over seven times more likely to have incident condyloma (relative risk [RR], 7.5; 95% confidence interval [CI], 3.1-18.1) and over 12 times more likely to have recurrent condyloma (RR, 12.8; 95% CI, 4.2-38.9) compared with women with only one sexual partner during this time period. An increased risk of incident condyloma was also associated with a history of any STD (RR, 2.6; 95% CI, 1.1-5.8), a history of oral herpes (RR, 2.2; 95% CI, 1.1-4.4), and a history of allergies (RR, 2.0 95% CI, 1.0-3.8). Our data did not support a strong association between risk of condyloma and smoking or recent use of oral contraceptives. CONCLUSION: Our results suggest that risk of condyloma is primarily related to sexual behavior. We did not observe a strong association between risk of condyloma and many of the exposures considered to be potential cofactors for anogenital cancers associated with other types of human papillomaviruses.

Adolescent↗

PubMed1998

Loss of heterozygosity at 5q21-22 (adenomatous polyposis coli gene region) in oral squamous cell carcinoma is common and correlated with advanced disease.

We determined the frequency of loss of heterozygosity (LOH) at chromosome 5q21-22 (adenomatous polyposis gene region) in oral SCC from 49 patients using PCR-based assays. Of 43 informative (heterozygous) tumors, 41.9% [95% confidence interval (CI)=27.0, 57.9] contained LOH at 5q21-22. LOH at 5q21-22 was strongly associated with stage at diagnosis: 100%, (3/3), 50% (13/26), and 14% (2/14) of tumors from patients with distant metastases, regional spread, and localized disease, respectively, contained this genetic alteration (P=0.01). There were no statistically significant associations between LOH at 5q21-22 and other patient or tumor characteristics, but LOH was more commonly found in the tumors of heavy smokers, infrequent alcohol consumers, and in tumors containing either p53 mutations or HPV-DNA. In univariate analyses, LOH at 5q21-22 was associated with poor prognosis (hazard ratio=1.8, 95%, CI 0.8, 4.5); this relationship did not persist after adjustment for stage of disease (hazard ratio=1.1, 95% CI=0.4, 3.1). These data provide further evidence that inactivation of the APC gene and/or other genes at 5q21-22 is common and may be involved in the development and/or progression of oral SCC. Larger studies are needed to determine whether LOH at 5q21-22 is linked to known oral SCC etiologic factors and/or the prognosis of oral SCC patients, as well as to genetic instability at other loci involved in these malignancies.

Adult↗