Cancer among children of parents with autoimmune diseases

Maternal autoimmune disease and its association with childhood cancer: A population-based case-control study in Denmark

Background

Autoimmune diseases have been linked to an increased risk of pregnancy-related complications. A family history of autoimmune diseases may be related to the risk of childhood cancer based on similar histocompatibility antigens. We utilized data from national registries in Denmark to examine associations between maternal autoimmune disease and cancer in their offspring.

Methods

We linked data from several national registries in Denmark to identify childhood cancer cases in children <20 years diagnosed between 1977 to 2016. Controls were selected from the Central Population Register and matched to cases by birth year and sex (25:1). Mothers with autoimmune disease diagnosed in pregnancy or prior were identified from the National Patient Register. Multivariable conditional logistic regression analyses were used to estimate associations between maternal autoimmune diseases and childhood cancer in offspring.

Results

Autoimmune diseases (all types) were positively associated with all childhood cancers combined (Odds Ratio (OR) = 1.25, 95% CI 1.06, 1.47), acute lymphoblastic leukemia (OR =1.52, 95% CI 1.09, 2.13), Burkitt lymphoma (OR = 2.69, 95% CI 1.04, 6.97), and central nervous system tumors (OR = 1.45, 95% CI 1.06, 1.99), especially astrocytoma (OR = 2.27, 95% CI 1.36, 3.77) and glioma (OR = 1.75, 95% CI 1.13, 2.73). When we examined mothers with rheumatoid arthritis, we observed an increased association for all cancers (OR = 2.15, 95% CI 1.40, 3.30), acute lymphoblastic leukemia (OR = 3.55, 95% CI 1.69, 7.47), and central nervous system tumors (OR = 2.91, 95% CI 1.46, 5.82), especially glioma (OR = 3.58, 95% CI 1.40, 9.18) in offspring.

Conclusion

There is a positive association between maternal autoimmune disease and childhood cancer. This association is especially prominent in the offspring of women with rheumatoid arthritis.

Dual direction associations between common autoimmune diseases and leukemia among children and young adults: A systematic review

BACKGROUND

Childhood leukemia and many autoimmune (AI) diseases are severe pediatric conditions with lifelong consequences. AI diseases form a heterogeneous disease group affecting about 5 % of children worldwide, while leukemia is the most common malignancy among children aged 0-14 years. The timing and similarities in suggested inflammatory and infectious triggers of AI disease and leukemia have raised a question whether the diseases share common etiological origins. We conducted a systematic review to evaluate the evidence linking childhood leukemia and AI diseases.

DATA SOURCES

In the systematic literature search CINAHL (from 1970), Cochrane Library (form 1981), PubMed (from 1926) and Scopus (from 1948) were queried in June 2023.

REVIEW METHODS

We included studies covering the association between any AI disease and acute leukemia, limiting it to children and adolescents under 25 years old. The studies were reviewed independently by two researchers and the risk of bias was assessed.

RESULTS

A total of 2119 articles were screened and 253 studies were selected for detailed evaluation. Nine studies met the inclusion criteria, of which eight were cohort studies and one was a systematic review. The diseases covered were type 1 diabetes mellitus, inflammatory bowel diseases and juvenile arthritis alongside acute leukemia. Five cohort studies were suitable for more detailed analysis: a rate ratio for leukemia diagnosis after any AI disease was 2.46 (95 % CI 1.17-5.18; heterogeneity I2 15 %) with a random-effects model.

CONCLUSIONS

The results of this systematic review indicate that AI diseases in childhood are associated with a moderately increased risk of leukemia. The association for individual AI diseases needs further investigation.

Maternal Thyroid Disease and the Risk of Childhood Cancer in the Offspring

Maternal thyroid disease, especially hypothyroidism, affects pregnancy and its outcome. In-utero exposure to autoimmune thyroid disease has been reported to associate with childhood ALL in the offspring. We evaluated the risk of childhood cancer in the offspring following exposure to maternal thyroid disease in a case-control setting using registry data. All patients with their first cancer diagnosis below the age of 20 years were identified from the Finnish Cancer Registry (n = 2037) and matched for sex and birth year at a 1:5 ratio to population controls identified from the Medical Birth Registry (n = 10,185). We collected national information on maternal thyroid disease from the Medical Birth Registry, Care Register for Health Care, Register for Reimbursed Drug Purchases and Register of Special Reimbursements. We used conditional logistic regression to analyze childhood cancer risk in the offspring. The adjusted OR for any childhood cancer was 1.41 (95%, CI 1.00-2.00) comparing the offspring of mothers with hypothyroidism and those with normal thyroid function. The risk of lymphomas was increased (adjusted OR for maternal hypothyroidism 3.66, 95%, CI 1.29-10.38). The results remained stable when mothers with cancer history were excluded from the analyses. Maternal hypothyroidism appears to be associated with an increased risk for childhood lymphoma in the offspring. The association exists even after excluding possible familial cancers.

Maternal autoimmune disease is not associated with cancer in the offspring

AIM

Autoimmune disease and its medication are associated with increased cancer risk in adults, but it is unknown whether maternal autoimmune disease and/or medication use in pregnancy are associated with increased cancer risk in offspring.

METHODS

In this case-control study, we identified all patients under 20 years of age with their first cancer diagnosis in 1996-2014 from the Finnish Cancer Registry (n = 2029) and 1:5 population-based controls (n = 10,103) from the Medical Birth Register. We obtained information on maternal autoimmune disease and its medication from the relevant Finnish registries and used conditional logistic regression to analyse the risk of offspring cancer after maternal autoimmune disease exposure.

RESULTS

The odds ratio (OR) for cancer in offspring following maternal autoimmune exposure was 0.76 (95% confidence interval [CI] 0.47-1.23). Individual ORs for inflammatory bowel and connective tissue diseases were 1.08 (95% CI 0.56-2.01) and 0.50 (95% CI 0.23-1.08), respectively. The OR for maternal autoimmune medication was 0.95 (95% CI 0.80-1.14) overall and similar by drug subtype. There was an increased risk with medication in late pregnancy but the ORs were unstable owing to small numbers.

CONCLUSION

Our study does not support an increased cancer risk among offspring of women with autoimmune disease or its medication during pregnancy.

Maternal diabetes and risk of childhood cancer in the offspring

An association between maternal diabetes, its medication and childhood cancer has not been previously explored in a registry-based setting. With a case-control design, we aimed to explore whether maternal diabetes is associated with an increased risk of childhood cancer in the offspring. Combining data from population-based registries, we analyzed a total of 2,029 cases, that is, persons with childhood cancer diagnosed under the age of 20 years between years 1996-2014 and a total of 10,103 matched population controls. The mothers of the cases/controls and their diagnoses of diabetes (DM) before/during pregnancy as well as their insulin/metformin prescriptions during pregnancy were identified. Conditional logistic regression modeling was used to analyze the risk of childhood cancer. The OR for childhood cancer among those exposed to any maternal diabetes was 1.32 (95% CI 1.14-1.54) compared to the offspring of the nondiabetic mothers. The effect of maternal diabetes on the risk of childhood cancer remained elevated even after adjusting for maternal age, parity and smoking. Our data suggest that maternal diabetes medication may reduce the risk for childhood cancer (adjusted OR 0.83, 95% CI 0.36-1.94), especially in gestational diabetes (adjusted OR 0.26, 95% CI 0.05-1.25), compared to the diabetic mothers without medication. The risk of childhood leukemia was significantly higher among children exposed to any maternal diabetes (OR 1.36, CI 1.04-1.77) compared to the unexposed. Maternal diabetes appears to be associated with an increased risk of childhood cancer in the offspring. The possible risk-reducing effect of an exposure to diabetes medication on offspring cancer risk warrants further investigation.

Children Born by Women With Rheumatoid Arthritis and Increased Susceptibility for Chronic Diseases: A Nationwide Cohort Study

OBJECTIVE

Fetal exposure to maternal rheumatoid arthritis (RA) might impact the long-term risk of disease in the offspring. We examined a possible association between maternal RA and 15 selected groups of chronic diseases in the offspring.

METHODS

This nationwide cohort study was based on the Danish health registries and included data on all children born alive in Denmark between January 1, 1989 and December 31, 2013. The cohort comprised 2,106 children born by women with RA (exposed), and 1,378,539 children born by women without RA (unexposed). Cox proportional hazards regression models were used, taking a large range of confounders into consideration, and the hazard ratios (HRs) of child and adolescent diseases were calculated.

RESULTS

In children exposed to maternal RA in utero, the HR of thyroid diseases was 2.19 (95% confidence interval [95% CI] 1.14-4.21), epilepsy 1.61 (95% CI 1.16-2.25), and RA 2.89 (95% CI 2.06-4.05). The HRs for anxiety and personality disorders and chronic lung disease including asthma were in the range of 1.15-1.16, but these were not statistically significant associations.

CONCLUSION

Our results suggest that in utero exposure to maternal RA is associated with an increased risk of thyroid disease and epilepsy in childhood and adolescence, and in particular an increased risk of RA, compared to children born to mothers without RA. These important findings should encourage pediatricians and general practitioners to have an increased awareness of certain chronic diseases in children exposed to RA in utero.

Acute lymphoblastic leukemia in a 2-year-old girl whose mother was previously diagnosed with antiphospholipid syndrome: a case report

BACKGROUND

The role of maternal exposures and conditions in the origin of childhood cancer has been a subject of growing interest, but current evidence is inconclusive.

CASE PRESENTATION

We present a case detected in a multicenter case-control study evaluating the association between parental risk factors and childhood acute lymphoblastic leukemia (ALL). The patient is a Colombian girl who was diagnosed with ALL-L1 when she was 2 years old. Her mother had been diagnosed with antiphospholipid syndrome before pregnancy and had also been treated with subcutaneous injections of heparin. Other potentially relevant maternal and patient exposures are also reported in this paper.

CONCLUSION

We hypothesize that the maternal autoimmune disease could be a contributor in the causality network of the daughter's leukemia. However, the role of other exposures cannot be excluded.

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.

Family history of cancer and non-malignant diseases and risk of childhood acute lymphoblastic leukemia: a Children's Oncology Group Study

BACKGROUND

Studies of family history of cancer and non-malignant diseases in childhood acute lymphoblastic leukemia (ALL) show inconsistent findings. Most studies show no increased risk with family history of cancer. Non-malignant diseases such as allergic diseases, autoimmune diseases, birth defects and thyroid diseases have been reported to be associated with ALL.

METHODS

We conducted a case-control study of family history of cancer and selected non-malignant conditions (allergic diseases, autoimmune diseases, birth defects, and thyroid diseases). ALL cases were obtained from Children's Cancer Group institutions from January 1989 to June 1993. Controls were recruited via random digit dialing. Family history for first degree relatives and grandparents of ALL cases and controls was collected by structured telephone questionnaires. Conditional logistical regression was used to calculate odds ratios adjusting for potential confounders.

RESULTS

We found a borderline association of ALL and having a family member with a history of cancer in cases (n=1842) compared to controls (n=1986) (OR=0.98, 95%CI=0.93, 1.00) and an inverse association for esophageal cancer based on small numbers. Family history of food and drug allergies demonstrated a modestly reduced risk (OR=0.83, 95%CI=0.73, 0.95) as did family history of rheumatoid arthritis (OR=0.79, 95%CI=0.65, 0.96). There were no associations with family history of any autoimmune diseases, immunodeficiencies, birth defects, thyroid diseases and risk of childhood ALL.

CONCLUSIONS

These results show no association of overall family history of cancer with childhood ALL, while providing additional evidence for an inverse association with family history of allergic disease. Two potentially new associations of ALL with family history of esophageal cancer and rheumatoid arthritis require confirmation in other studies and validation with medical records.

Survival patterns in patients with Hodgkin's lymphoma with a pre-existing hospital discharge diagnosis of autoimmune disease

PURPOSE

Autoimmune diseases (AIs) are associated with elevated risk for Hodgkin's lymphoma (HL); however, information on the interplay of AIs and HL on survival is sparse.

PATIENTS AND METHODS

We evaluated survival patterns for 7,414 patients with HL in relation to a pre-existing hospital discharge diagnosis of an AI. We also assessed survival patterns in relation to a prior AI diagnosis among 29,240 population-based matched controls.

RESULTS

Among female patients with HL with (v those without) a pre-existing AI, the 5-year and 10-year overall survival was 46.0% (63.3%) and 41.0% (51.9%); for males, the corresponding numbers were 48.5% (59.2%) and 43.6% (51.5%), respectively (P < .001). Among female controls with (v those without) a pre-existing AI, the 5-year and 10-year overall survival was 79.1% (90.2%) and 67.2% (83.3%); for males, the corresponding numbers were 82.5% (90.3%) and 68.6% (81.6%), respectively (P < .001). Female patients with HL with (v those without) a pre-existing AI had a 1.8-fold (range, 1.3- to 2.4-fold) increased relative risk of dying at 5 years of follow-up; for males, the corresponding excess relative risk of dying was 1.7-fold (range, 1.3- to 2.2-fold).

CONCLUSION

Patients with HL have an overall excellent outcome from treatment but also pose some of the most complex challenges of cancer survivorship due to many late effects (eg, second malignancies, thyroid disease, cardiovascular disease, and altered reproductive and sexual function). Our finding that patients with HL with a hospital discharge diagnosis of an AI have a substantially higher risk of dying, emphasizes that underlying chronic diseases, such as AIs, should be high of the list of survivorship concerns for clinicians that treat HL.

Current insight on trends, causes, and mechanisms of Hodgkin's lymphoma

Hodgkin's lymphoma (HL) has a unique and distinct history, epidemiology, treatment, and biology. A viral agent or infectious agent has long been considered as the etiologic agent and Epstein-Barr virus is the main candidate for the infectious agent causing HL; however, Epstein-Barr virus genome is found within the tumor in only about 20% to 40% of HL cases with a prior diagnosis of infectious mononucleosis. Recently, autoimmune and related conditions have drawn attention to a potential role for immune-related and inflammatory conditions in the etiology and pathogenesis of the malignancy. Evidence from multiply-affected families, a twin study, a case-control study, and population-based registry studies implicate genetic factors. Data from Eastern Asia and among Chinese immigrants in North America indicate increasing incidence trends for HL being associated with westernization. These results emphasize an interaction between environmental and genetic risk factors in HL.

Genetic susceptibility to childhood leukaemia

The aetiology of leukaemias among children is believed to be distinct from that of adults, mainly due to the clearer role for early life exposures, including those in utero. However, few risk factors have been established, because of the challenge of studying a disease with relatively low incidence. Identified risk factors, including ionizing radiation, chemotherapeutic agents and specific genetic abnormalities, explain < 10% of incidence. Although the causes for the remaining 90% are unknown, it is possible that genetic susceptibility factors, either alone or in conjunction with environmental factors, may be involved. In this paper, the authors (a) review the evidence surrounding genetic susceptibility factors, with emphasis on the genes' main effects; (b) review some recent developments in the Northern California Childhood Leukaemia Study (NCCLS) as a case study of design and practical considerations in genetic epidemiology research and (c) highlight both challenges and future directions in this exciting research area.

New aspects in descriptive, etiologic, and molecular epidemiology of Hodgkin's lymphoma

Epstein-Barr virus (EBV) has remained the main candidate suggested as the infection causing Hodgkin's lymphoma for several years. However, EBV genome has been found only within the tumor in about 20%-40% of Hodgkin's lymphoma cases with a prior diagnosis of infectious mononucleosis. Recently, autoimmune and related conditions have drawn attention to a potential role for immune-related and inflammatory conditions in the etiology and pathogenesis of the malignancy. Evidence from multiple affected families from case series, a twin study, a case-control study, and population-based registry studies implicate a role for genetic factors. Simultaneously, data from Eastern Asia and among Chinese immigrants in North America indicate increasing incidence trends for Hodgkin's lymphoma being associated with westernization. These results emphasize an interaction between environmental and genetic risk factors in Hodgkin's lymphoma.

Malignancy and rheumatoid arthritis

The occurrence of cancer is not an infrequent event in patients with rheumatoid arthritis (RA). Indeed, following diagnosis of RA at a typical age (55 years), one in five patients will be diagnosed with cancer. In the vast majority of such cases, the cancer has nothing to do with RA or its treatment; rather, it represents the "background" risk applicable to all humans. In some cases, the cancer occurs as a result of factors also associated with the risk of developing RA (eg, smoking), even though no direct link exists between the cancer and the RA. In a fraction of cases, however, the cancer is causally associated with the RA disease or its treatments. This review summarizes our current understanding of the occurrence of cancer in RA, possible links to RA disease and to traditional and newer RA treatments.

[CARIMS (Cancer Risk In Multiple Sclerosis) project: impact of long-term treatment]

Controversial results have been published on potential link between cancer and multiple sclerosis. Multiple sclerosis has been linked to reduced rates of cancer prior to the era of immunomodulating or immunosuppressive treatments and until today, only 9 studies can be found in the literature. New strategies and early use of IM or IS drugs in MS justify to study and follow patients to detect a potential increase of cancer's incidence in treated patients. It is important to follow and collect prospectively in MS centers, patients with history of cancer, to document histologies, and potential relations with repeated IM or IS treatments. A prospective study is in progress in French MS centers on behalf the Club Francophone de la SEP (CARIMS Project).

Autoimmunity and Susceptibility to Hodgkin Lymphoma: A Population-Based Case–Control Study in Scandinavia

BACKGROUND

Personal history of autoimmune diseases is consistently associated with increased risk of non-Hodgkin lymphoma. In contrast, there are limited data on risk of Hodgkin lymphoma following autoimmune diseases and almost no data addressing whether there is a familial association between the conditions.

METHODS

Using population-based linked registry data from Sweden and Denmark, 32 separate autoimmune and related conditions were identified from hospital diagnoses in 7476 case subjects with Hodgkin lymphoma, 18,573 matched control subjects, and more than 86,000 first-degree relatives of case and control subjects. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) as measures of relative risks for each condition using logistic regression and also applied multivariable hierarchical regression models. All P values are two-sided.

RESULTS

We found statistically significantly increased risks of Hodgkin lymphoma associated with personal histories of several autoimmune conditions, including rheumatoid arthritis (OR = 2.7, 95% CI = 1.9 to 4.0), systemic lupus erythematosus (OR = 5.8, 95% CI = 2.2 to 15.1), sarcoidosis (OR = 14.1, 95% CI = 5.4 to 36.8), and immune thrombocytopenic purpura (OR = infinity, P = .002). A statistically significant increase in risk of Hodgkin lymphoma was associated with family histories of sarcoidosis (OR = 1.8, 95% CI = 1.01 to 3.1) and ulcerative colitis (OR = 1.6, 95% CI = 1.02 to 2.6).

CONCLUSIONS

Personal or family history of certain autoimmune conditions was strongly associated with increased risk of Hodgkin lymphoma. The association between both personal and family histories of sarcoidosis and a statistically significantly increased risk of Hodgkin lymphoma suggests shared susceptibility for these conditions.

Patterns of autoimmunity and subsequent chronic lymphocytic leukemia in Nordic countries

A population-based case-control study was conducted to evaluate risk of developing chronic lymphocytic leukemia (CLL) associated with personal and/or family history of autoimmune and related diseases. Data were obtained for all (n = 7764) patients diagnosed with CLL in Sweden and Denmark over a 40-year period and with linkable relatives, 16,658 matched control subjects, and first-degree relatives of patients (n = 17,991) and control subjects (n = 39,388). Odds ratios (ORs) were calculated to quantify risk of CLL in relation to personal/family history of 32 autoimmune and related disorders. The risk of CLL was significantly increased among subjects with a personal history of pernicious anemia (OR = 1.94; 1.18-3.18), mainly in the 0- to 1-year latency period. A significantly decreased risk of CLL was found among individuals with a personal history of chronic rheumatic heart disease (OR = 0.55; 0.33-0.93), particularly persons with a long latency (10+ years) between the 2 conditions. We found no association between personal or familial occurrence of other autoimmune or related disorders and CLL. If our results are confirmed, mechanistic studies examining how pernicious anemia might promote increased occurrence of CLL and how chronic rheumatic heart disease protects against CLL, perhaps related to long-term antibiotics use, may provide insights to the as-yet-unknown etiology of CLL.

Personal and family history of autoimmune diabetes mellitus and susceptibility to young-adult-onset Hodgkin lymphoma

Young-adult-onset (15-44 years of age) Hodgkin lymphoma (HL) is believed to arise as a consequence of late primary infection in susceptible individuals. The properties of this susceptibility remain little understood. We have previously reported an increased occurrence of HL in patients with rheumatoid arthritis and among their offspring, suggesting that susceptibility to autoimmunity might be of importance also in the pathogenesis of HL. To explore this hypothesis, we assessed the association of personal and family history of diabetes mellitus, with risk of subsequent HL in a population-based case-control study, including as cases all individuals diagnosed with HL above 15 years of age 1964-1999 (n = 6,873) in Sweden, and matched population controls (n = 12,565). First-degree relatives of cases and controls were identified through linkage with the Multi-generation Register. We identified discharges listing diabetes mellitus through linkage with the Inpatient Register (1964-2000). We used odds ratios (OR) as measures of relative risk. Cases with young-adult-onset HL were less likely to have a personal (OR =0.5, 95% CI 0.2-1.1) or family (OR =0.7, 95% CI 0.6-0.8) history of diabetes mellitus. In contrast, HL diagnosed at older ages was neither associated with a personal (OR =1.0) nor family (OR =1.0) history of diabetes mellitus. These findings suggests that characteristics of the immune system associated with conditions such as diabetes mellitus type I are of importance in the pathogenesis of young-adult-onset HL.

National databases and rheumatology research I: longitudinal databases in Scandinavia

Nationwide population-based longitudinal databases provide excellent resources for medical research in Scandinavia. These include the Population Registry, the Cancer Registry, the Cause of Death Registry, the Hospital Discharge Registry, and other registers, and are linkable to each other by the personal identification code. The registers have long historical backgrounds, and are regulated strictly by law. This article describes features of the national databases and provides some examples of rheumatology research that use these databases.

Risks to the children born to mothers with autoimmune diseases

This article reviews current information regarding the development and long-term effects on children born to women with connective tissue diseases. There are few data on specific effects attributed to the underlying maternal disease, but fetal growth restriction and preterm birth are relatively common. Antenatal use of prednisone as treatment for these disorders appears to be safe, and most children have developed normally. However, there is growing concern that prolonged fetal exposure to other glucocorticoids such as dexamethasone or betamethasone may lead to decreased growth and abnormal neuronal development. Low birth weight is reportedly associated with long-term medical complications such as adult-onset hypertension. Evidence also suggests that immunosuppressive agents taken during pregnancy might predispose the progeny to autoimmune disorders, malignancies and reproductive problems. Further research is warranted to determine that there are no unrecognized long-term risks to the offspring of these women.

Childhood malignancy and maternal diabetes or other auto-immune disease during pregnancy

Among 4380 children born in 1987-1997 of women with a diagnosis of diabetes and alive at the age of one, 10 were registered in the Swedish Cancer Registry before the end of 1998. The odds ratio for having a childhood cancer after maternal diabetes, stratified for year of birth, maternal age, parity, multiple birth, and 500 g birth weight class was 2.25 (95%CI 1.22-4.15). Among 5842 children born during the period 1973-1997 whose mothers had other auto-immune diseases (SLE, rheumatoid arthritis, Crohn, ulcerous colitis, multiple sclerosis or thyroiditis), the number of observed childhood cancers (9) was close to that expected (8.5). Maternal diabetes but not other auto-immune diseases may be a risk factor for childhood cancer.