Shared and Study-specific Dietary Patterns and Head and Neck Cancer Risk in an International Consortium.

BACKGROUND: A few papers have considered reproducibility of a posteriori dietary patterns across populations, as well as pattern associations with head and neck cancer risk when multiple populations are available. METHODS: We used individual-level pooled data from seven case-control studies (3844 cases; 6824 controls) participating in the International Head and Neck Cancer Epidemiology consortium. We simultaneously derived shared and study-specific a posteriori patterns with a novel approach called multi-study factor analysis applied to 23 nutrients. We derived odds ratios (ORs) and 95% confidence intervals (CIs) for cancers of the oral cavity and pharynx combined, and larynx, from logistic regression models. RESULTS: We identified three shared patterns that were reproducible across studies (75% variance explained): the Antioxidant vitamins and fiber (OR = 0.57, 95% CI = 0.41, 0.78, highest versus lowest score quintile) and the Fats (OR = 0.80, 95% CI = 0.67, 0.95) patterns were inversely associated with oral and pharyngeal cancer risk. The Animal products and cereals (OR = 1.5, 95% CI = 1.1, 2.1) and the Fats (OR = 1.8, 95% CI = 1.4, 2.3) patterns were positively associated with laryngeal cancer risk, whereas a linear inverse trend in laryngeal cancer risk was evident for the Antioxidant vitamins and fiber pattern. We also identified four additional study-specific patterns, one for each of the four US studies examined. We named them all as Dairy products and breakfast cereals, and two were associated with oral and pharyngeal cancer risk. CONCLUSION: Multi-study factor analysis provides insight into pattern reproducibility and supports previous evidence on cross-country reproducibility of dietary patterns and on their association with head and neck cancer risk. See video abstract at, http://links.lww.com/EDE/B430.

Clustering of esophageal cancer among white men in the United States.

Studies of the geographic distribution of esophageal cancer in the United States have been limited. We aimed to examine geographic clustering of esophageal cancer in the United States and assess whether that clustering is explained by the distribution of known risk factors for esophageal cancer. We conducted cluster analyses derived from county mortality rates of esophageal cancer, using publicly available datasets. State incidence rates of esophageal adenocarcinoma were from the National Program of Cancer Registries, and county esophageal-cancer mortality rates were from the Vital Statistics Cooperative Program. County prevalences of cigarette use, alcohol use, obesity, education, and income were published estimates derived from the Behavioral Risk Factor Surveillance System and the American Community Survey. The primary outcomes were clusters of high and low esophageal-cancer mortality rates among non-Hispanic white men, both unadjusted and adjusted for risk factors. Age-standardized county rates of esophageal-cancer mortality among non-Hispanic white men ranged from 4.8 to 21.2 per 100,000/year. There was a cluster of high mortality in the Great Lakes states and New England and a cluster of low mortality in the Southeastern United States. State incidence rates of esophageal adenocarcinoma were consistent with this pattern. Adjusting for risk factors did little to change the pattern of observed rates or the clusters derived from them. Among non-Hispanic white men, there are clusters of high and low mortality rates with esophageal cancer within the United States, likely representing esophageal adenocarcinoma; but those clusters were not explained by several known risk factors. Focusing future efforts in the high-cluster areas might improve the efficiency of cancer screening and control.

The role of oral hygiene in head and neck cancer: results from International Head and Neck Cancer Epidemiology (INHANCE) consortium.

BACKGROUND: Poor oral hygiene has been proposed to contribute to head and neck cancer (HNC) risk, although causality and independency of some indicators are uncertain. This study investigates the relationship of five oral hygiene indicators with incident HNCs. METHODS: In a pooled analysis of 8925 HNC cases and 12 527 controls from 13 studies participating in the International Head and Neck Cancer Epidemiology Consortium, comparable data on good oral hygiene indicators were harmonized. These included: no denture wear, no gum disease (or bleeding), <5 missing teeth, tooth brushing at least daily, and visiting a dentist ≥once a year. Logistic regression was used to estimate the effects of each oral hygiene indicator and cumulative score on HNC risk, adjusting for tobacco smoking and alcohol consumption. RESULTS: Inverse associations with any HNC, in the hypothesized direction, were observed for <5 missing teeth [odds ratio (OR) = 0.78; 95% confidence interval (CI) 0.74, 0.82], annual dentist visit (OR = 0.82; 95% CI 0.78, 0.87), daily tooth brushing (OR = 0.83, 95% CI 0.79, 0.88), and no gum disease (OR = 0.94; 95% CI 0.89, 0.99), and no association was observed for wearing dentures. These associations were relatively consistent across specific cancer sites, especially for tooth brushing and dentist visits. The population attributable fraction for ≤ 2 out of 5 good oral hygiene indicators was 8.9% (95% CI 3.3%, 14%) for oral cavity cancer. CONCLUSION: Good oral hygiene, as characterized by few missing teeth, annual dentist visits, and daily tooth brushing, may modestly reduce the risk of HNC.

Vitamin E intake from natural sources and head and neck cancer risk: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium.

BACKGROUND: Evidence for the possible effect of vitamin E on head and neck cancers (HNCs) is limited. METHODS: We used individual-level pooled data from 10 case-control studies (5959 cases and 12 248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium to assess the association between vitamin E intake from natural sources and cancer of the oral cavity/pharynx and larynx. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models applied to quintile categories of non-alcohol energy-adjusted vitamin E intake. RESULTS: Intake of vitamin E was inversely related to oral/pharyngeal cancer (OR for the fifth vs the first quintile category=0.59, 95% CI: 0.49-0.71; P for trend <0.001) and to laryngeal cancer (OR=0.67, 95% CI: 0.54-0.83, P for trend <0.001). There was, however, appreciable heterogeneity of the estimated effect across studies for oral/pharyngeal cancer. Inverse associations were generally observed for the anatomical subsites of oral and pharyngeal cancer and within covariate strata for both sites. CONCLUSION: Our findings suggest that greater vitamin E intake from foods may lower HNC risk, although we were not able to explain the heterogeneity observed across studies or rule out certain sources of bias.

Comparison of three methods for measuring psoriasis severity in clinical studies (Part 2 of 2): use of quality of life to assess construct validity of the Lattice System Physician's Global Assessment, Psoriasis Area and Severity Index and Static Physician's Global Assessment.

BACKGROUND: Systems for determining psoriasis severity in clinical trials have not been sufficiently validated against patients' perceived quality of life. OBJECTIVE: To validate three systems of physician-determined psoriasis severity (the Lattice System Physician's Global Assessment [LS-PGA], Psoriasis Area and Severity Index [PASI] and static Physician's Global Assessment [sPGA]). METHODS: Data were from a 24-week randomized, double-blind, placebo-controlled, multicenter trial of therapy with oral calcineurin inhibitors in 445 patients. Construct validity was measured by correlations of the three severity scores with patients' self-reported quality of life (QoL) from the Dermatology Life Quality Index (DLQI) and a DLQI item about psoriasis symptoms. RESULTS: All severity systems were moderately and positively correlated with QoL, indicating construct validity. QoL was most consistently related to physicians' assessments of body surface area involved with psoriasis (iBSA) followed by, in the order of consistency, plaque elevation, erythema and scale. CONCLUSIONS: The LS-PGA weights iBSA and aspects of plaque morphology in concert with their relative effects on QoL. The LS-PGA, sPGA and PASI are validated by their relationship to QoL in a clinical trial.

Nutrient-based dietary patterns and the risk of head and neck cancer: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium.

BACKGROUND: The association between dietary patterns and head and neck cancer has rarely been addressed. PATIENTS AND METHODS: We used individual-level pooled data from five case-control studies (2452 cases and 5013 controls) participating in the International Head and Neck Cancer Epidemiology consortium. A posteriori dietary patterns were identified through a principal component factor analysis carried out on 24 nutrients derived from study-specific food-frequency questionnaires. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using unconditional logistic regression models on quintiles of factor scores. RESULTS: We identified three major dietary patterns named 'animal products and cereals', 'antioxidant vitamins and fiber', and 'fats'. The 'antioxidant vitamins and fiber' pattern was inversely related to oral and pharyngeal cancer (OR=0.57, 95% CI 0.43-0.76 for the highest versus the lowest score quintile). The 'animal products and cereals' pattern was positively associated with laryngeal cancer (OR=1.54, 95% CI 1.12-2.11), whereas the 'fats' pattern was inversely associated with oral and pharyngeal cancer (OR=0.78, 95% CI 0.63-0.97) and positively associated with laryngeal cancer (OR=1.69, 95% CI 1.22-2.34). CONCLUSIONS: These findings suggest that diets rich in animal products, cereals, and fats are positively related to laryngeal cancer, and those rich in fruit and vegetables inversely related to oral and pharyngeal cancer.

Intrauterine diabetes exposure and the risk of renal disease in diabetic Pima Indians.

The association between the diabetic intrauterine environment and renal disease was examined cross-sectionally in 503 Pima Indians with type 2 diabetes. Subjects were selected from participants in an ongoing study of diabetes and its complications in the Gila River Indian Community of Arizona. Subjects' exposure to diabetes in utero was established from periodic examinations conducted as part of the study. The prevalence of elevated urinary albumin excretion (UAE) (albumin-to-creatinine ratio > or = 30 mg/g) was 40% (83 of 207) in the offspring of nondiabetic mothers, 43% (105 of 246) in the offspring of prediabetic mothers (i.e., women who were not diabetic at the time of the pregnancy but who developed diabetes after the pregnancy), and 58% (29 of 50) in the offspring of mothers who had diabetes during pregnancy. After controlling for age, sex, duration of diabetes, HbA1c, and mean arterial pressure in the offspring in a logistic regression analysis using generalized estimating equations, maternal diabetes during pregnancy was strongly associated with elevated UAE. The odds of elevated UAE in the offspring of mothers who had diabetes during pregnancy was 3.8 times (95% CI 1.7-8.4) that of the offspring of prediabetic mothers; the odds of elevated UAE in the offspring of nondiabetic and prediabetic mothers were similar (odds ratio of 0.94; 95% CI 0.59-1.5). We concluded that exposure to a diabetic intrauterine environment increases the risk of elevated UAE in diabetic Pima Indians. The effect of this exposure appears to be independent of other susceptibility factors that lead to nephropathy in diabetes.

Identifying risk factors for tardive dyskinesia among long-term outpatients maintained with neuroleptic medications. Results of the Yale Tardive Dyskinesia Study.

OBJECTIVES: To describe the incidence of tardive dyskinesia (TD) in the Yale TD Study and to identify demographic, treatment, and clinical risk factors for TD occurrence. DESIGN: An ongoing prospective cohort study in which subjects have been examined every 6 months since 1985. SETTING: The outpatient division of the Connecticut Mental Health Center in New Haven. SUBJECTS: Three hundred ninety-eight adult outpatients who had been maintained with neuroleptics for 3 months to 33 years at intake and who were free of persistent TD at intake with no history of persistent TD movements. OUTCOME MEASURE: New cases of persistent TD were defined as the presence of mild or more severe dyskinetic movements at two successive follow-up visits, using the Abnormal Involuntary Movement Scale. RESULTS: As of July 1, 1990, there were 62 new persistent cases of TD, yielding an average incidence rate of 0.053 per year and a 5-year risk of 20%. The TD rate was positively affected by age, being nonwhite, and neuroleptic dose, and it was inversely affected by years of previous exposure. Little or no effects were found for age at first neuroleptic exposure, type of neuroleptic, use of other psychiatric medications, and psychiatric diagnosis. CONCLUSIONS: For outpatients maintained for many years with neuroleptics, dose should be minimized to reduce the risk of TD. This strategy does not appear to be negated by prescribing frequent changes in dosage. Although the TD rate is greatest during the first 5 years of neuroleptic treatment, new persistent cases continue to occur many years after first exposure.

Tardive dyskinesia. A discontinuation study.

Twenty-one nonschizophrenic and 12 schizophrenic outpatients with tardive dyskinesia (TD) were followed up for a mean of 12.0 and 8.6 months, respectively, following discontinuation of neuroleptic therapy. Of the 33 patients, only one demonstrated complete reversal of TD. Cumulative survival curves of the length of time to first improvement (reduction in movement ratings by 50% of baseline) did not differ between the two groups. The median time to first improvement was seven months. If a patient can be kept off of a neuroleptic regimen for 18 months, the estimated probability of showing a 50% reduction in movement is 87.2%. In the nonschizophrenic group, depressed mood was negatively correlated with severity of abnormal movements.

Bone marrow transplantation for acute myeloid leukemia: the EBMT experience. A prospective analysis from HLA-typing. The EMBT Leukemia Working Party.

In 1990, 4,234 BMT were performed in Europe; 2,097 autologous BMT (388 AML) and 2,137 allogeneic BMT (494 AML). Although an established therapy with leukemia free survival (LFS) at five years of 41% +/- 5% (EBMT results) its value compared to alternative therapies remains controversial. During the year 1985, the EBMT conducted a prospective evaluation study. In 12 centres 168 patients with AML were registered at the time of HLA-typing. Basic patient data and treatment intention were recorded. 79 patients were HLA-typed at diagnosis. 68 patients in 1st CR and 21 at other stages. Follow-up of these patients was obtained as of January 1, 1991. Three-year LFS is 44% for patients with an HLA-identical donor and 21% for those without (p = 0.02). Of the 68 patients HLA-typed in first CR, 40 had an HLA-identical donor and 28 no donor. Three-year LFS is 42% and 35%. resp. (n.s.). The difference in results between patients typed at diagnosis and first CR patients illustrates the problem of selection. We conclude that patient registration early in the disease can give insight into the process of selection. Allogeneic BMT incorporated prospectively at diagnosis into therapy offers a survival advantage for patients in this age category compared to alternative therapies.

Postdischarge geriatric assessment of hospitalized frail elderly patients.

BACKGROUND: The diffusion of comprehensive geriatric assessment services has been rather limited in North America partly because of reimbursement and organizational constraints. OBJECTIVE: To evaluate the impact of a comprehensive geriatric assessment intervention for frail older patients that is started before hospital discharge and is continued at home. METHODS: Patients older than 65 years were selected who had either unstable medical problems, recent functional limitations, or potentially reversible geriatric clinical problems. Patients (n = 354) were randomly assigned to either the intervention group or a control group. Information on survival, readmissions, nursing home placement, medication use, and health status was collected at 30 and 60 days after hospital discharge. RESULTS: No differences were observed between the two treatment groups in survival, hospital readmission, or nursing home placement by 60 days. After adjustment for baseline characteristics, no significant differences were observed between the two groups on measures of physical functioning, social functioning, role limitations, health perceptions, pain, mental health, energy and/or fatigue, health change, or overall well-being. CONCLUSIONS: Although efficacy has been demonstrated for some forms of comprehensive geriatric assessment, the types of services that are easier to establish (inpatient consultation services and ambulatory assessment) have not been shown to improve outcomes. Our results indicate that outcomes are unaffected by a limited form of comprehensive geriatric assessment begun in the hospital and completed at home. Further efforts are needed to develop and to evaluate realistic approaches to comprehensive geriatric assessment.

Handedness and the risk of tardive dyskinesia.

Previous results from five cross-sectional studies are conflicting about the relationship between hand preference and tardive dyskinesia (TD): two report a greater TD prevalence in left handers, and three report a greater prevalence in right handers. To help resolve these inconsistencies, the handedness-TD association was assessed in the Yale TD Study, a large prospective cohort investigation of outpatients maintained with neuroleptics. A consistent monotonic association was observed between the handedness score and TD incidence (p = 0.009). The estimated rate ratio, comparing left and mixed handers with pure right handers, adjusted for confounders, was 0.25 (95% confidence interval = 0.09, 0.70). The handedness effect (higher TD rate in right handers) was stronger for subjects with fewer negative symptoms, and it was stronger for men than for women. Although the specific biological mechanisms are unclear, these findings may reflect cerebral laterality in the pathophysiology of psychiatric disorders, possibly in combination with asymmetrical action of neuroleptic exposure.

Demographic predictors of the use of injectable versus oral antipsychotic medications in outpatients.

The authors examined the records of 397 outpatients maintained on antipsychotic medication to identify demographic characteristics that predicted use of depot medication. Patients maintained on long-acting antipsychotics tended to be young, male, and black. The age effect was largely restricted to white patients.

Dimensions of delusional experience.

The authors describe a scale designed to measure five dimensions of delusional experience: conviction, extension, bizarreness, disorganization, and pressure. Reliability was adequate to excellent on four of the dimensions, but only fair on the dimension of bizarreness. In 52 delusional patients, no two dimensions correlated highly with each other, indicating that the dimensions were not redundant. Factor analysis identified two factors from the five dimensions--delusional involvement and delusional construct. On the basis of these results the authors suggest that delusions are a multidimensional phenomenon; the results have implications for the measurement of delusions in clinical research and for the understanding of the structure of psychotic experience.

Identifying modifiable risk factors for rehospitalization: a case-control study of seriously mentally ill persons in Mississippi.

OBJECTIVE: The authors sought to identify risk factors for rehospitalization in a seriously mentally ill population, focusing on factors that have the potential to be modified through community-based interventions. METHOD: A case-control design was used in which 101 "case" subjects (recently readmitted psychiatric patients) and a comparison group of 101 subjects living in the community who had been previously hospitalized at the same time as the case subjects, but who in contrast had not been readmitted, were matched on gender, ethnicity, and length of time at risk for rehospitalization. The setting was the Mississippi public mental health system during the first 3 months of 1988, including Mississippi State Hospital and the 10 community mental health regions in its catchment area. The subjects were between the ages of 18 and 55 years, had had at least one previous Mississippi State Hospital admission, and had a primary chart diagnosis of schizophrenia; 197 informants, mostly family members, were also included in the study. Data were collected from structured interviews of subjects and informants, direct observation ratings of subjects, Mississippi State Hospital administrative records, and community mental health center administrative records. RESULTS: Medication noncompliance, comorbid alcohol abuse, and a high level of criticism of subjects by informants were associated with greater risk of rehospitalization, while types and extent of outpatient service use, access to care, quality of life, and demographic variables (other than ethnicity and gender) were not. CONCLUSIONS: These findings imply that interventions aimed at improving medication compliance, reducing alcohol abuse, and helping families cope with their mentally ill relatives could reduce the risk of hospitalization in this population.

Low education as a possible risk factor for cognitive abnormalities in HIV-1: findings from the multicenter AIDS Cohort Study (MACS).

The present study reports new and unexpected results of cognitive abnormalities among human immunodeficiency virus type 1 (HIV-1) asymptomatic subjects in the Multicenter AIDS Cohort Study. The major purpose of our analyses is to estimate the separate and combined effects of serostatus and education level on the prevalence of cognitive abnormality. Cognitive "abnormality" was defined as performance that deviated > or = 2 SDs below the mean of the total seronegative group on at least one of the five neuropsychological screening tests (Grooved Pegboard, Verbal Fluency, Digit Span, Symbol Digit Modalities, Rey Auditory Verbal Learning). The predicted prevalence of cognitive abnormality was 38% in seropositive individuals with no more than 12 years of education, compared with < 17% in the other education-serostatus groups. This interaction between education level and serostatus remained after controlling for the possible confounding effects of age, ethnicity, CD4 level, depression, prior drug history, and learning disability using logistic regression. To account for these findings, we suggest that low education might reflect an indirect index of lower reserve capacity (i.e., a risk factor) that lowers the threshold for neuropsychological abnormalities in cases of early HIV-1 infection.

Impact of immunosuppression on health care use by men in the Multicenter AIDS Cohort Study (MACS).

The effects of human immunodeficiency virus type 1 (HIV-1) serostatus, AIDS, and level of immunosuppression on health service use were examined in the Multicenter AIDS Cohort Study. Data on self-reported hospitalizations, outpatient medical services (non-emergency room) and emergency room care during the preceding 6 months were collected for 3,447 homosexual/bisexual men returning for their 14th and/or 15th semiannual visits in Chicago, Baltimore, Los Angeles, and Pittsburgh. AIDS-free seropositive men with CD4+ cells < 200/microliters were more likely to be hospitalized [odds ratio (OR) = 2.3, 95% confidence limits (CL) = 1.4, 3.8] and use outpatient medical care (OR = 7.9, 95% CL = 4.9, 12.6), compared with seronegative men. Increased outpatient care was initiated at the earliest stages of HIV-1 infection, even when CD4+ cells were > 500/microliter. Dramatic increases in outpatient care for each level of immunosuppression were observed. HIV-1-related symptoms were associated with increased hospitalizations (OR = 4.8, 95% CL = 3.2, 7.3), use of outpatient medical services (OR = 3.3, 95% CL = 1.9, 5.6), and emergency room care (OR = 3.1, 95% CL = 2.1, 4.6). Persons with AIDS and < or = 50 CD4+ cells/microliter most likely to be hospitalized (OR = 8.1; 95% CL = 4.4, 14.9). No significant difference (p > 0.05) in emergency room use was observed according to HIV-1 serostatus, AIDS, or immunosuppression, after adjusting for insurance and clinical symptoms. To the extent that CD4+ cell counts are used as one of the criteria for an AIDS diagnosis and such a diagnosis broadens available benefits to persons with HIV disease, the pattern of health care services described here will be important for health care providers and planners.

Environmental tobacco smoking, mutagen sensitivity, and head and neck squamous cell carcinoma.

Although active tobacco smoking has been considered a major risk factor for head and neck cancer, few studies have evaluated environmental tobacco smoke (ETS) and its interaction with mutagen sensitivity on the risk of head and neck cancer. We investigated the relationship between ETS and head and neck cancer in a case-control study of 173 previously untreated cases with pathologically confirmed diagnoses of squamous cell carcinoma of the head and neck and 176 cancer-free controls at Memorial Sloan-Kettering Cancer Center between 1992 and 1994. A structured questionnaire was used to collect ETS exposure and other covariates including a history of active tobacco smoking and alcohol use. ETS measures include a history of ETS exposure at home and at workplace. The associations between passive smoking and head and neck cancer were analyzed by Mantel-Haenszel methods and logistic regression models. Additive and multiplicative models were used to evaluate effect modifications between ETS and mutagen sensitivity. The crude odds ratio (OR) for ETS exposure was 2.8 [95% confidence intervals (CI), 1.3-6.0]. Controlling for age, sex, race, education, alcohol consumption, pack-years of cigarette smoking, and marijuana use, the risk of squamous cell carcinoma of the head and neck was increased with ETS (adjusted OR, 2.4; 95% CI, 0.9-6.8). Dose-response relationships were observed for the degree of ETS exposure; the adjusted ORs were 2.1 (95% CI, 0.7-6.1) for those with moderate exposure and 3.6 (95% CI, 1.1-11.5) for individuals with heavy exposure (P for trend = 0.025), in comparison with those who never had ETS exposures. These associations and the dose-response relationships were still present when the analysis was restricted to nonactive smoking cases and controls (crude OR, 2.2; 95% CI, 0.6-8.4). Crude odds ratios were 1.8 for those with moderate ETS exposure and 4.3 for individuals with heavy ETS exposure among nonsmoking cases and controls (P for trend = 0.008). More than multiplicative interaction was suggested between passive smoking and mutagen sensitivity. This study suggests that ETS exposure may increase the risk of head and neck cancer with a dose-response pattern. Our analysis indicated that passive smoking may interact with mutagen sensitivity and other risk factors to increase the risk of head and neck cancer. Our results need to be interpreted with caution because of potential residual confounding effects of active tobacco smoking and other methodological limitations. Future large-scale studies are warranted to confirm our findings.

Recent use of hormone replacement therapy and the prevalence of colorectal adenomas.

The etiological role of hormone replacement therapy (HRT) (including estrogen only, combined estrogen-progesterone, and progesterone only) in colorectal neoplasia remains unclear. Several large studies have reported a reduced risk of colorectal cancer among HRT users; however, other studies have given inconsistent results. We examined the association between HRT and colorectal adenomatous polyps, precursors of colorectal cancer, among female participants in a case-control study. Subjects were members of a prepaid health plan in Los Angeles who underwent sigmoidoscopy in 1991-1993. Participants received an in-person interview and completed a food frequency questionnaire. A total of 187 histologically confirmed cases and 188 controls, ages 50-75 years, were included in the analysis. Compared with women who did not use HRT during the year before sigmoidoscopy, recent users had an adjusted odds ratio of 0.57 (95% confidence interval, 0.35-0.94). Duration of use was inversely related to the prevalence of colorectal adenomas, with a multivariate-adjusted odds ratio of 0.49 (95% confidence interval, 0.25-0.97) for use of 5 years or more. These results support a protective effect of HRT on colorectal adenomatous polyps.

Marijuana use and increased risk of squamous cell carcinoma of the head and neck.

Marijuana is the most commonly used illegal drug in the United States. In some subcultures, it is widely perceived to be harmless. Although the carcinogenic properties of marijuana smoke are similar to those of tobacco, no epidemiological studies of the relationship between marijuana use and head and neck cancer have been published. The relationship between marijuana use and head and neck cancer was investigated by a case-control study of 173 previously untreated cases with pathologically confirmed diagnoses of squamous cell carcinoma of the head and neck and 176 cancer-free controls at Memorial Sloan-Kettering Cancer Center between 1992 and 1994. Epidemiological data were collected by using a structured questionnaire, which included history of tobacco smoking, alcohol use, and marijuana use. The associations between marijuana use and head and neck cancer were analyzed by Mantel-Haenszel methods and logistic regression models. Controlling for age, sex, race, education, alcohol consumption, pack-years of cigarette smoking, and passive smoking, the risk of squamous cell carcinoma of the head and neck was increased with marijuana use [odds ratio (OR) comparing ever with never users, 2.6; 95% confidence interval (CI), 1.1-6.6]. Dose-response relationships were observed for frequency of marijuana use/day (P for trend <0.05) and years of marijuana use (P for trend <0.05). These associations were stronger for subjects who were 55 years of age and younger (OR, 3.1; 95% CI, 1.0-9.7). Possible interaction effects of marijuana use were observed with cigarette smoking, mutagen sensitivity, and to a lesser extent, alcohol use. Our results suggest that marijuana use may increase the risk of head and neck cancer with a strong dose-response pattern. Our analysis indicated that marijuana use may interact with mutagen sensitivity and other risk factors to increase the risk of head and neck cancer. The results need to be interpreted with some caution in drawing causal inferences because of certain methodological limitations, especially with regard to interactions.