The Role of Childhood Infections and Immunizations on Childhood Rhabdomyosarcoma: A Report From the Children's Oncology Group

BACKGROUND

Rhabdomyosarcoma (RMS) is a rare, highly malignant tumor arising from primitive mesenchymal cells that differentiate into skeletal muscle. Relatively little is known about RMS susceptibility. Based on growing evidence regarding the role of early immunologic challenges on RMS development, we evaluated the role of infections and immunizations on this clinically significant pediatric malignancy.

PROCEDURE

RMS cases (n = 322) were enrolled from the third trial coordinated by the Intergroup Rhabdomyosarcoma Study Group. Population-based controls (n = 322) were pair matched to cases on race, sex, and age. The following immunizations were assessed: diphtheria, pertussis, and tetanus (DPT); measles, mumps, and rubella; and oral polio vaccine. We also evaluated if immunizations were complete versus incomplete. We examined selected infections including chickenpox, mumps, pneumonia, scarlet fever, rubella, rubeola, pertussis, mononucleosis, and lung infections. Conditional logistic regression models were used to calculate an odds ratio (OR) and 95% confidence interval (CI) for each exposure, adjusted for maternal education and total annual income.

RESULTS

Incomplete immunization schedules (OR = 5.30, 95% CI: 2.47-11.33) and incomplete DPT immunization (OR = 1.56, 95% CI: 1.06-2.29) were positively associated with childhood RMS. However, infections did not appear to be associated with childhood RMS.

CONCLUSIONS

This is the largest study of RMS to date demonstrating a possible protective effect of immunizations against the development of childhood RMS. Further studies are needed to validate our findings. Our findings add to the growing body of literature, suggesting a protective role of routine vaccinations in childhood cancer and specifically in childhood RMS.

Family history of cancer and risk of pediatric and adolescent Hodgkin lymphoma: A Children's Oncology Group study

Family history of lymphoid neoplasm (LN) is a strong and consistently observed Hodgkin lymphoma (HL) risk factor, although it has been only marginally examined in pediatric/adolescent patients. Here, healthy control children identified by random digit dialing were matched on sex, race/ethnicity and age to HL cases diagnosed at 0-14 years at Children's Oncology Group institutions in 1989-2003. Detailed histories were captured by structured telephone interviews with parents of 517 cases and 783 controls. Epstein-Barr virus (EBV) RNA detection was performed for 355 available case tumors. Two analytic strategies were applied to estimate associations between family cancer history and pediatric/adolescent HL. In a standard case-control approach, multivariate conditional logistic regression was used to calculate odds ratios and 95% confidence intervals (CIs). In a reconstructed cohort approach, each relative was included as a separate observation, and multivariate proportional hazards regression was used to produce hazard ratios (HRs) and 95% CIs. Using the latter, pediatric/adolescent HL was associated with a positive family history (HR = 1.20, 95% CI: 1.06-1.36), particularly early-onset cancers (HR = 1.30, 95% CI: 1.06-1.59) and those in the paternal lineage (HR = 1.38, 95% CI: 1.16-1.65), with a suggested association for LN in first-degree relatives (HR = 3.61, 95% CI: 0.87-15.01). There were no discernable patterns for EBV+ versus EBV- HL. The clustering of LN within pedigrees may signal shared genetic susceptibility or common environmental exposures. Heritable genetic risk variants have only recently begun to be discovered, however. These results are consistent with other studies and provide a compelling rationale for family-based studies to garner information about genetic susceptibility to HL.

Family history of cancer and childhood rhabdomyosarcoma: a report from the Children's Oncology Group and the Utah Population Database

Relatively little is known about the epidemiology and factors underlying susceptibility to childhood rhabdomyosarcoma (RMS). To better characterize genetic susceptibility to childhood RMS, we evaluated the role of family history of cancer using data from the largest case–control study of RMS and the Utah Population Database (UPDB). RMS cases (n = 322) were obtained from the Children's Oncology Group (COG). Population-based controls (n = 322) were pair-matched to cases on race, sex, and age. Conditional logistic regression was used to evaluate the association between family history of cancer and childhood RMS. The results were validated using the UPDB, from which 130 RMS cases were identified and matched to controls (n = 1300) on sex and year of birth. The results were combined to generate summary odds ratios (OR^s) and 95% confidence intervals (CI). Having a first-degree relative with a cancer history was more common in RMS cases than controls (OR^s = 1.39, 95% CI: 0.97–1.98). Notably, this association was stronger among those with embryonal RMS (OR^s = 2.44, 95% CI: 1.54–3.86). Moreover, having a first-degree relative who was younger at diagnosis of cancer (<30 years) was associated with a greater risk of RMS (OR^s = 2.37, 95% CI: 1.34–4.18). In the largest analysis of its kind, we found that most children diagnosed with RMS did not have a family history of cancer. However, our results indicate an increased risk of RMS (particularly embryonal RMS) in children who have a first-degree relative with cancer, and among those whose relatives were diagnosed with cancer at <30 years of age.

Parental military service, agent orange exposure, and the risk of rhabdomyosarcoma in offspring

OBJECTIVE

To evaluate the role of parental military service-related exposures and rhabdomyosarcoma (RMS) risk in offspring using data from a large case-control study of childhood RMS.

STUDY DESIGN

Cases (n = 319) were enrolled from the third trial run by the Intergroup Rhabdomyosarcoma Study Group. Population-based controls (n = 319) were pair-matched to cases on race, sex, and age. Conditional logistic regression was used to evaluate parental military service-related exposures and their associations with childhood RMS by generating aORs and 95% CIs. Statistical significance was defined as P < .05.

RESULTS

There were no significant associations between parental military service and childhood RMS. The strongest association was with maternal military service; however, this association was attenuated and did not remain significant after adjusting for covariates (aOR = 2.75, 95% CI 0.71, 10.62). An elevated effect estimate was found when assessing paternal exposure to Agent Orange (AO) and childhood RMS but was not statistically significant (aOR = 1.72, 95% CI 0.55, 5.41).

CONCLUSIONS

We found little evidence that parental military service of AO exposure influences the risk of RMS in offspring. These findings are notable in light of the continuing controversies surrounding the intergenerational effects of AO exposure.

Abstract 1296: Family history of cancer and rhabdomyosarcoma in children: a report from the Children's Oncology Group

Introduction: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. In the United States, about 350 children are diagnosed with RMS per year. The two major histologic subtypes of RMS are embryonal (ERMS; approximately 70% of cases) and alveolar (ARMS; approximately 30% of cases). A small percentage of RMS cases are associated with germline mutations in TP53, HRAS, and NF1. However, it has been difficult to show if inherited susceptibility may play a role in sporadic cases due to the rarity of these tumors and the potential etiologic heterogeneity between subtypes.

Objective: In order to better characterize genetic susceptibility to childhood RMS, we evaluated the role of family history of cancer using data from the largest case-control study of RMS to date.

Methods: Cases (n=322) were enrolled from the third trial run by the Intergroup Rhabdomyosarcoma Study Group. Population-based controls (n=322) were pair matched to cases on race, sex, and age. Conditional logistic regression was used to evaluate cancer history among first- and second-degree relatives and the association with childhood RMS by generating adjusted odds ratios (aOR) and 95% confidence intervals (CI). Stratified analyses were conducted to independently evaluate the association of family cancer history and childhood RMS for children who had relatives diagnosed with a cancer before the age of 40 years and those with relatives diagnosed when older than 40 years. The association of family cancer history and childhood RMS was also assessed separately for children diagnosed with ERMS and those diagnosed with ARMS.

Results: While there were no statistically significant associations, three patterns appeared to emerge: 1) having any first degree relative with a history of cancer was more common in RMS cases than controls (aOR=1.46, 95% CI: 0.72-2.97); 2) having a first degree relative who was younger at diagnosis (&lt;40 years of age) appeared to convey a greater risk of RMS (aOR=1.55, 95% CI: 0.96-2.51); and 3) having a first degree relative with cancer was more common for those with ERMS compared to ARMS (aOR=1.58, 95% CI: 0.61-4.10 vs. aOR=1.01, 95% CI: 0.29-3.50, respectively).

Conclusions: In the largest analysis of its kind to date, we found that family history of cancer appeared to increase the risk of childhood RMS. While the associations were not statistically significant, this is likely due to the low prevalence of family cancer history in this population (i.e., 6.6% overall). Ultimately, these findings tentatively support the role of inherited genetic susceptibility in the development of childhood RMS.

Citation Format: Philip J. Lupo, Heather E. Danysh, Sharon E. Plon, David Malkin, Simone Hettmer, Douglas S. Hawkins, Stephen X. Skapek, Logan G. Spector, Karin Papworth, Beatrice Melin, Erik B. Erhardt, Seymour Grufferman. Family history of cancer and rhabdomyosarcoma in children: a report from the Children's Oncology Group. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1296. doi:10.1158/1538-7445.AM2014-1296

Infectious, autoimmune and allergic diseases and risk of Hodgkin lymphoma in children and adolescents: a Children's Oncology Group study

An infectious origin for pediatric Hodgkin lymphoma (HL) has long been suspected and Epstein-Barr virus (EBV) has been implicated in a subset of cases. Increased HL incidence in children with congenital and acquired immunodeficiencies, consistent associations between autoimmune diseases and adult HL and genome-wide association and other genetic studies together suggest immune dysregulation is involved in lymphomagenesis. Here, healthy control children identified by random digit dialing were matched on sex, race/ethnicity and age to HL diagnosed in 1989-2003 at 0-14 years at Children's Oncology Group institutions. Parents of 517 cases and 784 controls completed telephone interviews, including items regarding medical histories. Tumor EBV status was determined for 355 cases. Using conditional logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) for risk of HL. Cases were more likely to have had an infection>1 year prior to HL diagnosis (OR=1.69, 95% CI: 0.98-2.91); case siblings were also more likely to have had a prior infection (OR=2.04, 95% CI: 1.01-4.14). Parental history of autoimmunity associated with increased EBV+ HL risk (OR=2.97, 95% CI: 1.34-6.58), while having a parent (OR=1.47, 95% CI: 1.01-2.14) or sibling (OR=1.62, 95% CI: 1.11-2.36) with an allergy was associated with EBV - HL. These results may indicate true increased risk for infections and increased risk with family history of autoimmune and allergic conditions that varies by tumor EBV status, or they may be attributable to inaccurate recall. In addition to employing biomarkers to confirm the role of immune-modulating conditions in pediatric HL, future studies should focus on family based designs.

Allergies, atopy, immune-related factors and childhood rhabdomyosarcoma: a report from the Children's Oncology Group

Rhabdomyosarcoma (RMS) is a highly malignant tumor of developing muscle that can occur anywhere in the body. Due to its rarity, relatively little is known about the epidemiology of RMS. Atopic disease is hypothesized to be protective against several malignancies; however, to our knowledge, there have been no assessments of atopy and childhood RMS. Therefore, we explored this association in a case-control study of 322 childhood RMS cases and 322 pair-matched controls. Cases were enrolled in a trial run by the Intergroup Rhabdomyosarcoma Study Group. Controls were matched to cases on race, sex and age. The following atopic conditions were assessed: allergies, asthma, eczema and hives; in addition, we examined other immune-related factors: birth order, day-care attendance and breastfeeding. Conditional logistic-regression models were used to calculate an odds ratio (OR) and 95% confidence interval (CI) for each exposure, adjusted for age, race, sex, household income and parental education. As the two most common histologic types of RMS are embryonal (n=215) and alveolar (n=66), we evaluated effect heterogeneity of these exposures. Allergies (OR=0.60, 95% CI: 0.41-0.87), hives (OR = 0.61, 95% CI: 0.38-0.97), day-care attendance (OR=0.48, 95% CI: 0.32-0.71) and breastfeeding for ≥ 12 months (OR=0.36, 95% CI: 0.18-0.70) were inversely associated with childhood RMS. These exposures did not display significant effect heterogeneity between histologic types (p>0.52 for all exposures). This is the first study indicating that atopic exposures may be protective against childhood RMS, suggesting additional studies are needed to evaluate the immune system's role in the development of this tumor.

Abstract 2537: Infectious, autoimmune, and allergic diseases and risk of Hodgkin lymphoma in children and adolescents: A Children's Oncology Group (COG) study

Relatively little research has been devoted to understanding the causes of Hodgkin lymphoma (HL) in children. HL diagnosed at &lt;15 years has incidence patterns and clinical characteristics distinct from HL in older adolescents and adults. Because of these differences, different underlying causes have also been postulated. Nevertheless, similar to adult HL, an infectious origin for pediatric HL has long been suspected and Epstein-Barr virus (EBV) has been implicated in a subset of cases. Results of genome-wide association studies in adult HL, consistent associations between autoimmune diseases and HL in adults, and increased HL incidence in children with congenital and acquired immunodeficiencies together suggest a role for immune dysregulation in lymphomagenesis. Here we examined associations between personal and family histories of infectious, autoimmune, and allergic diseases and HL in children and adolescents using data from the largest case-control study conducted to date. Healthy control children identified by random digit dialing were matched on sex, race/ethnicity, and date of birth to cases diagnosed in 1989-2003 at 0-14 years at North American COG institutions. Parents of 517 cases and 784 controls completed standardized 1-hour telephone interviews, including items regarding medical histories. Tumor EBV status was determined by detection of EBV-encoded RNAs via digoxigenin-based in situ hybridization. Using multivariate conditional logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) for risk of HL overall, and by tumor EBV status (EBV+, EBV-) and HL subtypes (nodular sclerosis, mixed cellularity, lymphocyte predominant) after adjusting for income, education, and birth order. Cases (OR=1.79, 95% CI: 1.04-3.08) were more likely to have had an infection &gt;1 year prior to HL diagnosis, and EBV+ cases were more likely to report prior sore throats (including strep throat, scarlet fever, tonsillitis; OR=2.19, 95% CI: 1.06-4.53) and infectious mononucleosis (OR=9.10, 95% CI: 0.81-102.3). Case siblings were also more likely to have had an infection prior to HL diagnosis (OR=2.04, 95% CI: 1.01-4.14). In index children, autoimmune (OR=0.46, 95% CI: 0.16-1.38) and allergic (OR=1.22, 95% CI: 0.93-1.59) diseases identified &gt;1 year before HL diagnosis were not associated with HL overall or by EBV status or subtype. There were no notable associations for autoimmune or allergic diseases in parents or siblings. These results may indicate a true increased risk for infections and lack of association with history of conditions imparting immune dysregulation, or they may be attributable to inaccurate recall. Future studies should employ biomarkers to understand differences in immune function preceding pediatric HL.

Supported by NIH Grants R01 CA047473 and K05 CA157439, and Children's Cancer Research Fund, Minneapolis, MN.

Citation Format: Amy M. Linabery, Erik B. Erhardt, Rachel K. Fonstad, Seymour Grufferman, Richard F. Ambinder, Greta R. Bunin, Julie A. Ross, Logan G. Spector. Infectious, autoimmune, and allergic diseases and risk of Hodgkin lymphoma in children and adolescents: A Children's Oncology Group (COG) study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2537. doi:10.1158/1538-7445.AM2013-2537

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Prenatal X-ray exposure and rhabdomyosarcoma in children: a report from the children's oncology group

The association between antenatal diagnostic X-ray exposure and risk of rhabdomyosarcoma in children was assessed in a national case-control study of 319 rhabdomyosarcoma cases and 319 matched controls. Data were collected by telephone interviews of subjects' parents. Overall, an odds ratio (OR) of 1.9 [95% confidence interval (CI), 1.1-3.4] was found for any X-ray examination of the mother during pregnancy. Risk was greatest for X-ray exposure during the first trimester (OR, 5.7; 95% CI, 1.2-27.8) and was also increased for the third trimester (OR, 2.0; 95% CI, 0.9-4.6), whereas second trimester exposure was not associated with increased risk. A nonsignificant increase in risk was found for any X-rays of the abdomen, pelvis, chest, or back. Increased risk was significantly associated with "other" X-ray exposures (relative risk, 2.9; 95% CI, 1.1-7.7), primarily composed of dental X-rays. The association was strongest between embryonal rhabdomyosarcoma and first trimester exposure (relative risk, 10.5; 95% CI, 1.5-458.4). This observation regarding embryonal rhabdomyosarcoma, and our previous report of an increased frequency of major malformations in rhabdomyosarcoma are compatible with findings from animal studies in which Ptc heterozygous knockout mice exhibited an increased risk of radiation-induced development defects and of spontaneously occurring embryonal rhabdomyosarcoma.

Secular trends in response rates for controls selected by random digit dialing in childhood cancer studies: a report from the Children's Oncology Group

Since the mid-1990s, epidemiologists have anecdotally reported difficulty in recruiting controls using random digit dialing (RDD), but few empirical data have been published. From 1982 to 2003, epidemiologists from the Children's Oncology Group conducted 17 case-control studies using RDD controls. Data for calculating RDD and field response rates were available from eight and 13 of these studies, respectively. Over the period of analysis, the contact rate declined 2.5% per year (95% confidence interval (CI): -3.4, -1.6; p = 0.001), from above 90% in the 1980s to 63-69% in the most recent studies. The response rate (the product of the contact and cooperation rates) showed a decline parallel to that of the contact rate (-2.4% per year, 95% CI: -3.2, -1.6; p < 0.001), from above 80% in the 1980s to 50-67% after the mid-1990s. Field response rates appeared to have declined modestly. The overall response rate (the product of the RDD response and field response rates) paralleled that of the RDD response rate and decreased 2.4% per year (95% CI: -2.7, -2.0; p < 0.001). The current low response rates for RDD indicate a substantial potential for selection bias and a need to seek alternative sources of controls.

Predictors of colorectal cancer screening in diverse primary care practices

BACKGROUND

To explain why rates of colorectal cancer (CRC) screening including fecal occult blood testing (FOBT), flexible sigmoidoscopy (FS), colonoscopy (CS), and barium enema (BE), are low, this study assessed determinants of CRC screening from medical records.

METHODS

Data were abstracted from patients aged > or =64 years selected from each clinician from 30 diverse primary care practices (n = 981). Measurements included the rates of annual FOBT, ever receiving FOBT, ever receiving FS/CS/BE under a combination variable, endoscopy/barium enema (EBE).

RESULTS

Over five years, 8% had received annual FOBT, 53% had ever received FOBT and 22% had ever received EBE. Annual FOBT was negatively associated with female gender, odds ratio (OR) = .23; 95% confidence interval = .12-.44 and positively associated with routinely receiving influenza vaccine, OR = 2.55 (1.45-4.47); and more office visits: 3 to <5 visits/year, OR = 2.78 (1.41-5.51), and > or =5 visits/year, OR = 3.35 (1.52-7.42). Ever receiving EBE was negatively associated with age > or =75 years, OR = .66 (.46-.95); being widowed, OR = .59 (.38-.92); and positively associated with more office visits: 3 to <5 visits/year, OR = 1.83 (1.18-2.82) and > or =5 visits/year, OR = 2.01 (1.14-3.55).

CONCLUSION

Overall CRC screening rates were low, but were related to the number of primary care office visits. FOBT was related to immunization status, suggesting the possible benefit of linking these preventive services.

Antibody responses to Epstein-Barr virus-encoded latent membrane protein-1 (LMP1) and expression of LMP1 in juvenile Hodgkin's disease

A large group of juvenile Hodgkin's disease patients (n = 242, mean age 11.7 years, 75% [n = 181] seropositive) was evaluated for anti-Epstein-Barr virus (EBV) antibody responses and the presence of EBV-encoded EBER-RNA and latent membrane protein-1 (LMP1)-protein expression in the tumor. The molecular diversity of anti-EBV antibody responses in Hodgkin's disease patients with EBV-positive and-negative tumors was studied by enzyme-linked immunosorbent assay (ELISA) and immunoblot. Using purified recombinant LMP1 protein as antigen, the presence of antibodies to LMP1 was related to expression of LMP1 in the tumor cells and specific EBV-serological patterns. Antibodies to LMP1 were detected in 30% of the EBV-seropositive Hodgkin's disease patients. The presence of antibodies to LMP1 was not associated with a distinct anti-EBV antibody diversity profile (ELISA), but a significantly higher percentage of patients with antibodies to LMP1 had antibodies to ZEBRA and viral capsid antigen (VCA)-p18 (Immunoblot). Significantly more patients with an EBV-positive tumor had detectable antibody responses to LMP1, but the presence of antibodies to LMP1 did not reflect the expression of LMP1 protein in the tumor cells. Interestingly, all patients with the strongest antibody responses to LMP1 had EBV-negative tumors, suggesting immunological selection in vivo.

Parental occupational exposures to electromagnetic fields and radiation and the incidence of neuroblastoma in offspring

We examined parental occupational exposures to electromagnetic fields and radiation and the incidence of neuroblastoma in offspring. Cases were 538 children diagnosed with neuroblastoma between 1992 and 1994 in the United States or Canada. Age-matched controls were selected by random-digit dialing. Occupational exposures to electrical equipment and radiation sources were classified by an industrial hygienist, and average exposures to extremely low frequency magnetic fields were estimated using a job exposure matrix. Maternal exposure to a broad grouping of sources that produce radiofrequency radiation was associated with an increased incidence of neuroblastoma (odds ratio = 2.8; 95% confidence interval = 0.9-8.7). Paternal exposure to battery-powered forklifts was positively associated with neuroblastoma (odds ratio = 1.6; 95% confidence interval = 0.8-3.2), as were some types of equipment that emit radiofrequency radiation (odds ratios congruent with 2.0); however, the broad groupings of sources that produce ELF fields, radiofrequency radiation, or ionizing radiation were not associated with neuroblastoma. Paternal average extremely low frequency magnetic field exposure >0.4 microTesla was weakly associated with neuroblastoma (odds ratio = 1.6; 95% confidence interval = 0.9-2.8), whereas maternal exposure was not. Overall, there was scant supportive evidence of strong associations between parental exposures in electromagnetic spectrum and neuroblastoma in offspring.

Hormone and fertility drug use and the risk of neuroblastoma: a report from the Children's Cancer Group and the Pediatric Oncology Group

Previous epidemiologic studies have suggested an association between maternal sex hormone use during pregnancy, including infertility medication, and an increased risk of neuroblastoma in the offspring. The authors conducted a case-control interview study from 1992 to 1996 that included 504 children less than 19 years of age whose newly diagnosed neuroblastoma was identified by two national collaborative clinical trials groups in the United States and Canada, the Children's Cancer Group and the Pediatric Oncology Group. Controls, matched to cases on age, were identified by random digit dialing. No association was found for use of oral contraceptives before or during pregnancy (first trimester odds ratio (OR) = 1.0, 95% confidence interval (CI): 0.5, 2.1). The odds ratio was slightly elevated for history of infertility (OR = 1.4, 95% CI: 0.9, 2.1) and ever use of any infertility medication (OR = 1.2, 95% CI: 0.7, 2.2). Specifically, ever use of clomiphene was associated with a 1.6-fold increased risk (95% CI: 0.8, 3.0) but not periconceptionally or during the index pregnancy. A suggestive pattern was found for gender of the offspring, with an increased risk for males but not for females after exposure to oral contraceptives or clomiphene. This study did not find consistent and large increased risks for maternal use of hormones, but the suggestion of an association for male offspring requires further consideration.

Methodologic approaches to studying environmental factors in childhood cancer

Little is known about environmental causes of childhood cancer. This is probably due to the relative rarity of cancer in children. In the United States, cancer incidence in adults is over 20 times greater than cancer incidence in children. The situation is compounded by the fact that two groups of cancers, leukemias and brain and spinal tumors, account for half of all childhood cancers. The rarity of childhood cancer renders the conduct of most cohort studies infeasible. The majority of studies assessing potential environmental risk factors for childhood cancers have been case-control studies, which are highly efficient for studying rare diseases. Case-control studies of childhood cancers have been greatly facilitated by using cooperative clinical trial groups for case identification. The national studies that have emerged utilize random-digit telephone dialing and telephone interviewing as feasible and economic means of identifying and interviewing controls. Other approaches such as descriptive epidemiology, ecologic studies, and studies of cancer clusters have proven to be disappointing in elucidating environmental causes of childhood cancer. Descriptive and ecologic studies provide no information on specific exposures of study subjects; rather, they use population levels as surrogates for individual exposure. Studies of cancer clusters have also proven to be disappointing. Although there are numerous difficulties in conducting research on the causes of childhood cancer, these difficulties can be remedied by using carefully designed and conducted studies. It should be remembered that the epidemiologic approach is probably the most likely research venue for uncovering environmental causes of childhood cancer.

Impact of free vaccine and insurance status on physician referral of children to public vaccine clinics

CONTEXT

Concerns about financial barriers to vaccination led to the development of the Vaccines for Children (VFC) program, which provides free vaccines to states for children who are uninsured, Medicaid eligible, or Native American or Native Alaskan.

OBJECTIVE

To understand the effect of economic factors on physician likelihood of referring children to public vaccine clinics for immunizations and to evaluate the VFC program.

DESIGN

A standardized survey was conducted in 1995 by trained personnel using computer-assisted telephone interviewing.

SETTING AND PARTICIPANTS

A stratified random sample of family physicians, pediatricians, and general practitioners younger than 65 years who were in office-based practices across the United States.

MAIN OUTCOME MEASURES

Likelihood of referral of a child to a health department for vaccination by child's insurance status and by the physician's receipt of free vaccines.

RESULTS

Of the 1769 physicians with whom an interviewer spoke, 1236 participated. Most respondents (66%) were likely to refer an uninsured child to the health department for vaccination, whereas only 8% were likely to refer a child who had insurance that covers vaccination. The majority (58%) of physicians reported differential referral based on insurance status. Among physicians who received free vaccine supplies from the VFC program or elsewhere, 44% were likely to refer an uninsured child whereas 90% of those not receiving free vaccine were likely to refer the same child (P<.001). In regression analysis, the receipt of free vaccine supplies accounted for 24% of the variance in the likelihood to refer an uninsured child for vaccination.

CONCLUSIONS

Physicians receiving free vaccine supplies report being less likely to refer children to public clinics for vaccinations.

Barriers to measles and pertussis immunization: the knowledge and attitudes of Pennsylvania primary care physicians

OBJECTIVES

To understand the causes of low childhood immunization rates, physicians were interviewed about their knowledge, attitudes, and self-reported immunization practices.

METHODS

Trained interviewers conducted a standardized telephone survey of physicians. A random sample of Pennsylvania family physicians, pediatricians, and general practitioners younger than 65 years of age who were in office-based practices was selected from the combined listings of the American Medical Association and American Osteopathic Association. Physicians seeing > or = 5 patients per week under age 6 years, seeing a total of > or = 15 patients per week, and having > or = 50% primary care patients were eligible. Of 383 eligible physicians, 70% (268) responded. The questionnaire was designed using the Health Belief Model, immunization barriers, and input from practitioners in primary care, pediatric infectious disease, maternal/ child health, and preventive medicine.

RESULTS

Respondents were more likely to refer to public vaccine clinics those children without insurance (P < .001) or with Medicaid (P < .001) than children with insurance. Almost all (> 90%) respondents thought that vaccine efficacy was high and that the likelihood of serious side effects was low. However, only 37% gave estimates that corresponded with the literature regarding the likelihood of an infant with pertussis to need hospitalization. Many respondents used invalid vaccine contraindications; for instance, 37% would not administer MMR to a boy whose mother was pregnant. Many respondents (21%) would not administer four vaccines simultaneously.

CONCLUSIONS

If the Healthy People 2000 goal to eliminate indigenous cases of measles is to be achieved, free vaccine supplies and increased provider education are needed.

International patterns in the occurrence of Hodgkin's disease in children and young adult males

It was reported over 20 years ago that there were distinct age-specific patterns of Hodgkin's disease incidence in countries with different levels of economic development, and that there was an inverse relationship between the incidence of Hodgkin's disease in children and young adults within countries. Such observations were important, leading to hypotheses on the possibly infectious aetiology of the disease. Since the initial report, diverging trends in the incidence of Hodgkin's disease in children and young adults have been observed, and data from a much larger number of countries and cancer registries have become available. This led us to reassess international age-related incidence patterns of Hodgkin's disease occurrence. Recent data show distinct differences in age-specific Hodgkin's disease incidence patterns in different geographic regions. In general, the United States (US) and European countries had the pattern of low childhood rates and high young adulthood rates. However, countries which are not part of the European Union (EU), mainly Baltic states and countries of central and eastern Europe, showed a variant of this pattern: similarly high young adult rates, but rates in children higher than those in the US and EU. Incidence-rate patterns for Latin American countries differed from those previously observed, with a shift towards patterns observed in more economically developed countries. Analysis of incidence data from earlier sources dating back to 1963 confirmed the original finding of an inverse association in incidence rates (c. 1963-1967) using a selected group of cancer registries, but not when all data were considered. This association has become weaker over the past 20 years. Using current incidence rates (1983-1987), no association between Hodgkin's disease rates in children aged 5 to 14 years (as well as 0 to 9 years) and young adults (20 to 34 years) was found.

Association of childhood rhabdomyosarcoma with neurofibromatosis type I and birth defects

Rhabdomyosarcoma (RMS) is an uncommon malignant soft tissue sarcoma whose cause is largely unknown. Reported risk factors include genetic alterations (e.g., p53 mutations, a defective gene at 11p15.5, or specific chromosomal translocation of t(2:13)), and parents' use of drugs around the time of conception. We present results from a national, case-control study of 249 RMS cases (170 males and 79 females) and 302 controls (196 males and 106 females). The cases, aged 0-20 years at diagnosis, were identified via the Intergroup RMS Study-III during 1982-1988. Controls were selected by random digit telephone dialing. As a supplement to the original study, information on genetic diseases and birth defects (BD) was collected from the subjects' parents by telephone interview. Fifty-six (22.5%) cases and 55 (18.2%) controls were reported to have genetic diseases or BD (odds ratio [OR] = 1.30,95% confidence interval [CI] = 0.85-2.02, P = .21). The case group had a significantly higher frequency of neurofibromatosis type I (NF1) than did the control group, i.e., five cases (2.0%) had NF1 vs. zero controls (P = .02). The case group also had a higher frequency of major BDs than did the control group (6.0% vs. 2.6%, OR = 2.36, 95% CI = 0.92-6.52, P = .05). However, this excess was only observed in males (7.6% vs. 2.6%, OR = 3.16, 95% CI = 1.02-10.41, P = .02). Among the 15 cases having both RMS and major BDs, six (40.0%) had both conditions in the same regional anatomic site: Two (13.3%) had both in the extremities, two (13.3%) in the genitourinary system, and two in the head and neck. These findings suggest that common genetic mechanisms or in utero exposures may be involved in the development of many childhood tumors and congenital abnormalities.

Risk factors for Wilms tumor. Report from the National Wilms Tumor Study

BACKGROUND

Previous epidemiologic studies have indicated that several factors may be associated with an increased risk of Wilms tumor including paternal occupational exposures, maternal exposure during pregnancy to cigarettes, coffee or tea, oral contraceptives, hormonal pregnancy tests, hair-coloring products, maternal hypertension, vaginal infection during pregnancy, and higher birth weight of the child. The current study examines the nonoccupational risk factors using questionnaire data from a large national collaborative clinical trial.

METHODS

Parents of 200 children registered with the National Wilms Tumor Study and 233 matched controls, identified using telephone random-digit dialing, completed a self-administered questionnaire about a variety of risk factors.

RESULTS

As opposed to some previous studies, no association was found for mother's smoking during pregnancy (10+ cigarettes per day; odds ratio [OR] = 0.73; 95% confidence interval [CI] = 0.40-1.34), maternal consumption of coffee or tea during pregnancy (4+ cups per day; OR = 1.31; CI = 0.57-3.01), or hypertension during pregnancy (OR = 0.96; CI = 0.45-2.06). In addition, no association was found in this study for hormone exposure during pregnancy, hair dye use, vaginal infection during pregnancy, or high birth weight. A previously unreported association with a history of household insect extermination was found (OR = 2.16; CI = 1.24-3.75).

CONCLUSIONS

In general, the study failed to confirm most of the previously reported maternal risk factors for Wilms tumor. Understanding the possible role of paternal exposures may be the best objective for further research on potential risk factors for Wilms tumor.

Parents' use of cocaine and marijuana and increased risk of rhabdomyosarcoma in their children

Parents' use of marijuana and cocaine was evaluated in a national (United States) case-control study of childhood rhabdomyosarcoma (RMS). Subjects were 322 RMS cases, aged 0-20 years, from the Intergroup Rhabdomyosarcoma Study, and 322 matched controls identified by random-digit telephone dialing. Parents of subjects were interviewed by telephone using a structured questionnaire. Mothers' marijuana use during the year before their child's birth was associated with a 3.0-fold increased risk of RMS in the child (95% confidence interval [CI] = 1.4-6.5) and maternal cocaine use was associated with a 5.1-fold increased risk (CI = 1.0-25.0). Risk was increased 3.1-fold (CI = 1.4-6.7) with use of any recreational drug. Fathers' marijuana use was associated with a 2.0-fold increased risk (CI = 1.3-3.3), cocaine use with a 2.1-fold increased risk (CI = 0.9-4.9), and use of any recreational drug with a 2.0-fold (CI = 1.3-3.3) increased risk. Case mothers' cocaine use and both parents' marijuana use were associated with their children being diagnosed at a significantly younger age. It was not possible to determine whether cocaine and marijuana have independent effects, since use of the two drugs was materially correlated. Similarly, mothers' and fathers' use of these drugs was highly correlated. In summary, parents' marijuana and cocaine use during the year preceding their child's birth may increase, by twofold to fivefold, the risk of RMS in their children.

Epstein-Barr virus and childhood Hodgkin's disease in Honduras and the United States

In industrialized populations, Hodgkin's disease (HD) has an initial peak in young adulthood, whereas in economically developing populations the initial peak occurs in childhood. This pattern resembles that of infection with poliovirus and suggests an infectious cofactor in the etiology. Serologic studies have linked Epstein-Barr virus (EBV) to young adult and adult HD, and viral nucleic acids and antigens have been detected in a subset of Hodgkin's tumor specimens. To investigate the association of childhood HD with EBV we studied tumor specimens from 11 children treated in Honduras and 25 children treated in the United States using in situ hybridization and antigen detection techniques. Among the patients from Honduras, tumor specimens from all cases were EBV positive. Among the patients from the United States, tumor specimens from six of seven patients with mixed cellularity histology, 2 of 15 with nodular sclerosis histology, and neither of two patients with lymphocyte-predominant histologies were EBV positive. These findings support the hypothesis that EBV contributes to the pathogenesis of HD in children, particularly in mixed cellularity HD, and raises the possibility that there are important geographic, racial, or ethnic factors in the EBV association with HD.

Issues and problems in the conduct of epidemiologic research on chronic fatigue syndrome

The epidemiologic research approach is perhaps most appropriate for initial studies of chronic fatigue syndrome since the syndrome is vaguely defined, scientific knowledge about it is limited, and an infectious etiology is suspected. Several priority needs appropriate for epidemiologic research are identified, including a refinement of diagnostic criteria; a greater understanding of the natural history of the syndrome; basic incidence, prevalence, and mortality statistics; information on whether asymptomatic cases exist; etiologic studies of possible heterogeneity of cases; investigations of clusters of cases; and determinations of whether patients with the syndrome have an increased risk of malignancy. Because of the lack of cogent etiologic hypotheses regarding the syndrome, case-control studies are identified as a high priority for research. The many difficulties encountered in conducting such research are discussed and approaches to dealing with these problems are suggested.

Are stressful life events risk factors for herpes zoster?

To determine if psychologically stressful life events are risk factors for herpes zoster, we conducted a case-control study of zoster and self-reported recent negative life events and major changes in spousal relationships. The subjects were 101 healthy community-dwelling cases of zoster and 101 healthy controls matched for age, sex, and race and generated by random digit dialing. The Geriatric Scale of Recent Life Events was administered to case and control subjects, and additional questions were asked regarding the perception of the life event. The results showed that case subjects experienced negative life events significantly more often than subjects in the control groups in the 2 months before zoster onset by analysis of discordant pairs (26 versus 10, odds ratio 2.60, 95% confidence interval [CI] 1.13, 6.27, P = .012), 3 months before (29 versus 11, odds ratio 2.64, 95% CI 1.20, 6.04, P = .007), or 6 months before (35 versus 16, odds ratio 2.00, 95% CI 1.04, 3.93, P = .012). The mean number of total life events was significantly higher in cases at 6 months before zoster (case means = 2.64, control means = 1.82, P = .008), but there were no significant differences at 2, 3, or 12 months before. There were no significant differences between case subjects and control subjects for spousal events, or any given single life event. In conclusion, we found that whereas patients with herpes zoster experienced the same kinds of life events in the year preceding the illness as did control subjects, recent events perceived as stressful were significantly more common among patients with zoster.(ABSTRACT TRUNCATED AT 250 WORDS)

Wilms' tumor and paternal occupation

A case-control study was conducted to examine the relationship between Wilms' tumor and paternal occupational exposures. The case group consisted of 200 children diagnosed as having Wilms' tumor who were registered at selected National Wilms' Tumor Study institutions during the period June 1, 1984, to May 31, 1986. Disease-free controls were matched to each case using a random digit dialing procedure. The parents of cases and controls completed a self-administered questionnaire. There was no consistent pattern of increased risk for paternal occupational exposure to hydrocarbons or lead found in this study. However, certain paternal occupations were found to have an elevated odds ratio (OR) of Wilms' tumor, including vehicle mechanics, auto body repairmen, and welders. Offspring of fathers who were auto mechanics had a 4- to 7-fold increased risk of Wilms' tumor for all 3 time periods. The largest increased odds ratio for auto mechanics was in the preconception period [OR = 7.58; 95% confidence interval (CI) = 0.90-63.9]. Welders had a 4- to 8-fold increased odds ratio, with the strongest association during pregnancy (OR = 8.22; CI = 0.95-71.3). Although chance cannot be excluded as a possible explanation, association of Wilms' tumor with these occupations has been reported in previous studies. Further study is needed to provide data on the specific occupational exposures involved.

Survival of the older patient compared with the younger patient with Hodgkin's disease. Influence of histologic type, staging, and treatment

Age as an independent risk factor for survival of Hodgkin's disease (HD) was investigated using data for the 6345 patients in the American College of Surgeons, Patterns of Care Study. Patients were divided into those 15 to 34 years of age, and those older than 50 years. Older patients had higher rates of advanced stage and B symptoms (e.g., Stage IVB, 19.7% compared with 7.7%) and significantly higher rates of poor prognosis histologic types, odds ratio (OR) = 3.7. The older population with clinical stage (CS) I and II disease was also less likely to have received any of the selected staging procedures, bone marrow biopsy, lymphogram, or laparotomy (OR = 4.48). The two populations were equivalently understaged when CS was compared with pathologic stage (PS). In each category the older patients were more likely to have received no therapy; for PS I and II disease the OR for older patients compared with the younger patient was 2.14. When stratified by PS, B symptom status, histologic type, and treatment the older patients continued to show poorer 5-year survival by the life-table method. The authors' hypothesis--that older patients equivalently staged and treated would have no significant difference in long-term survival--was not substantiated by the data. However, in the analyses in which corrections for the known risk factors were made, the difference in survival was not as great as that in the crude, unstratified data. This study, as well as other recent studies utilizing smaller numbers of patients, finds age an independent predictor of poorer survival in HD patients.

Familial aggregation of multiple myeloma and central nervous system diseases

Degenerative central nervous system diseases such as Alzheimer's disease and lymphoreticular malignancies such as multiple myeloma occur with increased frequency with advancing age. Relatives of early-onset Alzheimer's disease patients may have an increased risk of lymphoreticular malignancies. This led us to evaluate the family history of central nervous system diseases in a case-control study of multiple myeloma. Thirteen of 439 multiple myeloma cases had one or more first-degree relatives with degenerative or demyelinating central nervous system disease. In comparison, there were nine "positive" family histories in 1,317 matched hospital controls (relative risk = 4.4, 95% confidence interval = 1.9-10.3). Relative risks for the component categories of Parkinson's disease, multiple sclerosis, and miscellaneous degenerative central nervous system diseases were 3.0, 4.0 and 11.9, respectively. Our findings suggest that the degenerative and demyelinating central nervous system diseases and the lymphoreticular malignancies may comprise an etiologically related group of "protean diseases." These diseases may have a shared genetic susceptibility, possibly an immunologic abnormality. The varied disease manifestation in family members suggests a second necessary etiologic step of a variable and possibly environmental nature.

Seizures and seizure care in an emergency department

We evaluated the nature and significance of seizure problems in an emergency department (ED) by studying seizures in an urban community hospital. In 6 months, there were 29,131 ED visits; of these, 200 (0.7%) were for diagnosed seizures. Among these 200 seizure visits, were 69 (34.5%) new-onset seizures, 30 (15%) febrile seizures, and 92 (46%) seizures in epilepsy patients with prescribed antiepileptic drugs (AEDs). These seizures were often serious and complicated by medical and psychosocial problems; e.g., 37 patients (18.5%) had multiple seizures, 14 (7%) had status epilepticus, and 63 (31.5%) required hospitalization. Associated psychosocial problems included 61 patients (31%) who had no medical insurance, 62 others (31%) who were judged indigent, and 60 (30%) who abused alcohol. Of 92 epilepsy patients receiving AEDs, 52 (56.5%) had subtherapeutic blood levels and were noncompliant with AED prescription patients. Problems with continuity of care were demonstrated by the failure of the ED to communicate with primary care providers about drug levels, noncompliance, and changes in therapy in greater than 85% of patients. A hospital ED is a major source for epilepsy and seizure care, but this care is not always optimum. EDs need to be prepared to manage common acute seizure problems. However, EDs must also place greater emphasis on significant nonemergency aspects of seizure care such as AED compliance, associated psychosocial problems, and effective communication with primary care providers.

Increasing incidence of primary brain lymphoma in the US

There have been a number of clinical reports suggesting an increasing incidence of primary brain lymphoma unrelated to acquired immune deficiency syndrome (AIDS) and organ transplantation. To investigate this issue, the US incidence of this rare lymphoma was assessed using data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program (1973 through 1984). Never-married men, a relatively high risk group for AIDS, were excluded from the analyses. Brain lymphoma incidence increased from 2.7 in 1973 through 1975 to 7.5 cases per ten million population in 1982 through 1984 (chi-square trend, 15.25; P less than 0.001), and it increased among both men (chi-square trend, 6.74; P = 0.009) and women (chi-square trend, 10.48; P = 0.001). Increases in incidence also were observed among persons younger than 60 years of age (chi-square trend, 4.10; P = 0.04) and persons 60 years of age and older (chi-square trend, 9.16; P = 0.002). This increased incidence of brain lymphoma appears to be real: It antedates the AIDS epidemic and does not appear to be related to organ transplantation, another cause of increased risk of brain lymphoma. Although part of the increase may be an artifact of improvements in diagnostic technology and practice, most of the observed increase antedates the widespread use of such technologies. Finally, the increase in incidence of brain lymphoma does not appear to be related to overall trends in the incidence of brain tumors and non-Hodgkin's lymphoma, and it is not related to time trends in nosology.

Antibody reactivity with HBLV (HHV-6) in U.S. populations

500 sera representing healthy blood donors and a random representation of the U.S. population collected 10 years ago were screened by ELISA for antibody reactivity with purified, disrupted HBLV virions. In each group, the ELISA results were normally distributed with no evidence of bimodality. All sera were subsequently retested after preincubation of each with well-characterized preparations of disrupted HSB-2 cells or HBLV-infected HSB-2 cells. Sera showing significant levels of HBLV-specific neutralization (50% or more) were found in Minneapolis, Kansas City, and in a random population survey (81, 88 and 97% of donors, respectively). Mean ELISA test values were the same for all groups and for males and females within the same group. Sera from these normal donors reacted preferentially with viral antigens of 120 and 58 kDa by Western blot. In a hospital-based prevalence study, frequent IgM and IgG seroconversions were apparent among infants less than 1 year old, and mean ELISA test values reached the adult level before school age. Antigen preparations used in blocking experiments showed no competitive cross-reactivity with antisera against EBV, CMV, HSV, VZV, HIV, or adenovirus type 2 at levels which reduced antibody binding to HBLV by more than 90%. Antibody cross-reactivities towards HBLV and other human herpesviruses were assessed by cross-correlation of viral antibody titers against all of the viruses and by cross-absorptions of antisera against the other viruses with HBLV. In these experiments no antibody cross-reactivity between HBLV and other human herpesviruses were detected. The significance of these findings with respect to health/disease status is presently unknown. Further seroepidemiologic studies of quantitative levels of HBLV antibody reactivity to measure the age of primary infection and progressive changes in healthy and selected disease populations are needed to determine the risk of disease associated with HBLV infection.

Hospital versus random digit dialing controls in the elderly. Observations from two case-control studies

Finding an optimal source of controls is a major consideration in the design of case-control studies. While hospital patients can provide a relatively economical and convenient source of controls, hospital controls may have diseases independently associated with the exposures being studied. Results of a recent case-control study of multiple myeloma suggest that the problems of using hospital controls may be exacerbated in studies of diseases affecting the elderly, especially when considering risk factors which might be associated with chronic diseases. Apparently, the authors have encountered a modern analog of "Berkson's bias" in which cancer cases are referred to a tertiary care center for a single disease. On the other hand, noncancer patients who might serve as controls tend to be referred selectively if they have multiple diseases. This article reports some of the difficulties encountered in a case-control study whose mean case age was 63.4 years and suggests that community controls selected by random digit dialing may be preferable to hospital controls for hypothesis-generating case-control studies of diseases in the elderly.

Effects of socioeconomic and clinical factors on survival in multiple myeloma

It was recently reported that low socioeconomic status (SES) in multiple myeloma (MM) patients is associated with a poorer prognosis. To reassess this finding in another group of MM patients, we used data from interviews of 153 MM patients seen at Duke University Medical Center over a 6-year period. Medical records were also reviewed for data on traditional clinical prognostic factors. Using proportional hazard survival analysis, no SES variables were associated with survival. Current income, highest income, occupation, type of dwelling, years of education, and crowding did not enter the stepwise regression model at alpha = .10. In contrast, many clinical factors predicted prognosis (calcium, P = .019; percent plasma cells on initial bone marrow, P = .019; history of transfusions, P = .015; WBC count, P = .007; pathologic fractures, P = .001; and urate, P less than .001). Thus, we do not confirm the previously reported association between social class and myeloma survival.

Case-control study of hepatocellular carcinoma, occupation, and chemical exposures

The relation of hepatocellular carcinoma (HCC) to occupation and chemical exposures was evaluated in a case-control study. The study included 80 cases and 146 matched hospital controls on whom a work history was obtained. No persuasively positive association between HCC and any particular occupation, industry, or chemical exposure was found. However, the relative rate (RR) of HCC for persons employed in highway construction compared with those never so employed is 5.0 with 95% confidence limits (CL), 1.0 to 26. The RR for farming occupations, 1.4 (95% CL, 0.7 to 2.9), is also slightly elevated. The RR for persons exposed to pesticides compared with those not exposed is 2.4 (95% CL, 0.9 to 6.5). Asphalt exposures are associated with a RR of 3.2 (95% CL, 0.9, 11). These findings are compared to the results of other epidemiologic studies.

Familial Hodgkin's disease. A clinical and laboratory investigation

A three to sevenfold increased risk of Hodgkin's disease has been noted in families of patients. We report the first family in which all four of a four member sibship had Hodgkin's disease. In these four sibling cases, we were able to explore markers of infectious etiologic factors by measuring antibodies to Epstein-Barr virus (EBV) and human T-cell lymphotropic virus (HTLV), and possible genetic risk factors by human leukocyte antigen (HLA) typing and chromosome analysis. All three men were diagnosed within six months of their 30th birthday. HLA typing revealed that all four siblings share the DR5 antigen, and two siblings share HLA-B27. Chromosome analysis on peripheral lymphocytes revealed no abnormalities. A detailed, structured interview failed to elicit evidence of unusual exposures. The EBV antibody titers are probably within the normal range and none of the family had antibodies to HTLV-III. Observations on this family suggest that genetic factors play a greater role than environmental factors in the etiology of familial Hodgkin's disease.

Role of immune stimulation in the etiology of multiple myeloma: a case control study

A hospital-based case-control study of 153 multiple myeloma (MM) cases and 459 controls was conducted to evaluate the hypothesis that chronic or frequent infections or allergic and autoimmune diseases might be of higher prevalence in individuals who develop MM. Information was obtained by direct interviews of subjects. Controls were matched to cases on age, sex, race, and hospital. "Immune-stimulating conditions" included chronic infections such as pyelonephritis, urinary tract infections (UTIs), prostatitis, rheumatoid arthritis and other collagen vascular diseases, allergies, bronchitis, tuberculosis, cholecystitis, diverticulitis, and osteomyelitis. The overall odds ratio (OR) (odds of history of immune-stimulating conditions in cases versus controls) was 0.4 (95% confidence interval = 0.3-0.7) which suggested that cases had significantly less immune-stimulating conditions than did controls. The exposure rate for these conditions was high for cases (0.7) as well as for all control groups (0.8). These findings suggest that immune-stimulating conditions alone are not the causative factor in the etiology of MM, though they may play a role in the predisposed individual.

Thallium poisoning in cocaine abusers

The users of illicit drugs is endangered by both unpredictable concentrations of the drugs and by unexpected adulterants that may be present. Cocaine has been adulterated or admixed with numerous substances, among them local anesthetics, amphetamine, phencyclidine, and strychnine. We report three cases of thallium poisoning following nasal insufflation of a substance that was believed to have been cocaine.

Familial aggregation of melanoma, basal cell carcinoma, and gastric adenocarcinoma

A family with four cases of melanoma, seven cases of basal cell carcinoma, and two cases of gastric adenocarcinoma, is described. The proband, who had three different primary tumors, died of gastric cancer, as did his father. Four of the proband's six siblings were affected with melanoma or basal cell cancer, as were two of his three children. Both daughters of one melanoma patient developed basal cell cancers. No spouses were affected, the cases were widely separated in time and place, and no unusual exposures were reported. HLA analysis of affected and unaffected first-degree relatives showed no association with antigens previously described in familial melanoma or segregation with a specific HLA haplotype. Although there was no association with HLA phenotype, these results suggest that melanoma, basal cell carcinoma, and gastric adenocarcinoma can be inherited in an autosomally dominant pattern similar to other familial tumor syndromes.

A case-control study of hepatocellular carcinoma and the hepatitis B virus, cigarette smoking, and alcohol consumption

A case-control study was undertaken to evaluate the roles of the hepatitis B virus (HBV), cigarette smoking, and alcohol use in the etiology of hepatocellular carcinoma (HCC). A major purpose of the study was to evaluate the effect of cigarette smoking on HCC among hepatitis B surface antigen (HBsAg)-negative persons, since it had been suggested that the relative effect of cigarette smoking on HCC was higher among HBsAg-negative persons than among HBsAg-positive persons. Eighty-six cases and 161 hospital controls were included in the study. This study confirmed the strong relationship between the HBV and HCC. Twelve of 67 cases and none of 63 controls were chronically infected with HBV as evidenced by serum HBsAg. The study also found a moderately strong relationship between alcohol use and HCC. The results of the present study do not support the hypothesis that cigarette smoking is a risk factor for HCC. Among all subjects, the relative rate of HCC for cigarette smokers compared with nonsmokers after adjustment for alcohol consumption was 1.0 with 95% confidence limits, 0.5 to 1.8. Among HBsAg-negative subjects, the relative rate was 1.1 with 95% confidence limits, 0.5 to 2.4. There was also no consistent dose-response relationship between quantity smoked and HCC in this study.

Value of sonographic screening for gallstones in patients with chest pain and normal coronary arteries

The prevalence of sonographically detectable gallstones in patients with chest pain and normal coronary arteries was compared with the prevalence of gallstones in patients referred to sonography for nonbiliary disease. Among 545 patients with chest pain and normal coronary arteriograms, 101 (18.5%) were referred for sonographic examination of the gallbladder. This test group was compared to a matched control group (n = 101) undergoing abdominal sonography for nonbiliary disease. Six patients (5.9%) in the test group and eight patients (7.9%) in the control group were found to have gallstones by accepted sonographic criteria. Studies based on oral cholecystogram screening of healthy populations have claimed a prevalence of cholelithiasis of 2.3%-6.2% for males and 2.3%-12% for females. The authors were unable to demonstrate a higher prevalence of sonographically identified gallstones in patients with chest pain and normal coronary arteries than in patients examined for nonbiliary disease. The frequency of gallstones in this test group is comparable to that reported for a screened population of healthy men and women.